CSC517 OffScreenCanvas Servo: Difference between revisions

From Expertiza_Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
'''About Off Screen Canvas:'''
'''About Off Screen Canvas:'''
The HTML specification defines a <canvas> element that can use a 2d or 3d rendering context. A new specification was recently developed that defines a canvas that can be used without being associated with an in-page canvas element, allowing for more efficient rendering.


The HTML specification defines a <canvas> element that can use a 2d or 3d rendering context. A new specification was recently developed that defines a canvas that can be used without being associated with an in-page canvas element, allowing for more efficient rendering. To use the OffscreenCanvas API, we have used a RenderingContext that has been obtained from an OffscreenCanvas object to generate new frames. Once a new frame has finished rendering in this context,  the transferToImageBitmap() method can be called to save the most recent rendered image. This method returns an ImageBitmap object, which can be used in a variety of Web APIs and also in a second canvas without creating a transfer copy.
'''Problem Statement:'''


'''Problem Statement:'''


The following tasks were accomplished in the project:
<pre>
typedef (OffscreenCanvasRenderingContext2D or WebGLRenderingContext or WebGL2RenderingContext) OffscreenRenderingContext;
 
dictionary ImageEncodeOptions {
  DOMString type = "image/png";
  unrestricted double quality = 1.0;
};


1) Creating the OffscreenCanvas and OffscreenCanvasRenderingContext2d interfaces with stub method implementations.
enum OffscreenRenderingContextId { "2d", "webgl", "webgl2" };


2) Implementing the OffscreenCanvas Constructor [https://html.spec.whatwg.org/multipage/scripting.html#dom-offscreencanvas] that creates a new canvas.
[Constructor([EnforceRange] unsigned long long width, [EnforceRange] unsigned long long height), Exposed=(Window,Worker), Transferable]
[Pref="dom.offscreen_canvas.enabled"]
interface OffscreenCanvas : EventTarget {
  attribute [EnforceRange] unsigned long long width;
  attribute [EnforceRange] unsigned long long height;


3)
  OffscreenRenderingContext? getContext(OffscreenRenderingContextId contextId, optional any options = null);
  ImageBitmap transferToImageBitmap();
  //Promise<Blob> convertToBlob(optional ImageEncodeOptions options);
};
</pre>

Revision as of 02:54, 3 November 2018

About Off Screen Canvas: The HTML specification defines a <canvas> element that can use a 2d or 3d rendering context. A new specification was recently developed that defines a canvas that can be used without being associated with an in-page canvas element, allowing for more efficient rendering.

Problem Statement: 


typedef (OffscreenCanvasRenderingContext2D or WebGLRenderingContext or WebGL2RenderingContext) OffscreenRenderingContext;

dictionary ImageEncodeOptions {
  DOMString type = "image/png";
  unrestricted double quality = 1.0;
};

enum OffscreenRenderingContextId { "2d", "webgl", "webgl2" };

[Constructor([EnforceRange] unsigned long long width, [EnforceRange] unsigned long long height), Exposed=(Window,Worker), Transferable]
[Pref="dom.offscreen_canvas.enabled"]
interface OffscreenCanvas : EventTarget {
  attribute [EnforceRange] unsigned long long width;
  attribute [EnforceRange] unsigned long long height;

  OffscreenRenderingContext? getContext(OffscreenRenderingContextId contextId, optional any options = null);
  ImageBitmap transferToImageBitmap();
  //Promise<Blob> convertToBlob(optional ImageEncodeOptions options);
};
Retrieved from "https://wiki.expertiza.ncsu.edu/index.php?title=CSC517_OffScreenCanvas_Servo&oldid=118496"