<!--
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>GLSL compiler bug referencing gl_FragCoord</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>
</head>
<body>
<!-- These shaders were extracted from Skia's GPU accelerated backend "Ganesh". -->
<script id="shader-vs" type="x-shader/x-vertex">
uniform mat3 uViewM;
uniform mat3 uStageMatrix_Stage1;
uniform vec4 urtAdjustment;
attribute vec2 aPosition;
attribute vec4 aColor;
varying vec4 vColor;
varying vec2 vMatrixCoord_Stage1;
void main() {
    vec3 pos3 = uViewM * vec3(aPosition, 1);
    vColor = aColor;
    { // Stage 0: XferEffect
    }
    vMatrixCoord_Stage1 = (uStageMatrix_Stage1 * vec3(aPosition, 1)).xy;
    { // Stage 1: Texture
    }
    gl_Position = vec4(dot(pos3.xz, urtAdjustment.xy), dot(pos3.yz, urtAdjustment.zw), 0, pos3.z);
}
</script>

<script id="shader-fs" type="x-shader/x-fragment">
precision mediump float;
uniform sampler2D uDstCopySampler;
uniform vec2 uDstCopyUpperLeft;
uniform vec2 uDstCopyCoordScale;
uniform float uRTHeight;
uniform sampler2D uSampler0_Stage1;
varying vec4 vColor;
varying vec2 vMatrixCoord_Stage1;
void main() {
    vec4 fragCoordYDown = vec4(gl_FragCoord.x, uRTHeight - gl_FragCoord.y, gl_FragCoord.zw);
    // Read color from copy of the destination.
    vec2 _dstTexCoord = (fragCoordYDown.xy - uDstCopyUpperLeft) * uDstCopyCoordScale;
    _dstTexCoord.y = 1.0 - _dstTexCoord.y;
    vec4 _dstColor = texture2D(uDstCopySampler, _dstTexCoord);

    vec4 output_Stage0;
    { // Stage 0: XferEffect
        // SkXfermode::Mode: Multiply
        output_Stage0.a = vColor.a + (1.0 - vColor.a) * _dstColor.a;
        output_Stage0.rgb = (1.0 - vColor.a) * _dstColor.rgb + (1.0 - _dstColor.a) * vColor.rgb + vColor.rgb * _dstColor.rgb;
    }
    vec4 output_Stage1;
    { // Stage 1: Texture
    output_Stage1 = texture2D(uSampler0_Stage1, vMatrixCoord_Stage1);
    }
    gl_FragColor = ((output_Stage0 * output_Stage1) + ((vec4(1) - output_Stage1) * _dstColor));
}
</script>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";

description();
debug("");
debug('Verify shaders using gl_FragCoord z and w components compile and link correctly');
debug('Regression test for Qualcomm bug ID CR649654');
var wtu = WebGLTestUtils;
var gl = wtu.create3DContext();
if (!gl) {
  testFailed("context does not exist");
} else {
  var program = wtu.setupProgram(gl, ["shader-vs", "shader-fs"], null, null, true);
  if (program) {
    testPassed("Program compiled and linked successfully");
  } else {
    testFailed("Program failed to compile and link");
  }
}

var successfullyParsed = true;
</script>
<script src="../../../js/js-test-post.js"></script>
</body>
</html>
