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  • Direct2D window black when not in focus

    - by Saul Rennison
    Hi all, I have a Direct2D window which paints fine when in focus; however, when focus moves to another window (same application or another), the entire window goes black. I pinned the issue down to the use of ID2D1HwndRenderTarget::Clear. This function is vital to my application as without it, painting becomes rather... weird. Is there a way an un-focused Direct2D window can paint as normal (note: WM_PAINT is being called as usual, as is Clear, BeginPaint, etc. all without error) Thanks in advance.

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  • Setting foreground color for HSSFCellStyle is always coming out black

    - by Ascalonian
    I am using POI to create an Excel spreadsheet in Java. I have the following code used for creating a header row: HSSFWorkbook wb = new HSSFWorkbook(); HSSFSheet sheet = wb.createSheet("Report"); // some more code HSSFRow row = sheet.createRow(0); HSSFCell cell = row.createCell(cellNumber); HSSFCellStyle cellStyle = wb.createCellStyle(); cellStyle.setFillBackgroundColor(HSSFColor.GREY_25_PERCENT.index); cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND); HSSFFont font = wb.createFont(); font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); font.setColor(HSSFColor.WHITE.index); cellStyle.setFont(font); cell.setCellStyle(cellStyle); The issue I am having is that setting the fill background color on the cell always comes out black, no matter what color I pick. What am I doing wrong? If I don't use the "setFillPattern" line, no color shows up at all.

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  • Activity should be transparent, but has black background

    - by Uwe Krass
    I followed the instructions of writing a transparent layout. My res/values/style.xml looks like this: <resources> <style name="Theme" parent="android:Theme" /> <style name="Theme.Transparent"> <item name="android:windowBackground">@drawable/transparent_background</item> </style> <drawable name="transparent_background">#00000000</drawable> </resources> The activity snippet looks like this: <activity android:name=".Controlls" android:label="Controlls" android:theme="@style/Theme.Transparent"> When I start this activity from my root activity, the layout gets drawn correctly, but the background stays black.

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  • String to image only produces black background

    - by Phil Jackson
    Hi im really having a problem find how to fix this. $string = "foo"; $font = 4; $width = ImageFontWidth($font) * strlen($string); $height = ImageFontHeight($font); $im = @imagecreatetruecolor ($width,$height); $bg = imagecolorallocate($im, 255, 255, 255); $textcolor = imagecolorallocate($im, 0, 0, 0); imagestring($im, 5, 0, 0, $string, $textcolor); imagegif($im, 'somefile.gif', 8); imagedestroy($im); I cannot seem to change the background from black. Does anyone have any ideas?

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  • How to avoid Black Screen on starting an application

    - by ganesh
    hi, When i start my application initially ,i get a black screen which stays for a few seconds before my main activity starts.In case of iphone an image with name default is displayed for that split second.I am not sure how to do the same in android.Any help .I tried as below in vain <activity android:name=".Index" android:label="@string/app_name" android:screenOrientation="portrait" android:theme="@drawable/defaultimage"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>

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  • [Android] Weird black line on top of list view

    - by CaseyB
    I am creating a layout with a ListView and at the very top of the list there is this weird black line that I can't seem to figure out how to get rid of! It's part of the ListView because it moves up and down as I size the ListView. Has anyone ran into this before? I couldn't get DDMS to take a screen capture for some reason so I took a picture of the screen with my G1, so please forgive the quality! As you can see the line is there at the top of the fade out in the list.

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  • Build turns partially transparent image pixels black

    - by Sean O'Hollaren
    I'm very new to C# and I've run into a problem and haven't been able to solve it. I have a row of buttons that have .png images assigned to them. The images are in .png format to allow transparency, and smoothing the edges in GIMP leaves some semi-transparent pixels. I've set the Image List Toolbar (imglToolbar)'s properties to recognize "Transparent" as the designated color to show up as transparent. I'm working in Visual Studio 2005. The strange thing is that everything looks great when I'm viewing the Visual C# form preview window. The icons look exactly as they should. However, once I actually build the project, the buttons treat every semi-transparent pixel near the edge of the image as if it's black. It seems like it can't handle one that's both transparent and has color. Image of it via the Visual C# form editor: Image of what it looks like when built: Any ideas as to why this is happening?

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  • MFMessageComposeViewControllerDelegate error - black screen

    - by user1053839
    I'm using the following code to show in-app sms. My app don't have a status bar. (I'm using 320x480 pixels screen in portrait view). the problem is that when I load the controller, the screen becomes black as you can see from the image... http://desmond.imageshack.us/Himg211/scaled.php?server=211&filename=schermata092456187alle1.png&res=landing this is the code: MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init]; picker.messageComposeDelegate = self; picker.recipients = [NSArray arrayWithObject:@"123456789"]; // your recipient number or self for testing picker.body = @"test"; [self presentModalViewController:picker animated:YES];

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  • Facebook Black Screen when in IFrame

    - by Rico
    I have Facebook in an Iframe for the convenience of my clients. But all of a sudden it doesn't work.. It simply covers itself with a black screen. Is there a work around? Something I can do. Maybe even have someone code to their API to get all the functionality back. Is there a sollution already out there?? <html> <body> <iframe src="http://www.facebook.com/" width=800 height=600 /> </body> </html>

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  • Detect a white square in a black and white image

    - by gcc
    I saw that question i one web site (cite name like that programm.) then i tried to solve but icannot (not my and myfriend homework ) how can i approach to that one (in program.net no solution there is ) Read black & white image data from standard input, and detect a white square in the image. Output the coordinates of the upper left corner of the square, and the width of the square. In the preliminary work, you can print the output and terminate your program after you detect your first square. If you can't find any square on the image, you will print the string: "NO DETECTION". Input (which represents a 2 by 2 square in the center of a 5 by 4 image): 2 2 5 4 0 0 0 0 0 0 0 255 255 0 0 0 255 255 0 0 0 0 0 0 Output: 3 2 2 Input (more comprehensible format of the image, with the same output): 2 6 4 000 000 000 000 000 000 000 000 255 255 255 000 000 000 000 255 255 000 000 000 000 000 000 000 Output: no detection Input can be: 000 255 255 000 000 000 000 255 255 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 255 255 255 000 000 000 255 255 255 000 000 000 255 255 255 000 000 000 000 000 000 000 If there are two squares detected, we should use the biggest one

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  • imagecreatefrompng() Makes a black background instead of transparent?

    - by Emily
    Hi, I make thumbnails using PHP and GD library but my code turn png transparency into a solid black color, Is there a solution to improve my code? this is my php thumbnail maker code: function cropImage($nw, $nh, $source, $stype, $dest) { $size = getimagesize($source); $w = $size[0]; $h = $size[1]; switch($stype) { case 'gif': $simg = imagecreatefromgif($source); break; case 'jpg': $simg = imagecreatefromjpeg($source); break; case 'png': $simg = imagecreatefrompng($source); break; } $dimg = imagecreatetruecolor($nw, $nh); $wm = $w/$nw; $hm = $h/$nh; $h_height = $nh/2; $w_height = $nw/2; if($w> $h) { $adjusted_width = $w / $hm; $half_width = $adjusted_width / 2; $int_width = $half_width - $w_height; imagecopyresampled($dimg,$simg,-$int_width,0,0,0,$adjusted_width,$nh,$w,$h); } elseif(($w <$h) || ($w == $h)) { $adjusted_height = $h / $wm; $half_height = $adjusted_height / 2; $int_height = $half_height - $h_height; imagecopyresampled($dimg,$simg,0,-$int_height,0,0,$nw,$adjusted_height,$w,$h); } else { imagecopyresampled($dimg,$simg,0,0,0,0,$nw,$nh,$w,$h); } imagejpeg($dimg,$dest,100); } Thank you

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  • There's a black hole in my server (TcpClient, TcpListener)

    - by Matías
    Hi, I'm trying to build a server that will receive files sent by clients over a network. If the client decides to send one file at a time, there's no problem, I get the file as I expected, but if it tries to send more than one I only get the first one. Here's the server code: I'm using one Thread per connected client public void ProcessClients() { while (IsListening) { ClientHandler clientHandler = new ClientHandler(listener.AcceptTcpClient()); Thread thread = new Thread(new ThreadStart(clientHandler.Process)); thread.Start(); } } The following code is part of ClientHandler class public void Process() { while (client.Connected) { using (MemoryStream memStream = new MemoryStream()) { int read; while ((read = client.GetStream().Read(buffer, 0, buffer.Length)) > 0) { memStream.Write(buffer, 0, read); } if (memStream.Length > 0) { Packet receivedPacket = (Packet)Tools.Deserialize(memStream.ToArray()); File.WriteAllBytes(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory), Guid.NewGuid() + receivedPacket.Filename), receivedPacket.Content); } } } } On the first iteration I get the first file sent, but after it I don't get anything. I've tried using a Thread.Sleep(1000) at the end of every iteration without any luck. On the other side I have this code (for clients) . . client.Connect(); foreach (var oneFilename in fileList) client.Upload(oneFilename); client.Disconnect(); . . The method Upload: public void Upload(string filename) { FileInfo fileInfo = new FileInfo(filename); Packet packet = new Packet() { Filename = fileInfo.Name, Content = File.ReadAllBytes(filename) }; byte[] serializedPacket = Tools.Serialize(packet); netStream.Write(serializedPacket, 0, serializedPacket.Length); netStream.Flush(); } netStream (NetworkStream) is opened on Connect method, and closed on Disconnect. Where's the black hole? Can I send multiple objects as I'm trying to do? Thanks for your time.

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  • Resizing window causes black strips

    - by Paja
    I have a form, which sets these styles in constructor: this.SetStyle(ControlStyles.AllPaintingInWmPaint, true); this.SetStyle(ControlStyles.UserPaint, true); this.SetStyle(ControlStyles.ResizeRedraw, true); this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true); And I draw some rectangles in Paint event. There are no controls on the form. Hovewer, when I resize the form, there are black strips at right and bottom of the form. Is there any way to get rid of them? I've tried everything, listening for WM_ERASEBKGND in WndProc, manually drawing the form on WM_PAINT, implementing custom double buffer, etc. Is there anything else I could try? I've found this: https://connect.microsoft.com/VisualStudio/feedback/details/522441/custom-resizing-of-system-windows-window-flickers and it looks like it is a bug in DWM, but I just hope I can do some workaround. Please note that I must use double buffering, since I want to draw pretty intense graphic presentation in the Paint event. I develop in C# .NET 2.0, Win7.

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  • how to make the red div don't alert 'ss' when drag the black div on it ,

    - by zjm1126
    i using jquery and jquery-ui, this is my code: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta name="viewport" content="width=device-width, user-scalable=no"> </head> <body> <style type="text/css" media="screen"> </style> <div id=a style="width:300px;height:300px;background:blue;position:absolute;"></div> <div id=b style="width:100px;height:100px;background:red;position:absolute;"></div> <div id=c style="width:50px;height:50px;background:black;clear:both"></div> <script src="jquery-1.4.2.js" type="text/javascript"></script> <script src="jquery-ui-1.8rc3.custom.min.js" type="text/javascript"></script> <script type="text/javascript" charset="utf-8"> $("#c").draggable({}); $("#b").droppable('disable');//this is not useful $("#a").droppable({ drop: function(event,ui) { alert('ss') } }); </script> </body> </html>

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  • imageconvolution leaves black dot in the upper left corner

    - by Peter O.
    I'm trying to sharp resized images using this code: imageconvolution($imageResource, array( array( -1, -1, -1 ), array( -1, 16, -1 ), array( -1, -1, -1 ), ), 8, 0); When the transparent PNG image is sharpened, using code above, it appears with a black dot in the upper left corner (I have tried different convolution kernels, but the result is the same). After resizing the image looked OK. 1st image is the original one 2nd image is the sharpened one EDIT: What am I going wrong? I'm using the color retrieved from pixel. $color = imagecolorat($imageResource, 0, 0); imageconvolution($imageResource, array( array( -1, -1, -1 ), array( -1, 16, -1 ), array( -1, -1, -1 ), ), 8, 0); imagesetpixel($imageResource, 0, 0, $color); Is imagecolorat the right function? Or is the position correct? EDIT2: I have changed coordinates, but still no luck. I've check the transparency given by imagecolorat (according to this post). This is the dump: array(4) { red => 0 green => 0 blue => 0 alpha => 127 } Alpha 127 = 100% transparent. Those zeroes might cause the problem...

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  • iOS Simulator is black on app execution

    - by Terryn
    I am running xcode 5.1.1 and have been trying to learn objective C / iOS development. Right now whenever I try to run my code on the emulator (I do not have an actual device atm) it comes up with a black screen. Code can be found here. Compiling and running gives me the following error: 2014-08-23 10:42:57.429 Calculator[1862:60b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<XYZViewController 0xe436640> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key didgetPressed.' *** First throw call stack: ( 0 CoreFoundation 0x017ed1e4 __exceptionPreprocess + 180 1 libobjc.A.dylib 0x0156c8e5 objc_exception_throw + 44 2 CoreFoundation 0x0187cfe1 -[NSException raise] + 17 3 Foundation 0x0122cd9e -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282 4 Foundation 0x011991d7 _NSSetUsingKeyValueSetter + 88 5 Foundation 0x01198731 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267 6 Foundation 0x011fab0a -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 412 7 UIKit 0x004e31f4 -[UIRuntimeOutletConnection connect] + 106 8 libobjc.A.dylib 0x0157e7de -[NSObject performSelector:] + 62 9 CoreFoundation 0x017e876a -[NSArray makeObjectsPerformSelector:] + 314 10 UIKit 0x004e1d4d -[UINib instantiateWithOwner:options:] + 1417 11 UIKit 0x0034a6f5 -[UIViewController _loadViewFromNibNamed:bundle:] + 280 12 UIKit 0x0034ae9d -[UIViewController loadView] + 302 13 UIKit 0x0034b0d3 -[UIViewController loadViewIfRequired] + 78 14 UIKit 0x0034b5d9 -[UIViewController view] + 35 15 UIKit 0x0026b267 -[UIWindow addRootViewControllerViewIfPossible] + 66 16 UIKit 0x0026b5ef -[UIWindow _setHidden:forced:] + 312 17 UIKit 0x0026b86b -[UIWindow _orderFrontWithoutMakingKey] + 49 18 UIKit 0x002763c8 -[UIWindow makeKeyAndVisible] + 65 19 UIKit 0x00226bc0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 2097 20 UIKit 0x0022b667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824 21 UIKit 0x0023ff92 -[UIApplication handleEvent:withNewEvent:] + 3517 22 UIKit 0x00240555 -[UIApplication sendEvent:] + 85 23 UIKit 0x0022d250 _UIApplicationHandleEvent + 683 24 GraphicsServices 0x037e2f02 _PurpleEventCallback + 776 25 GraphicsServices 0x037e2a0d PurpleEventCallback + 46 26 CoreFoundation 0x01768ca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53 27 CoreFoundation 0x017689db __CFRunLoopDoSource1 + 523 28 CoreFoundation 0x0179368c __CFRunLoopRun + 2156 29 CoreFoundation 0x017929d3 CFRunLoopRunSpecific + 467 30 CoreFoundation 0x017927eb CFRunLoopRunInMode + 123 31 UIKit 0x0022ad9c -[UIApplication _run] + 840 32 UIKit 0x0022cf9b UIApplicationMain + 1225 33 Calculator 0x00002c8d main + 141 34 libdyld.dylib 0x01e34701 start + 1 35 ??? 0x00000001 0x0 + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb) I have attempted the following things, and so far nothing has worked 1) checked the deployment info, it has the main interface set to main 2) double checked all break points to turn them off and disabled all of them through Debug-Disable Breakpoints 3) Reset Content and Settings on the iOS Simulator. 4) Checked the issue with the LLDB Debugger, however from what I have read the issue is no longer present with the 5.1.1 xcode. 5) checked the local host is still set to 127.0.0.1 Thanks! - Terryn

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  • Black Corners On Grouped UITableViewCells Only After Navigation Pops

    - by coneybeare
    I am not graphics expert but I somehow managed to make some good looking custom grouped UITableViewCells by setting the background view to a backgroundView with some CG code. In all SDK's up to 3.1.3 (maybe 3.2... I haven't tested on the iPad) this was working great, but I think a more recent SDK has introduced a change in the way graphics are cached offscreen. Upon first render, everything is great: The drawing is fine and the corners are transparent. If I push a couple of view controllers on the navigation stack and come back, there are now black corners that appear in the views: BEFORE && AFTER I have tons of code, most of which is written up here. I have tried tweaking to the best of my ability, looking at the docs for applicable changes, but after at least 8 hours in I still cannot find what might cause this. I have tried setting every view I can think of to be backgroundColor=clearColor and opaque=NO What else am I missing? Any debugging tips? UPDATE: I have some debug code in viewDidAppear that prints the backgroundColor and class description of all the subviews. - (void)debugView:(UIView *)view { DebugLog(@"%@ - %@", view.backgroundColor, [[view class] description]); for (UIView* child in view.subviews) { [self debugView:child]; } } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [DownloadController.networkQueue setSuspended:NO]; for (TTTableViewCell *cell in [self.tableView visibleCells]) { [cell debugView:cell]; } } With this code, I inspect the backgroundColor settings of the cell views on first load, when it is fine, and then again after coming back. There are some differences, but all the colors are still set to be clear. This leads me to believe the issue is underneath the UITableViewCell. UPDATE 2: I have created a simple sample application to highlight the problem here

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  • AndEngine: Black screen when using LayoutGameActivity

    - by Lemuel Hogben
    I used to use SimpleBaseGameActivity for my app and everything was ok, but now I want to add some ads into the app, so I tried to use LayoutGameActivity. But I get the screen completely black and I don't know why. That's my code: public class AcGame extends LayoutGameActivity { [...] @Override protected int getLayoutID() { return R.layout.ad; } @Override protected int getRenderSurfaceViewID() { return R.id.layout_render; } @Override public EngineOptions onCreateEngineOptions() { [...] return new EngineOptions(true, ScreenOrientation.PORTRAIT_FIXED, resolution, camera); } @Override public void onCreateResources(OnCreateResourcesCallback pOnCreateResourcesCallback) throws Exception { createResources(); pOnCreateResourcesCallback.onCreateResourcesFinished(); } @Override public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback) throws Exception { pOnCreateSceneCallback.onCreateSceneFinished(createScene()); } @Override public void onPopulateScene(Scene pScene, OnPopulateSceneCallback pOnPopulateSceneCallback) throws Exception { pOnPopulateSceneCallback.onPopulateSceneFinished(); } And that's my layout: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="top" android:id="@+id/layout_ad" > <Button android:layout_width="fill_parent" android:layout_height="fill_parent" android:text="Ad Sample"/> </LinearLayout> <org.andengine.opengl.view.RenderSurfaceView android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:id="@+id/layout_render" /> </LinearLayout> When I'm trying to debug, I can see that EngineOptions are creating, but no one of the LayoutGameActivity's methods was called (onCreateResources, onCreateScene or onPopulateScene). Can someone tell me what I've missed?

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  • iPhone:How to make navigation top bar style to same like "Black Navigation Bar" programmatically?

    - by Getsy
    I have a Navigation project which has only a TableView. By default, i could see the navigation bar there when running the application. I want to change the navigation bar style to same like if we see in I.B there is one called "Top Bar" which has "Black Navigation Bar" style (Which shows Black navigation top bar but some kind of Gray shade will be there). I want the same in my navigation bar now, not any other color or style. How do i fix it? Note: 1. I used "self.navigationController.navigationBar.barStyle = UIBarStyleBlack;" , but it shows the navigation bar in utter black color. I don't want that, i want some kind of Gray shade in black, similar to "Top Bar" which has "Black Navigation Bar". I tried some tint color addition to the above, like "self.navigationController.navigationBar.tintColor = [UIColor grayColor];" but i observe the same utter black shows in navigation bar. I tried "navigationBar.barStyle = UIBarStyleBlackTranslucent;" but it doesn't fit and show with status bar properly. Instead it overlaps(hidden) half black with status bar and half black shows outside. Could someone teach me? Thank you.

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  • Phantomjs creating black output from SVG using page.render

    - by Neil Young
    I have been running PhantomJS 1.9.6 happily on a turnkey Linux server for about 4 months now. Its purpose is to take an SVG file and create different sizes using the page.render function. This has been doing this but since a few days ago has started to generate a black mono output. Please see below: The code: var page = require('webpage').create(), system = require('system'), address, output, ext, width, height; if ( system.args.length !== 4 ) { console.log("{ \"result\": false, \"message\": \"phantomjs.rasterize: error need address, output, extension arguments\" }"); //console.log('phantomjs.rasterize: error need address, output, extension arguments'); phantom.exit(1); } else if( system.args[3] !== "jpg" && system.args[3] !== "png"){ console.log("{ \"result\": false, \"message\": \"phantomjs.rasterize: error \"jpg\" or \"png\" only please\" }"); //console.log('phantomjs.rasterize: error "jpg" or "png" only please'); phantom.exit(1); } else { address = system.args[1]; output = system.args[2]; ext = system.args[3]; width = 1044; height = 738; page.viewportSize = { width: width, height: height }; //postcard size page.open(address, function (status) { if (status !== 'success') { console.log("{ \"result\": false, \"message\": \"phantomjs.rasterize: error loading address ["+address+"]\" }"); //console.log('phantomjs.rasterize: error loading address ['+address+'] '); phantom.exit(); } else { window.setTimeout(function () { //--> redner full size postcard page.render( output + "." + ext ); //--> redner smaller postcard page.zoomFactor = 0.5; page.clipRect = {top:0, left:0, width:width*0.5, height:height*0.5}; page.render( output + ".50." + ext); //--> redner postcard thumb page.zoomFactor = 0.25; page.clipRect = {top:0, left:0, width:width*0.25, height:height*0.25}; page.render( output + ".25." + ext); //--> exit console.log("{ \"result\": true, \"message\": \"phantomjs.rasterize: success ["+address+"]>>["+output+"."+ext+"]\" }"); //console.log('phantomjs.rasterize: success ['+address+']>>['+output+'.'+ext+']'); phantom.exit(); }, 100); } }); } Does anyone know what can be causing this? There have been no server configuration changes that I know of. Many thanks for your help.

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  • Persistent (purely functional) Red-Black trees on disk performance

    - by Waneck
    I'm studying the best data structures to implement a simple open-source object temporal database, and currently I'm very fond of using Persistent Red-Black trees to do it. My main reasons for using persistent data structures is first of all to minimize the use of locks, so the database can be as parallel as possible. Also it will be easier to implement ACID transactions and even being able to abstract the database to work in parallel on a cluster of some kind. The great thing of this approach is that it makes possible implementing temporal databases almost for free. And this is something quite nice to have, specially for web and for data analysis (e.g. trends). All of this is very cool, but I'm a little suspicious about the overall performance of using a persistent data structure on disk. Even though there are some very fast disks available today, and all writes can be done asynchronously, so a response is always immediate, I don't want to build all application under a false premise, only to realize it isn't really a good way to do it. Here's my line of thought: - Since all writes are done asynchronously, and using a persistent data structure will enable not to invalidate the previous - and currently valid - structure, the write time isn't really a bottleneck. - There are some literature on structures like this that are exactly for disk usage. But it seems to me that these techniques will add more read overhead to achieve faster writes. But I think that exactly the opposite is preferable. Also many of these techniques really do end up with a multi-versioned trees, but they aren't strictly immutable, which is something very crucial to justify the persistent overhead. - I know there still will have to be some kind of locking when appending values to the database, and I also know there should be a good garbage collecting logic if not all versions are to be maintained (otherwise the file size will surely rise dramatically). Also a delta compression system could be thought about. - Of all search trees structures, I really think Red-Blacks are the most close to what I need, since they offer the least number of rotations. But there are some possible pitfalls along the way: - Asynchronous writes -could- affect applications that need the data in real time. But I don't think that is the case with web applications, most of the time. Also when real-time data is needed, another solutions could be devised, like a check-in/check-out system of specific data that will need to be worked on a more real-time manner. - Also they could lead to some commit conflicts, though I fail to think of a good example of when it could happen. Also commit conflicts can occur in normal RDBMS, if two threads are working with the same data, right? - The overhead of having an immutable interface like this will grow exponentially and everything is doomed to fail soon, so this all is a bad idea. Any thoughts? Thanks! edit: There seems to be a misunderstanding of what a persistent data structure is: http://en.wikipedia.org/wiki/Persistent_data_structure

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  • PHP+GD creating random black thumbnails

    - by rroberto
    Hello, This function is creating some random black images like.. 10% of the time, is not much, but.. you know.. shouldnt be happening. class ImgResizer { private $originalFile = ''; public function __construct($originalFile = '') { $this -> originalFile = $originalFile; } public function resize($newWidth, $targetFile) { if (empty($newWidth) || empty($targetFile)) { return false; } $src = imagecreatefromjpeg($this -> originalFile); list($width, $height) = getimagesize($this -> originalFile); $newHeight = ($height / $width) * $newWidth; if ($newHeight<'335') { //$newHeight='335'; } $tmp = imagecreatetruecolor($newWidth, $newHeight); #$tmp = imagecreate($newWidth, $newHeight); imagecopyresampled($tmp, $src, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height); if (file_exists($targetFile)) { unlink($targetFile); } imagejpeg($tmp, $targetFile, 85); // 85 is my choice, make it between 0 – 100 for output image quality with 100 being the most luxurious } } no errors given in error_log. Here is gd_info(): Array( [GD Version] => bundled (2.0.34 compatible) [FreeType Support] => [T1Lib Support] => [GIF Read Support] => 1 [GIF Create Support] => 1 [JPG Support] => 1 [PNG Support] => 1 [WBMP Support] => 1 [XPM Support] => 1 [XBM Support] => 1 [JIS-mapped Japanese Font Support] => )1 server is linux. function is being called like this: assuming $imagen is the actual source image, and $imagendestino is the path and filename of the new thumbnail. if (!file_exists($imagendestino)) { $work = new ImgResizer($imagen); $work -> resize(475, $imagendestino); } Thanks in advance!

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  • opengl, Black lines in-between tiles

    - by MiJyn
    When its translated in an integral value (1,2,3, etc....), there are no black lines in-between the tiles, it looks fine. But when it's translated to a non-integral (1.1, 1.5, 1.67), there are small blackish lines between each tile (I'm imagining that it's due to subpixel rendering, right?) ... and it doesn't look pretty =P So... what should I do? This is my image-loading code, by the way: bool Image::load_opengl() { this->id = 0; glGenTextures(1, &this->id); this->bind(); // Parameters... TODO: Should we change this? glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, this->size.x, this->size.y, 0, GL_BGRA, GL_UNSIGNED_BYTE, (void*) FreeImage_GetBits(this->data)); this->unbind(); return true; } I've also tried using: glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); and: glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); Here is my image drawing code: void Image::draw(Pos pos, CROP crop, SCALE scale) { if (!this->loaded || this->id == 0) { return; } // Start position & size Pos s_p; Pos s_s; // End size Pos e_s; if (crop.active) { s_p = crop.pos / this->size; s_s = crop.size / this->size; //debug("%f %f", s_s.x, s_s.y); s_s = s_s + s_p; s_s.clamp(1); //debug("%f %f", s_s.x, s_s.y); } else { s_s = 1; } if (scale.active) { e_s = scale.size; } else if (crop.active) { e_s = crop.size; } else { e_s = this->size; } // FIXME: Is this okay? s_p.y = 1 - s_p.y; s_s.y = 1 - s_s.y; // TODO: Make this use VAO/VBO's!! glPushMatrix(); glTranslate(pos.x, pos.y, 0); this->bind(); glBegin(GL_QUADS); glTexCoord2(s_p.x, s_p.y); glVertex2(0, 0); glTexCoord2(s_s.x, s_p.y); glVertex2(e_s.x, 0); glTexCoord2(s_s.x, s_s.y); glVertex2(e_s.x, e_s.y); glTexCoord2(s_p.x, s_s.y); glVertex2(0, e_s.y); glEnd(); this->unbind(); glPopMatrix(); } OpenGL Initialization code: void game__gl_init() { glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, config.window.size.x, config.window.size.y, 0.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glDisable(GL_DEPTH_TEST); glEnable(GL_BLEND); glEnable(GL_TEXTURE_2D); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); } Screenshots of the issue:

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  • Image Resizing: Poor jpeg quality and black PNG backgrounds

    - by azz0r
    Hello, I have two issues with my class, basically the quality of the jpeg images is quite poor, but I'm not sure if thats down to my ratio resizing. Ideally I'd like this class to be strict with image sizes and crop into them, but I cant get my head around it. My main issue is that pngs always have a black bg, does anyone have experience with this happening? <?php class OpenSource_ImageResize { function __construct($theFile, $toWhere, $mime, $extension, $newWidth, $newHeight) { if ($mime == NULL) { $mime = getimagesize($theFile); $mime = $mime['mime']; } if ($mime == 'image/jpeg') { $size = getimagesize($theFile); if ($size[0] > $newWidth || $size[1] > $newHeight) { $sourceImage = imagecreatefromjpeg($theFile); } else { return copy($theFile, $toWhere); throw new exception('Could not create jpeg'); return false; } } else if ($mime == 'image/png') { $size = getimagesize($theFile); if ($size[0] > $newWidth || $size[1] > $newHeight) { $sourceImage = imagecreatefrompng($theFile); } else { return copy($theFile, $toWhere); //throw new exception('Could not create png'); return false; } } else if ($mime == 'image/gif') { $size = getimagesize($theFile); if ($size[0] > $newWidth || $size[1] > $newHeight) { $sourceImage = imagecreatefromgif ($theFile); } else { return copy($theFile, $toWhere); //throw new exception('Could not create gif'); return false; } } else { throw new exception('Not a valid mime type'); return false; } $oldX = imageSX($sourceImage); $oldY = imageSY($sourceImage); if ($newWidth == NULL) { $thumbHeight = $newHeight; $thumbWidth = round($newHeight/($oldY/$oldX)); } else if ($oldX > $oldY) { $thumbWidth = $newWidth; $thumbHeight = $oldY * ($newHeight/$oldX); } if ($oldX < $oldY) { $thumbWidth = round($newHeight/($oldY/$oldX)); $thumbHeight = $newHeight; } if ($oldX == $oldY) { $thumbWidth = $newWidth; $thumbHeight = $newHeight; } if (!gd_info()) { $dstImage = ImageCreate($thumbWidth, $thumbHeight); imagecopyresized($dstImage, $sourceImage, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $oldX, $oldY); } else { $dstImage = ImageCreateTrueColor($thumbWidth, $thumbHeight); imagecopyresampled($dstImage, $sourceImage, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $oldX, $oldY); } if ($mime == 'image/png') { $xparent = imagecolorresolvealpha($dstImage, 255,2,240, 0) ; imagecolortransparent($dstImage,$xparent); imagealphablending($dstImage,true); imagepng($dstImage, $toWhere); } else if ($mime == 'image/jpeg') { imagejpeg($dstImage, $toWhere); } else if ($mime == 'image/gif') { imagegif ($dstImage, $toWhere); } imagedestroy($dstImage); imagedestroy($sourceImage); return true; } }

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  • Screen capture code produces black bitmap

    - by wadetandy
    I need to add the ability to take a screenshot of the entire screen, not just the current window. The following code produces a bmp file with the correct dimensions, but the image is completely black. What am I doing wrong? void CaptureScreen(LPCTSTR lpszFilePathName) { BITMAPFILEHEADER bmfHeader; BITMAPINFO *pbminfo; HBITMAP hBmp; FILE *oFile; HDC screen; HDC memDC; int sHeight; int sWidth; LPBYTE pBuff; BITMAP bmp; WORD cClrBits; RECT rcClient; screen = GetDC(0); memDC = CreateCompatibleDC(screen); sHeight = GetDeviceCaps(screen, VERTRES); sWidth = GetDeviceCaps(screen, HORZRES); //GetObject(screen, sizeof(BITMAP), &bmp); hBmp = CreateCompatibleBitmap ( screen, sWidth, sHeight ); // Retrieve the bitmap color format, width, and height. GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp) ; // Convert the color format to a count of bits. cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); if (cClrBits == 1) cClrBits = 1; else if (cClrBits bmiHeader.biSize = sizeof(BITMAPINFOHEADER); pbminfo-bmiHeader.biWidth = bmp.bmWidth; pbminfo-bmiHeader.biHeight = bmp.bmHeight; pbminfo-bmiHeader.biPlanes = bmp.bmPlanes; pbminfo-bmiHeader.biBitCount = bmp.bmBitsPixel; if (cClrBits bmiHeader.biClrUsed = (1bmiHeader.biCompression = BI_RGB; // Compute the number of bytes in the array of color // indices and store the result in biSizeImage. // The width must be DWORD aligned unless the bitmap is RLE // compressed. pbminfo-bmiHeader.biSizeImage = ((pbminfo-bmiHeader.biWidth * cClrBits +31) & ~31) /8 * pbminfo-bmiHeader.biHeight; // Set biClrImportant to 0, indicating that all of the // device colors are important. pbminfo-bmiHeader.biClrImportant = 0; CreateBMPFile(lpszFilePathName, pbminfo, hBmp, memDC); } void CreateBMPFile(LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC) { HANDLE hf; // file handle BITMAPFILEHEADER hdr; // bitmap file-header PBITMAPINFOHEADER pbih; // bitmap info-header LPBYTE lpBits; // memory pointer DWORD dwTotal; // total count of bytes DWORD cb; // incremental count of bytes BYTE *hp; // byte pointer DWORD dwTmp; int lines; pbih = (PBITMAPINFOHEADER) pbi; lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih-biSizeImage); // Retrieve the color table (RGBQUAD array) and the bits // (array of palette indices) from the DIB. lines = GetDIBits(hDC, hBMP, 0, (WORD) pbih-biHeight, lpBits, pbi, DIB_RGB_COLORS); // Create the .BMP file. hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL); hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M" // Compute the size of the entire file. hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih-biSize + pbih-biClrUsed * sizeof(RGBQUAD) + pbih-biSizeImage); hdr.bfReserved1 = 0; hdr.bfReserved2 = 0; // Compute the offset to the array of color indices. hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih-biSize + pbih-biClrUsed * sizeof (RGBQUAD); // Copy the BITMAPFILEHEADER into the .BMP file. WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL); // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih-biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL)); // Copy the array of color indices into the .BMP file. dwTotal = cb = pbih-biSizeImage; hp = lpBits; WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL); // Close the .BMP file. CloseHandle(hf); // Free memory. GlobalFree((HGLOBAL)lpBits); }

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