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  • background image disappears when position relative used in firefox

    - by toomanyairmiles
    So I'm trying to add a badge to the top right corner of a site I'm doing some work on. z-index works to float the object above the page content but each time i try to use position relative the background image disappears only position absolute shows the image. I don't really want to use absolute as the image needs to be positioned on the right hand side of the sites menu bar not the right hand side of the viewport. Any thoughts or advice appreciated <div class="badge-box"> <a href="http://www.google.com" class="badge">Book Now!</a> </div> <div id="header"> <a href="index.php"><img src="images/pixel.gif" width="378" height="31" alt="Welcome to Gwynfryn Farm Cottages" /></a> </div> <div id="main-menu"> <div> <a href="/">Home</a> <a href="/cottages.php">Our Cottages</a> <a href="/gwynfryn.php">Bed &amp; Breakfast</a> <a href="/rates.php">Price Guide</a> <a href="/llanbedr.php">Location &amp; Local Attractions</a> <a href="/news.php">News &amp; Special Offers</a> <a href="/contact.php">Contact Us</a> </div> </div> .badge-box { width: 1030px; margin-left: auto; margin-right: auto; border: 0px solid red; } .badge { background: url(../images/badge.png) 0px 0px no-repeat; width: 148px; height: 148px; text-indent: -10000px; position: relative; z-index: 999; } #header { width: 960px; height: 40px; margin-left:auto; margin-right:auto; margin-top:20px; padding: 20px 0px 0px 20px; background: #58564f url(../images/header-top-background.png); } #main-menu { width: 980px; margin-left: auto; margin-right: auto; height: 35px; /*background: red;*/ background: #58564f url(../images/header-bottom-background.png); font-family: Georgia, "Times New Roman", Times, serif; } #main-menu div { width: 776px; height: 35px; margin-left: auto; margin-right: auto; background: blue; } #main-menu div a { display: block; float: left; padding: 5px 10px 0px 10px; height: 30px; color: #FFFFFF; font-size: 1.2em; text-align: center; background: green; } #main-menu div a:hover { background-color: #333333; }

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  • getView only shows Flagged Backgrounds for drawn Views, It does not show Flagged Background when scroll to view more items on list

    - by Leoa
    I am trying to create a listview that receives a flagged list of items to indicate a status to the user. I have been able to create the flag display by using a yellow background (see image at bottom). In Theory, the flagged list can have many flagged items in it. However in my app, only the first three flagged backgrounds are shown. I believe this is because they are initially drawn to the screen. The Flagged background that are not drawn initially to the screen do not show. I'd like to know how to get the remaining flags to show in the list. ListView Recycling: The backgrounds in the listView are being recycled in getView(). This recycling goes from position 0 to position 9. I have flags that need to match at positions 13, 14 and so on. Those positions are not being displayed. listView.getCheckedItemPositions() for multiple selections: This method will not work in my case because the user will not selected the flags. The flags are coming from the server. setNotifyOnChange() and/or public virtual void SetNotifyOnChange (bool notifyOnChange): I'm not adding new data to the list, so I don't see how this method would work for my program. Does this method communicate to getview when it is recycling data? I was unable to find an answer to this in my research. public void registerDataSetObserver: This may be overkill for my problem, but is it possible to have an observer object that keeps track of the all the positions in my items list and in my flag list no matter if the view is recycled and match them on the screen? Code: package com.convention.notification.app; import java.util.Iterator; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.graphics.Color; import android.os.Bundle; import android.text.Html; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.TextView; public class NewsRowAdapter extends ArrayAdapter<Item> { private Activity activity; private List<Item> items; private Item objBean; private int row; private List<Integer> disable; View view ; int disableView; public NewsRowAdapter(Activity act, int resource, List<Item> arrayList, List<Integer> disableList) { super(act, resource, arrayList); this.activity = act; this.row = resource; this.items = arrayList; this.disable=disableList; System.out.println("results of delete list a:"+disable.toString()); } public int getCount() { return items.size(); } public Item getItem(int position) { return items.get(position); } public long getItemId(int position) { return position; } @Override public int getItemViewType(int position) { for(int k =0;k < disable.size();k++){ if(position==disable.get(k)){ //System.out.println( "is "+position+" value of disable "+disable.get(k)); disableView=disable.get(k); //AdapterView.getItemAtPosition(position); } } return position; } @Override public View getView(final int position, View convertView, ViewGroup parent) { View view = convertView; ViewHolder holder; if (view == null) { LayoutInflater inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); view = inflater.inflate(row, null); getItemViewType(position); long id=getItemId(position); if(position==disableView){ view.setBackgroundColor(Color.YELLOW); System.out.println(" background set to yellow at position "+position +" disableView is at "+disableView); }else{ view.setBackgroundColor(Color.WHITE); System.out.println(" background set to white at position "+position +" disableView is at "+disableView); } //ViewHolder is a custom class that gets TextViews by name: tvName, tvCity, tvBDate, tvGender, tvAge; holder = new ViewHolder(); /* setTag Sets the tag associated with this view. A tag can be used to * mark a view in its hierarchy and does not have to be unique * within the hierarchy. Tags can also be used to store data within * a view without resorting to another data structure. */ view.setTag(holder); } else { //the Object stored in this view as a tag holder = (ViewHolder) view.getTag(); } if ((items == null) || ((position + 1) > items.size())) return view; objBean = items.get(position); holder.tv_event_name = (TextView) view.findViewById(R.id.tv_event_name); holder.tv_event_date = (TextView) view.findViewById(R.id.tv_event_date); holder.tv_event_start = (TextView) view.findViewById(R.id.tv_event_start); holder.tv_event_end = (TextView) view.findViewById(R.id.tv_event_end); holder.tv_event_location = (TextView) view.findViewById(R.id.tv_event_location); if (holder.tv_event_name != null && null != objBean.getName() && objBean.getName().trim().length() > 0) { holder.tv_event_name.setText(Html.fromHtml(objBean.getName())); } if (holder.tv_event_date != null && null != objBean.getDate() && objBean.getDate().trim().length() > 0) { holder.tv_event_date.setText(Html.fromHtml(objBean.getDate())); } if (holder.tv_event_start != null && null != objBean.getStartTime() && objBean.getStartTime().trim().length() > 0) { holder.tv_event_start.setText(Html.fromHtml(objBean.getStartTime())); } if (holder.tv_event_end != null && null != objBean.getEndTime() && objBean.getEndTime().trim().length() > 0) { holder.tv_event_end.setText(Html.fromHtml(objBean.getEndTime())); } if (holder.tv_event_location != null && null != objBean.getLocation () && objBean.getLocation ().trim().length() > 0) { holder.tv_event_location.setText(Html.fromHtml(objBean.getLocation ())); } return view; } public class ViewHolder { public TextView tv_event_name, tv_event_date, tv_event_start, tv_event_end, tv_event_location /*tv_event_delete_flag*/; } } Logcat: 06-12 20:54:12.058: I/System.out(493): item disalbed is at postion :0 06-12 20:54:12.058: I/System.out(493): item disalbed is at postion :4 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :5 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :13 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :14 06-12 20:54:12.069: I/System.out(493): item disalbed is at postion :17 06-12 20:54:12.069: I/System.out(493): results of delete list :[0, 4, 5, 13, 14, 17] 06-12 20:54:12.069: I/System.out(493): results of delete list a:[0, 4, 5, 13, 14, 17] 06-12 20:54:12.069: I/System.out(493): set adapaer to list view called; 06-12 20:54:12.128: I/System.out(493): background set to yellow at position 0 disableView is at 0 06-12 20:54:12.628: I/System.out(493): background set to white at position 1 disableView is at 0 06-12 20:54:12.678: I/System.out(493): background set to white at position 2 disableView is at 0 06-12 20:54:12.708: I/System.out(493): background set to white at position 3 disableView is at 0 06-12 20:54:12.738: I/System.out(493): background set to yellow at position 4 disableView is at 4 06-12 20:54:12.778: I/System.out(493): background set to yellow at position 5 disableView is at 5 06-12 20:54:12.808: I/System.out(493): background set to white at position 6 disableView is at 5 06-12 20:54:12.838: I/System.out(493): background set to white at position 7 disableView is at 5 This is a link to my first question a day ago: Change Background on a specific row based on a condition in Custom Adapter I appreciate your help!

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  • Calculate lookat vector from position and Euler angles

    - by Jaap
    I've implemented an FPS style camera, with the camera consisting of a position vector, and Euler angles pitch and yaw (x and y rotations). After setting up the projection matrix, I then translate to camera coordinates by rotating, then translating to the inverse of the camera position: // Load projection matrix glMatrixMode(GL_PROJECTION); glLoadIdentity(); // Set perspective gluPerspective(m_fFOV, m_fWidth/m_fHeight, m_fNear, m_fFar); // Load modelview matrix glMatrixMode(GL_MODELVIEW); glLoadIdentity(); // Position camera glRotatef(m_fRotateX, 1.0, 0.0, 0.0); glRotatef(m_fRotateY, 0.0, 1.0, 0.0); glTranslatef(-m_vPosition.x, -m_vPosition.y, -m_vPosition.z); Now I've got a few viewports set up, each with its own camera, and from every camera I render the position of the other cameras (as a simple box). I'd like to also draw the view vector for these cameras, except I haven't a clue how to calculate the lookat vector from the position and Euler angles. I've tried to multiply the original camera vector (0, 0, -1) by a matrix representing the camera rotations then adding the camera position to the transformed vector, but that doesn't work at all (most probably because I'm way off base): vector v1(0, 0, -1); matrix m1 = matrix::IDENTITY; m1.rotate(m_fRotateX, 0, 0); m1.rotate(0, m_fRotateY, 0); vector v2 = v1 * m1; v2 = v2 + m_vPosition; // add camera position vector glBegin(GL_LINES); glVertex3fv(m_vPosition); glVertex3fv(v2); glEnd(); What I'd like is to draw a line segment from the camera towards the lookat direction. I've looked all over the place for examples of this, but can't seem to find anything. Thanks a lot!

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  • css background image is being cut off..

    - by Ronedog
    I have an unordered list and the background image is being cut off when trying to place it next to the text. I'm using jquery to add the class to the anchor tag to display the image, and its working fine, the only problem is the image gets cut off. I've been playing around with the css, but can't seem to figure out how to make the image display properly...it seems like the < li is hiding the image behind it somehow...can I place the image in front of the < li to make it display...or am I missing something else? Can someone help me? Thanks. Here's the HTML: <ul id="nav> <li> <a class="folder_closed">Item 1</a> </li> </ul> Here's the CSS: ul#nav{ margin-left:0; margin-right:0; padding-left:0px; text-indent:15px; } #nav > li{ vertical-align: top; text-align:left; clear: both; margin-left:0px; margin-right:0px; padding-right:0px; padding-left:15px; } .folder_open{ position:relative; background-image: url(../images/maximize.png); background-repeat: no-repeat; background-position: -5px 1px; } .folder_closed{ position:relative; background-image: url(../images/minimize.png); background-repeat: no-repeat; background-position: -5px 1px; }

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  • RetinaJS and LESS : Background image doesn't show on iOS

    - by jidma
    I am trying to make a background image into a retina image using LESS CSS and RetinaJs: in my index.html file : <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=0, minimum-scale=1.0, maximum-scale=1.0"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> [...] <link type="text/css" rel="stylesheet/less" href="resources/css/retina.less"> <script type="text/javascript" src="resources/js/less-1.3.0.minjs" ></script> [...] </head> <body> [...] <script type="text/javascript" src="resources/js/retina.js"></script> </body> </html> in my retina.less file: .at2x(@path, @w: auto, @h: auto) { background-image: url("@{path}"); @at2x_path: ~`"@{path}".split('.').slice(0, "@{path}".split('.').length - 1).join(".") + "@2x" + "." + "@{path}".split('.')["@{path}".split('.').length - 1]`; @media all and (-webkit-min-device-pixel-ratio : 1.5) { background-image: url("@{at2x_path}"); background-size: @w @h; } } .topMenu { .at2x('../../resources/img/topMenuTitle.png'); } I have both topMenuTitle.png (320px x 40px) and [email protected] (640px x 80px) in the same folder. When test this code: In Firefox i have the normal Background In the XCode iPhone simulator I also have the normal Background In the iPhone device, I don't have any background at all. I'm using GWT if that matters. Any suggestions ? Thanks.

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  • Collision detection problems...

    - by thyrgle
    Hi, I have written the following: -(void) checkIfLineCollidesWithAll { float slope = ((160-L1Circle1.position.y)-(160-L1Circle2.position.y))/((240-L1Circle1.position.x)-(240-L1Circle2.position.x)); float b = (160-L1Circle1.position.y) - slope * (240-L1Circle1.position.x); if ((240-L1Sensor1.position.x) < (240-L1Circle1.position.x) && (240-L1Sensor1.position.x) < (240-L1Circle2.position.x) || ((240-L1Sensor1.position.x) > (240-L1Circle1.position.x) && (240-L1Sensor1.position.x) > (240-L1Circle2.position.x))) { [L1Sensor1 setTexture:[[CCTextureCache sharedTextureCache] addImage:@"SensorOk.png"]]; } else if (slope == INFINITY || slope == -INFINITY) { if (L1Circle1.position.y + 16 >= L1Sensor1.position.y || L1Circle1.position.y - 16 <= L1Sensor1.position.y) { [L1Sensor1 setTexture:[[CCTextureCache sharedTextureCache] addImage:@"SensorBad.png"]]; } else { [L1Sensor1 setTexture:[[CCTextureCache sharedTextureCache] addImage:@"SensorOk.png"]]; } } else if (160-L1Sensor1.position.y + 12 >= slope*(240-L1Sensor1.position.x) + b && 160-L1Sensor1.position.y - 12 <= slope*(240-L1Sensor1.position.x) + b) { [L1Sensor1 setTexture:[[CCTextureCache sharedTextureCache] addImage:@"SensorBad.png"]]; } else { [L1Sensor1 setTexture:[[CCTextureCache sharedTextureCache] addImage:@"SensorOk.png"]]; } } Basically what this does is finds m and b in the well known equation: y = mx + b and then substitutes coordinates of the L1Sensor1 (the circle I'm trying to detect if it it intersects with the line segment) to see if y = mx + b hold true. But, there are two problems, first, when slope approaches infinity the range of what the L1Sensor1 should "react" to (it "reacts" by changing its image) becomes smaller. Also, the code that should handle infinity is not working. Thanks for the help in advanced.

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  • CSS Background-Images Loading after HTML Images (Involves Javascript)

    - by Kevin C.
    I threw together a quick little microsite that you can see at http://monterraauction.com. If you don't have a super-fast connection (and nothing's cached), the very last items to load are the background-images that are used for CSS image-text replacement (primarily, that h1#head at the top, with a 7kb background image). Nothing debilitating, but it looks slightly awkward. And I'm asking this question as a matter of curiosity more than anything else ;) Also, please note that this occurs in Firefox, but not Chrome. Now, underneath the h1#head I have a jquery.cycle.lite-powered slideshow in div#photo. In the HTML markup there are a total of 13, heavy image files that make up each of the slides. If I remove all but the first slide, then the problem goes away! So the CSS background-images are loading after...those HTML images are done? But here's what's confusing: I check it out in YSlow...the CSS background-images have a much lower response time than all of the slides in #photo. Right after all the JS files finish loading, in fact. So why aren't they showing up first? I tried $('#photo img:last-child').load(function() { alert('Locked and Loaded!')});, but the background-images pop up a while before the alert does, so I'm assuming it's not waiting until the last slide has loaded (admittedly I'm a bit of JS noob so maybe I'm just making a wrong assumption). I also tried commenting out all the jquery.cycle.lite stuff, so that I knew I didn't have any JS manipulating the DOM elements in #photo, but that wasn't the problem. I tried putting all the JS at the bottom of the document, right before </body>, but that didn't work. Lastly, I tried turning off javascript, and of course the css background-image loads way before the images in #photo, so it's definitely a JS thing (amirite?) I guess the obvious solution here is to mark the slides up as LINKS rather than IMGs, and have Javascript insert those 12 extra slideshow images after the DOM is ready--users without javascript shouldn't need to download the extra images anyways. But again, I'm curious: Why does removing the extra HTML images from within #photo solve the problem? And why are the CSS background-images showing up after the HTML images have loaded, even though YSlow says the css background-images loaded first? Seeing as how it happens in FF but not Chrome, is it simply a browser issue? I appreciate any insight you guys could give me!

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  • print CSS still showing some background images when printing

    - by RyanP13
    I am receiving some strange begaviour in IE6 when printing a page. For some reason it is printing out parts of a CSS background image sprite. I have overridden all background-image declarations with: * {background-image:none !important;} But to no avail. I didn't think background images were supported by default anyways so this is a new one on me.

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  • get the start position of an item using the jquery ui sortable plugin

    - by Rippo
    I am using the jQuery UI sortable plugin and I am trying to get 2 alerts I want the staring position of the element and the finished position of the element. $(function() { $("#filterlist ul").sortable({ opacity: 0.6, cursor: 'move', update: function(event, ui) { alert(ui.item.prevAll().length + 1); } }); }); I can get the position of the item after it has been dragged by using:- ui.item.prevAll().length + 1 What do I use to get the position it started from?

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  • get the start position of an item using the jquery ui sortable plugin

    - by Rippo
    I am using the jQuery UI sortable plugin and I am trying to get 2 alerts I want the staring position of the element and the finished position of the element. $(function() { $("#filterlist ul").sortable({ opacity: 0.6, cursor: 'move', update: function(event, ui) { alert(ui.item.prevAll().length + 1); } }); }); I can get the position of the item after it has been dragged by using:- ui.item.prevAll().length + 1 What do I use to get the position it started from?

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  • jQuery background image transition

    - by Hock
    I have a div that has a 'home.jpg' image as background and I want the background to be 'another_image.jpg' when I click something. The thing is that I want the new background to fadeIn and not just to appear (by doing some .css('background', url('another_image.jpg')); ) Is there a way to do that? I've tried the bgImageTransition plugin but it just adds another element on top of the div I had... Thanks,

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  • wicket: how to add table background image

    - by vivmal
    Hi All Can anyone please tell me how to add table background image in wicket. Actually I've tried a lot like <table background="images/logo.jpg"> also <style>table {background-image: url('images/logo.jpg')}</style> also <table style="background-image: url('images/logo.jpg')"> But nothing works. Please help. Thanks in advance.

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  • CSS overflow character not pushing down <div>

    - by Uncle Toby
    I have a <div> called bigbox which contain a <div>called wrapper . The wrapper contain 2 <div> called textbox and checkbox. If the characters inside textbox overflow , it doesn't push the other wrapper below . How can I make the below wrapper go down ? here is the jsfiddle : http://jsfiddle.net/WA63P/ <html> <head> <title>Page</title> <script type="text/javascript" src="jquery-1.9.1.min.js"></script> <style type="text/css"> .bigbox { background-color: #F5E49C; color: #000; padding: 0 5px; width:280px; height:500px; position: absolute; text-align: center;content: "";display: block;clear: both; } .box { background-color: #272822; color: #9C5A3C; height:100px; width:260px; margin-bottom: 10px; position: relative; top:10px; } .textbox { background-color: #FFFFFF; color: #272822; height:100px; width:160px;float:left;text-align: left } .checkbox { background-color: #FFFFFF; height:50px; width:50px; float:right; d } </style> <div class="bigbox"> <div class="box"> <div class="textbox">background background background background background background background background background background background background background background background background background background background background background background </div> <div class="checkbox"> </div> </div> <div class="box"> <div class="textbox"> </div> <div class="checkbox"> </div> </div> </body> </html>

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  • Keep background image fixed during scroll using css

    - by Jean
    Hello, This is going to be rather silly of me asking, but how do I keep the background image fixed during a page scroll. I have this css code, and the image is a background of the body and not ** body{ background-position:center; background-image:url(../images/images5.jpg); } Thanks Jean

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  • Tiled Image for background of DIV is making IE sllllowww when scrolling

    - by Nissan Fan
    Take a look at http://www.pmverge.com at the "We're in Bootstrap Mode" DIV on the right-hand side. Having that background tile image is causing the IE browser (all versions) to drag when scrolling. What can I do to keep that tiled style but not have it slow down IE. background-image: url(http://blog.pmverge.com/assets/images/background.gif) NOTES Yes this is the Stackoverflow.com engine as I'm licensing it. The background watermark image is not slowing the page down (though it has about 50k).

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  • Property trigger in XAML for IsMouseOver fails to set Border.Background

    - by Mal Ross
    I'm currently trying to create a ControlTemplate for the Button class in WPF, replacing the usual visual tree with something that makes the button look similar to the little (X) close icon on Google Chrome's tabs. I decided to use a Path object in XAML to achieve the effect. Using a property trigger, the control responds to a change in the IsMouseOver property by setting the icon's red background. Here's the XAML from a test app: <Window x:Class="Widgets.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300"> <Window.Resources> <Style x:Key="borderStyle" TargetType="Border"> <Style.Triggers> <Trigger Property="IsMouseOver" Value="True"> <Setter Property="Background"> <Setter.Value> <SolidColorBrush Color="#CC0000"/> </Setter.Value> </Setter> </Trigger> </Style.Triggers> </Style> <ControlTemplate x:Key="closeButtonTemplate" TargetType="Button"> <Border Width="12" Height="12" CornerRadius="6" BorderBrush="#AAAAAA" Background="Transparent" Style="{StaticResource borderStyle}" ToolTip="Close"> <Viewbox Margin="2.75"> <Path Data="M 0,0 L 10,10 M 0,10 L 10,0" Stroke="{Binding BorderBrush, RelativeSource={RelativeSource FindAncestor, AncestorType=Border, AncestorLevel=1}}" StrokeThickness="1.8"/> </Viewbox> </Border> </ControlTemplate> </Window.Resources> <Grid Background="White"> <Button Template="{StaticResource closeButtonTemplate}"/> </Grid> </Window> Note that the circular background is always there - it's just transparent when the mouse isn't over it. The problem with this is that the trigger just isn't working. Nothing changes in the button's appearance. However, if I remove the Background="Transparent" value from the Border object in the ControlTemplate, the trigger does work (albeit only when over the 'X'). I really can't explain this. Setters for any other properties placed in the borderStyle resource work fine, but the Background setter fails as soon as the default background is specified in the ControlTemplate. Any ideas why it's happening and how I can fix it? I know I could easily replace this code with, for example, a .PNG-based image, but I want to understand why the current implementation isn't working. Thanks! :)

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  • Set Round Border of an android TextView already having a background color

    - by vaibhav
    I want a TextView to have a rounded border. This can be done by using a drawable, specifying a shape in the drawable, and then using the drawable as the background of the TextView. android:background="@layout/border" Also shown here However, my TextView already has a background color (which is gray) and thus I'm unable to use the above method to set a rounded border. Is there any other method to do this which allows the background color of the TextView to remain gray and also surrounds it with a rounded border?

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  • Is there a way to fix the background image of a UITableView

    - by user337174
    Hi I have set the background of my UITable with a custom image. self.tableView.backgroundColor = [UIColor clearColor]; self.tableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"background.png"]]; The problem im having is the background image is scrolling and doesn't look good at the top and bottom of the screen where you see the image being joined. Is there a way to fix the position of the background image and just have the table scroll over the top of it?

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  • Position:absolute

    - by Andrew
    I have I have a div called logo. I want the logo to be on top of other areas and to overlap into the the preface top of a drupal site, the logo currently sits in the header area. I looked up position absolute and I think that what I need to use but when I use position absolute the logo disappears, I can see it if I use position fixed, relative etc. I thought the logo was being hidden because I was not using a z-index but even with that I cant see the logo. What am I doing wrong? #logo { position: absolute; top: 30px; /* 30 pixels from the top of the page */ left: 80px; /* 80 pixels from the left hand side */ z-index:1099; border: 1px solid red; /* So we can see what is happening */ } Also does anyone know of a really good free online css course? Here is some additional information, namely the CSS and the page.tpl.php: <?php // $Id: page.tpl.php,v 1.1.2.5 2010/04/08 07:02:59 sociotech Exp $ ?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" lang="<?php print $language->language; ?>" xml:lang="<?php print $language->language; ?>"> <head> <title><?php print $head_title; ?></title> <?php print $head; ?> <?php print $styles; ?> <?php print $setting_styles; ?> <!--[if IE 8]> <?php print $ie8_styles; ?> <![endif]--> <!--[if IE 7]> <?php print $ie7_styles; ?> <![endif]--> <!--[if lte IE 6]> <?php print $ie6_styles; ?> <![endif]--> <?php print $local_styles; ?> <?php print $scripts; ?> </head> <body id="<?php print $body_id; ?>" class="<?php print $body_classes; ?>"> <div id="page" class="page"> <div id="page-inner" class="page-inner"> <div id="skip"> <a href="#main-content-area"><?php print t('Skip to Main Content Area'); ?></a> </div> <!-- header-top row: width = grid_width --> <?php print theme('grid_row', $header_top, 'header-top', 'full-width', $grid_width); ?> <!-- header-group row: width = grid_width --> <div id="header-group-wrapper" class="header-group-wrapper full-width"> <div id="header-group" class="header-group row <?php print $grid_width; ?>"> <div id="header-group-inner" class="header-group-inner inner clearfix"> <?php print theme('grid_block', theme('links', $secondary_links), 'secondary-menu'); ?> <?php print theme('grid_block', $search_box, 'search-box'); ?> <?php if ($logo || $site_name || $site_slogan): ?> <div id="header-site-info" class="header-site-info block"> <div id="header-site-info-inner" class="header-site-info-inner inner"> <?php if ($logo): ?> <div id="logo"> <a href="<?php print check_url($front_page); ?>" title="<?php print t('Home'); ?>"><img src="<?php print $logo; ?>" alt="<?php print t('Home'); ?>" /></a> </div> <?php endif; ?> <?php if ($site_name || $site_slogan): ?> <div id="site-name-wrapper" class="clearfix"> <?php if ($site_name): ?> <span id="site-name"><a href="<?php print check_url($front_page); ?>" title="<?php print t('Home'); ?>"><?php print $site_name; ?></a></span> <?php endif; ?> <?php if ($site_slogan): ?> <span id="slogan"><?php print $site_slogan; ?></span> <?php endif; ?> </div><!-- /site-name-wrapper --> <?php endif; ?> </div><!-- /header-site-info-inner --> </div><!-- /header-site-info --> <?php endif; ?> <?php print $header; ?> <?php print theme('grid_block', $primary_links_tree, 'primary-menu'); ?> </div><!-- /header-group-inner --> </div><!-- /header-group --> </div><!-- /header-group-wrapper --> <!-- preface-top row: width = grid_width --> <?php print theme('grid_row', $preface_top, 'preface-top', 'full-width', $grid_width); ?> <!-- main row: width = grid_width --> <div id="main-wrapper" class="main-wrapper full-width<?php if ($is_front) { print ' front'; } ?>"> <div id="main" class="main row <?php print $grid_width; ?>"> <div id="main-inner" class="main-inner inner clearfix"> <?php print theme('grid_row', $sidebar_first, 'sidebar-first', 'nested', $sidebar_first_width); ?> <!-- main group: width = grid_width - sidebar_first_width --> <div id="main-group" class="main-group row nested <?php print $main_group_width; ?>"> <div id="main-group-inner" class="main-group-inner inner"> <?php print theme('grid_row', $preface_bottom, 'preface-bottom', 'nested'); ?> <div id="main-content" class="main-content row nested"> <div id="main-content-inner" class="main-content-inner inner"> <!-- content group: width = grid_width - (sidebar_first_width + sidebar_last_width) --> <div id="content-group" class="content-group row nested <?php print $content_group_width; ?>"> <div id="content-group-inner" class="content-group-inner inner"> <?php print theme('grid_block', $breadcrumb, 'breadcrumbs'); ?> <?php if ($content_top || $help || $messages): ?> <div id="content-top" class="content-top row nested"> <div id="content-top-inner" class="content-top-inner inner"> <?php print theme('grid_block', $help, 'content-help'); ?> <?php print theme('grid_block', $messages, 'content-messages'); ?> <?php print $content_top; ?> </div><!-- /content-top-inner --> </div><!-- /content-top --> <?php endif; ?> <div id="content-region" class="content-region row nested"> <div id="content-region-inner" class="content-region-inner inner"> <a name="main-content-area" id="main-content-area"></a> <?php print theme('grid_block', $tabs, 'content-tabs'); ?> <div id="content-inner" class="content-inner block"> <div id="content-inner-inner" class="content-inner-inner inner"> <?php if ($title): ?> <h1 class="title"><?php print $title; ?></h1> <?php endif; ?> <?php if ($content): ?> <div id="content-content" class="content-content"> <?php print $content; ?> <?php print $feed_icons; ?> </div><!-- /content-content --> <?php endif; ?> </div><!-- /content-inner-inner --> </div><!-- /content-inner --> </div><!-- /content-region-inner --> </div><!-- /content-region --> <?php print theme('grid_row', $content_bottom, 'content-bottom', 'nested'); ?> </div><!-- /content-group-inner --> </div><!-- /content-group --> <?php print theme('grid_row', $sidebar_last, 'sidebar-last', 'nested', $sidebar_last_width); ?> </div><!-- /main-content-inner --> </div><!-- /main-content --> <?php print theme('grid_row', $postscript_top, 'postscript-top', 'nested'); ?> </div><!-- /main-group-inner --> </div><!-- /main-group --> </div><!-- /main-inner --> </div><!-- /main --> </div><!-- /main-wrapper --> <!-- postscript-bottom row: width = grid_width --> <?php print theme('grid_row', $postscript_bottom, 'postscript-bottom', 'full-width', $grid_width); ?> <!-- footer row: width = grid_width --> <?php print theme('grid_row', $footer, 'footer', 'full-width', $grid_width); ?> <!-- footer-message row: width = grid_width --> <div id="footer-message-wrapper" class="footer-message-wrapper full-width"> <div id="footer-message" class="footer-message row <?php print $grid_width; ?>"> <div id="footer-message-inner" class="footer-message-inner inner clearfix"> <?php print theme('grid_block', $footer_message, 'footer-message-text'); ?> </div><!-- /footer-message-inner --> </div><!-- /footer-message --> </div><!-- /footer-message-wrapper --> </div><!-- /page-inner --> </div><!-- /page --> <?php print $closure; ?> </body> </html> CSS /* $Id: style.css,v 1.1.2.11 2010/07/02 22:11:04 sociotech Exp $ */ /* Margin, Padding, Border Resets -------------------------------------------------------------- */ html, body, div, span, p, dl, dt, dd, ul, ol, li, h1, h2, h3, h4, h5, h6, form, fieldset, input, textarea { margin: 0; padding: 0; } img, abbr, acronym { border: 0; } /* HTML Elements -------------------------------------------------------------- */ p { margin: 1em 0; } h1, h2, h3, h4, h5, h6 { margin: 0 0 0.5em 0; } h1 { color: white !important; text-shadow: black !important; } ul, ol, dd { margin-bottom: 1.5em; margin-left: 2em; /* LTR */ } li ul, li ol { margin-bottom: 0; } ul { list-style-type: disc; } ol { list-style-type: decimal; } a { margin: 0; padding: 0; text-decoration: none; } a:link, a:visited { } a:hover, a:focus, a:active { text-decoration: underline; } blockquote { } hr { height: 1px; border: 1px solid gray; } /* tables */ table { border-spacing: 0; width: 100%; } tr.even td, tr.odd td { background-color: #FFFFFF; border: 1px solid #dbdbdb; } caption { text-align: left; } th { margin: 0; padding: 0 10px 0 0; } th.active img { display: inline; } thead th { padding-right: 10px; } td { margin: 0; padding: 3px; } /* Remove grid block styles from Drupal's table ".block" class */ td.block { border: none; float: none; margin: 0; } /* Maintain light background/dark text on dragged table rows */ tr.drag td, tr.drag-previous td { background: #FFFFDD; color: #000; } /* Accessibility /-------------------------------------------------------------- */ /* skip-link to main content, hide offscreen */ #skip a, #skip a:hover, #skip a:visited { height: 1px; left: 0px; overflow: hidden; position: absolute; top: -500px; width: 1px; } /* make skip link visible when selected */ #skip a:active, #skip a:focus { background-color: #fff; color: #000; height: auto; padding: 5px 10px; position: absolute; top: 0; width: auto; z-index: 99; } #skip a:hover { text-decoration: none; } /* Helper Classes /-------------------------------------------------------------- */ .hide { display: none; visibility: hidden; } .left { float: left; } .right { float: right; } .clear { clear: both; } /* clear floats after an element */ /* (also in ie6-fixes.css, ie7-fixes.css) */ .clearfix:after, .clearfix .inner:after { clear: both; content: "."; display: block; font-size: 0; height: 0; line-height: 0; overflow: auto; visibility: hidden; } /* Grid Layout Basics (specifics in 'gridnn_x.css') -------------------------------------------------------------- */ /* center page and full rows: override this for left-aligned page */ .page, .row { margin: 0 auto; } /* fix layout/background display on floated elements */ .row, .nested, .block { overflow: hidden; } /* full-width row wrapper */ div.full-width { width: 100%; } /* float, un-center & expand nested rows */ .nested { float: left; /* LTR */ margin: 0; width: 100%; } /* allow Superfish menus to overflow */ #sidebar-first.nested, #sidebar-last.nested, div.superfish { overflow: visible; } /* sidebar layouts */ .sidebars-both-first .content-group { float: right; /* LTR */ } .sidebars-both-last .sidebar-first { float: right; /* LTR */ } /* Grid Mask Overlay -------------------------------------------------------------- */ #grid-mask-overlay { display: none; left: 0; opacity: 0.75; position: absolute; top: 0; width: 100%; z-index: 997; } #grid-mask-overlay .row { margin: 0 auto; } #grid-mask-overlay .block .inner { background-color: #e3fffc; outline: none; } .grid-mask #grid-mask-overlay { display: block; } .grid-mask .block { overflow: visible; } .grid-mask .block .inner { outline: #f00 dashed 1px; } #grid-mask-toggle { background-color: #777; border: 2px outset #fff; color: #fff; cursor: pointer; font-variant: small-caps; font-weight: normal; left: 0; -moz-border-radius: 5px; padding: 0 5px 2px 5px; position: absolute; text-align: center; top: 22px; -webkit-border-radius: 5px; z-index: 998; } #grid-mask-toggle.grid-on { border-style: inset; font-weight: bold; } /* Site Info -------------------------------------------------------------- */ #header-site-info { width: auto; } #site-name-wrapper { float: left; /* LTR */ } #site-name, #slogan { display: block; } #site-name a:link, #site-name a:visited, #site-name a:hover, #site-name a:active { text-decoration: none; } #site-name a { outline: 0; } /* Regions -------------------------------------------------------------- */ /* Header Regions -------------------------------------------------------------- */ #header-group { overflow: visible; } /* Content Regions (Main) -------------------------------------------------------------- */ .node-bottom { margin: 1.5em 0 0 0; } /* Clear floats on regions -------------------------------------------------------------- */ #header-top-wrapper, #header-group-wrapper, #preface-top-wrapper, #main-wrapper, #preface-bottom, #content-top, #content-region, #content-bottom, #postscript-top, #postscript-bottom-wrapper, #footer-wrapper, #footer-message-wrapper { clear: both; } /* Drupal Core /-------------------------------------------------------------- */ /* Lists /-------------------------------------------------------------- */ .item-list ul li { margin: 0; } .block ul, .block ol { margin-left: 2em; /* LTR */ padding: 0; } .content-inner ul, .content-inner ol { margin-bottom: 1.5em; } .content-inner li ul, .content-inner li ol { margin-bottom: 0; } .block ul.links { margin-left: 0; /* LTR */ } /* Menus /-------------------------------------------------------------- */ ul.menu li, ul.links li { margin: 0; padding: 0; } /* Primary Menu /-------------------------------------------------------------- */ /* use ID to override overflow: hidden for .block, dropdowns should always be visible */ #primary-menu { overflow: visible; } /* remove left margin from primary menu list */ #primary-menu.block ul { margin-left: 0; /* LTR */ } /* remove bullets, float left */ .primary-menu ul li { float: left; /* LTR */ list-style: none; position: relative; } /* style links, and unlinked parent items (via Special Menu Items module) */ .primary-menu ul li a, .primary-menu ul li .nolink { display: block; padding: 0.75em 1em; text-decoration: none; } /* Add cursor style for unlinked parent menu items */ .primary-menu ul li .nolink { cursor: default; } /* remove outline */ .primary-menu ul li:hover, .primary-menu ul li.sfHover, .primary-menu ul a:focus, .primary-menu ul a:hover, .primary-menu ul a:active { outline: 0; } /* Secondary Menu /-------------------------------------------------------------- */ .secondary-menu-inner ul.links { margin-left: 0; /* LTR */ } /* Skinr styles /-------------------------------------------------------------- */ /* Skinr selectable helper classes */ .fusion-clear { clear: both; } div.fusion-right { float: right; /* LTR */ } div.fusion-center { float: none; margin-left: auto; margin-right: auto; } .fusion-center-content .inner { text-align: center; } .fusion-center-content .inner ul.menu { display: inline-block; text-align: center; } /* required to override drupal core */ .fusion-center-content #user-login-form { text-align: center; } .fusion-right-content .inner { text-align: right; /* LTR */ } /* required to override drupal core */ .fusion-right-content #user-login-form { text-align: right; /* LTR */ } /* Large, bold callout text style */ .fusion-callout .inner { font-weight: bold; } /* Extra padding on block */ .fusion-padding .inner { padding: 30px; } /* Adds 1px border and padding */ .fusion-border .inner { border-width: 1px; border-style: solid; padding: 10px; } /* Single line menu with separators */ .fusion-inline-menu .inner ul.menu { margin-left: 0; /* LTR */ } .fusion-inline-menu .inner ul.menu li { border-right-style: solid; border-right-width: 1px; display: inline; margin: 0; padding: 0; white-space: nowrap; } .fusion-inline-menu .inner ul.menu li a { padding: 0 8px 0 5px; /* LTR */ } .fusion-inline-menu .inner ul li.last { border: none; } /* Hide second level (and beyond) menu items */ .fusion-inline-menu .inner ul li.expanded ul { display: none; } /* Multi-column menu style with bolded top level menu items */ .fusion-multicol-menu .inner ul { margin-left: 0; /* LTR */ text-align: left; /* LTR */ } .fusion-multicol-menu .inner ul li { border-right: none; display: block; font-weight: bold; } .fusion-multicol-menu .inner ul li.last { border-right: none; } .fusion-multicol-menu .inner ul li.last a { padding-right: 0; /* LTR */ } .fusion-multicol-menu .inner ul li.expanded, .fusion-multicol-menu .inner ul li.leaf { float: left; /* LTR */ list-style-image: none; margin-left: 50px; /* LTR */ } .fusion-multicol-menu .inner ul.menu li.first { margin-left: 0; /* LTR */ } .fusion-multicol-menu .inner ul li.expanded li.leaf { float: none; margin-left: 0; /* LTR */ } .fusion-multicol-menu .inner ul li.expanded ul { display: block; margin-left: 0; /* LTR */ } .fusion-multicol-menu .inner ul li.expanded ul li { border: none; margin-left: 0; /* LTR */ text-align: left; /* LTR */ } .fusion-multicol-menu .inner ul.menu li ul.menu li { font-weight: normal; } /* Split list across multiple columns */ .fusion-2-col-list .inner .item-list ul li, .fusion-2-col-list .inner ul.menu li { float: left; /* LTR */ width: 50%; } .fusion-3-col-list .inner .item-list ul li, .fusion-3-col-list .inner ul.menu li { float: left; /* LTR */ width: 33%; } .fusion-2-col-list .inner .item-list ul.pager li, .fusion-3-col-list .inner .item-list ul.pager li { float: none; width: auto; } /* List with bottom border Fixes a common issue when list items have bottom borders and appear to be doubled when nested lists end and begin. This removes the extra border-bottom */ .fusion-list-bottom-border .inner ul li { list-style: none; list-style-type: none; list-style-image: none; } .fusion-list-bottom-border .inner ul li, .fusion-list-bottom-border .view-content div.views-row { padding: 0 0 0 10px; /* LTR */ border-bottom-style: solid; border-bottom-width: 1px; line-height: 216.7%; /* 26px */ } .fusion-list-bottom-border .inner ul { margin: 0; } .fusion-list-bottom-border .inner ul li ul { border-bottom-style: solid; border-bottom-width: 1px; } .fusion-list-bottom-border .inner ul li ul li.last { border-bottom-style: solid; border-bottom-width: 1px; margin-bottom: -1px; margin-top: -1px; } #views_slideshow_singleframe_pager_slideshow-page_2 .pager-item { display:block; } #views_slideshow_singleframe_pager_slideshow-page_2 { position:absolute; right:0; top:0; } #header-group-wrapper { background: none; } #page { background-color:#F3F3F3; background-image:url('/sites/all/themes/fusion/fusion_core/images/runswithgradient.jpg'); background-repeat:no-repeat; background-attachment: fixed; width: auto; } #views_slideshow_singleframe_pager_slideshow-page_2 div a img { top:0px; height:60px; width:80px; padding-right:10px; padding-bottom:19px; } #mycontent{ width: 720px; } .product-body { -moz-border-radius: 4px 4px 4px 4px; margin: 0 0 20px; overflow: hidden; padding: 20px; background: none repeat scroll 0 0 #F7F7F7; border: 1px solid #000000; border-style:solid; border-width:thin; color:#000000; } #product-details { background: none repeat scroll 0 0 #F7F7F7 !important; border: 1px solid #000000 !important; color: #8E8E8E; } #logo { position: relative; top: 30px; /* 30 pixels from the top of the page */ left: 80px; /* 80 pixels from the left hand side */ z-index:1099; border: 1px solid red; /* So we can see what is happening */ } #breadcrumbs-inner { background: none; border-color: transparent; border-style: none; } #block-views-new_products-block_1{ height:200px; } /* List with no bullet and extra padding This is a common style for menus, which removes the bullet and adds more vertical padding for a simple list style */ .fusion-list-vertical-spacing .inner ul, .fusion-list-vertical-spacing div.views-row-first { margin-left: 0; margin-top: 10px; } .fusion-list-vertical-spacing .inner ul li, .fusion-list-vertical-spacing div.views-row { line-height: 133.3%; /* 16px/12px */ margin-bottom: 10px; padding: 0; } .fusion-list-vertical-spacing .inner ul li { list-style: none; list-style-image: none; list-style-type: none; } .fusion-list-vertical-spacing .inner ul li ul { margin-left: 10px; /* LTR */ } /* Bold all links */ .fusion-bold-links .inner a { font-weight: bold; } /* Float imagefield images left and add margin */ .fusion-float-imagefield-left .field-type-filefield, .fusion-float-imagefield-left .image-insert, .fusion-float-imagefield-left .imagecache { float: left; /* LTR */ margin: 0 15px 15px 0; /* LTR */ } /* Clear float on new Views item so each row drops to a new line */ .fusion-float-imagefield-left .views-row { clear: left; /* LTR */ } /* Float imagefield images right and add margin */ .fusion-float-imagefield-right .field-type-filefield, .fusion-float-imagefield-right .image-insert .fusion-float-imagefield-right .imagecache { float: right; /* LTR */ margin: 0 0 15px 15px; /* LTR */ } /* Clear float on new Views item so each row drops to a new line */ .fusion-float-imagefield-right .views-row { clear: right; /* LTR */ } /* Superfish: all menus */ .sf-menu li { list-style: none; list-style-image: none; list-style-type: none; } /* Superfish: vertical menus */ .superfish-vertical { position: relative; z-index: 9; } ul.sf-vertical { background: #fafafa; margin: 0; width: 100%; } ul.sf-vertical li { border-bottom: 1px solid #ccc; font-weight: bold; line-height: 200%; /* 24px */ padding: 0; width: 100%; } ul.sf-vertical li a:link, ul.sf-vertical li a:visited, ul.sf-vertical li .nolink { margin-left: 10px; padding: 2px; } ul.sf-vertical li a:hover, ul.sf-vertical li a.active { text-decoration: underline; } ul.sf-vertical li ul { background: #fafafa; border-top: 1px solid #ccc; margin-left: 0; width: 150px; } ul.sf-vertical li ul li.last { border-top: 1px solid #ccc; margin-bottom: -1px; margin-top: -1px; } ul.sf-vertical li ul { border-top: none; padding: 4px 0; } ul.sf-vertical li ul li { border-bottom: none; line-height: 150%; /* 24px */ More below but I can't paste that much Thanks for the suggestion I've tried this #header-group { position: relative; z-index: 9; } #logo { position: abosolute; top: 230px; /* 30 pixels from the top of the page */ left: 10px; /* 80 pixels from the left hand side */ z-index: 999; } but it's not working. I've taken a screen shot of the div to show the structure. http://i.stack.imgur.com/ff4DP.png

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  • Design by Contract with Microsoft .Net Code Contract

    - by Fredrik N
    I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are a terrible thing! Protect your self from them ”Human users have a gift for doing the worst possible thing at the worst possible time.” – Michael T. Nygard, Release It! The kind of users Michael T. Nygard are talking about is the users of a system. We also have users that uses our code, the users I’m going to focus on is the users of our code. Me and you and another developers. “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler Good programmers also writes code that humans know how to use, good programmers also make sure software behave in a predictable manner despise inputs or user actions. Design by Contract   Design by Contract (DbC) is a way for us to make a contract between us (the code writer) and the users of our code. It’s about “If you give me this, I promise to give you this”. It’s not about business validations, that is something completely different that should be part of the domain model. DbC is to make sure the users of our code uses it in a correct way, and that we can rely on the contract and write code in a way where we know that the users will follow the contract. It will make it much easier for us to write code with a contract specified. Something like the following code is something we may see often: public void DoSomething(Object value) { value.DoIKnowThatICanDoThis(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Where “value” can be uses directly or passed to other methods and later be used. What some of us can easily forget here is that the “value” can be “null”. We will probably not passing a null value, but someone else that uses our code maybe will do it. I think most of you (including me) have passed “null” into a method because you don’t know if the argument need to be specified to a valid value etc. I bet most of you also have got the “Null reference exception”. Sometimes this “Null reference exception” can be hard and take time to fix, because we need to search among our code to see where the “null” value was passed in etc. Wouldn’t it be much better if we can as early as possible specify that the value can’t not be null, so the users of our code also know it when the users starts to use our code, and before run time execution of the code? This is where DbC comes into the picture. We can use DbC to specify what we need, and by doing so we can rely on the contract when we write our code. So the code above can actually use the DoIKnowThatICanDoThis() method on the value object without being worried that the “value” can be null. The contract between the users of the code and us writing the code, says that the “value” can’t be null.   Pre- and Postconditions   When working with DbC we are specifying pre- and postconditions.  Precondition is a condition that should be met before a query or command is executed. An example of a precondition is: “The Value argument of the method can’t be null”, and we make sure the “value” isn’t null before the method is called. Postcondition is a condition that should be met when a command or query is completed, a postcondition will make sure the result is correct. An example of a postconditon is “The method will return a list with at least 1 item”. Commands an Quires When using DbC, we need to know what a Command and a Query is, because some principles that can be good to follow are based on commands and queries. A Command is something that will not return anything, like the SQL’s CREATE, UPDATE and DELETE. There are two kinds of Commands when using DbC, the Creation commands (for example a Constructor), and Others. Others can for example be a Command to add a value to a list, remove or update a value etc. //Creation commands public Stack(int size) //Other commands public void Push(object value); public void Remove(); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   A Query, is something that will return something, for example an Attribute, Property or a Function, like the SQL’s SELECT.   There are two kinds of Queries, the Basic Queries  (Quires that aren’t based on another queries), and the Derived Queries, queries that is based on another queries. Here is an example of queries of a Stack: //Basic Queries public int Count; public object this[int index] { get; } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To understand about some principles that are good to follow when using DbC, we need to know about the Commands and different Queries. The 6 Principles When working with DbC, it’s advisable to follow some principles to make it easier to define and use contracts. The following DbC principles are: Separate commands and queries. Separate basic queries from derived queries. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries. For each command, write a postcondition that specifies the value of every basic query. For every query and command, decide on a suitable precondition. Write invariants to define unchanging properties of objects. Before I will write about each of them I want you to now that I’m going to use .Net 4.0 Code Contract. I will in the rest of the post uses a simple Stack (Yes I know, .Net already have a Stack class) to give you the basic understanding about using DbC. A Stack is a data structure where the first item in, will be the first item out. Here is a basic implementation of a Stack where not contract is specified yet: public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } //Is related to Count and this[] Query public object Top() { return this[Count]; } //Creation commands public Stack(uint size) { Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { this[++Count] = value; } public void Remove() { this[Count] = null; Count--; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The Stack is implemented in a way to demonstrate the use of Code Contract in a simple way, the implementation may not look like how you would implement it, so don’t think this is the perfect Stack implementation, only used for demonstration.   Before I will go deeper into the principles I will simply mention how we can use the .Net Code Contract. I mention before about pre- and postcondition, is about “Require” something and to “Ensure” something. When using Code Contract, we will use a static class called “Contract” and is located in he “System.Diagnostics.Contracts” namespace. The contract must be specified at the top or our member statement block. To specify a precondition with Code Contract we uses the Contract.Requires method, and to specify a postcondition, we uses the Contract.Ensure method. Here is an example where both a pre- and postcondition are used: public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The contract above requires that the Count is greater than 0, if not we can’t get the item at the Top of a Stack. We also Ensures that the results (By using the Contract.Result method, we can specify a postcondition that will check if the value returned from a method is correct) of the Top query is equal to this[Count].   1. Separate Commands and Queries   When working with DbC, it’s important to separate Command and Quires. A method should either be a command that performs an Action, or returning information to the caller, not both. By asking a question the answer shouldn’t be changed. The following is an example of a Command and a Query of a Stack: public void Push(object value) public object Top() .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The Push is a command and will not return anything, just add a value to the Stack, the Top is a query to get the item at the top of the stack.   2. Separate basic queries from derived queries There are two different kinds of queries,  the basic queries that doesn’t rely on another queries, and derived queries that uses a basic query. The “Separate basic queries from derived queries” principle is about about that derived queries can be specified in terms of basic queries. So this principles is more about recognizing that a query is a derived query or a basic query. It will then make is much easier to follow the other principles. The following code shows a basic query and a derived query: //Basic Queries public uint Count; //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   We can see that IsEmpty will use the Count query, and that makes the IsEmpty a Derived query.   3. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries.   When the derived query is recognize we can follow the 3ed principle. For each derived query, we can create a postcondition that specifies what result our derived query will return in terms of one or more basic queries. Remember that DbC is about contracts between the users of the code and us writing the code. So we can’t use demand that the users will pass in a valid value, we must also ensure that we will give the users what the users wants, when the user is following our contract. The IsEmpty query of the Stack will use a Count query and that will make the IsEmpty a Derived query, so we should now write a postcondition that specified what results will be returned, in terms of using a basic query and in this case the Count query, //Basic Queries public uint Count; //Derived Queries public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } The Contract.Ensures is used to create a postcondition. The above code will make sure that the results of the IsEmpty (by using the Contract.Result to get the result of the IsEmpty method) is correct, that will say that the IsEmpty will be either true or false based on Count is equal to 0 or not. The postcondition are using a basic query, so the IsEmpty is now following the 3ed principle. We also have another Derived Query, the Top query, it will also need a postcondition and it uses all basic queries. The Result of the Top method must be the same value as the this[] query returns. //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count and this[] Query public object Top() { Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   4. For each command, write a postcondition that specifies the value of every basic query.   For each command we will create a postconditon that specifies the value of basic queries. If we look at the Stack implementation we will have three Commands, one Creation command, the Constructor, and two others commands, Push and Remove. Those commands need a postcondition and they should include basic query to follow the 4th principle. //Creation commands public Stack(uint size) { Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   As you can see the Create command will Ensures that Count will be 0 when the Stack is created, when a Stack is created there shouldn’t be any items in the stack. The Push command will take a value and put it into the Stack, when an item is pushed into the Stack, the Count need to be increased to know the number of items added to the Stack, and we must also make sure the item is really added to the Stack. The postconditon of the Push method will make sure the that old value of the Count (by using the Contract.OldValue we can get the value a Query has before the method is called)  plus 1 will be equal to the Count query, this is the way we can ensure that the Push will increase the Count with one. We also make sure the this[] query will now contain the item we pushed into the Stack. The Remove method must make sure the Count is decreased by one when the top item is removed from the Stack. The Commands is now following the 4th principle, where each command now have a postcondition that used the value of basic queries. Note: The principle says every basic Query, the Remove only used one Query the Count, it’s because this command can’t use the this[] query because an item is removed, so the only way to make sure an item is removed is to just use the Count query, so the Remove will still follow the principle.   5. For every query and command, decide on a suitable precondition.   We have now focused only on postcondition, now time for some preconditons. The 5th principle is about deciding a suitable preconditon for every query and command. If we starts to look at one of our basic queries (will not go through all Queries and commands here, just some of them) the this[] query, we can’t pass an index that is lower then 1 (.Net arrays and list are zero based, but not the stack in this blog post ;)) and the index can’t be lesser than the number of items in the stack. So here we will need a preconditon. public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Think about the Contract as an documentation about how to use the code in a correct way, so if the contract could be specified elsewhere (not part of the method body), we could simply write “return _array[index]” and there is no need to check if index is greater or lesser than Count, because that is specified in a “contract”. The implementation of Code Contract, requires that the contract is specified in the code. As a developer I would rather have this contract elsewhere (Like Spec#) or implemented in a way Eiffel uses it as part of the language. Now when we have looked at one Query, we can also look at one command, the Remove command (You can see the whole implementation of the Stack at the end of this blog post, where precondition is added to more queries and commands then what I’m going to show in this section). We can only Remove an item if the Count is greater than 0. So we can write a precondition that will require that Count must be greater than 0. public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   6. Write invariants to define unchanging properties of objects.   The last principle is about making sure the object are feeling great! This is done by using invariants. When using Code Contract we can specify invariants by adding a method with the attribute ContractInvariantMethod, the method must be private or public and can only contains calls to Contract.Invariant. To make sure the Stack feels great, the Stack must have 0 or more items, the Count can’t never be a negative value to make sure each command and queries can be used of the Stack. Here is our invariant for the Stack object: [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The ObjectInvariant method will be called every time after a Query or Commands is called. Here is the full example using Code Contract:   public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } set { Contract.Requires(index >= 1); Contract.Requires(index <= Count); _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } //Is related to Count and this[] Query public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } //Creation commands public Stack(uint size) { Contract.Requires(size > 0); Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Requires(value != null); Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Summary By using Design By Contract we can make sure the users are using our code in a correct way, and we must also make sure the users will get the expected results when they uses our code. This can be done by specifying contracts. To make it easy to use Design By Contract, some principles may be good to follow like the separation of commands an queries. With .Net 4.0 we can use the Code Contract feature to specify contracts.

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  • Make Windows Position Your Dual Monitors Correctly

    - by Mysticgeek
    If you have a dual monitor setup and each monitor is a different size or height, it can be annoying trying to move the mouse pointer between them. Here is a quick tip that will help make the process easier. Align Monitors In our example, we’re using Windows 7, but the process is essentially the same in all versions, but getting to Display Settings is different. In Windows 7 open the Start menu and type display settings into the search box and hit Enter. In Vista right-click the desktop and click Personalize. Then from the Personalize appearance and sounds menu click on Display Settings. In XP right-click on the desktop and select Properties then in Display Properties click the Settings tab. Now here is where you can change the appearance of your monitors. In this example we have a larger 22” LCD and a smaller 19” and it can be annoying getting the mouse pointer from one to another depending where you are on each monitor. So what you want to do is simply move each display around to a particular height so it’s easier to get the pointer over. For example with this setting we know we’ll have no problem moving the pointer to the other screen at the top of each display.   Of course here you can flip your monitors around, change the display resolution, orientation, etc. If you have dual monitors where one might be larger or set up higher than the other, then this is a great way to get them finely tuned. You will have to play around with the settings a bit to settle on what works best for you. Similar Articles Productive Geek Tips GeekNewb: Get to Know These Windows 7 HotkeysDual Monitors: Use a Different Wallpaper on Each DesktopSet Windows as Default OS when Dual Booting UbuntuEasily Set Default OS in a Windows 7 / Vista and XP Dual-boot SetupSet XP as the Default OS in a Windows Vista Dual-Boot Setup TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Download Wallpapers From National Geographic Site Spyware Blaster v4.3 Yes, it’s Patch Tuesday Generate Stunning Tag Clouds With Tagxedo Install, Remove and HIDE Fonts in Windows 7 Need Help with Your Home Network?

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  • Deferred rendering with VSM - Scaling light depth loses moments

    - by user1423893
    I'm calculating my shadow term using a VSM method. This works correctly when using forward rendered lights but fails with deferred lights. // Shadow term (1 = no shadow) float shadow = 1; // [Light Space -> Shadow Map Space] // Transform the surface into light space and project // NB: Could be done in the vertex shader, but doing it here keeps the // "light shader" abstraction and doesn't limit the number of shadowed lights float4x4 LightViewProjection = mul(LightView, LightProjection); float4 surf_tex = mul(position, LightViewProjection); // Re-homogenize // 'w' component is not used in later calculations so no need to homogenize (it will equal '1' if homogenized) surf_tex.xyz /= surf_tex.w; // Rescale viewport to be [0,1] (texture coordinate system) float2 shadow_tex; shadow_tex.x = surf_tex.x * 0.5f + 0.5f; shadow_tex.y = -surf_tex.y * 0.5f + 0.5f; // Half texel offset //shadow_tex += (0.5 / 512); // Scaled distance to light (instead of 'surf_tex.z') float rescaled_dist_to_light = dist_to_light / LightAttenuation.y; //float rescaled_dist_to_light = surf_tex.z; // [Variance Shadow Map Depth Calculation] // No filtering float2 moments = tex2D(ShadowSampler, shadow_tex).xy; // Flip the moments values to bring them back to their original values moments.x = 1.0 - moments.x; moments.y = 1.0 - moments.y; // Compute variance float E_x2 = moments.y; float Ex_2 = moments.x * moments.x; float variance = E_x2 - Ex_2; variance = max(variance, Bias.y); // Surface is fully lit if the current pixel is before the light occluder (lit_factor == 1) // One-tailed inequality valid if float lit_factor = (rescaled_dist_to_light <= moments.x - Bias.x); // Compute probabilistic upper bound (mean distance) float m_d = moments.x - rescaled_dist_to_light; // Chebychev's inequality float p = variance / (variance + m_d * m_d); p = ReduceLightBleeding(p, Bias.z); // Adjust the light color based on the shadow attenuation shadow *= max(lit_factor, p); This is what I know for certain so far: The lighting is correct if I do not try and calculate the shadow term. (No shadows) The shadow term is correct when calculated using forward rendered lighting. (VSM works with forward rendered lights) With the current rescaled light distance (lightAttenuation.y is the far plane value): float rescaled_dist_to_light = dist_to_light / LightAttenuation.y; The light is correct and the shadow appears to be zoomed in and misses the blurring: When I do not rescale the light and use the homogenized 'surf_tex': float rescaled_dist_to_light = surf_tex.z; the shadows are blurred correctly but the lighting is incorrect and the cube model is no longer lit Why is scaling by the far plane value (LightAttenuation.y) zooming in too far? The only other factor involved is my world pixel position, which is calculated as follows: // [Position] float4 position; // [Screen Position] position.xy = input.PositionClone.xy; // Use 'x' and 'y' components already homogenized for uv coordinates above position.z = tex2D(DepthSampler, texCoord).r; // No need to homogenize 'z' component position.z = 1.0 - position.z; position.w = 1.0; // 1.0 = position.w / position.w // [World Position] position = mul(position, CameraViewProjectionInverse); // Re-homogenize position (xyz AND w, otherwise shadows will bend when camera is close) position.xyz /= position.w; position.w = 1.0; Using the inverse matrix of the camera's view x projection matrix does work for lighting but maybe it is incorrect for shadow calculation? EDIT: Light calculations for shadow including 'dist_to_light' // Work out the light position and direction in world space float3 light_position = float3(LightViewInverse._41, LightViewInverse._42, LightViewInverse._43); // Direction might need to be negated float3 light_direction = float3(-LightViewInverse._31, -LightViewInverse._32, -LightViewInverse._33); // Unnormalized light vector float3 dir_to_light = light_position - position; // Direction from vertex float dist_to_light = length(dir_to_light); // Normalise 'toLight' vector for lighting calculations dir_to_light = normalize(dir_to_light); EDIT2: These are the calculations for the moments (depth) //============================================= //---[Vertex Shaders]-------------------------- //============================================= DepthVSOutput depth_VS( float4 Position : POSITION, uniform float4x4 shadow_view, uniform float4x4 shadow_view_projection) { DepthVSOutput output = (DepthVSOutput)0; // First transform position into world space float4 position_world = mul(Position, World); output.position_screen = mul(position_world, shadow_view_projection); output.light_vec = mul(position_world, shadow_view).xyz; return output; } //============================================= //---[Pixel Shaders]--------------------------- //============================================= DepthPSOutput depth_PS(DepthVSOutput input) { DepthPSOutput output = (DepthPSOutput)0; // Work out the depth of this fragment from the light, normalized to [0, 1] float2 depth; depth.x = length(input.light_vec) / FarPlane; depth.y = depth.x * depth.x; // Flip depth values to avoid floating point inaccuracies depth.x = 1.0f - depth.x; depth.y = 1.0f - depth.y; output.depth = depth.xyxy; return output; } EDIT 3: I have tried the folloiwng: float4 pp; pp.xy = input.PositionClone.xy; // Use 'x' and 'y' components already homogenized for uv coordinates above pp.z = tex2D(DepthSampler, texCoord).r; // No need to homogenize 'z' component pp.z = 1.0 - pp.z; pp.w = 1.0; // 1.0 = position.w / position.w // Determine the depth of the pixel with respect to the light float4x4 LightViewProjection = mul(LightView, LightProjection); float4x4 matViewToLightViewProj = mul(CameraViewProjectionInverse, LightViewProjection); float4 vPositionLightCS = mul(pp, matViewToLightViewProj); float fLightDepth = vPositionLightCS.z / vPositionLightCS.w; // Transform from light space to shadow map texture space. float2 vShadowTexCoord = 0.5 * vPositionLightCS.xy / vPositionLightCS.w + float2(0.5f, 0.5f); vShadowTexCoord.y = 1.0f - vShadowTexCoord.y; // Offset the coordinate by half a texel so we sample it correctly vShadowTexCoord += (0.5f / 512); //g_vShadowMapSize This suffers the same problem as the second picture. I have tried storing the depth based on the view x projection matrix: output.position_screen = mul(position_world, shadow_view_projection); //output.light_vec = mul(position_world, shadow_view); output.light_vec = output.position_screen; depth.x = input.light_vec.z / input.light_vec.w; This gives a shadow that has lots surface acne due to horrible floating point precision errors. Everything is lit correctly though. EDIT 4: Found an OpenGL based tutorial here I have followed it to the letter and it would seem that the uv coordinates for looking up the shadow map are incorrect. The source uses a scaled matrix to get the uv coordinates for the shadow map sampler /// <summary> /// The scale matrix is used to push the projected vertex into the 0.0 - 1.0 region. /// Similar in role to a * 0.5 + 0.5, where -1.0 < a < 1.0. /// <summary> const float4x4 ScaleMatrix = float4x4 ( 0.5, 0.0, 0.0, 0.0, 0.0, -0.5, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.5, 0.5, 0.5, 1.0 ); I had to negate the 0.5 for the y scaling (M22) in order for it to work but the shadowing is still not correct. Is this really the correct way to scale? float2 shadow_tex; shadow_tex.x = surf_tex.x * 0.5f + 0.5f; shadow_tex.y = surf_tex.y * -0.5f + 0.5f; The depth calculations are exactly the same as the source code yet they still do not work, which makes me believe something about the uv calculation above is incorrect.

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  • Exporting SWF With Transparent Background For Scaleform/UDK

    - by Alex Shepard
    After looking all over in the UDN and forums I have yet to find a solution for this: I am currently using Flash CS3 and Actionscript 2.0 to build my scaleform menus and I can use them in the UDK. For various reasons I can't use the handy plugin Autodesk supplies to enable this export so I publish my flash documents to swf the old fassioned way and manually use the gfxexport.exe tool to get my .gfx file. I can then import into the UDK the normal way. My problem is that the flash movies that I import will not alpha blend even if the material is set to blend in the alpha channel of the target render texture. My project images are set up to export properly. My classpath for Actionscript 2.0 is set to the correct location. My HTML publish settings have window mode set to Transparent Windowless. Is it possible to export without the scaleform flash extension and still get the desired effects and if so how might I do so? Am I merely missing something from my project setup?

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  • Movement and Collision with AABB

    - by Jeremy Giberson
    I'm having a little difficulty figuring out the following scenarios. http://i.stack.imgur.com/8lM6i.png In scenario A, the moving entity has fallen to (and slightly into the floor). The current position represents the projected position that will occur if I apply the acceleration & velocity as usual without worrying about collision. The Next position, represents the corrected projection position after collision check. The resulting end position is the falling entity now rests ON the floor--that is, in a consistent state of collision by sharing it's bottom X axis with the floor's top X axis. My current update loop looks like the following: // figure out forces & accelerations and project an objects next position // check collision occurrence from current position -> projected position // if a collision occurs, adjust projection position Which seems to be working for the scenario of my object falling to the floor. However, the situation becomes sticky when trying to figure out scenario's B & C. In scenario B, I'm attempt to move along the floor on the X axis (player is pressing right direction button) additionally, gravity is pulling the object into the floor. The problem is, when the object attempts to move the collision detection code is going to recognize that the object is already colliding with the floor to begin with, and auto correct any movement back to where it was before. In scenario C, I'm attempting to jump off the floor. Again, because the object is already in a constant collision with the floor, when the collision routine checks to make sure moving from current position to projected position doesn't result in a collision, it will fail because at the beginning of the motion, the object is already colliding. How do you allow movement along the edge of an object? How do you allow movement away from an object you are already colliding with. Extra Info My collision routine is based on AABB sweeping test from an old gamasutra article, http://www.gamasutra.com/view/feature/3383/simple_intersection_tests_for_games.php?page=3 My bounding box implementation is based on top left/bottom right instead of midpoint/extents, so my min/max functions are adjusted. Otherwise, here is my bounding box class with collision routines: public class BoundingBox { public XYZ topLeft; public XYZ bottomRight; public BoundingBox(float x, float y, float z, float w, float h, float d) { topLeft = new XYZ(); bottomRight = new XYZ(); topLeft.x = x; topLeft.y = y; topLeft.z = z; bottomRight.x = x+w; bottomRight.y = y+h; bottomRight.z = z+d; } public BoundingBox(XYZ position, XYZ dimensions, boolean centered) { topLeft = new XYZ(); bottomRight = new XYZ(); topLeft.x = position.x; topLeft.y = position.y; topLeft.z = position.z; bottomRight.x = position.x + (centered ? dimensions.x/2 : dimensions.x); bottomRight.y = position.y + (centered ? dimensions.y/2 : dimensions.y); bottomRight.z = position.z + (centered ? dimensions.z/2 : dimensions.z); } /** * Check if a point lies inside a bounding box * @param box * @param point * @return */ public static boolean isPointInside(BoundingBox box, XYZ point) { if(box.topLeft.x <= point.x && point.x <= box.bottomRight.x && box.topLeft.y <= point.y && point.y <= box.bottomRight.y && box.topLeft.z <= point.z && point.z <= box.bottomRight.z) return true; return false; } /** * Check for overlap between two bounding boxes using separating axis theorem * if two boxes are separated on any axis, they cannot be overlapping * @param a * @param b * @return */ public static boolean isOverlapping(BoundingBox a, BoundingBox b) { XYZ dxyz = new XYZ(b.topLeft.x - a.topLeft.x, b.topLeft.y - a.topLeft.y, b.topLeft.z - a.topLeft.z); // if b - a is positive, a is first on the axis and we should use its extent // if b -a is negative, b is first on the axis and we should use its extent // check for x axis separation if ((dxyz.x >= 0 && a.bottomRight.x-a.topLeft.x < dxyz.x) // negative scale, reverse extent sum, flip equality ||(dxyz.x < 0 && b.topLeft.x-b.bottomRight.x > dxyz.x)) return false; // check for y axis separation if ((dxyz.y >= 0 && a.bottomRight.y-a.topLeft.y < dxyz.y) // negative scale, reverse extent sum, flip equality ||(dxyz.y < 0 && b.topLeft.y-b.bottomRight.y > dxyz.y)) return false; // check for z axis separation if ((dxyz.z >= 0 && a.bottomRight.z-a.topLeft.z < dxyz.z) // negative scale, reverse extent sum, flip equality ||(dxyz.z < 0 && b.topLeft.z-b.bottomRight.z > dxyz.z)) return false; // not separated on any axis, overlapping return true; } public static boolean isContactEdge(int xyzAxis, BoundingBox a, BoundingBox b) { switch(xyzAxis) { case XYZ.XCOORD: if(a.topLeft.x == b.bottomRight.x || a.bottomRight.x == b.topLeft.x) return true; return false; case XYZ.YCOORD: if(a.topLeft.y == b.bottomRight.y || a.bottomRight.y == b.topLeft.y) return true; return false; case XYZ.ZCOORD: if(a.topLeft.z == b.bottomRight.z || a.bottomRight.z == b.topLeft.z) return true; return false; } return false; } /** * Sweep test min extent value * @param box * @param xyzCoord * @return */ public static float min(BoundingBox box, int xyzCoord) { switch(xyzCoord) { case XYZ.XCOORD: return box.topLeft.x; case XYZ.YCOORD: return box.topLeft.y; case XYZ.ZCOORD: return box.topLeft.z; default: return 0f; } } /** * Sweep test max extent value * @param box * @param xyzCoord * @return */ public static float max(BoundingBox box, int xyzCoord) { switch(xyzCoord) { case XYZ.XCOORD: return box.bottomRight.x; case XYZ.YCOORD: return box.bottomRight.y; case XYZ.ZCOORD: return box.bottomRight.z; default: return 0f; } } /** * Test if bounding box A will overlap bounding box B at any point * when box A moves from position 0 to position 1 and box B moves from position 0 to position 1 * Note, sweep test assumes bounding boxes A and B's dimensions do not change * * @param a0 box a starting position * @param a1 box a ending position * @param b0 box b starting position * @param b1 box b ending position * @param aCollisionOut xyz of box a's position when/if a collision occurs * @param bCollisionOut xyz of box b's position when/if a collision occurs * @return */ public static boolean sweepTest(BoundingBox a0, BoundingBox a1, BoundingBox b0, BoundingBox b1, XYZ aCollisionOut, XYZ bCollisionOut) { // solve in reference to A XYZ va = new XYZ(a1.topLeft.x-a0.topLeft.x, a1.topLeft.y-a0.topLeft.y, a1.topLeft.z-a0.topLeft.z); XYZ vb = new XYZ(b1.topLeft.x-b0.topLeft.x, b1.topLeft.y-b0.topLeft.y, b1.topLeft.z-b0.topLeft.z); XYZ v = new XYZ(vb.x-va.x, vb.y-va.y, vb.z-va.z); // check for initial overlap if(BoundingBox.isOverlapping(a0, b0)) { // java pass by ref/value gotcha, have to modify value can't reassign it aCollisionOut.x = a0.topLeft.x; aCollisionOut.y = a0.topLeft.y; aCollisionOut.z = a0.topLeft.z; bCollisionOut.x = b0.topLeft.x; bCollisionOut.y = b0.topLeft.y; bCollisionOut.z = b0.topLeft.z; return true; } // overlap min/maxs XYZ u0 = new XYZ(); XYZ u1 = new XYZ(1,1,1); float t0, t1; // iterate axis and find overlaps times (x=0, y=1, z=2) for(int i = 0; i < 3; i++) { float aMax = max(a0, i); float aMin = min(a0, i); float bMax = max(b0, i); float bMin = min(b0, i); float vi = XYZ.getCoord(v, i); if(aMax < bMax && vi < 0) XYZ.setCoord(u0, i, (aMax-bMin)/vi); else if(bMax < aMin && vi > 0) XYZ.setCoord(u0, i, (aMin-bMax)/vi); if(bMax > aMin && vi < 0) XYZ.setCoord(u1, i, (aMin-bMax)/vi); else if(aMax > bMin && vi > 0) XYZ.setCoord(u1, i, (aMax-bMin)/vi); } // get times of collision t0 = Math.max(u0.x, Math.max(u0.y, u0.z)); t1 = Math.min(u1.x, Math.min(u1.y, u1.z)); // collision only occurs if t0 < t1 if(t0 <= t1 && t0 != 0) // not t0 because we already tested it! { // t0 is the normalized time of the collision // then the position of the bounding boxes would // be their original position + velocity*time aCollisionOut.x = a0.topLeft.x + va.x*t0; aCollisionOut.y = a0.topLeft.y + va.y*t0; aCollisionOut.z = a0.topLeft.z + va.z*t0; bCollisionOut.x = b0.topLeft.x + vb.x*t0; bCollisionOut.y = b0.topLeft.y + vb.y*t0; bCollisionOut.z = b0.topLeft.z + vb.z*t0; return true; } else return false; } }

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