1 files changed, 321 insertions, 0 deletions
diff --git a/testing/web-platform/tests/webcodecs/webgl-test-utils.js b/testing/web-platform/tests/webcodecs/webgl-test-utils.js
new file mode 100644
index 0000000000..f623a6c986
--- /dev/null
+++ b/testing/web-platform/tests/webcodecs/webgl-test-utils.js
@@ -0,0 +1,321 @@
+// Copyright 2011 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+WebGLTestUtils = (function() {
+  /**
+   * Converts a WebGL enum to a string
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {number} value The enum value.
+   * @return {string} The enum as a string.
+   */
+  var glEnumToString = function(gl, value) {
+    for (var p in gl) {
+      if (gl[p] == value) {
+        return p;
+      }
+    }
+    return '0x' + value.toString(16);
+  };
+
+  var lastError = '';
+
+  /**
+   * Returns the last compiler/linker error.
+   * @return {string} The last compiler/linker error.
+   */
+  var getLastError = function() {
+    return lastError;
+  };
+
+  // clang-format off
+
+  /**
+   * A vertex shader for a single texture.
+   * @type {string}
+   */
+  var simpleTextureVertexShader = [
+    'attribute vec4 vPosition;',  //
+    'attribute vec2 texCoord0;',
+    'varying vec2 texCoord;',
+    'void main() {',
+    '    gl_Position = vPosition;',
+    '    texCoord = texCoord0;',
+    '}'
+  ].join('\n');
+
+  /**
+   * A fragment shader for a single texture.
+   * @type {string}
+   */
+  var simpleTextureFragmentShader = [
+    'precision mediump float;',
+    'uniform sampler2D tex;',
+    'varying vec2 texCoord;',
+    'void main() {',
+    '    gl_FragData[0] = texture2D(tex, texCoord);',
+    '}'
+  ].join('\n');
+
+  // clang-format on
+
+  /**
+   * Creates a simple texture vertex shader.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @return {!WebGLShader}
+   */
+  var setupSimpleTextureVertexShader = function(gl) {
+    return loadShader(gl, simpleTextureVertexShader, gl.VERTEX_SHADER);
+  };
+
+  /**
+   * Creates a simple texture fragment shader.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @return {!WebGLShader}
+   */
+  var setupSimpleTextureFragmentShader = function(gl) {
+    return loadShader(gl, simpleTextureFragmentShader, gl.FRAGMENT_SHADER);
+  };
+
+  /**
+   * Creates a program, attaches shaders, binds attrib locations, links the
+   * program and calls useProgram.
+   * @param {!Array.<!WebGLShader>} shaders The shaders to attach .
+   * @param {!Array.<string>} opt_attribs The attribs names.
+   * @param {!Array.<number>} opt_locations The locations for the attribs.
+   */
+  var setupProgram = function(gl, shaders, opt_attribs, opt_locations) {
+    var realShaders = [];
+    var program = gl.createProgram();
+    for (var ii = 0; ii < shaders.length; ++ii) {
+      var shader = shaders[ii];
+      if (typeof shader == 'string') {
+        var element = document.getElementById(shader);
+        if (element) {
+          shader = loadShaderFromScript(gl, shader);
+        } else {
+          shader = loadShader(
+              gl, shader, ii ? gl.FRAGMENT_SHADER : gl.VERTEX_SHADER);
+        }
+      }
+      gl.attachShader(program, shader);
+    }
+    if (opt_attribs) {
+      for (var ii = 0; ii < opt_attribs.length; ++ii) {
+        gl.bindAttribLocation(
+            program, opt_locations ? opt_locations[ii] : ii, opt_attribs[ii]);
+      }
+    }
+    gl.linkProgram(program);
+
+    // Check the link status
+    var linked = gl.getProgramParameter(program, gl.LINK_STATUS);
+    if (!linked) {
+      gl.deleteProgram(program);
+      return null;
+    }
+
+    gl.useProgram(program);
+    return program;
+  };
+
+  /**
+   * Creates a simple texture program.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {number} opt_positionLocation The attrib location for position.
+   * @param {number} opt_texcoordLocation The attrib location for texture
+   *     coords.
+   * @return {WebGLProgram}
+   */
+  var setupSimpleTextureProgram = function(
+      gl, opt_positionLocation, opt_texcoordLocation) {
+    opt_positionLocation = opt_positionLocation || 0;
+    opt_texcoordLocation = opt_texcoordLocation || 1;
+    var vs = setupSimpleTextureVertexShader(gl);
+    var fs = setupSimpleTextureFragmentShader(gl);
+    if (!vs || !fs) {
+      return null;
+    }
+    var program = setupProgram(
+        gl, [vs, fs], ['vPosition', 'texCoord0'],
+        [opt_positionLocation, opt_texcoordLocation]);
+    if (!program) {
+      gl.deleteShader(fs);
+      gl.deleteShader(vs);
+    }
+    gl.useProgram(program);
+    return program;
+  };
+
+  /**
+   * Creates buffers for a textured unit quad and attaches them to vertex
+   * attribs.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {number} opt_positionLocation The attrib location for position.
+   * @param {number} opt_texcoordLocation The attrib location for texture
+   *     coords.
+   * @return {!Array.<WebGLBuffer>} The buffer objects that were
+   *      created.
+   */
+  var setupUnitQuad = function(gl, opt_positionLocation, opt_texcoordLocation) {
+    opt_positionLocation = opt_positionLocation || 0;
+    opt_texcoordLocation = opt_texcoordLocation || 1;
+    var objects = [];
+
+    var vertexObject = gl.createBuffer();
+    gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
+    gl.bufferData(
+        gl.ARRAY_BUFFER, new Float32Array([
+          1.0, 1.0, 0.0, -1.0, 1.0, 0.0, -1.0, -1.0, 0.0, 1.0, 1.0, 0.0, -1.0,
+          -1.0, 0.0, 1.0, -1.0, 0.0
+        ]),
+        gl.STATIC_DRAW);
+    gl.enableVertexAttribArray(opt_positionLocation);
+    gl.vertexAttribPointer(opt_positionLocation, 3, gl.FLOAT, false, 0, 0);
+    objects.push(vertexObject);
+
+    var vertexObject = gl.createBuffer();
+    gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
+    gl.bufferData(
+        gl.ARRAY_BUFFER,
+        new Float32Array(
+            [1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, 0.0]),
+        gl.STATIC_DRAW);
+    gl.enableVertexAttribArray(opt_texcoordLocation);
+    gl.vertexAttribPointer(opt_texcoordLocation, 2, gl.FLOAT, false, 0, 0);
+    objects.push(vertexObject);
+    return objects;
+  };
+
+  /**
+   * Creates a program and buffers for rendering a textured quad.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {number} opt_positionLocation The attrib location for position.
+   * @param {number} opt_texcoordLocation The attrib location for texture
+   *     coords.
+   * @return {!WebGLProgram}
+   */
+  var setupTexturedQuad = function(
+      gl, opt_positionLocation, opt_texcoordLocation) {
+    var program = setupSimpleTextureProgram(
+        gl, opt_positionLocation, opt_texcoordLocation);
+    setupUnitQuad(gl, opt_positionLocation, opt_texcoordLocation);
+    return program;
+  };
+
+  /**
+   * Draws a previously setup quad.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {!Array.<number>} opt_color The color to fill clear with before
+   *        drawing. A 4 element array where each element is in the range 0 to
+   *        255. Default [255, 255, 255, 255]
+   */
+  var drawQuad = function(gl, opt_color) {
+    opt_color = opt_color || [255, 255, 255, 255];
+    gl.clearColor(
+        opt_color[0] / 255, opt_color[1] / 255, opt_color[2] / 255,
+        opt_color[3] / 255);
+    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
+    gl.drawArrays(gl.TRIANGLES, 0, 6);
+  };
+
+  /**
+   * Links a WebGL program, throws if there are errors.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {!WebGLProgram} program The WebGLProgram to link.
+   * @param {function(string): void) opt_errorCallback callback for errors.
+   */
+  var linkProgram = function(gl, program, opt_errorCallback) {
+    // Link the program
+    gl.linkProgram(program);
+
+    // Check the link status
+    var linked = gl.getProgramParameter(program, gl.LINK_STATUS);
+    if (!linked) {
+      // something went wrong with the link
+      gl.deleteProgram(program);
+      return false;
+    }
+
+    return true;
+  };
+
+  /**
+   * Loads a shader.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {string} shaderSource The shader source.
+   * @param {number} shaderType The type of shader.
+   * @param {function(string): void) opt_errorCallback callback for errors.
+   * @return {!WebGLShader} The created shader.
+   */
+  var loadShader =
+      function(gl, shaderSource, shaderType, opt_errorCallback) {
+    var errFn = opt_errorCallback || (_ => {});
+    // Create the shader object
+    var shader = gl.createShader(shaderType);
+    if (shader == null) {
+      errFn('*** Error: unable to create shader \'' + shaderSource + '\'');
+      return null;
+    }
+
+    // Load the shader source
+    gl.shaderSource(shader, shaderSource);
+    var err = gl.getError();
+    if (err != gl.NO_ERROR) {
+      errFn(
+          '*** Error loading shader \'' + shader +
+          '\':' + glEnumToString(gl, err));
+      return null;
+    }
+
+    // Compile the shader
+    gl.compileShader(shader);
+
+    // Check the compile status
+    var compiled = gl.getShaderParameter(shader, gl.COMPILE_STATUS);
+    if (!compiled) {
+      // Something went wrong during compilation; get the error
+      lastError = gl.getShaderInfoLog(shader);
+      errFn('*** Error compiling shader \'' + shader + '\':' + lastError);
+      gl.deleteShader(shader);
+      return null;
+    }
+
+    return shader;
+  }
+
+  /**
+   * Loads shaders from source, creates a program, attaches the shaders and
+   * links.
+   * @param {!WebGLContext} gl The WebGLContext to use.
+   * @param {string} vertexShader The vertex shader.
+   * @param {string} fragmentShader The fragment shader.
+   * @param {function(string): void) opt_errorCallback callback for errors.
+   * @return {!WebGLProgram} The created program.
+   */
+  var loadProgram = function(
+      gl, vertexShader, fragmentShader, opt_errorCallback) {
+    var program = gl.createProgram();
+    gl.attachShader(
+        program,
+        loadShader(gl, vertexShader, gl.VERTEX_SHADER, opt_errorCallback));
+    gl.attachShader(
+        program,
+        loadShader(gl, fragmentShader, gl.FRAGMENT_SHADER, opt_errorCallback));
+    return linkProgram(gl, program, opt_errorCallback) ? program : null;
+  };
+
+  return {
+    drawQuad: drawQuad,
+    getLastError: getLastError,
+    glEnumToString: glEnumToString,
+    loadProgram: loadProgram,
+    loadShader: loadShader,
+    setupProgram: setupProgram,
+    setupSimpleTextureFragmentShader: setupSimpleTextureFragmentShader,
+    setupSimpleTextureProgram: setupSimpleTextureProgram,
+    setupSimpleTextureVertexShader: setupSimpleTextureVertexShader,
+    setupTexturedQuad: setupTexturedQuad,
+    setupUnitQuad: setupUnitQuad,
+  };
+}());