Added OSMesa based GLContext.

- Renders 3D using Mesa offscreen software renderer.
- Will be used to run 3D tests on bots that do not support native OpenGL.
- Extended glew library to use the osmesa shared library instead of the regular OpenGL one if it is in the search path.
- Only works on Windows with this changelist, though other platforms will continue to use native OpenGL.
- Added a stub GLContext implementation for use in unit tests.

Review URL: http://codereview.chromium.org/1629029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@45093 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 54 insertions, 0 deletions

diff --git a/third_party/glew/include/GL/glew.h b/third_party/glew/include/GL/glew.h
index 90438a7..34183a9 100644
--- a/third_party/glew/include/GL/glew.h
+++ b/third_party/glew/include/GL/glew.h
@@ -12863,6 +12863,8 @@ GLEW_VAR_EXPORT GLboolean __GLEW_WIN_swap_hint;
 }; /* GLEWContextStruct */
 #endif /* GLEW_MX */
 
+typedef void* (GLAPIENTRY * PFNOSMESAGETPROCADDRESSPROC) (const GLubyte* name);
+
 /* ------------------------------------------------------------------------- */
 
 /* error codes */
@@ -12898,6 +12900,7 @@ GLEWAPI GLboolean glewContextIsSupported (GLEWContext* ctx, const char* name);
 
 #else /* GLEW_MX */
 
+void osmewContextInit ();
 GLEWAPI GLenum glewInit ();
 GLEWAPI GLenum glewInitGL2Hack ();
 GLEWAPI GLboolean glewIsSupported (const char* name);
diff --git a/third_party/glew/include/GL/osmew.h b/third_party/glew/include/GL/osmew.h
new file mode 100644
index 0000000..4816694
--- /dev/null
+++ b/third_party/glew/include/GL/osmew.h
@@ -0,0 +1,51 @@
+// Copyright (c) 2009 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.
+
+#ifndef __osmew_h__
+#define __osmew_h__
+#define __OSMEW_H__
+
+#include <GL/glew.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if !defined(GLAPIENTRY)
+#if defined(_WIN32)
+#define GLAPIENTRY __stdcall
+#else
+#define GLAPIENTRY
+#endif
+#endif
+
+#define OSMEW_GET_FUN(x) x
+
+// Subset of OSMesa functions.
+
+typedef struct osmesa_context *OSMesaContext;
+typedef OSMesaContext (GLAPIENTRY * PFNOSMESACREATECONTEXTPROC) (GLenum format, OSMesaContext sharelist);
+typedef void (GLAPIENTRY * PFNOSMESADESTROYCONTEXTPROC) (OSMesaContext ctx);
+typedef GLboolean (GLAPIENTRY * PFNOSMESAMAKECURRENTPROC) (OSMesaContext ctx, void* buffer, GLenum type, GLsizei width, GLsizei height);
+typedef OSMesaContext (GLAPIENTRY * PFNOSMESAGETCURRENTCONTEXTPROC) (void);
+
+#define OSMesaCreateContext OSMEW_GET_FUN(__osmesaCreateContext)
+#define OSMesaDestroyContext OSMEW_GET_FUN(__osmesaDestroyContext)
+#define OSMesaMakeCurrent OSMEW_GET_FUN(__osmesaMakeCurrent)
+#define OSMesaGetCurrentContext OSMEW_GET_FUN(__osmesaGetCurrentContext)
+
+extern PFNOSMESACREATECONTEXTPROC __osmesaCreateContext;
+extern PFNOSMESADESTROYCONTEXTPROC __osmesaDestroyContext;
+extern PFNOSMESAMAKECURRENTPROC __osmesaMakeCurrent;
+extern PFNOSMESAGETCURRENTCONTEXTPROC __osmesaGetCurrentContext;
+
+void osmewInit ();
+
+#undef GLAPIENTRY
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __osmew_h__ */