Implement ES2 backend for Angle translator.
With this CL, we have the option to select a code output backend: GLSL, GLSL ES, or HLSL.
Note that we always emit the highest supported float precision for fragment shader due to anglebug 168. Although this is a temporary solution, it's not against GLSL ES spec, because it's ok for implementation to upgrade precision.
Tested with WebGL conformance test suite, GLES2 conformance test suite (only failed 2/1198), and a few webgl demos, including worlds of webgl, aquarium, etc.
anglebug=81
test=translator emitting correct GLSL ES code when ES2 backend is selected.
Review URL: http://codereview.appspot.com/4550129
git-svn-id: https://angleproject.googlecode.com/svn/trunk@687 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/compiler/TranslatorESSL.cpp b/src/compiler/TranslatorESSL.cpp
new file mode 100644
index 0000000..62b645f
--- /dev/null
+++ b/src/compiler/TranslatorESSL.cpp
@@ -0,0 +1,46 @@
+//
+// Copyright (c) 2002-2011 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "compiler/TranslatorESSL.h"
+
+#include "compiler/OutputESSL.h"
+
+TranslatorESSL::TranslatorESSL(ShShaderType type, ShShaderSpec spec)
+ : TCompiler(type, spec) {
+}
+
+void TranslatorESSL::translate(TIntermNode* root) {
+ TInfoSinkBase& sink = getInfoSink().obj;
+
+ // Write built-in extension behaviors.
+ writeExtensionBehavior();
+
+ // FIXME(zmo): no need to emit default precision if all variables emit
+ // their own precision.
+ // http://code.google.com/p/angleproject/issues/detail?id=168
+ if (this->getShaderType() == SH_FRAGMENT_SHADER) {
+ // Write default float precision.
+ sink << "#if defined(GL_FRAGMENT_PRECISION_HIGH)\n"
+ << "precision highp float;\n"
+ << "#else\n"
+ << "precision mediump float;\n"
+ << "#endif\n";
+ }
+
+ // Write translated shader.
+ TOutputESSL outputESSL(sink);
+ root->traverse(&outputESSL);
+}
+
+void TranslatorESSL::writeExtensionBehavior() {
+ TInfoSinkBase& sink = getInfoSink().obj;
+ const TExtensionBehavior& extensionBehavior = getExtensionBehavior();
+ for (TExtensionBehavior::const_iterator iter = extensionBehavior.begin();
+ iter != extensionBehavior.end(); ++iter) {
+ sink << "#extension " << iter->first << " : "
+ << getBehaviorString(iter->second) << "\n";
+ }
+}