Namespace SpiderGL.WebGL.Context

Namespace Detail

Field Detail

See:

SpiderGL.WebGL.Context.DEFAULT_UNPACK_FLIP_Y

SpiderGL.WebGL.Context.DEFAULT_UNPACK_PREMULTIPLY_ALPHA

SpiderGL.WebGL.Context.setStandardGLUnpack

Default Value:

WebGLRenderingContext.NONE

See:

SpiderGL.WebGL.Context.DEFAULT_UNPACK_PREMULTIPLY_ALPHA

SpiderGL.WebGL.Context.DEFAULT_UNPACK_COLORSPACE_CONVERSION

SpiderGL.WebGL.Context.setStandardGLUnpack

Default Value:

true

See:

SpiderGL.WebGL.Context.DEFAULT_UNPACK_FLIP_Y

SpiderGL.WebGL.Context.DEFAULT_UNPACK_COLORSPACE_CONVERSION

SpiderGL.WebGL.Context.setStandardGLUnpack

Default Value:

true

See:

SpiderGL.WebGL.Context.get

Method Detail

• <static> {WebGLRenderingContext} SpiderGL.WebGL.Context.get(canvas, args)
  Retrieves the WebGLRenderingContext from a canvas. The WebGLRenderingContext is obtained by calling the getContext() method of the canvas object.

  Parameters:

  {HTMLCanvasElement} canvas

  The HTMLCanvasElement from which retrieve the WebGL context.

  {object} args

  The optional WebGL context arguments.

  Returns:

  {WebGLRenderingContext} The canvas WebGL rendering context.

  See:

  SpiderGL.WebGL.Context.hijack

  SpiderGL.WebGL.Context.getHijacked
• <static> {WebGLRenderingContext} SpiderGL.WebGL.Context.getHijacked(canvas, args)
  Creates a WebGLRenderingContext and hijacks it. The WebGLRenderingContext obtained from the canvas parameter with optional arguments is hijacked.

  Parameters:

  {HTMLCanvasElement} canvas

  The HTMLCanvasElement from which retrieve the WebGL context.

  {object} args

  The optional WebGL context arguments.

  Returns:

  {WebGLRenderingContext} The hijacked canvas WebGL rendering context.

  See:

  SpiderGL.WebGL.Context.get

  SpiderGL.WebGL.Context.getHijacked

  SpiderGL.WebGL.Context.isHijacked
• <static> {bool} SpiderGL.WebGL.Context.hijack(gl)
  Hijacks a WebGLRenderingContext for SpiderGL.WebGL.ObjectGL wrappers. The WebGLRenderingContext is modified to allow SpiderGL.WebGL.ObjectGL wrappers to be edited without explicit bind and without affecting the WebGL object bindings. Most WebGL objects follow the "bind to edit" / "bind to use" paradigm. This means that the object must be bound to the WebGL context to modify some parameter or its resource data. As a side effect, binding the object just to modify it has the same result of binding it to be used during rendering. To prevent this side effect, all the WebGLRenderingContext functions that bind and modify object parameters or data, as long as the rendering functions, are wrapped. This allows SpiderGL wrappers (derived from SpiderGL.WebGL.ObjectGL) to be edited without affecting the binding state of the WebGLRenderingContext. The following example clarifies how bindings are handled.

  var textureA = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_2D, textureA);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
  // other texture calls
  var textureB = new SpiderGL.WebGL.Texture2D(gl, parameters);
  textureB.minFilter = gl.LINEAR; // textureB is hiddenly bound to modify the minification filter
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR); // textureA is automatically re-bound to keep WebGL semantic
  textureB.magFilter = gl.LINEAR; // textureB is hiddenly bound to modify another parameter
  gl.drawArrays(gl.TRIANGLES, 0, 3); // textureA is automatically re-bound to keep WebGL semantic
  textureB.bind(); // bind textureB to WebGL, breaking the binding with textureA
  gl.drawArrays(gl.TRIANGLES, 0, 3); // textureA is used

  Parameters:

  {WebGLRenderingContext} gl

  The WebGLRenderingContext to modify.

  Returns:

  {bool} True on success, false if the gl argument is not valid or has already been modified.

  See:

  SpiderGL.WebGL.Context.isHijacked

  SpiderGL.WebGL.Context.getHijacked

  SpiderGL.WebGL.Context.get

  SpiderGL.WebGL.ObjectGL
• <static> {bool} SpiderGL.WebGL.Context.isHijacked(gl)
  Tests whether a WebGLRenderingContext is hijacked. The WebGLRenderingContext is hijacked after a successful call to SpiderGL.WebGL.Context.hijack.

  Parameters:

  {WebGLRenderingContext} gl

  The WebGLRenderingContext to test.

  Returns:

  {bool} True on success, false if the gl argument is not valid or has already been modified.

  See:

  SpiderGL.WebGL.Context.hijack

  SpiderGL.WebGL.Context.getHijacked

  SpiderGL.WebGL.Context.get
• <static> SpiderGL.WebGL.Context.setStandardGLUnpack(gl)
  Sets pixel store unpack parameters to standard OpenGL SpiderGL values. The parameters to be set are UNPACK_FLIP_Y_WEBGL (true), UNPACK_PREMULTIPLY_ALPHA_WEBGL (false) and UNPACK_COLORSPACE_CONVERSION_WEBGL (WebGLRenderingContext.NONE).

  Parameters:

  {WebGLRenderingContext} gl

  The target WebGLRenderingContext.