<html>
<head>
<script src="../../../resources/js-test.js"></script>
<script src="resources/webgl-test.js"></script>
<script id="vshader" type="x-shader/x-vertex">
attribute vec3 g_Position;
attribute vec2 g_TexCoord0;

varying vec2 texCoord;

void main()
{
    gl_Position = vec4(g_Position.x, g_Position.y, g_Position.z, 1.0);
    texCoord = g_TexCoord0;
}
</script>

<script id="fshader" type="x-shader/x-fragment">
#ifdef GL_ES
precision mediump float;
#endif
uniform sampler2D tex;
varying vec2 texCoord;
void main()
{
    gl_FragColor = texture2D(tex, texCoord);
}
</script>

<script>

function init()
{
    if (window.initNonKhronosFramework) {
        window.initNonKhronosFramework(true);
    }

    description('Verify copyTexImage2D and copyTexSubImage2D');

    runTest();
}

// These two declarations need to be global for "shouldBe" to see them
var pixel = [0, 0, 0];
var correctColor = null;
var gl = null;

function runTestIteration(antialias)
{
    if (antialias)
        gl = initWebGL("antialiasOn", "vshader", "fshader", [ "g_Position", "g_TexCoord0" ], [ 0, 0, 0, 1 ], 1);
    else
        gl = initWebGL("antialiasOff", "vshader", "fshader", [ "g_Position", "g_TexCoord0" ], [ 0, 0, 0, 1 ], 1, { antialias: false });

    var textureLoc = gl.getUniformLocation(gl.program, "tex");

    var vertices = new Float32Array([
         1.0,  1.0, 0.0,
        -1.0,  1.0, 0.0,
        -1.0, -1.0, 0.0,
         1.0,  1.0, 0.0,
        -1.0, -1.0, 0.0,
         1.0, -1.0, 0.0]);
    var texCoords = new Float32Array([
        1.0, 1.0,
        0.0, 1.0,
        0.0, 0.0,
        1.0, 1.0,
        0.0, 0.0,
        1.0, 0.0]);
    var texCoordOffset = vertices.byteLength;

    var vbo = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, vbo);
    gl.bufferData(gl.ARRAY_BUFFER,
                  texCoordOffset + texCoords.byteLength,
                  gl.STATIC_DRAW);
    gl.bufferSubData(gl.ARRAY_BUFFER, 0, vertices);
    gl.bufferSubData(gl.ARRAY_BUFFER, texCoordOffset, texCoords);

    gl.enableVertexAttribArray(0);
    gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(1);
    gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, texCoordOffset);

    gl.colorMask(1, 1, 1, 0);
    gl.disable(gl.BLEND);
    debug('Testing copyTexImage2D');

    // Red canvas
    gl.clearColor(1, 0, 0, 1);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

    var texture = gl.createTexture();
    // Bind the texture to texture unit 0
    gl.bindTexture(gl.TEXTURE_2D, texture);
    // Set up texture
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 2, 2, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);

    glErrorShouldBe(gl, gl.NO_ERROR);
    gl.copyTexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 0, 0, 2, 2, 0);
    glErrorShouldBe(gl, gl.NO_ERROR);

    // Green canvas
    gl.clearColor(0, 1, 0, 1);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

    // Point the uniform sampler to texture unit 0
    gl.uniform1i(textureLoc, 0);
    // Draw the triangles
    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // Read back the rendering results, should be red
    var buf = new Uint8Array(2 * 2 * 4);
    gl.readPixels(0, 0, 2, 2, gl.RGBA, gl.UNSIGNED_BYTE, buf);
    var idx = 0;
    correctColor = [255, 0, 0];
    for (var y = 0; y < 2; y++) {
        for (var x = 0; x < 2; x++) {
            idx = (y * 2 + x) * 4;
            pixel[0] = buf[idx];
            pixel[1] = buf[idx + 1];
            pixel[2] = buf[idx + 2];
            shouldBe("pixel", "correctColor");
        }
    }

    debug('Testing copyTexSubImage2D');

    // Green canvas
    gl.clearColor(0, 1, 0, 1);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

    glErrorShouldBe(gl, gl.NO_ERROR);
    gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, 2, 2);
    glErrorShouldBe(gl, gl.NO_ERROR);

    // Blue canvas
    gl.clearColor(0, 0, 1, 1);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

    // Draw the triangles
    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // Read back the rendering results, should be green
    gl.readPixels(0, 0, 2, 2, gl.RGBA, gl.UNSIGNED_BYTE, buf);
    correctColor = [0, 255, 0];
    for (var y = 0; y < 2; y++) {
        for (var x = 0; x < 2; x++) {
            idx = (y * 2 + x) * 4;
            pixel[0] = buf[idx];
            pixel[1] = buf[idx + 1];
            pixel[2] = buf[idx + 2];
            shouldBe("pixel", "correctColor");
        }
    }
}

function runTest(antialias)
{
    debug("Testing with antialias on");
    runTestIteration(true);
    debug("Testing with antialias off");
    runTestIteration(false);
    var epilogue = document.createElement("script");
    epilogue.onload = finish;
    epilogue.src = "../../../resources/js-test-post.js";
    document.body.appendChild(epilogue);
}

function finish() {
    if (window.nonKhronosFrameworkNotifyDone) {
        window.nonKhronosFrameworkNotifyDone();
    }
}
</script>
</head>
<body onload="init()">
<canvas id="antialiasOn" width="2px" height="2px"></canvas>
<canvas id="antialiasOff" width="2px" height="2px"></canvas>
<div id="description"></div>
<div id="console"></div>
</body>
</html>