Further Explorations - HTML5 Canvas - page 576

void main(void) {
gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
vColor = aVertexColor;
}
</script>
<script type="text/javascript">
window.addEventListener("load", eventWindowLoaded, false);
function eventWindowLoaded () {
canvasApp();
}
function canvasSupport () {
return Modernizr.canvas;
}
function webglSupport() {
return Modernizr.webgl;
}
function canvasApp () {
function drawScreen() {
webGLContext.viewport(0, 0, webGLContext.viewportWidth,
webGLContext.viewportHeight);
webGLContext.clear(webGLContext.COLOR_BUFFER_BIT | webGLContext.DEPTH_BUFFER_BIT);
perspective(25, (webGLContext.viewportWidth / webGLContext.viewportHeight),
0.1, 100.0);
loadIdentity();
mvTranslate([0, 0.0, -10.0])
mvPushMatrix();
mvRotate(rotateCube, [0, .5, .5]);
webGLContext.bindBuffer(webGLContext.ARRAY_BUFFER, cubeVertexPositionBuffer);
webGLContext.vertexAttribPointer(shaderProgram.vertexPositionAttribute,
cubeVertexPositionBuffer.itemSize, webGLContext.FLOAT, false, 0, 0);
webGLContext.bindBuffer(webGLContext.ARRAY_BUFFER, cubeVertexColorBuffer);
webGLContext.vertexAttribPointer(shaderProgram.vertexColorAttribute,
cubeVertexColorBuffer.itemSize, webGLContext.FLOAT, false, 0, 0);
webGLContext.bindBuffer(webGLContext.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
setMatrixUniforms();
webGLContext.drawElements(webGLContext.TRIANGLES, cubeVertexIndexBuffer.numItems,
webGLContext.UNSIGNED_SHORT, 0);
mvPopMatrix();
rotateCube += 2;
}