Make it possible to use OSMesa on Android

ui/gl/gl_implementation_android.cc

 // Copyright (c) 2012 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.
 
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
@@ skipping 27 matching lines @@
 }
 
 base::NativeLibrary LoadLibrary(const char* filename) {
   return LoadLibrary(base::FilePath(filename));
 }
 
 }  // namespace
 
 void GetAllowedGLImplementations(std::vector<GLImplementation>* impls) {
   impls->push_back(kGLImplementationEGLGLES2);
+  impls->push_back(kGLImplementationOSMesaGL);
+}
+
+bool InitializeGLBindingsOSMesaGL() {
+  base::FilePath module_path;
+  if (!PathService::Get(base::DIR_MODULE, &module_path)) {
+    LOG(ERROR) << "PathService::Get failed.";
+    return false;
+  }
+
+  base::NativeLibrary library = LoadLibrary(module_path.Append("libosmesa.so"));
+  if (!library)
+    return false;
+
+  GLGetProcAddressProc get_proc_address =
+      reinterpret_cast<GLGetProcAddressProc>(
+          base::GetFunctionPointerFromNativeLibrary(library,
+                                                    "OSMesaGetProcAddress"));
+  if (!get_proc_address) {
+    LOG(ERROR) << "OSMesaGetProcAddress not found.";
+    base::UnloadNativeLibrary(library);
+    return false;
+  }
+
+  SetGLGetProcAddressProc(get_proc_address);
+  AddGLNativeLibrary(library);
+  SetGLImplementation(kGLImplementationOSMesaGL);
+
+  InitializeGLBindingsGL();
+  InitializeGLBindingsOSMESA();
+  return true;
 }

[piman, 2013/09/19 19:48:37]

nit: since this looks like a copy&paste from gl_implementation_linux.cc, could
we have instead android also inherit gl_implementation_linux.cc, to avoid
duplication? It'll also give you the LoadLibrary for free.

[Peter Beverloo, 2013/10/03 19:46:42]

Done, except for the problem I pointed out in gl.gyp..

 
 bool InitializeGLBindings(GLImplementation implementation) {
   // Prevent reinitialization with a different implementation. Once the gpu
   // unit tests have initialized with kGLImplementationMock, we don't want to
   // later switch to another GL implementation.
   if (GetGLImplementation() != kGLImplementationNone)
     return true;
 
   switch (implementation) {
     case kGLImplementationEGLGLES2: {
@@ skipping 24 matching lines @@
 
       InitializeGLBindingsGL();
       InitializeGLBindingsEGL();
 
       // These two functions take single precision float rather than double
       // precision float parameters in GLES.
       ::gfx::g_driver_gl.fn.glClearDepthFn = MarshalClearDepthToClearDepthf;
       ::gfx::g_driver_gl.fn.glDepthRangeFn = MarshalDepthRangeToDepthRangef;
       break;
     }
+    case kGLImplementationOSMesaGL:
+      return InitializeGLBindingsOSMesaGL();
     case kGLImplementationMockGL: {
       SetGLGetProcAddressProc(GetMockGLProcAddress);
       SetGLImplementation(kGLImplementationMockGL);
       InitializeGLBindingsGL();
       break;
     }
     default:
       NOTIMPLEMENTED() << "InitializeGLBindings on Android";
       return false;
   }
 
   return true;
 }
 
 bool InitializeGLExtensionBindings(GLImplementation implementation,
                                    GLContext* context) {
   switch (implementation) {
     case kGLImplementationEGLGLES2:
       InitializeGLExtensionBindingsGL(context);
       InitializeGLExtensionBindingsEGL(context);
       break;
+    case kGLImplementationOSMesaGL:
+      InitializeGLExtensionBindingsGL(context);
+      InitializeGLExtensionBindingsOSMESA(context);
+      break;
     case kGLImplementationMockGL:
       InitializeGLExtensionBindingsGL(context);
       break;
     default:
       return false;
   }
 
   return true;
 }
 
@@ skipping 12 matching lines @@
   switch (GetGLImplementation()) {
     case kGLImplementationEGLGLES2:
       return GetGLWindowSystemBindingInfoEGL(info);
     default:
       return false;
   }
   return false;
 }
 
 }  // namespace gfx