<!--

/*
** Copyright (c) 2012 The Khronos Group Inc.
**
** Permission is hereby granted, free of charge, to any person obtaining a
** copy of this software and/or associated documentation files (the
** "Materials"), to deal in the Materials without restriction, including
** without limitation the rights to use, copy, modify, merge, publish,
** distribute, sublicense, and/or sell copies of the Materials, and to
** permit persons to whom the Materials are furnished to do so, subject to
** the following conditions:
**
** The above copyright notice and this permission notice shall be included
** in all copies or substantial portions of the Materials.
**
** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
*/

-->

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL OES_texture_float Conformance Tests</title>
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../resources/desktop-gl-constants.js" type="text/javascript"></script>
<script src="../../resources/js-test-pre.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>
<!-- Shaders for testing floating-point textures -->
<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 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 the OES_texture_float extension, if it is available.");

debug("");

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas);

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

  var texturedShaders = [
      wtu.setupSimpleTextureVertexShader(gl),
      "testFragmentShader"
  ];
  var testProgram =
      wtu.setupProgram(gl,
                       texturedShaders,
                       ['vPosition', 'texCoord0'],
                       [0, 1]);
  var quadParameters = wtu.setupUnitQuad(gl, 0, 1);

  // First verify that allocation of floating-point textures fails if
  // the extension has not been enabled yet.
  runTextureCreationTest(testProgram, false);

  if (!gl.getExtension("OES_texture_float")) {
      testPassed("No OES_texture_float support -- this is legal");
  } else {
      testPassed("Successfully enabled OES_texture_float extension");
      runTextureCreationTest(testProgram, true, gl.RGBA, 4, [10000, 10000, 10000, 10000]);
      runTextureCreationTest(testProgram, true, gl.RGB, 3, [10000, 10000, 10000, 0]);
      runTextureCreationTest(testProgram, true, gl.LUMINANCE, 1, [10000, 10000, 10000, 0]);
      runTextureCreationTest(testProgram, true, gl.ALPHA, 1, [0, 0, 0, 10000]);
      runTextureCreationTest(testProgram, true, gl.LUMINANCE_ALPHA, 2, [10000, 10000, 10000, 10000]);
      runRenderTargetTest(testProgram);
      runUniqueObjectTest();
  }
}

// Needs to be global for shouldBe to see it.
var pixels;

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

function runTextureCreationTest(testProgram, extensionEnabled, opt_format, opt_numChannels, opt_subtractor)
{
    var format = opt_format || gl.RGBA;
    var numberOfChannels = opt_numChannels || 4;
    var expectFailure = !extensionEnabled;
    var subtractor = opt_subtractor || [10000, 10000, 10000, 10000];

    debug("");
    debug("testing format: " + wtu.glEnumToString(gl, format) +
          " expect:" + (extensionEnabled ? "success" : "failure"));

    var texture = allocateTexture();
    // Generate data.
    var width = 2;
    var height = 2;
    var data = new Float32Array(width * height * numberOfChannels);
    for (var ii = 0; ii < data.length; ++ii) {
        data[ii] = 10000;
    }
    gl.texImage2D(gl.TEXTURE_2D, 0, format, width, height, 0, format, gl.FLOAT, data);
    if (expectFailure) {
        glErrorShouldBe(gl, gl.INVALID_ENUM, "floating-point texture allocation must be disallowed if OES_texture_float isn't enabled");
        return;
    } else {
        glErrorShouldBe(gl, gl.NO_ERROR, "floating-point texture allocation should succeed if OES_texture_float is enabled");
    }
    // Verify that the texture actually works for sampling and contains the expected data.
    gl.uniform1i(gl.getUniformLocation(testProgram, "tex"), 0);
    gl.uniform4fv(gl.getUniformLocation(testProgram, "subtractor"), subtractor);
    wtu.clearAndDrawUnitQuad(gl);
    checkRenderingResults();
}

function runRenderTargetTest(testProgram)
{
    debug("");
    debug("testing floating-point render targets");

    var texture = allocateTexture();
    var width = 2;
    var height = 2;
    var numberOfChannels = 4;
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.FLOAT, null);
    glErrorShouldBe(gl, gl.NO_ERROR, "floating-point texture allocation should succeed if OES_texture_float is enabled");

    // Try to use this texture as a 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_float extension to
    // support floating-point textures but not as attachments to framebuffer objects.
    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE) {
        debug("floating-point render targets not supported -- this is legal");
        return;
    }

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

    // Now sample from the floating-point texture and verify we got the correct values.
    gl.bindFramebuffer(gl.FRAMEBUFFER, null);
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.useProgram(testProgram);
    gl.uniform1i(gl.getUniformLocation(testProgram, "tex"), 0);
    wtu.clearAndDrawUnitQuad(gl);
    glErrorShouldBe(gl, gl.NO_ERROR, "rendering from floating-point texture should succeed");
    checkRenderingResults();
}

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


debug("");
var successfullyParsed = true;
</script>
<script src="../../resources/js-test-post.js"></script>

</body>
</html>