<!DOCTYPE html>
<html>
<body>
<script src="../resources/runner.js"></script>
<script>

var sourceCanvas3D = document.createElement('canvas');
var sourceCtx = sourceCanvas3D.getContext('experimental-webgl');
var destCanvas3D = document.createElement('canvas');
var destCtx = destCanvas3D.getContext('experimental-webgl');
if (!sourceCtx || !destCtx)
    PerfTestRunner.log("\nWebGL is not supported or enabled on this platform!\n");
var MEASURE_DRAW_TIMES = 100;
var MAX_COUNT = 60000;
var count = 0;
 
function setSize(width, height) {
    sourceCanvas3D.width = width;
    sourceCanvas3D.height = height;
    destCanvas3D.width = width;
    destCanvas3D.height = height;
}

function rand(range) {
    return Math.floor(Math.random() * range);
}

function renderWebGL(gl) {
    gl.disable(gl.SCISSOR_TEST);
    gl.clear(gl.COLOR_BUFER_BIT);
    gl.enable(gl.SCISSOR_TEST);
    gl.scissor(rand(1024), rand(1024), rand(1024), rand(1024));
    gl.clearColor(Math.random(), Math.random(), Math.random(), 1);
    gl.clear(gl.COLOR_BUFFER_BIT);
}

function uploadWebGLToWebGLTexture() {
    if (sourceCtx && destCtx) {
        var tex = destCtx.createTexture();
        destCtx.bindTexture(destCtx.TEXTURE_2D, tex);

        var start = PerfTestRunner.now();

        for (var i = 0; i < MEASURE_DRAW_TIMES; i++) {
            destCtx.texImage2D(destCtx.TEXTURE_2D, 0, destCtx.RGBA, destCtx.RGBA, destCtx.UNSIGNED_BYTE, sourceCanvas3D);
        }
        destCtx.readPixels(0, 0, 1, 1, sourceCtx.RGBA, sourceCtx.UNSIGNED_BYTE, new Uint8Array(4));
        destCtx.deleteTexture(tex);
        count++;

        var elapsedTime = PerfTestRunner.now() - start;
        PerfTestRunner.measureValueAsync(MEASURE_DRAW_TIMES * 1000 / elapsedTime);
    } else
        PerfTestRunner.measureValueAsync(0);
    if (count < MAX_COUNT)
        requestAnimationFrame(uploadWebGLToWebGLTexture);
}

function onCompletedRun() {
    count = MAX_COUNT;
}

window.onload = function () {
    PerfTestRunner.prepareToMeasureValuesAsync({done: onCompletedRun, unit: 'runs/s',
        description: "This benchmark checks the speed on uploading WebGL(1024x1024) to WebGL Texture(1024x1024)."});
    setSize(1024, 1024);
    if (sourceCtx)
        renderWebGL(sourceCtx);
    uploadWebGLToWebGLTexture();
}

</script>
</body>
</html>