From 40313e5a6d44480936b3199e6695bf303eb4f4a9 Mon Sep 17 00:00:00 2001
From: Vladimir Vukicevic <vladimir@pobox.com>
Date: Thu, 24 Jul 2014 11:58:43 -0400
Subject: [PATCH] b=965848; implement EXT_shader_texture_lod for WebGL;
 r=jgilbert, r=bz

---
 dom/bindings/Bindings.conf                    |   5 +
 dom/canvas/WebGLContextExtensions.cpp         |   6 +
 dom/canvas/WebGLContextGL.cpp                 |   3 +
 dom/canvas/WebGLExtensionShaderTextureLod.cpp |  21 ++
 dom/canvas/WebGLExtensions.h                  |  10 +
 dom/canvas/WebGLTypes.h                       |   1 +
 dom/canvas/moz.build                          |   1 +
 .../conformance/extensions/00_test_list.txt   |   1 +
 .../extensions/ext-shader-texture-lod.html    | 280 ++++++++++++++++++
 .../mochitest-conformance-files.ini           |   1 +
 dom/webidl/WebGLRenderingContext.webidl       |   5 +
 gfx/gl/GLContext.cpp                          |   1 +
 gfx/gl/GLContext.h                            |   1 +
 13 files changed, 336 insertions(+)
 create mode 100644 dom/canvas/WebGLExtensionShaderTextureLod.cpp
 create mode 100644 dom/canvas/test/webgl-conformance/conformance/extensions/ext-shader-texture-lod.html

diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index 7f88cabb3e56..4946696fbfca 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -1461,6 +1461,11 @@ DOMInterfaces = {
     'headerFile': 'WebGLExtensions.h'
 },
 
+'WebGLExtensionShaderTextureLod': {
+    'nativeType': 'mozilla::WebGLExtensionShaderTextureLod',
+    'headerFile': 'WebGLExtensions.h'
+},
+
 'WebGLExtensionTextureFilterAnisotropic': {
     'nativeType': 'mozilla::WebGLExtensionTextureFilterAnisotropic',
     'headerFile': 'WebGLExtensions.h'
diff --git a/dom/canvas/WebGLContextExtensions.cpp b/dom/canvas/WebGLContextExtensions.cpp
index 1c1986d42704..8d1839cf7a1b 100644
--- a/dom/canvas/WebGLContextExtensions.cpp
+++ b/dom/canvas/WebGLContextExtensions.cpp
@@ -35,6 +35,7 @@ WebGLContext::GetExtensionString(WebGLExtensionID ext)
         WEBGL_EXTENSION_IDENTIFIER(EXT_color_buffer_half_float)
         WEBGL_EXTENSION_IDENTIFIER(EXT_frag_depth)
         WEBGL_EXTENSION_IDENTIFIER(EXT_sRGB)
+        WEBGL_EXTENSION_IDENTIFIER(EXT_shader_texture_lod)
         WEBGL_EXTENSION_IDENTIFIER(EXT_texture_filter_anisotropic)
         WEBGL_EXTENSION_IDENTIFIER(OES_element_index_uint)
         WEBGL_EXTENSION_IDENTIFIER(OES_standard_derivatives)
@@ -155,6 +156,8 @@ bool WebGLContext::IsExtensionSupported(WebGLExtensionID ext) const
             return WebGLExtensionDrawBuffers::IsSupported(this);
         case WebGLExtensionID::EXT_frag_depth:
             return WebGLExtensionFragDepth::IsSupported(this);
+        case WebGLExtensionID::EXT_shader_texture_lod:
+            return gl->IsExtensionSupported(GLContext::EXT_shader_texture_lod);
         default:
             // For warnings-as-errors.
             break;
@@ -334,6 +337,9 @@ WebGLContext::EnableExtension(WebGLExtensionID ext)
         case WebGLExtensionID::EXT_blend_minmax:
             obj = new WebGLExtensionBlendMinMax(this);
             break;
+        case WebGLExtensionID::EXT_shader_texture_lod:
+            obj = new WebGLExtensionShaderTextureLod(this);
+            break;
         default:
             MOZ_ASSERT(false, "should not get there.");
     }
diff --git a/dom/canvas/WebGLContextGL.cpp b/dom/canvas/WebGLContextGL.cpp
index 9afc5a53a8df..788885ed3e33 100644
--- a/dom/canvas/WebGLContextGL.cpp
+++ b/dom/canvas/WebGLContextGL.cpp
@@ -3041,6 +3041,9 @@ WebGLContext::CompileShader(WebGLShader *shader)
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_draw_buffers))
         resources.EXT_draw_buffers = 1;
 
+    if (IsExtensionEnabled(WebGLExtensionID::EXT_shader_texture_lod))
+        resources.EXT_shader_texture_lod = 1;
+
     // Tell ANGLE to allow highp in frag shaders. (unless disabled)
     // If underlying GLES doesn't have highp in frag shaders, it should complain anyways.
     resources.FragmentPrecisionHigh = mDisableFragHighP ? 0 : 1;
diff --git a/dom/canvas/WebGLExtensionShaderTextureLod.cpp b/dom/canvas/WebGLExtensionShaderTextureLod.cpp
new file mode 100644
index 000000000000..2dcef6168a07
--- /dev/null
+++ b/dom/canvas/WebGLExtensionShaderTextureLod.cpp
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebGLContext.h"
+#include "WebGLExtensions.h"
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+
+using namespace mozilla;
+
+WebGLExtensionShaderTextureLod::WebGLExtensionShaderTextureLod(WebGLContext* context)
+    : WebGLExtensionBase(context)
+{
+}
+
+WebGLExtensionShaderTextureLod::~WebGLExtensionShaderTextureLod()
+{
+}
+
+IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionShaderTextureLod)
diff --git a/dom/canvas/WebGLExtensions.h b/dom/canvas/WebGLExtensions.h
index b8e58259df08..af2d81a4d488 100644
--- a/dom/canvas/WebGLExtensions.h
+++ b/dom/canvas/WebGLExtensions.h
@@ -178,6 +178,16 @@ public:
     DECL_WEBGL_EXTENSION_GOOP
 };
 
+class WebGLExtensionShaderTextureLod
+    : public WebGLExtensionBase
+{
+public:
+    WebGLExtensionShaderTextureLod(WebGLContext*);
+    virtual ~WebGLExtensionShaderTextureLod();
+
+    DECL_WEBGL_EXTENSION_GOOP
+};
+
 class WebGLExtensionTextureFilterAnisotropic
     : public WebGLExtensionBase
 {
diff --git a/dom/canvas/WebGLTypes.h b/dom/canvas/WebGLTypes.h
index e4bf6a0ae034..5acc0356a7f0 100644
--- a/dom/canvas/WebGLTypes.h
+++ b/dom/canvas/WebGLTypes.h
@@ -150,6 +150,7 @@ MOZ_BEGIN_ENUM_CLASS(WebGLExtensionID, uint8_t)
     EXT_color_buffer_half_float,
     EXT_frag_depth,
     EXT_sRGB,
+    EXT_shader_texture_lod,
     EXT_texture_filter_anisotropic,
     OES_element_index_uint,
     OES_standard_derivatives,
diff --git a/dom/canvas/moz.build b/dom/canvas/moz.build
index c2528cde2b3a..065fa6d7031c 100644
--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -73,6 +73,7 @@ if CONFIG['MOZ_WEBGL']:
         'WebGLExtensionFragDepth.cpp',
         'WebGLExtensionInstancedArrays.cpp',
         'WebGLExtensionLoseContext.cpp',
+        'WebGLExtensionShaderTextureLod.cpp',
         'WebGLExtensionSRGB.cpp',
         'WebGLExtensionStandardDerivatives.cpp',
         'WebGLExtensionTextureFilterAnisotropic.cpp',
diff --git a/dom/canvas/test/webgl-conformance/conformance/extensions/00_test_list.txt b/dom/canvas/test/webgl-conformance/conformance/extensions/00_test_list.txt
index a1b753dbcd9e..0b2d6ee2888b 100644
--- a/dom/canvas/test/webgl-conformance/conformance/extensions/00_test_list.txt
+++ b/dom/canvas/test/webgl-conformance/conformance/extensions/00_test_list.txt
@@ -8,3 +8,4 @@ webgl-compressed-texture-etc1.html
 webgl-compressed-texture-s3tc.html
 --min-version 1.0.2 webgl-depth-texture.html
 ext-sRGB.html
+ext-shader-texture-lod.html
diff --git a/dom/canvas/test/webgl-conformance/conformance/extensions/ext-shader-texture-lod.html b/dom/canvas/test/webgl-conformance/conformance/extensions/ext-shader-texture-lod.html
new file mode 100644
index 000000000000..e53e35270314
--- /dev/null
+++ b/dom/canvas/test/webgl-conformance/conformance/extensions/ext-shader-texture-lod.html
@@ -0,0 +1,280 @@
+<!--
+Copyright (c) 2011 The Chromium Authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+ -->
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>WebGL EXT_shader_texture_lod Conformance Tests</title>
+<link rel="stylesheet" href="../../resources/js-test-style.css"/>
+<script src="../../resources/desktop-gl-constants.js" type="text/javascript"></script>
+<script src="../../resources/js-test-pre.js"></script>
+<script src="../resources/webgl-test.js"></script>
+<script src="../resources/webgl-test-utils.js"></script>
+</head>
+<body>
+<div id="description"></div>
+<canvas id="canvas" width="256" height="256" style="width: 50px; height: 50px;"> </canvas>
+<div id="console"></div>
+<!-- Shaders for testing standard derivatives -->
+
+<!-- Shader omitting the required #extension pragma -->
+<script id="missingPragmaFragmentShader" type="x-shader/x-fragment">
+precision mediump float;
+varying vec2 texCoord0v;
+void main() {
+    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
+    gl_FragColor = vec4(dx, dy, w, 1.0);
+}
+</script>
+
+<!-- Shader to test macro definition -->
+<script id="macroFragmentShader" type="x-shader/x-fragment">
+precision mediump float;
+void main() {
+#ifdef GL_EXT_shader_texture_lod
+    gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
+#else
+    // Error expected
+    #error no GL_EXT_shader_texture_lod;
+#endif
+}
+</script>
+
+<!-- Shader with required #extension pragma -->
+<script id="testFragmentShader" type="x-shader/x-fragment">
+#extension GL_EXT_shader_texture_lod : enable
+precision mediump float;
+varying vec2 texCoord0v;
+uniform float lod;
+uniform sampler2D tex;
+void main() {
+    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
+    gl_FragColor = color;
+}
+</script>
+
+<!-- Shaders to link with test fragment shaders -->
+<script id="goodVertexShader" type="x-shader/x-vertex">
+attribute vec4 vPosition;
+attribute vec2 texCoord0;
+varying vec2 texCoord0v;
+void main() {
+    texCoord0v = texCoord0;
+    gl_Position = vPosition;
+}
+</script>
+
+<!-- Shaders to test output -->
+<script id="outputVertexShader" type="x-shader/x-vertex">
+attribute vec4 vPosition;
+attribute vec2 texCoord0;
+varying vec2 texCoord0v;
+void main() {
+    texCoord0v = texCoord0;
+    gl_Position = vPosition;
+}
+</script>
+<script id="outputFragmentShader" type="x-shader/x-fragment">
+#extension GL_EXT_shader_texture_lod : require
+precision mediump float;
+varying vec2 texCoord0v;
+uniform float lod;
+uniform sampler2D tex;
+void main() {
+    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
+    gl_FragColor = color;
+}
+</script>
+
+<script>
+description("This test verifies the functionality of the EXT_shader_texture_lod extension, if it is available.");
+
+debug("");
+
+var wtu = WebGLTestUtils;
+var canvas = document.getElementById("canvas");
+
+shouldBe("canvas.width", "256");
+shouldBe("canvas.height", "256");
+
+var gl = wtu.create3DContext(canvas);
+var ext = null;
+
+if (!gl) {
+    testFailed("WebGL context does not exist");
+} else {
+    testPassed("WebGL context exists");
+
+    // Run tests with extension disabled
+    runShaderTests(false);
+
+    // Query the extension and store globally so shouldBe can access it
+    ext = gl.getExtension("EXT_shader_texture_lod");
+    if (!ext) {
+        testPassed("No EXT_shader_texture_lod support -- this is legal");
+
+        runSupportedTest(false);
+    } else {
+        testPassed("Successfully enabled EXT_shader_texture_lod extension");
+
+        runSupportedTest(true);
+
+        runShaderTests(true);
+        runOutputTests();
+        runUniqueObjectTest();
+        runReferenceCycleTest();
+    }
+}
+
+function runSupportedTest(extensionEnabled) {
+    var supported = gl.getSupportedExtensions();
+    if (supported.indexOf("EXT_shader_texture_lod") >= 0) {
+        if (extensionEnabled) {
+            testPassed("EXT_shader_texture_lod listed as supported and getExtension succeeded");
+        } else {
+            testFailed("EXT_shader_texture_lod listed as supported but getExtension failed");
+        }
+    } else {
+        if (extensionEnabled) {
+            testFailed("EXT_shader_texture_lod not listed as supported but getExtension succeeded");
+        } else {
+            testPassed("EXT_shader_texture_lod not listed as supported and getExtension failed -- this is legal");
+        }
+    }
+}
+
+function runShaderTests(extensionEnabled) {
+    debug("");
+    debug("Testing various shader compiles with extension " + (extensionEnabled ? "enabled" : "disabled"));
+
+    // Expect the macro shader to succeed ONLY if enabled
+    var macroFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "macroFragmentShader");
+    if (extensionEnabled) {
+        if (macroFragmentProgram) {
+            // Expected result
+            testPassed("GL_EXT_shader_texture_lod defined in shaders when extension is enabled");
+        } else {
+            testFailed("GL_EXT_shader_texture_lod not defined in shaders when extension is enabled");
+        }
+    } else {
+        if (macroFragmentProgram) {
+            testFailed("GL_EXT_shader_texture_lod defined in shaders when extension is disabled");
+        } else {
+            testPassed("GL_EXT_shader_texture_lod not defined in shaders when extension disabled");
+        }
+    }
+
+    // Always expect the shader missing the #pragma to fail (whether enabled or not)
+    var missingPragmaFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "missingPragmaFragmentShader");
+    if (missingPragmaFragmentProgram) {
+        testFailed("Shader built-ins allowed without #extension pragma");
+    } else {
+        testPassed("Shader built-ins disallowed without #extension pragma");
+    }
+
+    // Try to compile a shader using the built-ins that should only succeed if enabled
+    var testFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "testFragmentShader");
+    if (extensionEnabled) {
+        if (testFragmentProgram) {
+            testPassed("Shader built-ins compiled successfully when extension enabled");
+        } else {
+            testFailed("Shader built-ins failed to compile when extension enabled");
+        }
+    } else {
+        if (testFragmentProgram) {
+            testFailed("Shader built-ins compiled successfully when extension disabled");
+        } else {
+            testPassed("Shader built-ins failed to compile when extension disabled");
+        }
+    }
+}
+
+function runOutputTests() {
+    debug("Testing various draws for valid built-in function behavior");
+
+    canvas.width = 256; canvas.height = 256;
+    gl.viewport(0, 0, canvas.width, canvas.height);
+
+    var program = wtu.setupProgram(gl, ["outputVertexShader", "outputFragmentShader"], ['vPosition', 'texCoord0'], [0, 1]);
+    var quadParameters = wtu.setupUnitQuad(gl, 0, 1);
+
+    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]},
+    ];
+
+    if (colors.length != 9) {
+	testFailed("9 colors are needed (9 mips for 256x256 texture), only have " + colors.length);
+    } else {
+	testPassed("9 colors found (9 mips for 256x256 texture)");
+    }
+
+    var tex = gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, tex);
+    gl.texParameteri(
+	gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST_MIPMAP_LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);
+
+    for (var ii = 0; ii < colors.length; ++ii) {
+	var color = colors[ii];
+	var size = Math.pow(2, colors.length - ii - 1);
+	wtu.fillTexture(gl, tex, size, size, color.color, ii);
+    }
+
+    var loc = gl.getUniformLocation(program, "lod");
+
+    for (var ii = 0; ii < colors.length; ++ii) {
+	gl.uniform1f(loc, ii);
+	var color = colors[ii];
+	wtu.drawQuad(gl);
+	wtu.checkCanvas(
+	    gl, color.color,
+	    "256x256 texture drawn to 256x256 dest with lod = " + ii +
+		" should be " + color.name);
+    }
+
+    glErrorShouldBe(gl, gl.NO_ERROR, "Should be no errors.");
+}
+
+function runUniqueObjectTest()
+{
+    debug("Testing that getExtension() returns the same object each time");
+    gl.getExtension("EXT_shader_texture_lod").myProperty = 2;
+    gc();
+    shouldBe('gl.getExtension("EXT_shader_texture_lod").myProperty', '2');
+}
+
+function runReferenceCycleTest()
+{
+    // create some reference cycles. The goal is to see if they cause leaks. The point is that
+    // some browser test runners have instrumentation to detect leaked refcounted objects.
+
+    debug("Testing reference cycles between context and extension objects");
+    var ext = gl.getExtension("EXT_shader_texture_lod");
+
+    // create cycle between extension and context, since the context has to hold a reference to the extension
+    ext.context = gl;
+
+    // create a self-cycle on the extension object
+    ext.ext = ext;
+}
+
+debug("");
+successfullyParsed = true;
+</script>
+<script>finishTest();</script>
+
+</body>
+</html>
diff --git a/dom/canvas/test/webgl-conformance/mochitest-conformance-files.ini b/dom/canvas/test/webgl-conformance/mochitest-conformance-files.ini
index cc1c6d7d1603..060a41b24d40 100644
--- a/dom/canvas/test/webgl-conformance/mochitest-conformance-files.ini
+++ b/dom/canvas/test/webgl-conformance/mochitest-conformance-files.ini
@@ -39,6 +39,7 @@ support-files =
   conformance/extensions/00_test_list.txt
   conformance/extensions/ext-sRGB.html
   conformance/extensions/ext-texture-filter-anisotropic.html
+  conformance/extensions/ext-shader-texture-lod.html
   conformance/extensions/oes-standard-derivatives.html
   conformance/extensions/oes-texture-float.html
   conformance/extensions/oes-vertex-array-object.html
diff --git a/dom/webidl/WebGLRenderingContext.webidl b/dom/webidl/WebGLRenderingContext.webidl
index e826931528af..b5806ae45026 100644
--- a/dom/webidl/WebGLRenderingContext.webidl
+++ b/dom/webidl/WebGLRenderingContext.webidl
@@ -916,6 +916,11 @@ interface WebGLExtensionTextureFloatLinear
 {
 };
 
+[NoInterfaceObject]
+interface WebGLExtensionShaderTextureLod
+{
+};
+
 [NoInterfaceObject]
 interface WebGLExtensionTextureHalfFloat
 {
diff --git a/gfx/gl/GLContext.cpp b/gfx/gl/GLContext.cpp
index b7e4e8d888c6..936ec42f1731 100644
--- a/gfx/gl/GLContext.cpp
+++ b/gfx/gl/GLContext.cpp
@@ -142,6 +142,7 @@ static const char *sExtensionNames[] = {
     "GL_EXT_frag_depth",
     "GL_OES_compressed_ETC1_RGB8_texture",
     "GL_EXT_draw_range_elements",
+    "GL_EXT_shader_texture_lod",
     nullptr
 };
 
diff --git a/gfx/gl/GLContext.h b/gfx/gl/GLContext.h
index 144b73716827..132e557047d7 100644
--- a/gfx/gl/GLContext.h
+++ b/gfx/gl/GLContext.h
@@ -412,6 +412,7 @@ public:
         EXT_frag_depth,
         OES_compressed_ETC1_RGB8_texture,
         EXT_draw_range_elements,
+        EXT_shader_texture_lod,
         Extensions_Max,
         Extensions_End
     };