1 files changed, 92 insertions, 0 deletions
diff --git a/src/gpu/gl/win/GrGLMakeNativeInterface_win.cpp b/src/gpu/gl/win/GrGLMakeNativeInterface_win.cpp
new file mode 100644
index 0000000000..77db59a754
--- /dev/null
+++ b/src/gpu/gl/win/GrGLMakeNativeInterface_win.cpp
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SkTypes.h"
+#if defined(SK_BUILD_FOR_WIN32)
+
+#include "SkLeanWindows.h"
+
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLAssembleInterface.h"
+#include "gl/GrGLUtil.h"
+
+class AutoLibraryUnload {
+public:
+    AutoLibraryUnload(const char* moduleName) {
+        fModule = LoadLibraryA(moduleName);
+    }
+    ~AutoLibraryUnload() {
+        if (fModule) {
+            FreeLibrary(fModule);
+        }
+    }
+    HMODULE get() const { return fModule; }
+
+private:
+    HMODULE fModule;
+};
+
+class GLProcGetter {
+public:
+    GLProcGetter() : fGLLib("opengl32.dll") {}
+
+    bool isInitialized() const { return SkToBool(fGLLib.get()); }
+
+    GrGLFuncPtr getProc(const char name[]) const {
+        GrGLFuncPtr proc;
+        if ((proc = (GrGLFuncPtr) GetProcAddress(fGLLib.get(), name))) {
+            return proc;
+        }
+        if ((proc = (GrGLFuncPtr) wglGetProcAddress(name))) {
+            return proc;
+        }
+        return nullptr;
+    }
+
+private:
+    AutoLibraryUnload fGLLib;
+};
+
+static GrGLFuncPtr win_get_gl_proc(void* ctx, const char name[]) {
+    SkASSERT(ctx);
+    SkASSERT(wglGetCurrentContext());
+    const GLProcGetter* getter = (const GLProcGetter*) ctx;
+    return getter->getProc(name);
+}
+
+/*
+ * Windows makes the GL funcs all be __stdcall instead of __cdecl :(
+ * This implementation will only work if GR_GL_FUNCTION_TYPE is __stdcall.
+ * Otherwise, a springboard would be needed that hides the calling convention.
+ */
+sk_sp<const GrGLInterface> GrGLMakeNativeInterface() {
+    if (nullptr == wglGetCurrentContext()) {
+        return nullptr;
+    }
+
+    GLProcGetter getter;
+    if (!getter.isInitialized()) {
+        return nullptr;
+    }
+
+    GrGLGetStringProc getString = (GrGLGetStringProc)getter.getProc("glGetString");
+    if (nullptr == getString) {
+        return nullptr;
+    }
+    const char* verStr = reinterpret_cast<const char*>(getString(GR_GL_VERSION));
+    GrGLStandard standard = GrGLGetStandardInUseFromString(verStr);
+
+    if (kGLES_GrGLStandard == standard) {
+        return GrGLAssembleGLESInterface(&getter, win_get_gl_proc);
+    } else if (kGL_GrGLStandard == standard) {
+        return GrGLAssembleGLInterface(&getter, win_get_gl_proc);
+    }
+    return nullptr;
+}
+
+const GrGLInterface* GrGLCreateNativeInterface() { return GrGLMakeNativeInterface().release(); }
+
+#endif//defined(SK_BUILD_FOR_WIN32)