<!--
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
-->

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL draw with uniform blocks conformance tests</title>
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"></script>
<script id="vshader" type="x-shader/x-vertex">#version 300 es
in vec4 a_vertex;
void main(void) {
  gl_Position = a_vertex;
}
</script>
<script id="fshader" type="x-shader/x-fragment">#version 300 es
precision mediump float;
layout (std140) uniform color_ubo {
  vec4 color;
};
out vec4 fragColor;
void main(void) {
  fragColor = color;
}
</script>
</head>
<body>
<canvas id="example" width="100", height="100"></canvas>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";
debug("");

// Ported from: https://github.com/google/angle/blob/master/src/tests/gl_tests/UniformBufferTest.cpp#L1507
description("Regression test for https://bugs.chromium.org/p/chromium/issues/detail?id=792966");

var wtu = WebGLTestUtils;
var gl = wtu.create3DContext("example", undefined, 2);

function runTest() {
    var program = wtu.setupProgram(gl, ['vshader', 'fshader'], ['a_vertex']);
    var uboIndex = gl.INVALID_INDEX;
    if (program)
        uboIndex = gl.getUniformBlockIndex(program, "color_ubo");
    if (!program || uboIndex == gl.INVALID_INDEX) {
        testFailed("Loading program failed");
        return;
    }
    testPassed("Loading program succeeded");

    var vertices = new Float32Array([
        -1, -1, 0,
         1, -1, 0,
        -1,  1, 0,
         1,  1, 0
    ]);
    var vertexBuf = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuf);
    gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
    gl.enableVertexAttribArray(0);
    gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

    var indexBuf = gl.createBuffer();
    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuf);
    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Int16Array([ 0, 1, 2, 2, 1, 3 ]), gl.STATIC_DRAW);

    var uboDataSize = gl.getActiveUniformBlockParameter(
        program, uboIndex, gl.UNIFORM_BLOCK_DATA_SIZE);
    if (uboDataSize == 0) {
        testFailed("uniform block data size invalid");
        return;
    }

    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "No errors from setup");

    debug("draw lower triangle - should be red");
    var uboBuf1 = gl.createBuffer();
    gl.bindBufferBase(gl.UNIFORM_BUFFER, 0, uboBuf1);
    gl.bufferData(gl.UNIFORM_BUFFER, uboDataSize, gl.STATIC_DRAW);
    gl.bufferSubData(gl.UNIFORM_BUFFER, 0, new Float32Array([ 1, 0, 0, 1 ]));
    gl.uniformBlockBinding(program, uboIndex, 0);
    gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 0);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "No errors from draw");

    // Resize the buffer - triggers a re-allocation in the D3D11 back-end.
    debug("draw upper triangle - should be green");
    var bigData = new Float32Array(128 * 4);
    bigData.set([ 0, 1, 0, 1 ]);
    gl.bufferData(gl.UNIFORM_BUFFER, bigData, gl.STATIC_DRAW);
    gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 6);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "No errors from draw");

    var width = 100, height = 100;
    wtu.checkCanvasRectColor(gl, 0, 0, width/2-5, height/2-5, [255, 0, 0, 255], 2,
        function() { testPassed("lower left should be red"); },
        function() { testFailed("lower left should be red"); });
    wtu.checkCanvasRectColor(gl, width/2+5, height/2+5, width/2-5, height/2-5, [0, 255, 0, 255], 2,
        function() { testPassed("top right should be green"); },
        function() { testFailed("top right should be green"); });
}

if (!gl) {
    testFailed("WebGL context creation failed");
} else {
    testPassed("WebGL context creation succeeded");
    runTest();
}

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

</body>
</html>
