http://codereview.appspot.com/4373057/


git-svn-id: http://skia.googlecode.com/svn/trunk@1135 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/unix/GrGLDefaultInterface_unix.cpp b/gpu/src/unix/GrGLDefaultInterface_unix.cpp
new file mode 100644
index 0000000..6d6873d
--- /dev/null
+++ b/gpu/src/unix/GrGLDefaultInterface_unix.cpp
@@ -0,0 +1,170 @@
+/*
+    Copyright 2011 Google Inc.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+ */
+
+#include "GrGLInterface.h"
+
+#include <GL/glx.h>
+#include <GL/gl.h>
+#include <GL/glext.h>
+#include <GL/glu.h>
+
+#define GR_GL_GET_PROC(F) gDefaultInterface.f ## F = (GrGLInterface::GrGL ## F ## Proc) \
+        glXGetProcAddress(reinterpret_cast<const GLubyte*>("gl" #F));
+#define GR_GL_GET_PROC_SUFFIX(F, S) gDefaultInterface.f ## F = (GrGLInterface::GrGL ## F ## Proc) \
+        glXGetProcAddress(reinterpret_cast<const GLubyte*>("gl" #F #S));
+
+void GrGLSetDefaultGLInterface() {
+    static GrGLInterface gDefaultInterface;
+    static bool gDefaultInterfaceInit;
+    if (!gDefaultInterfaceInit && NULL != glXGetCurrentContext()) {
+        int major, minor;
+        const char* versionString = (const char*) glGetString(GL_VERSION);
+        const char* extString = (const char*) glGetString(GL_EXTENSIONS);
+        gl_version_from_string(&major, &minor, versionString);
+
+        if (major == 1 && minor < 5) {
+            // We must have array and element_array buffer objects.
+            return;
+        }
+
+        gDefaultInterface.fActiveTexture = glActiveTexture;
+        GR_GL_GET_PROC(AttachShader);
+        GR_GL_GET_PROC(BindAttribLocation);
+        GR_GL_GET_PROC(BindBuffer);
+        gDefaultInterface.fBindTexture = glBindTexture;
+        gDefaultInterface.fBlendColor = glBlendColor;
+        gDefaultInterface.fBlendFunc = glBlendFunc;
+        GR_GL_GET_PROC(BufferData);
+        GR_GL_GET_PROC(BufferSubData);
+        gDefaultInterface.fClear = glClear;
+        gDefaultInterface.fClearColor = glClearColor;
+        gDefaultInterface.fClearStencil = glClearStencil;
+        gDefaultInterface.fClientActiveTexture = glClientActiveTexture;
+        gDefaultInterface.fColorMask = glColorMask;
+        gDefaultInterface.fColorPointer = glColorPointer;
+        gDefaultInterface.fColor4ub = glColor4ub;
+        GR_GL_GET_PROC(CompileShader);
+        gDefaultInterface.fCompressedTexImage2D = glCompressedTexImage2D;
+        GR_GL_GET_PROC(CreateProgram);
+        GR_GL_GET_PROC(CreateShader);
+        gDefaultInterface.fCullFace = glCullFace;
+        GR_GL_GET_PROC(DeleteBuffers);
+        GR_GL_GET_PROC(DeleteProgram);
+        GR_GL_GET_PROC(DeleteShader);
+        gDefaultInterface.fDeleteTextures = glDeleteTextures;
+        gDefaultInterface.fDepthMask = glDepthMask;
+        gDefaultInterface.fDisable = glDisable;
+        gDefaultInterface.fDisableClientState = glDisableClientState;
+        GR_GL_GET_PROC(DisableVertexAttribArray);
+        gDefaultInterface.fDrawArrays = glDrawArrays;
+        gDefaultInterface.fDrawElements = glDrawElements;
+        gDefaultInterface.fEnable = glEnable;
+        gDefaultInterface.fEnableClientState = glEnableClientState;
+        GR_GL_GET_PROC(EnableVertexAttribArray);
+        gDefaultInterface.fFrontFace = glFrontFace;
+        GR_GL_GET_PROC(GenBuffers);
+        GR_GL_GET_PROC(GetBufferParameteriv);
+        gDefaultInterface.fGetError = glGetError;
+        gDefaultInterface.fGetIntegerv = glGetIntegerv;
+        GR_GL_GET_PROC(GetProgramInfoLog);
+        GR_GL_GET_PROC(GetProgramiv);
+        GR_GL_GET_PROC(GetShaderInfoLog);
+        GR_GL_GET_PROC(GetShaderiv);
+        gDefaultInterface.fGetString = glGetString;
+        gDefaultInterface.fGenTextures = glGenTextures;
+        GR_GL_GET_PROC(GetUniformLocation);
+        gDefaultInterface.fLineWidth = glLineWidth;
+        GR_GL_GET_PROC(LinkProgram);
+        gDefaultInterface.fLoadMatrixf = glLoadMatrixf;
+        GR_GL_GET_PROC(MapBuffer);
+        gDefaultInterface.fMatrixMode = glMatrixMode;
+        gDefaultInterface.fPointSize = glPointSize;
+        gDefaultInterface.fPixelStorei = glPixelStorei;
+        gDefaultInterface.fReadPixels = glReadPixels;
+        gDefaultInterface.fScissor = glScissor;
+        gDefaultInterface.fShadeModel = glShadeModel;
+        GR_GL_GET_PROC(ShaderSource);
+        gDefaultInterface.fStencilFunc = glStencilFunc;
+        GR_GL_GET_PROC(StencilFuncSeparate);
+        gDefaultInterface.fStencilMask = glStencilMask;
+        GR_GL_GET_PROC(StencilMaskSeparate);
+        gDefaultInterface.fStencilOp = glStencilOp;
+        GR_GL_GET_PROC(StencilOpSeparate);
+        gDefaultInterface.fTexCoordPointer = glTexCoordPointer;
+        gDefaultInterface.fTexEnvi = glTexEnvi;
+        // mac uses GLenum for internalFormat param (non-standard)
+        // amounts to int vs. uint.
+        gDefaultInterface.fTexImage2D = 
+                (GrGLInterface::GrGLTexImage2DProc)glTexImage2D;
+        gDefaultInterface.fTexParameteri = glTexParameteri;
+        gDefaultInterface.fTexSubImage2D = glTexSubImage2D;
+        GR_GL_GET_PROC(Uniform1fv);
+        GR_GL_GET_PROC(Uniform1i);
+        GR_GL_GET_PROC(Uniform4fv);
+        GR_GL_GET_PROC(UniformMatrix3fv);
+        GR_GL_GET_PROC(UnmapBuffer);
+        GR_GL_GET_PROC(UseProgram);
+        GR_GL_GET_PROC(VertexAttrib4fv);
+        GR_GL_GET_PROC(VertexAttribPointer);
+        gDefaultInterface.fVertexPointer = glVertexPointer;
+        gDefaultInterface.fViewport = glViewport;
+
+        // First look for GL3.0 FBO or GL_ARB_framebuffer_object (same since
+        // GL_ARB_framebuffer_object doesn't use ARB suffix.)
+        if (major >= 3 || has_gl_extension("GL_ARB_framebuffer_object")) {
+            GR_GL_GET_PROC(GenFramebuffers);
+            GR_GL_GET_PROC(BindFramebuffer);
+            GR_GL_GET_PROC(FramebufferTexture2D);
+            GR_GL_GET_PROC(CheckFramebufferStatus);
+            GR_GL_GET_PROC(DeleteFramebuffers);
+            GR_GL_GET_PROC(RenderbufferStorage);
+            GR_GL_GET_PROC(GenRenderbuffers);
+            GR_GL_GET_PROC(DeleteRenderbuffers);
+            GR_GL_GET_PROC(FramebufferRenderbuffer);
+            GR_GL_GET_PROC(BindRenderbuffer);
+            GR_GL_GET_PROC(RenderbufferStorageMultisample);
+            GR_GL_GET_PROC(BlitFramebuffer);
+        } else if (has_gl_extension_from_string("GL_EXT_framebuffer_object",
+                                                extString)) {
+            GR_GL_GET_PROC_SUFFIX(GenFramebuffers, EXT);
+            GR_GL_GET_PROC_SUFFIX(BindFramebuffer, EXT);
+            GR_GL_GET_PROC_SUFFIX(FramebufferTexture2D, EXT);
+            GR_GL_GET_PROC_SUFFIX(CheckFramebufferStatus, EXT);
+            GR_GL_GET_PROC_SUFFIX(DeleteFramebuffers, EXT);
+            GR_GL_GET_PROC_SUFFIX(RenderbufferStorage, EXT);
+            GR_GL_GET_PROC_SUFFIX(GenRenderbuffers, EXT);
+            GR_GL_GET_PROC_SUFFIX(DeleteRenderbuffers, EXT);
+            GR_GL_GET_PROC_SUFFIX(FramebufferRenderbuffer, EXT);
+            GR_GL_GET_PROC_SUFFIX(BindRenderbuffer, EXT);
+            if (has_gl_extension_from_string("GL_EXT_framebuffer_multisample",
+                                             extString)) {
+                GR_GL_GET_PROC_SUFFIX(RenderbufferStorageMultisample, EXT);
+            }
+            if (has_gl_extension_from_string("GL_EXT_framebuffer_blit",
+                                             extString)) {
+                GR_GL_GET_PROC_SUFFIX(BlitFramebuffer, EXT);
+            }
+        } else {
+            // we must have FBOs
+            return;
+        }
+        gDefaultInterface.fBindingsExported = kDesktop_GrGLBinding;
+
+        gDefaultInterfaceInit = true;
+    }
+    if (gDefaultInterfaceInit)
+        GrGLSetGLInterface(&gDefaultInterface);
+}