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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL OES_texture_half_float Conformance Tests</title>
<script src="resources/desktop-gl-constants.js" type="text/javascript"></script>
<script src="../../../resources/js-test.js"></script>
<script src="resources/webgl-test.js"></script>
<script src="resources/webgl-test-utils.js"></script>
</head>
<body>
<div id="description"></div>
<canvas id="canvas" style="width: 50px; height: 50px;"> </canvas>
<div id="console"></div>
<script id="testFragmentShader" type="x-shader/x-fragment">
precision mediump float;
uniform sampler2D tex;
uniform vec4 subtractor;
varying vec2 texCoord;
void main()
{
    vec4 color = texture2D(tex, texCoord);
    if (abs(color.r - subtractor.r) +
        abs(color.g - subtractor.g) +
        abs(color.b - subtractor.b) +
        abs(color.a - subtractor.a) < 8.0) {
        gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
    } else {
        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
    }
}
</script>
<!-- Shaders for testing half-floating-point render targets -->
<script id="positionVertexShader" type="x-shader/x-vertex">
attribute vec4 vPosition;
void main()
{
    gl_Position = vPosition;
}
</script>
<script id="floatingPointFragmentShader" type="x-shader/x-fragment">
void main()
{
    gl_FragColor = vec4(10000.0, 10000.0, 10000.0, 10000.0);
}
</script>
<script>
"use strict"
description("This test verifies the functionality of OES_texture_half_float with null/non-null ArrayBufferView");

debug("");
var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas);
// This constant must be defined in order to run the texture creation test without the extension enabled.
var halfFloatOESEnum = 0x8D61;
var ext = null;

if (!gl) {
    testFailed("WebGL context does not exists");
} else {
    testPassed("WebGL context exists");

    // Verify that allocation of texture fails if extension is not enabled
    runTextureCreationTest(false);

    if (!(ext = gl.getExtension("OES_texture_half_float"))) {
        testPassed("No OES_texture_half_float support. This is legal");
    } else {
        testPassed("Successfully enabled OES_texture_half_float extension");

        // Check if creation of texture succeed's with various formats and null ArrayBufferView
        var formats = [gl.RGBA, gl.RGB, gl.LUMINANCE, gl.ALPHA, gl.LUMINANCE_ALPHA];
        for (var i = 0; i < formats.length; i++) {
            runTextureCreationTest(true, formats[i], null);
        }

        // Texture creation should fail when passed with non-null ArrayBufferView
        for (var i = 0; i < formats.length; i++) {
            var width = 2;
            var height = 2;

            // Float32Array
            var float32Data = new Float32Array(width * height * getNumberOfChannels(formats[i]));
            for (var ii = 0; ii < float32Data.length; ii++) {
                float32Data[ii] = 1000;
            }
            runTextureCreationTest(true, formats[i], float32Data);

            // Int16Array
            var int16Data = new Int16Array(width * height * getNumberOfChannels(formats[i]));
            for (var ii = 0; ii <  int16Data.length; ii++) {
                int16Data[ii] = 1000;
            }
            runTextureCreationTest(true, formats[i], int16Data);

            // Uint16Array
            var uint16Data = new Uint16Array(width * height * getNumberOfChannels(formats[i]));
            for (var ii = 0; ii <  uint16Data.length; ii++) {
                uint16Data[ii] = 1000;
            }
            runTextureCreationTest(true, formats[i], uint16Data);
        }

        // Check if attaching texture as FBO target succeeds (Not mandatory)
        runRenderTargetTest();
        // Check of getExtension() returns same object
        runUniqueObjectTest();
    }
}

function getNumberOfChannels(format)
{
    if (format == gl.RGBA)
        return 4;
    else if (format == gl.RGB)
        return 3;
    else if (format == gl.LUMINANCE || format == gl.ALPHA)
        return 1;
    else if (format == gl.LUMINANCE_ALPHA)
        return 2;
}

function getFormatName(format)
{
    if (format == gl.RGBA)
        return "RGBA";
    else if (format == gl.RGB)
        return "RGB";
    else if (format == gl.LUMINANCE)
        return "LUMINANCE";
    else if (format == gl.ALPHA)
        return "ALPHA";
    else if (format == gl.LUMINANCE_ALPHA)
        return "LUMINANCE_ALPHA";
}

function allocateTexture()
{
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
    glErrorShouldBe(gl, gl.NO_ERROR, "texture parameter setup should succeed");
    return texture;
}

function runTextureCreationTest(extensionEnabled, opt_format, opt_data)
{
    var format = opt_format || gl.RGBA;
    var data = opt_data || null;
    var expectSuccess = true;

    if (!extensionEnabled || data)
        expectSuccess = false;
    debug("Testing texture creation with extension " + (extensionEnabled ? "enabled" : "disabled") +
          ", format " + getFormatName(format) + ", and data " + (data ? "non-null" : "null") +
          ". Expect " + (expectSuccess ? "Success" : "Failure"));

    var texture = allocateTexture();
    var width = 2;
    var height = 2;
    gl.texImage2D(gl.TEXTURE_2D, 0, format, width, height, 0, format, halfFloatOESEnum, data);
    if(!extensionEnabled) {
        glErrorShouldBe(gl, gl.INVALID_ENUM, "Half floating point texture must be disallowed if OES_texture_half_float isn't enabled");
        return;
    } else if (data) {
        glErrorShouldBe(gl, gl.INVALID_OPERATION, "Half floating point texture allocation must be disallowed when ArrayBufferView is not-null");
        return;
    } else {
        glErrorShouldBe(gl, gl.NO_ERROR, "Half floating point texture allocation should succeed if OES_texture_half_float is enabled");
    }
}

function checkRenderingResults()
{
    wtu.checkCanvas(gl, [0, 255, 0, 255], "should be green");
}

function runRenderTargetTest(testProgram)
{
    debug("");
    debug("Testing half floating point render target");

    var texture = allocateTexture();
    var width = 2;
    var height = 2;

    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, ext.HALF_FLOAT_OES, null);
    glErrorShouldBe(gl, gl.NO_ERROR, "Half floating point texture allocation should succeed if OES_texture_half_float is enabled");

    // Try to use this texture as render target
    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    gl.bindTexture(gl.TEXTURE_2D, null);

    // It is legal for a WebGL implementation exposing the OES_texture_half_float extension to
    // support half floating point textures but not as attachments to framebuffer objects.
    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE) {
        debug("Half floating point render targets not supported -- this is legal");
        return;
    }

    var renderProgram =
        wtu.setupProgram(gl,
                         ["positionVertexShader", "floatingPointFragmentShader"],
                         ['vPosition'],
                         [0]);
    wtu.drawQuad(gl);
    glErrorShouldBe(gl, gl.NO_ERROR, "Rendering to half floating point texture should succeed");

    // Now sample from the half floating-point texture and verify we got the correct values.
    var texturedShaders = [
      wtu.setupSimpleTextureVertexShader(gl),
          "testFragmentShader"
      ];
    var testProgram =
        wtu.setupProgram(gl,
                        [wtu.setupSimpleTextureVertexShader(gl), "testFragmentShader"],
                        ['vPosition', 'texCoord0'],
                        [0, 1]);
    var quadParameters = wtu.setupUnitQuad(gl, 0, 1);
    gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.useProgram(testProgram);
    gl.uniform1i(gl.getUniformLocation(testProgram, "tex"), 0);
    wtu.drawQuad(gl);
    glErrorShouldBe(gl, gl.NO_ERROR, "rendering from half floating point texture should succeed");
    checkRenderingResults();
}

function runUniqueObjectTest()
{
    debug("Testing that getExtension() returns the same object each time");
    gl.getExtension("OES_texture_half_float").myProperty = 2;
    gc();
    shouldBe('gl.getExtension("OES_texture_half_float").myProperty', '2');
}

debug("");
</script>
</body>
</html>