OpenGL Insights

41. Features and Design Choices in SpiderGL 593

gl._spidergl = { }; // private SpiderGL injections container.

gl._spidergl.setupXYZ = setupXYZ ;

gl._spidergl.xyz = null ;

// ... other extensions ...

// A reference to native getExtension is saved ...

gl._spidergl.getExtension =gl.getExtension;

// ... and replaced to expose new extensions

gl . getExtension = function ( name) {

var sgl = this ._spidergl;

switch (name) {

case "SGL_XYZ ":

if (!sgl.xyz) {

sgl. setupXYZ ( this); // setup extension on first call

}

return sgl .xyz;

// ... other extensions ...

default : // call to native getExtension

return sgl .getExtension. apply(this , arguments);

}

};

Listing 41.7.