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  • Using C#, can you drag a canvas in WPF?

    - by TERACytE
    Can you drag a canvas in WPF? How do you set the position of the canvas? Here is what I got so far: /// xaml <Window x:Class="TestApp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Height="350" Width="525" WindowStyle="None" ResizeMode="NoResize" AllowsTransparency="True" Background="Transparent" Loaded="MainWindow_Loaded"> <Canvas Name="ParentCanvas" Background="#FF6E798D"> </Canvas> </Window> /// code behind public partial class MainWindow : Window { private Boolean isMouseCapture; public MainWindow() { InitializeComponent(); } void MainWindow_Loaded(object sender, RoutedEventArgs e) { this.ParentCanvas.MouseLeftButtonDown += new MouseButtonEventHandler(_MouseLeftButtonDown); this.ParentCanvas.MouseLeftButtonUp += new MouseButtonEventHandler(_MouseLeftButtonUp); this.ParentCanvas.MouseMove += new MouseEventHandler(_MouseMove); } void _MouseLeftButtonUp(object sender, MouseButtonEventArgs e) { this.ParentCanvas.ReleaseMouseCapture(); isMouseCapture = false; } void _MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { this.ParentCanvas.CaptureMouse(); isMouseCapture = true; } void _MouseMove(object sender, MouseEventArgs e) { if (isMouseCapture) { this.ParentCanvas.X= e.GetPosition(this).X; this.ParentCanvas.Y = e.GetPosition(this).Y; } } } 'X' is not a property of Canvas (i.e."this.ParentCanvas.X"). What do I use to set the position?

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  • Android browser touch events stop display being updated inc. canvas/elements - How to work around?

    - by Ed Kirk
    On some android's native browser touching the page seems to stop the display from being updated until the finger is released. This occurs for both html element based animation (switching classes) and for canvas based animation. It does not however stop normal js execution and other events are fired as normal. On devices with this problem the dolphin browser also seems effected (not firefox though). Touchstart/move both have preventDefault() fired as well as stopPropergation(), cancelBubble = true; and e.returnValue = false;. In the CSS webkit selection has also been disabled. The page will not scroll. A similar question has been asked here: Does Android browser lock DOM on touchStart? but I'd like to find out if this behaviour can be overcome, or at least to discover what devices will be effected by the problem, is it a device or version android issue? If you cannot answer the question running the demo and reporting your experience along with your device model and useragent (displayed at bottom of demo page) as a comment might help others or myself answer the question. Here is a demo and steps to reproduce the behaviour. A QR code for the link can be found here https://s3-eu-west-1.amazonaws.com/canvas-test-pd/tmp.png. https://s3-eu-west-1.amazonaws.com/canvas-test-pd/index.html The web page has a canvas at the top and a div with a background image at the bottom. Every second the canvas is cleared and a different image displayed and the div has it's class switched (both toggle between 0 and 1 pngs). Once this has toggled a few times place your finger on the canvas (the top grey box) and hold it there. Wait to see if the animation continues (sometimes it will once or twice then stops) and if there are any visual distortions. Update It seems that the Galaxy Tab running 3.2 requires handlers for touchstart/end of document, not just required divs for the screen to continue updating the display. Thanks jimpic. I'm starting to believe it's an issue caused by manufacturers skins, although this is difficult to prove.

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  • Detecting HTML5/CSS3 Features using Modernizr

    - by dwahlin
    HTML5, CSS3, and related technologies such as canvas and web sockets bring a lot of useful new features to the table that can take Web applications to the next level. These new technologies allow applications to be built using only HTML, CSS, and JavaScript allowing them to be viewed on a variety of form factors including tablets and phones. Although HTML5 features offer a lot of promise, it’s not realistic to develop applications using the latest technologies without worrying about supporting older browsers in the process. If history has taught us anything it’s that old browsers stick around for years and years which means developers have to deal with backward compatibility issues. This is especially true when deploying applications to the Internet that target the general public. This begs the question, “How do you move forward with HTML5 and CSS3 technologies while gracefully handling unsupported features in older browsers?” Although you can write code by hand to detect different HTML5 and CSS3 features, it’s not always straightforward. For example, to check for canvas support you need to write code similar to the following:   <script> window.onload = function () { if (canvasSupported()) { alert('canvas supported'); } }; function canvasSupported() { var canvas = document.createElement('canvas'); return (canvas.getContext && canvas.getContext('2d')); } </script> If you want to check for local storage support the following check can be made. It’s more involved than it should be due to a bug in older versions of Firefox. <script> window.onload = function () { if (localStorageSupported()) { alert('local storage supported'); } }; function localStorageSupported() { try { return ('localStorage' in window && window['localStorage'] != null); } catch(e) {} return false; } </script> Looking through the previous examples you can see that there’s more than meets the eye when it comes to checking browsers for HTML5 and CSS3 features. It takes a lot of work to test every possible scenario and every version of a given browser. Fortunately, you don’t have to resort to writing custom code to test what HTML5/CSS3 features a given browser supports. By using a script library called Modernizr you can add checks for different HTML5/CSS3 features into your pages with a minimal amount of code on your part. Let’s take a look at some of the key features Modernizr offers.   Getting Started with Modernizr The first time I heard the name “Modernizr” I thought it “modernized” older browsers by added missing functionality. In reality, Modernizr doesn’t actually handle adding missing features or “modernizing” older browsers. The Modernizr website states, “The name Modernizr actually stems from the goal of modernizing our development practices (and ourselves)”. Because it relies on feature detection rather than browser sniffing (a common technique used in the past – that never worked that great), Modernizr definitely provides a more modern way to test features that a browser supports and can even handle loading additional scripts called shims or polyfills that fill in holes that older browsers may have. It’s a great tool to have in your arsenal if you’re a web developer. Modernizr is available at http://modernizr.com. Two different types of scripts are available including a development script and custom production script. To generate a production script, the site provides a custom script generation tool rather than providing a single script that has everything under the sun for HTML5/CSS3 feature detection. Using the script generation tool you can pick the specific test functionality that you need and ignore everything that you don’t need. That way the script is kept as small as possible. An example of the custom script download screen is shown next. Notice that specific CSS3, HTML5, and related feature tests can be selected. Once you’ve downloaded your custom script you can add it into your web page using the standard <script> element and you’re ready to start using Modernizr. <script src="Scripts/Modernizr.js" type="text/javascript"></script>   Modernizr and the HTML Element Once you’ve add a script reference to Modernizr in a page it’ll go to work for you immediately. In fact, by adding the script several different CSS classes will be added to the page’s <html> element at runtime. These classes define what features the browser supports and what features it doesn’t support. Features that aren’t supported get a class name of “no-FeatureName”, for example “no-flexbox”. Features that are supported get a CSS class name based on the feature such as “canvas” or “websockets”. An example of classes added when running a page in Chrome is shown next:   <html class=" js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"> Here’s an example of what the <html> element looks like at runtime with Internet Explorer 9:   <html class=" js no-flexbox canvas canvastext no-webgl no-touch geolocation postmessage no-websqldatabase no-indexeddb hashchange no-history draganddrop no-websockets rgba hsla multiplebgs backgroundsize no-borderimage borderradius boxshadow no-textshadow opacity no-cssanimations no-csscolumns no-cssgradients no-cssreflections csstransforms no-csstransforms3d no-csstransitions fontface generatedcontent video audio localstorage sessionstorage no-webworkers no-applicationcache svg inlinesvg smil svgclippaths">   When using Modernizr it’s a common practice to define an <html> element in your page with a no-js class added as shown next:   <html class="no-js">   You’ll see starter projects such as HTML5 Boilerplate (http://html5boilerplate.com) or Initializr (http://initializr.com) follow this approach (see my previous post for more information on HTML5 Boilerplate). By adding the no-js class it’s easy to tell if a browser has JavaScript enabled or not. If JavaScript is disabled then no-js will stay on the <html> element. If JavaScript is enabled, no-js will be removed by Modernizr and a js class will be added along with other classes that define supported/unsupported features. Working with HTML5 and CSS3 Features You can use the CSS classes added to the <html> element directly in your CSS files to determine what style properties to use based upon the features supported by a given browser. For example, the following CSS can be used to render a box shadow for browsers that support that feature and a simple border for browsers that don’t support the feature: .boxshadow #MyContainer { border: none; -webkit-box-shadow: #666 1px 1px 1px; -moz-box-shadow: #666 1px 1px 1px; } .no-boxshadow #MyContainer { border: 2px solid black; }   If a browser supports box-shadows the boxshadow CSS class will be added to the <html> element by Modernizr. It can then be associated with a given element. This example associates the boxshadow class with a div with an id of MyContainer. If the browser doesn’t support box shadows then the no-boxshadow class will be added to the <html> element and it can be used to render a standard border around the div. This provides a great way to leverage new CSS3 features in supported browsers while providing a graceful fallback for older browsers. In addition to using the CSS classes that Modernizr provides on the <html> element, you also use a global Modernizr object that’s created. This object exposes different properties that can be used to detect the availability of specific HTML5 or CSS3 features. For example, the following code can be used to detect canvas and local storage support. You can see that the code is much simpler than the code shown at the beginning of this post. It also has the added benefit of being tested by a large community of web developers around the world running a variety of browsers.   $(document).ready(function () { if (Modernizr.canvas) { //Add canvas code } if (Modernizr.localstorage) { //Add local storage code } }); The global Modernizr object can also be used to test for the presence of CSS3 features. The following code shows how to test support for border-radius and CSS transforms:   $(document).ready(function () { if (Modernizr.borderradius) { $('#MyDiv').addClass('borderRadiusStyle'); } if (Modernizr.csstransforms) { $('#MyDiv').addClass('transformsStyle'); } });   Several other CSS3 feature tests can be performed such as support for opacity, rgba, text-shadow, CSS animations, CSS transitions, multiple backgrounds, and more. A complete list of supported HTML5 and CSS3 tests that Modernizr supports can be found at http://www.modernizr.com/docs.   Loading Scripts using Modernizr In cases where a browser doesn’t support a specific feature you can either provide a graceful fallback or load a shim/polyfill script to fill in missing functionality where appropriate (more information about shims/polyfills can be found at https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills). Modernizr has a built-in script loader that can be used to test for a feature and then load a script if the feature isn’t available. The script loader is built-into Modernizr and is also available as a standalone yepnope script (http://yepnopejs.com). It’s extremely easy to get started using the script loader and it can really simplify the process of loading scripts based on the availability of a particular browser feature. To load scripts dynamically you can use Modernizr’s load() function which accepts properties defining the feature to test (test property), the script to load if the test succeeds (yep property), the script to load if the test fails (nope property), and a script to load regardless of if the test succeeds or fails (both property). An example of using load() with these properties is show next: Modernizr.load({ test: Modernizr.canvas, yep: 'html5CanvasAvailable.js’, nope: 'excanvas.js’, both: 'myCustomScript.js' }); In this example Modernizr is used to not only load scripts but also to test for the presence of the canvas feature. If the target browser supports the HTML5 canvas then the html5CanvasAvailable.js script will be loaded along with the myCustomScript.js script (use of the yep property in this example is a bit contrived – it was added simply to demonstrate how the property can be used in the load() function). Otherwise, a polyfill script named excanvas.js will be loaded to add missing canvas functionality for Internet Explorer versions prior to 9. Once excanvas.js is loaded the myCustomScript.js script will be loaded. Because Modernizr handles loading scripts, you can also use it in creative ways. For example, you can use it to load local scripts when a 3rd party Content Delivery Network (CDN) such as one provided by Google or Microsoft is unavailable for whatever reason. The Modernizr documentation provides the following example that demonstrates the process for providing a local fallback for jQuery when a CDN is down:   Modernizr.load([ { load: '//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js', complete: function () { if (!window.jQuery) { Modernizr.load('js/libs/jquery-1.6.4.min.js'); } } }, { // This will wait for the fallback to load and // execute if it needs to. load: 'needs-jQuery.js' } ]); This code attempts to load jQuery from the Google CDN first. Once the script is downloaded (or if it fails) the function associated with complete will be called. The function checks to make sure that the jQuery object is available and if it’s not Modernizr is used to load a local jQuery script. After all of that occurs a script named needs-jQuery.js will be loaded. Conclusion If you’re building applications that use some of the latest and greatest features available in HTML5 and CSS3 then Modernizr is an essential tool. By using it you can reduce the amount of custom code required to test for browser features and provide graceful fallbacks or even load shim/polyfill scripts for older browsers to help fill in missing functionality. 

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  • Detecting HTML5/CSS3 Features using Modernizr

    - by dwahlin
    HTML5, CSS3, and related technologies such as canvas and web sockets bring a lot of useful new features to the table that can take Web applications to the next level. These new technologies allow applications to be built using only HTML, CSS, and JavaScript allowing them to be viewed on a variety of form factors including tablets and phones. Although HTML5 features offer a lot of promise, it’s not realistic to develop applications using the latest technologies without worrying about supporting older browsers in the process. If history has taught us anything it’s that old browsers stick around for years and years which means developers have to deal with backward compatibility issues. This is especially true when deploying applications to the Internet that target the general public. This begs the question, “How do you move forward with HTML5 and CSS3 technologies while gracefully handling unsupported features in older browsers?” Although you can write code by hand to detect different HTML5 and CSS3 features, it’s not always straightforward. For example, to check for canvas support you need to write code similar to the following:   <script> window.onload = function () { if (canvasSupported()) { alert('canvas supported'); } }; function canvasSupported() { var canvas = document.createElement('canvas'); return (canvas.getContext && canvas.getContext('2d')); } </script> If you want to check for local storage support the following check can be made. It’s more involved than it should be due to a bug in older versions of Firefox. <script> window.onload = function () { if (localStorageSupported()) { alert('local storage supported'); } }; function localStorageSupported() { try { return ('localStorage' in window && window['localStorage'] != null); } catch(e) {} return false; } </script> Looking through the previous examples you can see that there’s more than meets the eye when it comes to checking browsers for HTML5 and CSS3 features. It takes a lot of work to test every possible scenario and every version of a given browser. Fortunately, you don’t have to resort to writing custom code to test what HTML5/CSS3 features a given browser supports. By using a script library called Modernizr you can add checks for different HTML5/CSS3 features into your pages with a minimal amount of code on your part. Let’s take a look at some of the key features Modernizr offers.   Getting Started with Modernizr The first time I heard the name “Modernizr” I thought it “modernized” older browsers by added missing functionality. In reality, Modernizr doesn’t actually handle adding missing features or “modernizing” older browsers. The Modernizr website states, “The name Modernizr actually stems from the goal of modernizing our development practices (and ourselves)”. Because it relies on feature detection rather than browser sniffing (a common technique used in the past – that never worked that great), Modernizr definitely provides a more modern way to test features that a browser supports and can even handle loading additional scripts called shims or polyfills that fill in holes that older browsers may have. It’s a great tool to have in your arsenal if you’re a web developer. Modernizr is available at http://modernizr.com. Two different types of scripts are available including a development script and custom production script. To generate a production script, the site provides a custom script generation tool rather than providing a single script that has everything under the sun for HTML5/CSS3 feature detection. Using the script generation tool you can pick the specific test functionality that you need and ignore everything that you don’t need. That way the script is kept as small as possible. An example of the custom script download screen is shown next. Notice that specific CSS3, HTML5, and related feature tests can be selected. Once you’ve downloaded your custom script you can add it into your web page using the standard <script> element and you’re ready to start using Modernizr. <script src="Scripts/Modernizr.js" type="text/javascript"></script>   Modernizr and the HTML Element Once you’ve add a script reference to Modernizr in a page it’ll go to work for you immediately. In fact, by adding the script several different CSS classes will be added to the page’s <html> element at runtime. These classes define what features the browser supports and what features it doesn’t support. Features that aren’t supported get a class name of “no-FeatureName”, for example “no-flexbox”. Features that are supported get a CSS class name based on the feature such as “canvas” or “websockets”. An example of classes added when running a page in Chrome is shown next:   <html class=" js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"> Here’s an example of what the <html> element looks like at runtime with Internet Explorer 9:   <html class=" js no-flexbox canvas canvastext no-webgl no-touch geolocation postmessage no-websqldatabase no-indexeddb hashchange no-history draganddrop no-websockets rgba hsla multiplebgs backgroundsize no-borderimage borderradius boxshadow no-textshadow opacity no-cssanimations no-csscolumns no-cssgradients no-cssreflections csstransforms no-csstransforms3d no-csstransitions fontface generatedcontent video audio localstorage sessionstorage no-webworkers no-applicationcache svg inlinesvg smil svgclippaths">   When using Modernizr it’s a common practice to define an <html> element in your page with a no-js class added as shown next:   <html class="no-js">   You’ll see starter projects such as HTML5 Boilerplate (http://html5boilerplate.com) or Initializr (http://initializr.com) follow this approach (see my previous post for more information on HTML5 Boilerplate). By adding the no-js class it’s easy to tell if a browser has JavaScript enabled or not. If JavaScript is disabled then no-js will stay on the <html> element. If JavaScript is enabled, no-js will be removed by Modernizr and a js class will be added along with other classes that define supported/unsupported features. Working with HTML5 and CSS3 Features You can use the CSS classes added to the <html> element directly in your CSS files to determine what style properties to use based upon the features supported by a given browser. For example, the following CSS can be used to render a box shadow for browsers that support that feature and a simple border for browsers that don’t support the feature: .boxshadow #MyContainer { border: none; -webkit-box-shadow: #666 1px 1px 1px; -moz-box-shadow: #666 1px 1px 1px; } .no-boxshadow #MyContainer { border: 2px solid black; }   If a browser supports box-shadows the boxshadow CSS class will be added to the <html> element by Modernizr. It can then be associated with a given element. This example associates the boxshadow class with a div with an id of MyContainer. If the browser doesn’t support box shadows then the no-boxshadow class will be added to the <html> element and it can be used to render a standard border around the div. This provides a great way to leverage new CSS3 features in supported browsers while providing a graceful fallback for older browsers. In addition to using the CSS classes that Modernizr provides on the <html> element, you also use a global Modernizr object that’s created. This object exposes different properties that can be used to detect the availability of specific HTML5 or CSS3 features. For example, the following code can be used to detect canvas and local storage support. You can see that the code is much simpler than the code shown at the beginning of this post. It also has the added benefit of being tested by a large community of web developers around the world running a variety of browsers.   $(document).ready(function () { if (Modernizr.canvas) { //Add canvas code } if (Modernizr.localstorage) { //Add local storage code } }); The global Modernizr object can also be used to test for the presence of CSS3 features. The following code shows how to test support for border-radius and CSS transforms:   $(document).ready(function () { if (Modernizr.borderradius) { $('#MyDiv').addClass('borderRadiusStyle'); } if (Modernizr.csstransforms) { $('#MyDiv').addClass('transformsStyle'); } });   Several other CSS3 feature tests can be performed such as support for opacity, rgba, text-shadow, CSS animations, CSS transitions, multiple backgrounds, and more. A complete list of supported HTML5 and CSS3 tests that Modernizr supports can be found at http://www.modernizr.com/docs.   Loading Scripts using Modernizr In cases where a browser doesn’t support a specific feature you can either provide a graceful fallback or load a shim/polyfill script to fill in missing functionality where appropriate (more information about shims/polyfills can be found at https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills). Modernizr has a built-in script loader that can be used to test for a feature and then load a script if the feature isn’t available. The script loader is built-into Modernizr and is also available as a standalone yepnope script (http://yepnopejs.com). It’s extremely easy to get started using the script loader and it can really simplify the process of loading scripts based on the availability of a particular browser feature. To load scripts dynamically you can use Modernizr’s load() function which accepts properties defining the feature to test (test property), the script to load if the test succeeds (yep property), the script to load if the test fails (nope property), and a script to load regardless of if the test succeeds or fails (both property). An example of using load() with these properties is show next: Modernizr.load({ test: Modernizr.canvas, yep: 'html5CanvasAvailable.js’, nope: 'excanvas.js’, both: 'myCustomScript.js' }); In this example Modernizr is used to not only load scripts but also to test for the presence of the canvas feature. If the target browser supports the HTML5 canvas then the html5CanvasAvailable.js script will be loaded along with the myCustomScript.js script (use of the yep property in this example is a bit contrived – it was added simply to demonstrate how the property can be used in the load() function). Otherwise, a polyfill script named excanvas.js will be loaded to add missing canvas functionality for Internet Explorer versions prior to 9. Once excanvas.js is loaded the myCustomScript.js script will be loaded. Because Modernizr handles loading scripts, you can also use it in creative ways. For example, you can use it to load local scripts when a 3rd party Content Delivery Network (CDN) such as one provided by Google or Microsoft is unavailable for whatever reason. The Modernizr documentation provides the following example that demonstrates the process for providing a local fallback for jQuery when a CDN is down:   Modernizr.load([ { load: '//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js', complete: function () { if (!window.jQuery) { Modernizr.load('js/libs/jquery-1.6.4.min.js'); } } }, { // This will wait for the fallback to load and // execute if it needs to. load: 'needs-jQuery.js' } ]); This code attempts to load jQuery from the Google CDN first. Once the script is downloaded (or if it fails) the function associated with complete will be called. The function checks to make sure that the jQuery object is available and if it’s not Modernizr is used to load a local jQuery script. After all of that occurs a script named needs-jQuery.js will be loaded. Conclusion If you’re building applications that use some of the latest and greatest features available in HTML5 and CSS3 then Modernizr is an essential tool. By using it you can reduce the amount of custom code required to test for browser features and provide graceful fallbacks or even load shim/polyfill scripts for older browsers to help fill in missing functionality. 

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  • android spinning image

    - by user270811
    hi, i am trying to create two spinning wheels, as in pulleys, so everytime the attached rope moves, the two pulleys will rotate. i have tried two approaches: 1) use Matrix.postRotate within the onDraw() method of the View class, which calls the following: private void drawSpinningWheel(Canvas canvas) { try { canvas.save(); Bitmap bitmapOrg = null; int iDrawable = R.drawable.spinning_button; bitmapOrg = BitmapFactory.decodeResource(getResources(), iDrawable); if(bitmapOrg != null) { int width = bitmapOrg.getWidth(); int height = bitmapOrg.getHeight(); int newWidth = 24; int newHeight = 24; // calculate the scale - in this case = 0.4f float scaleWidth = ((float) newWidth) / width; float scaleHeight = ((float) newHeight) / height; // createa matrix for the manipulation Matrix matrix = new Matrix(); // resize the bit map matrix.postScale(scaleWidth, scaleHeight); matrix.postRotate((float) mDegrees++); Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0, width, height, matrix, true); canvas.drawBitmap(resizedBitmap, matrix, null); } canvas.restore(); } catch(Exception e) { Log.e(TAG + "drawSpinningWheel", e.getMessage()); } } but it seems like the image not only spins but rotates around another axis 2) use SurfaceView and a separate thread, in the run() call this: private void doDraw(Canvas canvas) { // Draw the background image. Operations on the Canvas accumulate // so this is like clearing the screen. canvas.drawBitmap(mBackgroundImage, 0, 0, null); int yTop = mCanvasHeight - ((int) mY + mSpinningWheelImageHeight / 2); int xLeft = (int) mX - mSpinningWheelImageWidth / 2; ... // Draw the ship with its current rotation canvas.save(); canvas.rotate((float) mHeading++, (float) mX, mCanvasHeight - (float) mY); mSpinningWheelImage.setBounds(xLeft, yTop, xLeft + mSpinningWheelImageWidth, yTop + mSpinningWheelImageHeight); mSpinningWheelImage.draw(canvas); canvas.restore(); } i get the spinning to work but i can't add another spinning wheel. i even tried to create another thread for the second spinning wheel, only one shows up. can someone point me in the right direction? thanks.

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  • error: expected `;' before '{' token - What is the cause?

    - by melee
    Here is my implementation file: using namespace std; #include <iostream> #include <iomanip> #include <string> #include <stack> //line 5 #include "proj05.canvas.h" //----------------Constructor----------------// Canvas::Canvas() //line 10 { Title = ""; Nrow = 0; Ncol = 0; image[][100]; // line 15 position.r = 0; position.c = 0; } //-------------------Paint------------------// line 20 void Canvas::Paint(int R, int C, char Color) { cout << "Paint to be implemented" << endl; } The errors I'm getting are these: proj05.canvas.cpp: In function 'std::istream& operator>>(std::istream&, Canvas&)': proj05.canvas.cpp:11: error: expected `;' before '{' token proj05.canvas.cpp:22: error: a function-definition is not allowed here before '{' token proj05.canvas.cpp:24: error: expected `}' at end of input proj05.canvas.cpp:24: error: expected `}' at end of input These seem like simple syntax errors, but I am not sure what's wrong. Could someone decode these for me? I'd really appreciate it, thanks for your time! EDIT Here is the definition of Canvas in my .h file: #ifndef CANVAS_H #define CANVAS_H #include <iostream> #include <iomanip> #include <string> #include <stack> class Canvas { public: Canvas(); void Paint(int R, int C, char Color); const int Nrow; const int Ncol; string Title; int image[][100]; stack<int> path; struct PixelCoordinates { unsigned int r; unsigned int c; } position; }; #endif

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  • code for TouchPad works, but not for DPAD ...please help me to fix this..

    - by Chandan
    package org.coe.twoD; import android.app.Activity; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; //import android.graphics.Path; import android.graphics.Rect; //import android.graphics.RectF; import android.os.Bundle; //import android.util.Log; import android.util.Log; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import android.view.View.OnClickListener; public class TwoD extends Activity implements OnClickListener { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); View draw2d = findViewById(R.id.draw_button); draw2d.setOnClickListener(this); } public void onClick(View v) { if (R.id.draw_button == v.getId()) { setContentView(new draw2D(this)); } } public class draw2D extends View { private static final String TAG = "Sudoku"; private float width; // width of one tile private float height; // height of one tile private int selX; // X index of selection private int selY; // Y index of selection private final Rect selRect = new Rect(); public draw2D(Context context) { super(context); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { width = w / 9f; height = h / 9f; getRect(selX, selY, selRect); Log.d(TAG, "onSizeChanged: width " + width + ", height " + height); super.onSizeChanged(w, h, oldw, oldh); } @Override protected void onDraw(Canvas canvas) { // Draw the background... Paint background = new Paint(); background.setColor(getResources().getColor(R.color.background)); canvas.drawRect(0, 0, getWidth(), getHeight(), background); // Draw the board... // Define colors for the grid lines Paint dark = new Paint(); dark.setColor(getResources().getColor(R.color.dark)); Paint hilite = new Paint(); hilite.setColor(getResources().getColor(R.color.hilite)); Paint light = new Paint(); light.setColor(getResources().getColor(R.color.light)); // Draw the minor grid lines for (int i = 0; i < 9; i++) { canvas.drawLine(0, i * height, getWidth(), i * height, light); canvas.drawLine(0, i * height + 1, getWidth(), i * height + 1, hilite); canvas.drawLine(i * width, 0, i * width, getHeight(), light); canvas.drawLine(i * width + 1, 0, i * width + 1, getHeight(), hilite); } // Draw the major grid lines for (int i = 0; i < 9; i++) { if (i % 3 != 0) continue; canvas.drawLine(0, i * height, getWidth(), i * height, dark); canvas.drawLine(0, i * height + 1, getWidth(), i * height + 1, hilite); canvas.drawLine(i * width, 0, i * width, getHeight(), dark); canvas.drawLine(i * width + 1, 0, i * width + 1, getHeight(), hilite); } /* * dark.setColor(Color.MAGENTA); Path circle= new Path(); * circle.addCircle(150, 150, 100, Path.Direction.CW); * canvas.drawPath(circle, dark); * * * Path rect=new Path(); * * RectF rectf= new RectF(150,200,250,300); rect.addRect(rectf, * Path.Direction.CW); canvas.drawPath(rect, dark); * * * canvas.drawRect(0, 0,250, 250, dark); * * * canvas.drawText("Hello", 200,200, dark); */ Paint selected = new Paint(); selected.setColor(Color.GREEN); canvas.drawRect(selRect, selected); } /* * public boolean onTouchEvent(MotionEvent event){ * if(event.getAction()!=MotionEvent.ACTION_DOWN) return * super.onTouchEvent(event); * select((int)(event.getX()/width),(int)(event.getY()/height)); * * * return true; } */ private void select(int x, int y) { invalidate(selRect); selX = Math.min(Math.max(x, 0), 8); selY = Math.min(Math.max(y, 0), 8); getRect(selX, selY, selRect); invalidate(selRect); } @Override public boolean onKeyUp(int keyCode, KeyEvent event) { return super.onKeyUp(keyCode, event); } @Override public boolean onTouchEvent(MotionEvent event) { if (event.getAction() != MotionEvent.ACTION_DOWN) return super.onTouchEvent(event); select((int) (event.getX() / width), (int) (event.getY() / height)); // game.showKeypadOrError(selX, selY); Log.d(TAG, "onTouchEvent: x " + selX + ", y " + selY); return true; } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { Log.d(TAG, "onKeyDown: keycode=" + keyCode + ", event=" + event); switch (keyCode) { case KeyEvent.KEYCODE_DPAD_UP: select(selX, selY - 1); break; case KeyEvent.KEYCODE_DPAD_DOWN: select(selX, selY + 1); break; case KeyEvent.KEYCODE_DPAD_LEFT: select(selX - 1, selY); break; case KeyEvent.KEYCODE_DPAD_RIGHT: select(selX + 1, selY); break; default: return super.onKeyDown(keyCode, event); } return true; } private void getRect(int x, int y, Rect rect) { rect.set((int) (x * width), (int) (y * height), (int) (x * width + width), (int) (y * height + height)); } } }

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  • Can emsripten compile down to Canvas-based Js instead of WebGL?

    - by Sebastian Scholle
    I understand that emscripten compiles down LLVM to JS and it converts OpenGL Calls to WebGL. Thats a fairly simple translation. Is there a way to tell emscripten to use some other graphics Library ( for example Pixi JS ) for its rendering code translations? Is the compiled JS code easy to update or would it be better to merge in your own Graphics API that handles WebGL/Canvas calls. IE: can we use a C++ Graphics Wrapper Library that when compiles to JS, will simply plug into our own JS Graphics Wrapper Library? Im assuming YES, but has anyone tried this? And if So, what would be your technique, as my C++ skills are basic.

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  • WPF 3.5 WebBrowser control and ZIndex

    - by emsieja
    I'm trying to figure out why the control does not honor ZIndex. Example 1 - which works fine <Canvas> <Rectangle Canvas.ZIndex="1" Height="400" Width="600" Fill="Yellow"/> <Rectangle Canvas.ZIndex="2" Height="100" Width="100" Fill="Red"/> </Canvas> Example 2 - which does not work <Canvas> <WebBrowser Canvas.ZIndex="1" Height="400" Width="600" Source="http://www.stackoverflow.com"/> <Rectangle Canvas.ZIndex="2" Height="100" Width="100" Fill="Red"/> </Canvas> Thanks, -- Ed

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  • adding onTap method on path direction between 2 point

    - by idham
    I have a problem in my Android application I have a path direction on my application and I want to add an onTap method for the path, so if I touch that path my application will display information with alert dialog. This my activity code: hasilrute hr = new hasilrute(); for (int k = 0;k < hr.r2.size(); k++){ String angkot = hr.r2.get(i).angkot; Cursor c = db.getLatLong(hasilrute.a); Cursor cc = db.getLatLong(hasilrute.b); String x = (c.getString(3)+","+c.getString(2)); String xx = (cc.getString(3)+","+cc.getString(2)); String pairs[] = getDirectionData(x, xx); String[] lnglat = pairs[0].split(","); GeoPoint point = new GeoPoint((int) (Double.parseDouble(lnglat[1]) *1E6),(int)(Double.parseDouble(lnglat[0]) * 1E6)); GeoPoint gp1; GeoPoint gp2 = point; for (int j = 1;j < pairs.length; j++){ lnglat = pairs[j].split(","); gp1 = gp2; gp2 = new GeoPoint((int) (Double.parseDouble(lnglat[1]) *1E6),(int) (Double.parseDouble(lnglat[0]) * 1E6)); mapView.getOverlays().add(new jalur(gp1, gp2,angkot)); } } and it's my jalur.java code public class jalur extends Overlay { private GeoPoint gp1; private GeoPoint gp2; private String angkot; private Context mContext; public jalur(GeoPoint gp1, GeoPoint gp2, String angkot){ this.gp1 = gp1; this.gp2 = gp2; this.angkot = angkot; } @Override public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when){ Projection projection = mapView.getProjection(); if (shadow == false){ if (angkot.equals("Cimahi-Leuwipanjang")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(118,171,127)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Cangkorah")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(67,204,255)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimindi-Cipatik")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(42,82,0)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Jalan Kaki")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(0,0,0)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Padalarang")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(229,66,66)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); } if (angkot.equals("Pasantren-Sarijadi")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(4,39,255)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Parongpong")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(141,0,200)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Cibeber")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(255,246,0)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Cimindi")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(220,145,251)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Contong")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(242,138,138)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Soreang")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(0,255,78)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); }if (angkot.equals("Cimahi-Batujajar")){ Paint paint = new Paint(); paint.setAntiAlias(true); Point point = new Point(); projection.toPixels(gp1,point); Point point2 = new Point(); projection.toPixels(gp2, point2); paint.setColor(Color.rgb(137,217,51)); paint.setStrokeWidth(2); canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); } } return super.draw(canvas, mapView, shadow, when); } @Override public void draw(Canvas canvas, MapView mapView, boolean shadow){ super.draw(canvas, mapView, shadow); } } thanks for your attention :)

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  • How to rotate a drawable with anti-aliasing enabled

    - by Mike
    I need to rotate an ImageView by a few degrees. I'm doing this by subclassing ImageView and overloading onDraw() @Override protected void onDraw(Canvas canvas) { canvas.save(); canvas.scale(0.92f,0.92f); canvas.translate(14, 0); canvas.rotate(1,0,0); super.onDraw(canvas); canvas.restore(); } The problem is that the image that results shows a bunch of jaggies. How can I antialias an ImageView that I need to rotate in order to eliminate jaggies? Is there a better way to do this?

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  • Override onDraw to change how the drawing occurs (Android)

    - by Casebash
    I want to change how my UI elements display, so I am overriding onDraw. The following code allows me to change a View to be drawn using PorterDuff.Mode.DARKEN. Unfortunately, this method involves creating a bitmap the size of the entire screen, then drawing to it then drawing this large bitmap the main screen again, for each UI element. This isn't at all efficient. Is it possible to achieve this in a more effecient way? @Override protected void onDraw(Canvas canvas) { //TODO: Reduce the burden from multiple drawing Bitmap bitmap=Bitmap.createBitmap(canvas.getWidth(), canvas.getHeight(), Config.ARGB_8888); Log.e("tmp",canvas.getClipBounds().toString()); Canvas offscreen=new Canvas(bitmap); super.onDraw(offscreen); //Then draw onscreen Paint p=new Paint(); p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DARKEN)); canvas.drawBitmap(bitmap, 0, 0, p); }

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  • Can't see anything wrong with simple code

    - by melee
    Here is my implementation file: using namespace std; #include <iostream> #include <iomanip> #include <string> #include <stack> //line 5 #include "proj05.canvas.h" //----------------Constructor----------------// Canvas::Canvas() //line 10 { Title = ""; Nrow = 0; Ncol = 0; image[][]; // line 15 PixelCoordinates.r = 0; PixelCoordinates.c = 0; } //-------------------Paint------------------// line 20 void Canvas::Paint(int R, int C, char Color) { cout << "Paint to be implemented" << endl; } The errors I'm getting are these: proj05.canvas.cpp: In function 'std::istream& operator>>(std::istream&, Canvas&)': proj05.canvas.cpp:11: error: expected `;' before '{' token proj05.canvas.cpp:22: error: a function-definition is not allowed here before '{' token proj05.canvas.cpp:24: error: expected `}' at end of input proj05.canvas.cpp:24: error: expected `}' at end of input These seem like simple syntax errors, but I am not sure what's wrong. Could someone decode these for me? I'd really appreciate it, thanks for your time!

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  • How to store a captured image into MySQL database using JavaScript

    - by R J.
    I am capturing image using canvas and i want to store a captured image in MySQL Database using Javascript. This is my code: <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, maximum-scale=1.0"> <style> body {width: 100%;} canvas {display: none;} </style> <title>Instant Camera - Remote</title> <script> var video, canvas, msg; var load = function () { video = document.getElementById('video'); canvas = document.getElementById('canvas'); msg = document.getElementById('error'); if( navigator.getUserMedia ) { video.onclick = function () { var context = canvas.getContext("2d"); context.drawImage(video, 0, 0, 240, 320); var image1 = canvas.toDataURL("image/png"); document.write('<img src="' + image1 + '" />'); }; } else { msg.innerHTML = "Native web camera not supported :("; } }; window.addEventListener('DOMContentLoaded', load, false); </script> </head> <body> <video id="video" width="240" height="320" autoplay> </video> <p id="error">Click on the video to send a snapshot to the receiving screen</p> <canvas id="canvas" width="240" height="320"> </canvas> </body> </html>

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  • How do I clip an image in OpenGL ES on Android?

    - by Maxim Shoustin
    My game involves "wiping off" an image by touch: After moving a finger over it, it looks like this: At the moment, I'm implementing it with Canvas, like this: 9Paint pTouch; 9int X = 100; 9int Y = 100; 9Bitmap overlay; 9Canvas c2; 9Rect dest; pTouch = new Paint(Paint.ANTI_ALIAS_FLAG); pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT)); pTouch.setColor(Color.TRANSPARENT); pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL)); overlay = BitmapFactory.decodeResource(getResources(),R.drawable.wraith_spell).copy(Config.ARGB_8888, true); c2 = new Canvas(overlay); dest = new Rect(0, 0, getWidth(), getHeight()); Paint paint = new Paint();9 paint.setFilterBitmap(true); ... @Override protected void onDraw(Canvas canvas) { ... c2.drawCircle(X, Y, 80, pTouch); canvas.drawBitmap(overlay, 0, 0, null); ... } @Override 9public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: case MotionEvent.ACTION_MOVE: { X = (int) event.getX(); Y = (int) event.getY();9 invalidate(); c2.drawCircle(X, Y, 80, pTouch);9 break; } } return true; ... What I'm essentially doing is drawing transparency onto the canvas, over the red ball image. Canvas and Bitmap feel old... Surely there is a way to do something similar with OpenGL ES. What is it called? How do I use it? [EDIT] I found that if I draw an image and above new image with alpha 0, it goes to be transparent, maybe that direction? Something like: gl.glColor4f(0.0f, 0.0f, 0.0f, 0.01f);

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  • In html 5, how to positioning a div element on top of a canvas element?

    - by Unraised
    Hi. Can anyone help me: I'm trying to put a div (say, 10px by 10px) element on top (in front) of a canvas element (say 500px by 500px) in html. I have tried changing the z-index of each, to no avail. Does anybody have any ideas, or is it one of those things that you can't really do? I already know how to do absolute positioning and everything, the div element just hangs out in the background behind the canvas element. I need a way to bring it to the front and the canvas element to the back. Thanks!

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  • In C#, how do you send a refresh/repaint message to a WPF grid or canvas?

    - by xarzu
    How do you send a refresh message to a WPF grid or canvas? In other words, I have noticed while in debug mode, I can write code that sends a line to the display and then, if that line is not right, I can adjust it -- but the previous line is still there. Now, the code I am writing sends information to the display based on what the user clicks. So this must mean that the display is not refreshed each time a new set of lines and boxes and text goes to the grid or canvas in WPF. Using C# code, how do you send a refresh/repaint message to a WPF grid or canvas?

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  • 2D game - Missile shooting problem on Android

    - by Niksa
    Hello, I have to make a tank that sits still but moves his turret and shoots missiles. As this is my first Android application ever and I haven't done any game development either, I've come across a few problems... Now, I did the tank and the moving turret once I read the Android tutorial for the LunarLander sample code. So this code is based on the LunarLander code. But I'm having trouble doing the missile firing then SPACE button is being pressed. private void doDraw(Canvas canvas) { canvas.drawBitmap(backgroundImage, 0, 0, null); // draws the tank canvas.drawBitmap(tank, x_tank, y_tank, new Paint()); // draws and rotates the tank turret canvas.rotate((float) mHeading, (float) x_turret + mTurretWidth, y_turret); canvas.drawBitmap(turret, x_turret, y_turret, new Paint()); // draws the grenade that is a regular circle from ShapeDrawable class bullet.setBounds(x_bullet, y_bullet, x_bullet + width, y_bullet + height); bullet.draw(canvas); } UPDATE GAME method private void updateGame() throws InterruptedException { long now = System.currentTimeMillis(); if (mLastTime > now) return; double elapsed = (now - mLastTime) / 1000.0; mLastTime = now; // dUP and dDown, rotates the turret from 0 to 75 degrees. if (dUp) mHeading += 1 * (PHYS_SLEW_SEC * elapsed); if (mHeading >= 75) mHeading = 75; if (dDown) mHeading += (-1) * (PHYS_SLEW_SEC * elapsed); if (mHeading < 0) mHeading = 0; if (dSpace){ // missile Logic, a straight trajectorie for now x_bullet -= 1; y_bullet -= 1; //doesn't work, has to be updated every pixel or what? } boolean doKeyDown(int keyCode, KeyEvent msg) { boolean handled = false; synchronized (mSurfaceHolder) { if (keyCode == KeyEvent.KEYCODE_SPACE){ dSpace = true; handled = true; } if (keyCode == KeyEvent.KEYCODE_DPAD_UP){ dUp = true; handled = true; } if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN){ dDown = true; handled = true; } return handled; } } } a method run that runs the game... public void run() { while (mRun) { Canvas c = null; try { c = mSurfaceHolder.lockCanvas(null); synchronized (mSurfaceHolder) { if (mMode == STATE_RUNNING) updateGame(); doDraw(c); } } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { // do this in a finally so that if an exception is thrown // during the above, we don't leave the Surface in an // inconsistent state if (c != null) { mSurfaceHolder.unlockCanvasAndPost(c); } } } } So the question would be, how do I make that the bullet is fired on a single SPACE key press from the turret to the end of the screen? Could you help me out here, I seem to be in the dark here... Thanks, Niksa

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  • how to do android image animation

    - by user270811
    hi, i am trying to get a simple image animation going. i want to make it looks as if the helicopter's propeller blades are turning. i have 3 images for the helicopter, and i am showing one of these images depending on the animation progress. the problem is that all three images end up overlapping each other as opposed to just one image showing up at one time, thereby creating the animation. this is what i did so far, i even tried to clear canvas by doing this canvas.drawColor(Color.BLACK), but that would clear out the whole canvas, which is not what i want. this is what i have: 1) in the View class: static class Helicopter { private long mLastUpdate; private long mProgress = 0; private final float mX; private final float mY; private final Bitmap mHelicopter1; private final Bitmap mHelicopter2; private final Bitmap mHelicopter3; private final float mRadius; Helicopter(long mLastUpdate, float mX, float mY, Bitmap helicopter1, Bitmap helicopter2, Bitmap helicopter3) { this.mLastUpdate = mLastUpdate; this.mX = mX; this.mY = mY; this.mHelicopter1 = helicopter1; this.mHelicopter2 = helicopter2; this.mHelicopter3 = helicopter3; mRadius = ((float) mHelicopter1.getWidth()) / 2f; } public void update(long now) { mProgress += (now - mLastUpdate); if(mProgress >= 400L) { mProgress = 0; } mLastUpdate = now; } public void setNow(long now) { mLastUpdate = now; } public void draw(Canvas canvas, Paint paint) { if (mProgress < 150L) { canvas.drawBitmap(mHelicopter1, mX - mRadius, mY - mRadius, paint); } else if (mProgress < 300L) { canvas.drawBitmap(mHelicopter2, mX - mRadius, mY - mRadius, paint); } else if(mProgress < 400L) { canvas.drawBitmap(mHelicopter3, mX - mRadius, mY - mRadius, paint); } } public boolean done() { return mProgress > 700L; } } private ArrayList<Helicopter> mHelicopters = new ArrayList<Helicopter>(); 2) this is being called in the run() of a thread: private void doDraw(Canvas canvas) { final long now = SystemClock.elapsedRealtime(); canvas.save(); for (int i = 0; i < mHelicopters.size(); i++) { final Helicopter explosion = mHelicopters.get(i); explosion.update(now); } for (int i = 0; i < mHelicopters.size(); i++) { final Helicopter explosion = mHelicopters.get(i); explosion.draw(canvas, mPaint); } canvas.restore(); } can someone help me? i have looked at a lot of the examples on the web on animation, they seem to always involve text, but not images. thanks.

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  • Slow Javascript touch events on Android

    - by oneself
    I'm trying to write a simple html based drawing application (standalone simplified code attached bellow). I've tested this on the following devices: iPad 1 and 2: Works great ASUS T101 running Windows: Works great Samsung Galaxy Tab: Extremely slow and patchy -- unusable. Lenovo IdeaPad K1: Extremely slow and patchy -- unusable. Asus Transformer Prime: Noticeable lag compare with the iPad -- close to usable. The Asus tablet is running ICS, the other android tablets are running 3.1 and 3.2. I tested using the stock Android browser. I also tried the Android Chrome Beta, but that was even worse. My questions is why are the Android tablets so slow? Am I doing something wrong or is it an inherit problem with Android OS or browser, or is there anything I can do about it in my code? multi.html: <html> <body> <style media="screen"> canvas { border: 1px solid #CCC; } </style> <canvas style="" id="draw" height="450" width="922"></canvas> <script class="jsbin" src="jquery.js"></script> <script src="multi.js"></script> </body> </html> multi.js: var CanvasDrawr = function(options) { // grab canvas element var canvas = document.getElementById(options.id), ctxt = canvas.getContext("2d"); canvas.style.width = '100%' canvas.width = canvas.offsetWidth; canvas.style.width = ''; // set props from options, but the defaults are for the cool kids ctxt.lineWidth = options.size || Math.ceil(Math.random() * 35); ctxt.lineCap = options.lineCap || "round"; ctxt.pX = undefined; ctxt.pY = undefined; var lines = [,,]; var offset = $(canvas).offset(); var eventCount = 0; var self = { // Bind click events init: function() { // Set pX and pY from first click canvas.addEventListener('touchstart', self.preDraw, false); canvas.addEventListener('touchmove', self.draw, false); }, preDraw: function(event) { $.each(event.touches, function(i, touch) { var id = touch.identifier; lines[id] = { x : this.pageX - offset.left, y : this.pageY - offset.top, color : 'black' }; }); event.preventDefault(); }, draw: function(event) { var e = event, hmm = {}; eventCount += 1; $.each(event.touches, function(i, touch) { var id = touch.identifier, moveX = this.pageX - offset.left - lines[id].x, moveY = this.pageY - offset.top - lines[id].y; var ret = self.move(id, moveX, moveY); lines[id].x = ret.x; lines[id].y = ret.y; }); event.preventDefault(); }, move: function(i, changeX, changeY) { ctxt.strokeStyle = lines[i].color; ctxt.beginPath(); ctxt.moveTo(lines[i].x, lines[i].y); ctxt.lineTo(lines[i].x + changeX, lines[i].y + changeY); ctxt.stroke(); ctxt.closePath(); return { x: lines[i].x + changeX, y: lines[i].y + changeY }; }, }; return self.init(); }; $(function(){ var drawr = new CanvasDrawr({ id: "draw", size: 5 }); });

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  • How do I use setFilmSize in panda3d to achieve the correct view?

    - by lhk
    I'm working with Panda3d and recently switched my game to isometric rendering. I moved the virtual camera accordingly and set an orthographic lens. Then I implemented the classes "Map" and "Canvas". A canvas is a dynamically generated mesh: a flat quad. I'm using it to render the ingame graphics. Since the game itself is still set in a 3d coordinate system I'm planning to rely on these canvases to draw sprites. I could have named this class "Tile" but as I'd like to use it for non-tile sketches (enemies, environment) as well I thought canvas would describe it's function better. Map does exactly what it's name suggests. Its constructor receives the number of rows and columns and then creates a standard isometric map. It uses the canvas class for tiles. I'm planning to write a map importer that reads a file to create maps on the fly. Here's the canvas implementation: class Canvas: def __init__(self, texture, vertical=False, width=1,height=1): # create the mesh format=GeomVertexFormat.getV3t2() format = GeomVertexFormat.registerFormat(format) vdata=GeomVertexData("node-vertices", format, Geom.UHStatic) vertex = GeomVertexWriter(vdata, 'vertex') texcoord = GeomVertexWriter(vdata, 'texcoord') # add the vertices for a flat quad vertex.addData3f(1, 0, 0) texcoord.addData2f(1, 0) vertex.addData3f(1, 1, 0) texcoord.addData2f(1, 1) vertex.addData3f(0, 1, 0) texcoord.addData2f(0, 1) vertex.addData3f(0, 0, 0) texcoord.addData2f(0, 0) prim = GeomTriangles(Geom.UHStatic) prim.addVertices(0, 1, 2) prim.addVertices(2, 3, 0) self.geom = Geom(vdata) self.geom.addPrimitive(prim) self.node = GeomNode('node') self.node.addGeom(self.geom) # this is the handle for the canvas self.nodePath=NodePath(self.node) self.nodePath.setSx(width) self.nodePath.setSy(height) if vertical: self.nodePath.setP(90) # the most important part: "Drawing" the image self.texture=loader.loadTexture(""+texture+".png") self.nodePath.setTexture(self.texture) Now the code for the Map class class Map: def __init__(self,rows,columns,size): self.grid=[] for i in range(rows): self.grid.append([]) for j in range(columns): # create a canvas for the tile. For testing the texture is preset tile=Canvas(texture="../assets/textures/flat_concrete",width=size,height=size) x=(i-1)*size y=(j-1)*size # set the tile up for rendering tile.nodePath.reparentTo(render) tile.nodePath.setX(x) tile.nodePath.setY(y) # and store it for later access self.grid[i].append(tile) And finally the usage def loadMap(self): self.map=Map(10, 10, 1) this function is called within the constructor of the World class. The instantiation of world is the entry point to the execution. The code is pretty straightforward and runs good. Sadly the output is not as expected: Please note: The problem is not the white rectangle, it's my player object. The problem is that although the map should have equal width and height it's stretched weirdly. With orthographic rendering I expected the map to be a perfect square. What did I do wrong ? UPDATE: I've changed the viewport. This is how I set up the orthographic camera: lens = OrthographicLens() lens.setFilmSize(40, 20) base.cam.node().setLens(lens) You can change the "aspect" by modifying the parameters of setFilmSize. I don't know exactly how they are related to window size and screen resolution but after testing a little the values above seem to work for me. Now everything is rendered correctly as long as I don't resize the window. Every change of the window's size as well as switching to fullscreen destroys the correct rendering. I know that implementing a listener for resize events is not in the scope of this question. However I wonder why I need to make the Film's height two times bigger than its width. My window is quadratic ! Can you tell me how to find out correct setting for the FilmSize ? UPDATE 2: I can imagine that it's hard to envision the behaviour of the game. At first glance the obvious solution is to pass the window's width and height in pixels to setFilmSize. There are two problems with that approach. The parameters for setFilmSize are ingame units. You'll get a way to big view if you pass the pixel size For some strange reason the image is distorted if you pass equal values for width and height. Here's the output for setFilmSize(800,800) You'll have to stress your eyes but you'll see what I mean

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