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** 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:
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** The above copyright notice and this permission notice shall be included
** in all copies or substantial portions of the Materials.
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** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../resources/js-test-pre.js"></script>
<script src="../resources/webgl-test-utils.js"></script>
<script id="vshader" type="x-shader/x-vertex">
    attribute vec3 pos;
    attribute vec4 colorIn;
    uniform float pointSize;
    varying vec4 color;

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

<script id="fshader" type="x-shader/x-fragment">
    precision mediump float;
    varying vec4 color;

    void main()
    {
        gl_FragColor = color;
    }
</script>
</head>
<body>
<canvas id="testbed" width="2" height="2"></canvas>
<div id="description"></div>
<div id="console"></div>
<script>
    "use strict";
    description('Verify GL_VERTEX_PROGRAM_POINT_SIZE is enabled in WebGL');

    var wtu = WebGLTestUtils;
    var gl = wtu.create3DContext('testbed', { antialias: false });
    shouldBeNonNull("gl");

    gl.disable(gl.BLEND);

    // The choice of (0.4, 0.4) ensures that the centers of the surrounding
    // pixels are not contained within the point when it is of size 1, but
    // that they definitely are when it is of size 2.
    var vertices = new Float32Array([
        0.4, 0.4, 0.0]);
    var colors = new Uint8Array([
        255, 0, 0, 255]);

    var colorOffset = vertices.byteLength;

    var buf = new Uint8Array(2 * 2 * 4);
    var index = 0;

    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);

    function test(program) {
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

        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);

        var locPointSize = gl.getUniformLocation(program, 'pointSize');

        shouldBe('gl.getError()', 'gl.NO_ERROR');

        debug('Draw a point of size 1 and verify it does not touch any other pixels.');

        gl.uniform1f(locPointSize, 1.0);
        gl.drawArrays(gl.POINTS, 0, vertices.length / 3);
        
        shouldBe('gl.getError()', 'gl.NO_ERROR');

        for (var y = 0; y < 2; ++y) {
            for (var x = 0; x < 2; ++x) {
                var correctColor = (x == 1 && y == 1) ? [255, 0, 0] : [0, 0, 0];
                wtu.checkCanvasRect(gl, x, y, 1, 1, correctColor);
            }
        }
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

        debug('Draw a point of size 2 and verify it fills the appropriate region.');

        var pointSizeRange = gl.getParameter(gl.ALIASED_POINT_SIZE_RANGE);
        if (pointSizeRange[1] >= 2.0) {
            gl.uniform1f(locPointSize, 2.0);
            gl.drawArrays(gl.POINTS, 0, vertices.length / 3);
            shouldBe('gl.getError()', 'gl.NO_ERROR');
            wtu.checkCanvasRect(gl, 0, 0, 2, 2, [255, 0, 0]);
        }
    }

    debug('');
    debug('Pass 1');
    var program1 = wtu.setupProgram(gl, ['vshader', 'fshader'], ['pos', 'colorIn']);
    shouldBe('gl.getError()', 'gl.NO_ERROR');
    test(program1);

    // Under some versions of ANGLE point sprite shader programs were 
    // incorrectly reloaded from cache. Rebuilding the shader program and
    // repeating the test simulates the conditions that caused it to fail
    debug('');
    debug('Pass 2');
    var program2 = wtu.setupProgram(gl, ['vshader', 'fshader'], ['pos', 'colorIn']);
    shouldBe('gl.getError()', 'gl.NO_ERROR');
    test(program2);

    var successfullyParsed = true;
</script>

<script src="../../resources/js-test-post.js"></script>

</body>
</html>