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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.
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL texture2D GLSL conformance test.</title>
<link rel="stylesheet" href="../../../resources/js-test-style.css"/>
<link rel="stylesheet" href="../../../resources/glsl-feature-tests.css"/>
<script src="../../../js/js-test-pre.js"></script>
<script src="../../../js/webgl-test-utils.js"> </script>
</head>
<body>
<canvas id="example" width="256" height="256" style="width: 16px; height: 16px;"></canvas>
<div id="description"></div>
<div id="console"></div>
<script id="vshader2dvec3" type="x-shader/x-vertex">
attribute vec4 vPosition;
varying vec4 color;
uniform sampler2D tex;
uniform float divisor;
uniform float lod;
void main() {
    gl_Position = vPosition;
    color = texture2DProjLod(tex, vec3(0.75 * divisor, 0.25 * divisor, divisor), lod);
}
</script>
<script id="vshader2dvec4" type="x-shader/x-vertex">
attribute vec4 vPosition;
varying vec4 color;
uniform sampler2D tex;
uniform float divisor;
uniform float lod;
void main() {
    gl_Position = vPosition;
    color = texture2DProjLod(tex, vec4(0.75 * divisor, 0.25 * divisor, 123.0, divisor), lod);
}
</script>
<script id="fshader2d" type="x-shader/x-fragment">
precision mediump float;
varying vec4 color;
void main() {
    gl_FragData[0] = color;
}
</script>
<script>
"use strict";
description("tests GLSL texture2DProjLod function");

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

shouldBe("canvas.width", "256");
shouldBe("canvas.height", "256");

var colors = [
  {name: 'red', color:[255, 0, 0, 255]},
  {name: 'green', color:[0, 255, 0, 255]},
  {name: 'blue', color:[0, 0, 255, 255]},
  {name: 'yellow', color:[255, 255, 0, 255]},
  {name: 'magenta', color:[255, 0, 255, 255]},
  {name: 'cyan', color:[0, 255, 255, 255]},
  {name: 'pink', color:[255, 128, 128, 255]},
  {name: 'gray', color:[128, 128, 128, 255]},
  {name: 'light green', color:[128, 255, 128, 255]},
];
var contextTypes = ["2d", "webgl"];
var vectorTypes = ["vec3", "vec4"];

var gl = wtu.create3DContext(canvas);
if (gl.getParameter(gl.MAX_VERTEX_TEXTURE_IMAGE_UNITS) > 0) {
  runTest();
} else {
  testPassed("MAX_VERTEX_TEXTURE_IMAGE_UNITS == 0, this is okay.");
}


function runTest() {
  // Avoid creating a WebGL context for every test, as it causes:
  // Too many active WebGL contexts. Oldest context will be lost.
  var canvasWebGL = document.createElement("canvas");
  var ctxWebGL = canvasWebGL.getContext("webgl");

  // Might as well do the same for canvas 2d
  var canvas2d = document.createElement("canvas");
  var ctx2d = canvas2d.getContext("2d");

  shouldBe("colors.length", "9");
  contextTypes.forEach((context) => {
    vectorTypes.forEach((vectorType) => {
      debug("");
      debug(`testing ${context} context with ${vectorType} vertex shader`);
      var program = wtu.setupProgram(
          gl, ['vshader2d' + vectorType, 'fshader2d'], ['vPosition', 'texCoord0'], [0, 1]);
      wtu.setupUnitQuad(gl, 0, 1);

      var tex = gl.createTexture();
      gl.bindTexture(gl.TEXTURE_2D, tex);
      gl.texParameteri(
          gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST_MIPMAP_NEAREST);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);

      // Fill the top right quadrant of each texture level with one of the colors
      for (var ii = 0; ii < colors.length; ++ii) {
        var color = colors[ii];
        var size = Math.pow(2, colors.length - ii - 1);

        if (context === "2d") {
          canvas2d.width = size;
          canvas2d.height = size;
          ctx2d.fillStyle = "rgb(0,0,0)";
          ctx2d.fillRect(0, 0, size, size);
          ctx2d.fillStyle = "rgb(" + color.color[0] + "," + color.color[1] + "," + color.color[2] + ")";
          ctx2d.fillRect(size / 2, 0, size / 2, size / 2);
          gl.texImage2D(gl.TEXTURE_2D, ii, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, canvas2d);
        } else if (context === "webgl") {
          canvasWebGL.width = canvasWebGL.height = size;
          ctxWebGL.clearColor(0, 0, 0, 1);
          ctxWebGL.clear(gl.COLOR_BUFFER_BIT);
          ctxWebGL.enable(gl.SCISSOR_TEST);
          ctxWebGL.scissor(size/2, size/2, size/2, size/2)
          ctxWebGL.clearColor(color.color[0]/255, color.color[1]/255, color.color[2]/255, 1)
          ctxWebGL.clear(gl.COLOR_BUFFER_BIT);
          gl.texImage2D(gl.TEXTURE_2D, ii, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, canvasWebGL);
        }
      }

      var lodLoc = gl.getUniformLocation(program, "lod");
      var divLoc = gl.getUniformLocation(program, "divisor");

      for (var div = 1; div < 4; ++div) {
        for (var ii = 0; ii < colors.length - 1; ++ii) {
          gl.uniform1f(lodLoc, ii);
          gl.uniform1f(divLoc, div);
          var lodColor = colors[ii];
          var size = Math.pow(2, colors.length - ii - 1);
          wtu.clearAndDrawUnitQuad(gl);
          wtu.checkCanvas(
              gl, lodColor.color,
              "sampling with lod = " + ii +
              " divider = " + div +
              " should be " + lodColor.name);
        }
      }
    });
  });
  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be no errors.");
}

var successfullyParsed = true;

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

</body>
</html>
