
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="../../js/resources/js-test-style.css"/>
<script src="../../js/resources/js-test-pre.js"></script>
<script src="resources/webgl-test.js"></script>
<script id="vshader" type="x-shader/x-vertex">
attribute vec3 pos;
attribute vec4 colorIn;
varying vec4 color;

void main()
{
    color = colorIn;
    gl_Position = vec4(pos.xyz, 1.0);
}
</script>

<script id="fshader" type="x-shader/x-fragment">
precision mediump float;

varying vec4 color;

void main()
{
    gl_FragColor = color;
}
</script>

<script>
var successfullyParsed = false;

// These four declarations need to be global for "shouldBe" to see them
var gl;
var contextAttribs = null;
var pixel = [0, 0, 0, 1];
var correctColor = null;
var framebuffer;
var fbHasColor;
var fbHasDepth;
var fbHasStencil;

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

    description('Verify WebGLContextAttributes are working as specified, including alpha, depth, stencil, antialias, but not premultipliedAlpha');

    runTest();
}

function getWebGL(canvasWidth, canvasHeight, contextAttribs, clearColor, clearDepth, clearStencil)
{
    var canvas = document.createElement("canvas");
    if (!canvas)
        return null;
    canvas.width = canvasWidth;
    canvas.height = canvasHeight;

    gl = create3DContext(canvas, contextAttribs);
    if (!gl)
        return null;

    var program = createProgram(gl, "vshader", "fshader", ["pos", "colorIn"]);
    if (!program)
        return null;

    gl.useProgram(program);

    gl.enable(gl.DEPTH_TEST);
    gl.enable(gl.STENCIL_TEST);
    gl.disable(gl.BLEND);

    gl.clearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
    gl.clearDepth(clearDepth);
    gl.clearStencil(clearStencil);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT | gl.STENCIL_BUFFER_BIT);

    framebuffer = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.canvas.width, gl.canvas.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    fbHasStencil = false;
    fbHasDepth = false;
    fbHasColor = gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE;
    if (fbHasColor) {
      var depthStencil = gl.createRenderbuffer();
      gl.bindRenderbuffer(gl.RENDERBUFFER, depthStencil);
      gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_STENCIL, gl.canvas.width, gl.canvas.height);
      gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencil);
      fbHasDepth = gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE;
      if (!fbHasDepth) {
        gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, null);
        shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');
      } else {
        fbHasStencil = true;
      }
    }
    gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors");

    return gl;
}

function drawAndReadPixel(gl, vertices, colors, x, y)
{
    var colorOffset = vertices.byteLength;

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

    gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(0);
    gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, true, 0, colorOffset);
    gl.enableVertexAttribArray(1);

    gl.drawArrays(gl.TRIANGLES, 0, vertices.length / 3);

    var buf = new Uint8Array(1 * 1 * 4);
    gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
    return buf;
}

function testAlpha(alpha)
{
    debug("Testing alpha = " + alpha);
    if (alpha) {
        shouldBeNonNull("gl = getWebGL(1, 1, { alpha: true, depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 0 ], 1, 0)");
        shouldBeTrue("gl.getParameter(gl.ALPHA_BITS) >= 8");
    } else {
        shouldBeNonNull("gl = getWebGL(1, 1, { alpha: false, depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 0 ], 1, 0)");
        shouldBeTrue("gl.getParameter(gl.ALPHA_BITS) == 0");
    }
    shouldBeTrue("gl.getParameter(gl.RED_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.GREEN_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.BLUE_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) == 0");
    shouldBeTrue("gl.getParameter(gl.STENCIL_BITS) == 0");

    shouldBeNonNull("contextAttribs = gl.getContextAttributes()");
    shouldBeTrue("contextAttribs.alpha == " + alpha);

    var buf = new Uint8Array(1 * 1 * 4);
    gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
    pixel[0] = buf[0];
    pixel[1] = buf[1];
    pixel[2] = buf[2];
    pixel[3] = buf[3];
    correctColor = (contextAttribs.alpha ? [0, 0, 0, 0] : [0, 0, 0, 255]);
    shouldBe("pixel", "correctColor");

    if (fbHasColor) {
      gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
      gl.clearColor(0.5, 0.5, 0.5, 0.5);
      gl.clear(gl.COLOR_BUFFER_BIT);
      gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
      pixel[0] = buf[0];
      pixel[1] = buf[1];
      pixel[2] = buf[2];
      pixel[3] = buf[3];
      shouldBeTrue("Math.abs(pixel[0] - 127) <= 1 && Math.abs(pixel[1] - 127) <= 1 && Math.abs(pixel[2] - 127) <= 1 && Math.abs(pixel[3] - 127) <= 1");
      gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    }
}

function testDepth(depth)
{
    debug("Testing depth = " + depth);
    if (depth) {
        shouldBeNonNull("gl = getWebGL(1, 1, { stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0)");
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) >= 16");
    } else {
        shouldBeNonNull("gl = getWebGL(1, 1, { depth: false, stencil: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0)");
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) == 0");
    }
    shouldBeTrue("gl.getParameter(gl.RED_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.GREEN_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.BLUE_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.ALPHA_BITS) >= 8");

    shouldBeNonNull("contextAttribs = gl.getContextAttributes()");

    gl.depthFunc(gl.NEVER);

    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 colors = new Uint8Array([
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255]);

    var buf = drawAndReadPixel(gl, vertices, colors, 0, 0);
    pixel[0] = buf[0];
    pixel[1] = buf[1];
    pixel[2] = buf[2];
    pixel[3] = buf[3];
    correctColor = (contextAttribs.depth ? [0, 0, 0, 255] : [255, 0, 0, 255]);
    shouldBe("pixel", "correctColor");

    if (fbHasDepth) {
      gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
      gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
      var buf = drawAndReadPixel(gl, vertices, colors, 0, 0);
      pixel[0] = buf[0];
      pixel[1] = buf[1];
      pixel[2] = buf[2];
      pixel[3] = buf[3];
      shouldBe("pixel", "[0, 0, 0, 255]");
      gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    }
}

function testStencilAndDepth(stencil, depth)
{
    debug("Testing stencil = " + stencil + ", depth = " + depth);
    var creationString =
        "gl = getWebGL(1, 1, { depth: " + depth + ", stencil: " + stencil + ", antialias: false }, [ 0, 0, 0, 1 ], 1, 0)";
    shouldBeNonNull(creationString);

    shouldBeTrue("gl.getParameter(gl.RED_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.GREEN_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.BLUE_BITS) >= 8");
    shouldBeTrue("gl.getParameter(gl.ALPHA_BITS) >= 8");
    if (depth)
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) >= 16");
    else
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) == 0");

    if (stencil)
        shouldBeTrue("gl.getParameter(gl.STENCIL_BITS) >= 8");
    else
        shouldBeTrue("gl.getParameter(gl.STENCIL_BITS) == 0");

    shouldBeNonNull("contextAttribs = gl.getContextAttributes()");
    if (!depth && contextAttribs.depth) {
        testFailed("WebGL implementation provided a depth buffer when it should not have");
    }
    if (!contextAttribs.depth)
        depth = false;
    if (!stencil && contextAttribs.stencil) {
        testFailed("WebGL implementation provided a stencil buffer when it should not have");
    }
    if (!contextAttribs.stencil)
        stencil = false;

    gl.depthFunc(gl.ALWAYS);

    gl.stencilFunc(gl.NEVER, 1, 1);
    gl.stencilOp(gl.KEEP, gl.KEEP, gl.KEEP);

    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 colors = new Uint8Array([
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255]);

    var buf = drawAndReadPixel(gl, vertices, colors, 0, 0);
    pixel[0] = buf[0];
    pixel[1] = buf[1];
    pixel[2] = buf[2];
    pixel[3] = buf[3];
    correctColor = (stencil ? [0, 0, 0, 255] : [255, 0, 0, 255]);
    shouldBe("pixel", "correctColor");

    if (fbHasStencil) {
      gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
      gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
      var buf = drawAndReadPixel(gl, vertices, colors, 0, 0);
      pixel[0] = buf[0];
      pixel[1] = buf[1];
      pixel[2] = buf[2];
      pixel[3] = buf[3];
      shouldBe("pixel", "[0, 0, 0, 255]");
      gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    }
}

function testAntialias(antialias)
{
    debug("Testing antialias = " + antialias);
    if (antialias)
        shouldBeNonNull("gl = getWebGL(2, 2, { depth: false, stencil: false, alpha: false, antialias: true }, [ 0, 0, 0, 1 ], 1, 0)");
    else
        shouldBeNonNull("gl = getWebGL(2, 2, { depth: false, stencil: false, alpha: false, antialias: false }, [ 0, 0, 0, 1 ], 1, 0)");
    shouldBeNonNull("contextAttribs = gl.getContextAttributes()");

    var vertices = new Float32Array([
         1.0, 1.0, 0.0,
        -1.0, 1.0, 0.0,
        -1.0, -1.0, 0.0]);
    var colors = new Uint8Array([
        255, 0, 0, 255,
        255, 0, 0, 255,
        255, 0, 0, 255]);
    var buf = drawAndReadPixel(gl, vertices, colors, 0, 0);
    pixel[0] = buf[0];
    shouldBe("pixel[0] != 255 && pixel[0] != 0", "contextAttribs.antialias");
}

function runTest()
{

    testAlpha(true);
    testAlpha(false);
    testDepth(true);
    testDepth(false);
    testStencilAndDepth(true, false);
    testStencilAndDepth(false, false);
    testStencilAndDepth(true, true);
    testStencilAndDepth(false, true);
    testAntialias(true);
    testAntialias(false);

    finishTest();
}

</script>
</head>
<body onload="init()">
<div id="description"></div>
<div id="console"></div>
</body>
</html>