1 files changed, 69 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/js/tests/webgl-draw-buffers-utils.js b/dom/canvas/test/webgl-conf/checkout/js/tests/webgl-draw-buffers-utils.js
new file mode 100644
index 0000000000..ebd0c7ba68
--- /dev/null
+++ b/dom/canvas/test/webgl-conf/checkout/js/tests/webgl-draw-buffers-utils.js
@@ -0,0 +1,69 @@
+/*
+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.
+*/
+
+// This file contains utilities shared between tests for the WEBGL_draw_buffers extension and multiple draw buffers functionality in WebGL 2.0.
+
+'use strict';
+
+var WebGLDrawBuffersUtils = function(gl, ext) {
+
+  var getMaxUsableColorAttachments = function() {
+    var maxDrawingBuffers;
+    var maxColorAttachments;
+    if (ext) {
+      // EXT_draw_buffers
+      maxDrawingBuffers = gl.getParameter(ext.MAX_DRAW_BUFFERS_WEBGL);
+      maxColorAttachments = gl.getParameter(ext.MAX_COLOR_ATTACHMENTS_WEBGL);
+    } else {
+      // WebGL 2.0
+      maxDrawingBuffers = gl.getParameter(gl.MAX_DRAW_BUFFERS);
+      maxColorAttachments = gl.getParameter(gl.MAX_COLOR_ATTACHMENTS);
+    }
+    var maxUniformVectors = gl.getParameter(gl.MAX_FRAGMENT_UNIFORM_VECTORS);
+    return Math.min(maxDrawingBuffers, maxColorAttachments, maxUniformVectors);
+  };
+
+  var makeColorAttachmentArray = function(size) {
+    var array = []
+    for (var ii = 0; ii < size; ++ii) {
+      array.push(gl.COLOR_ATTACHMENT0 + ii);
+    }
+    return array;
+  }
+
+  var checkProgram = wtu.setupTexturedQuad(gl);
+
+  var checkAttachmentsForColorFn = function(attachments, colorFn) {
+    gl.bindFramebuffer(gl.FRAMEBUFFER, null);
+    gl.useProgram(checkProgram);
+    attachments.forEach(function(attachment, index) {
+      gl.bindTexture(gl.TEXTURE_2D, attachment.texture);
+      wtu.clearAndDrawUnitQuad(gl);
+      var expectedColor = colorFn(attachment, index);
+      var tolerance = 0;
+      expectedColor.forEach(function(v) {
+        if (v != 0 && v != 255) {
+          tolerance = 8;
+        }
+      });
+      wtu.checkCanvas(gl, expectedColor, "attachment " + index + " should be " + expectedColor.toString(), tolerance);
+    });
+    debug("");
+  };
+
+  var checkAttachmentsForColor = function(attachments, color) {
+    checkAttachmentsForColorFn(attachments, function(attachment, index) {
+      return color || attachment.color;
+    });
+  };
+
+  return {
+    getMaxUsableColorAttachments: getMaxUsableColorAttachments,
+    makeColorAttachmentArray: makeColorAttachmentArray,
+    checkAttachmentsForColorFn: checkAttachmentsForColorFn,
+    checkAttachmentsForColor: checkAttachmentsForColor
+  };
+};