Make GL calls go through subclassable class.

ui/gl/generate_bindings.py

Index: ui/gl/generate_bindings.py
diff --git a/ui/gl/generate_bindings.py b/ui/gl/generate_bindings.py
index 72c9eb1e1b84332bc19813b7af9415d48c9a33e8..009060233b7b4c3eb54d2e12920b8cb205a420a7 100755
--- a/ui/gl/generate_bindings.py
+++ b/ui/gl/generate_bindings.py
@@ -1145,10 +1145,6 @@ namespace gfx {
 
 class GLContext;
 
-void InitializeGLBindings%(name)s();
-void InitializeGLExtensionBindings%(name)s(GLContext* context);
-void InitializeDebugGLBindings%(name)s();
-void ClearGLBindings%(name)s();
 """ % {'name': set_name.upper()})
 
   # Write typedefs for function pointer types. Always use the GL name for the
@@ -1160,30 +1156,89 @@ void ClearGLBindings%(name)s();
 
   # Write declarations for booleans indicating which extensions are available.
   file.write('\n')
+  file.write("struct Extensions%s {\n" % set_name.upper())
   for extension, ext_functions in used_extension_functions:
-    file.write('GL_EXPORT extern bool g_%s;\n' % extension)
+    file.write('  bool b_%s;\n' % extension)
+  file.write('};\n')
+  file.write('\n')
+
+  # Write Procs struct.
+  file.write("struct Procs%s {\n" % set_name.upper())
+  for func in functions:
+    file.write('  %sProc %sFn;\n' % (func['names'][0], func['names'][0]))
+  file.write('};\n')
+  file.write('\n')
 
-  # Write declarations for function pointers. Always use the GL name for the
-  # declaration.
+  # Write Driver struct.
+  file.write(
+"""struct GL_EXPORT Driver%(name)s {
+  void InitializeBindings();
+  void InitializeExtensionBindings(GLContext* context);
+  void InitializeDebugBindings();
+  void ClearBindings();
+  void UpdateDebugExtensionBindings();
+
+  Procs%(name)s fn;
+  Procs%(name)s debug_fn;
+  Extensions%(name)s ext;
+""" % {'name': set_name.upper()})
+  file.write('};\n')
   file.write('\n')
+
+  # Write Api class.
+  file.write(
+"""class GL_EXPORT %(name)sApi {
+ public:
+  %(name)sApi();
+  virtual ~%(name)sApi();
+
+""" % {'name': set_name.upper()})
   for func in functions:
-    file.write('GL_EXPORT extern %sProc g_%s;\n' %
-               (func['names'][0], func['names'][0]))
+    file.write('  virtual %s %sFn(%s) = 0;\n' %
+      (func['return_type'], func['names'][0], func['arguments']))
+  file.write('};\n')
   file.write('\n')
+
   file.write( '}  // namespace gfx\n')
 
   # Write macros to invoke function pointers. Always use the GL name for the
   # macro.
   file.write('\n')
   for func in functions:
-    file.write('#define %s ::gfx::g_%s\n' %
-        (func['names'][0], func['names'][0]))
+    file.write('#define %s ::gfx::g_current_%s_context->%sFn\n' %
+        (func['names'][0], set_name.lower(), func['names'][0]))
 
   file.write('\n')
   file.write('#endif  //  UI_GFX_GL_GL_BINDINGS_AUTOGEN_%s_H_\n' %
       set_name.upper())
 
 
+def GenerateAPIHeader(file, functions, set_name, used_extension_functions):
+  """Generates gl_binding_api_autogen_x.h"""
+
+  # Write file header.
+  file.write(
+"""// 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.
+
+// This file is automatically generated.
+
+#ifndef UI_GFX_GL_GL_BINDINGS_API_AUTOGEN_%(name)s_H_
+#define UI_GFX_GL_GL_BINDINGS_API_AUTOGEN_%(name)s_H_
+
+""" % {'name': set_name.upper()})
+
+  # Write API declaration.
+  for func in functions:
+    file.write('  virtual %s %sFn(%s) OVERRIDE;\n' %
+      (func['return_type'], func['names'][0], func['arguments']))
+
+  file.write('\n')
+  file.write('#endif  //  UI_GFX_GL_GL_BINDINGS_API_AUTOGEN_%s_H_\n' %
+      set_name.upper())
+
+
 def GenerateSource(file, functions, set_name, used_extension_functions):
   """Generates gl_binding_autogen_x.cc"""
 
@@ -1200,53 +1255,47 @@ def GenerateSource(file, functions, set_name, used_extension_functions):
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_%s_api_implementation.h"
 
 using gpu::gles2::GLES2Util;
 
 namespace gfx {
-""")
-  # Write definitions for booleans indicating which extensions are available.
-  for extension, ext_functions in used_extension_functions:
-    file.write('bool g_%s;\n' % extension)
+""" % set_name.lower())
 
   # Write definitions of function pointers.
   file.write('\n')
   file.write('static bool g_debugBindingsInitialized;\n')
-  file.write('static void UpdateDebugGLExtensionBindings();\n')
+  file.write('Driver%s g_driver_%s;\n' % (set_name.upper(), set_name.lower()))
   file.write('\n')
-  for func in functions:
-    file.write('%sProc g_%s;\n' % (func['names'][0], func['names'][0]))
-
-  file.write('\n')
-  for func in functions:
-    file.write('static %sProc g_debug_%s;\n' %
-               (func['names'][0], func['names'][0]))
 
   # Write function to initialize the core function pointers. The code assumes
   # any non-NULL pointer returned by GetGLCoreProcAddress() is valid, although
   # it may be overwritten by an extension function pointer later.
   file.write('\n')
-  file.write('void InitializeGLBindings%s() {\n' % set_name.upper())
+  file.write('void Driver%s::InitializeBindings() {\n' %
+             set_name.upper())
   for func in functions:
     first_name = func['names'][0]
     for i, name in enumerate(func['names']):
       if i:
-        file.write('  if (!g_%s)\n  ' % first_name)
+        file.write('  if (!fn.%sFn)\n  ' % first_name)
       file.write(
-          '  g_%s = reinterpret_cast<%sProc>(GetGLCoreProcAddress("%s"));\n' %
-              (first_name, first_name, name))
+          '  fn.%sFn = reinterpret_cast<%sProc>('
+          'GetGLCoreProcAddress("%s"));\n' %
+          (first_name, first_name, name))
   file.write('}\n')
   file.write('\n')
 
   # Write function to initialize the extension function pointers. This function
   # uses a current context to query which extensions are actually supported.
-  file.write('void InitializeGLExtensionBindings%s(GLContext* context) {\n' %
-      set_name.upper())
+  file.write("""void Driver%s::InitializeExtensionBindings(
+    GLContext* context) {
+""" % set_name.upper())
   file.write('  DCHECK(context && context->IsCurrent(NULL));\n')
   for extension, ext_functions in used_extension_functions:
-    file.write('  g_%s = context->HasExtension("%s");\n' %
+    file.write('  ext.b_%s = context->HasExtension("%s");\n' %
         (extension, extension))
-    file.write('  if (g_%s) {\n' %
+    file.write('  if (ext.b_%s) {\n' %
         (extension))
     queried_entry_points = set()
     for entry_point_name, function_name in ext_functions:
@@ -1254,14 +1303,14 @@ namespace gfx {
       # alternatives for the same entry point (e.g.,
       # GL_ARB_blend_func_extended).
       if entry_point_name in queried_entry_points:
-        file.write('    if (!g_%s)\n  ' % entry_point_name)
+        file.write('    if (!fn.%sFn)\n  ' % entry_point_name)
       file.write(
-         '    g_%s = reinterpret_cast<%sProc>(GetGLProcAddress("%s"));\n' %
+         '    fn.%sFn = reinterpret_cast<%sProc>(GetGLProcAddress("%s"));\n' %
              (entry_point_name, entry_point_name, function_name))
       queried_entry_points.add(entry_point_name)
     file.write('  }\n')
   file.write('  if (g_debugBindingsInitialized)\n')
-  file.write('    UpdateDebugGLExtensionBindings();\n')
+  file.write('    UpdateDebugExtensionBindings();\n')
   file.write('}\n')
   file.write('\n')
 
@@ -1314,15 +1363,15 @@ namespace gfx {
     if return_type == 'void':
       file.write('  GL_SERVICE_LOG("%s" << "(" %s << ")");\n' %
           (function_name, log_argument_names))
-      file.write('  g_debug_%s(%s);\n' %
-          (function_name, argument_names))
+      file.write('  g_driver_%s.debug_fn.%sFn(%s);\n' %
+          (set_name.lower(), function_name, argument_names))
       if 'logging_code' in func:
         file.write("%s\n" % func['logging_code'])
     else:
       file.write('  GL_SERVICE_LOG("%s" << "(" %s << ")");\n' %
           (function_name, log_argument_names))
-      file.write('  %s result = g_debug_%s(%s);\n' %
-          (return_type, function_name, argument_names))
+      file.write('  %s result = g_driver_%s.debug_fn.%sFn(%s);\n' %
+          (return_type, set_name.lower(), function_name, argument_names))
       if 'logging_code' in func:
         file.write("%s\n" % func['logging_code'])
       else:
@@ -1333,12 +1382,13 @@ namespace gfx {
 
   # Write function to initialize the debug function pointers.
   file.write('\n')
-  file.write('void InitializeDebugGLBindings%s() {\n' % set_name.upper())
+  file.write('void Driver%s::InitializeDebugBindings() {\n' %
+             set_name.upper())
   for func in functions:
     first_name = func['names'][0]
-    file.write('  if (!g_debug_%s) {\n' % first_name)
-    file.write('    g_debug_%s = g_%s;\n' % (first_name, first_name))
-    file.write('    g_%s = Debug_%s;\n' % (first_name, first_name))
+    file.write('  if (!debug_fn.%sFn) {\n' % first_name)
+    file.write('    debug_fn.%sFn = fn.%sFn;\n' % (first_name, first_name))
+    file.write('    fn.%sFn = Debug_%s;\n' % (first_name, first_name))
     file.write('  }\n')
   file.write('  g_debugBindingsInitialized = true;\n')
   file.write('}\n')
@@ -1346,32 +1396,46 @@ namespace gfx {
   # Write function to update the debug function pointers to extension functions
   # after the extensions have been initialized.
   file.write('\n')
-  file.write('static void UpdateDebugGLExtensionBindings() {\n')
+  file.write('void Driver%s::UpdateDebugExtensionBindings() {\n' %
+             set_name.upper())
   for extension, ext_functions in used_extension_functions:
     for name, _ in ext_functions:
-      file.write('  if (g_debug_%s != g_%s &&\n' % (name, name))
-      file.write('      g_%s != Debug_%s) {\n' % (name, name))
-      file.write('    g_debug_%s = g_%s;\n' % (name, name))
-      file.write('    g_%s = Debug_%s;\n' % (name, name))
+      file.write('  if (debug_fn.%sFn != fn.%sFn &&\n' % (name, name))
+      file.write('      fn.%sFn != Debug_%s) {\n' % (name, name))
+      file.write('    debug_fn.%sFn = fn.%sFn;\n' % (name, name))
+      file.write('    fn.%sFn = Debug_%s;\n' % (name, name))
       file.write('  }\n')
   file.write('}\n')
 
   # Write function to clear all function pointers.
   file.write('\n')
-  file.write('void ClearGLBindings%s() {\n' % set_name.upper())
-  # Clear the availability of GL extensions.
-  for extension, ext_functions in used_extension_functions:
-    file.write('  g_%s = false;\n' % extension)
-  # Clear GL bindings.
-  file.write('\n')
-  for func in functions:
-    file.write('  g_%s = NULL;\n' % func['names'][0])
-  # Clear debug GL bindings.
-  file.write('\n')
+  file.write("""void Driver%s::ClearBindings() {
+  memset(this, 0, sizeof(*this));
+}
+""" % set_name.upper())
+
+  # Write RealGLApi functions
   for func in functions:
-    file.write('  g_debug_%s = NULL;\n' % func['names'][0])
-  file.write('  g_debugBindingsInitialized = false;\n')
-  file.write('}\n')
+    names = func['names']
+    return_type = func['return_type']
+    arguments = func['arguments']
+    file.write('\n')
+    file.write('%s Real%sApi::%sFn(%s) {\n' %
+        (return_type, set_name.upper(), names[0], arguments))
+    argument_names = re.sub(
+        r'(const )?[a-zA-Z0-9_]+\** ([a-zA-Z0-9_]+)', r'\2', arguments)
+    argument_names = re.sub(
+        r'(const )?[a-zA-Z0-9_]+\** ([a-zA-Z0-9_]+)', r'\2', argument_names)
+    if argument_names == 'void' or argument_names == '':
+      argument_names = ''
+    function_name = names[0]
+    if return_type == 'void':
+      file.write('  driver_->fn.%sFn(%s);\n' %
+          (function_name, argument_names))
+    else:
+      file.write('  return driver_->fn.%sFn(%s);\n' %
+          (function_name, argument_names))
+    file.write('}\n')
 
   file.write('\n')
   file.write('}  // namespace gfx\n')
@@ -1572,6 +1636,12 @@ def main(argv):
     GenerateHeader(header_file, functions, set_name, used_extension_functions)
     header_file.close()
 
+    header_file = open(
+        os.path.join(dir, 'gl_bindings_api_autogen_%s.h' % set_name), 'wb')
+    GenerateAPIHeader(
+        header_file, functions, set_name, used_extension_functions)
+    header_file.close()
+
     source_file = open(
         os.path.join(dir, 'gl_bindings_autogen_%s.cc' % set_name), 'wb')
     GenerateSource(source_file, functions, set_name, used_extension_functions)