/**
* Initialize an OpenGL context so that shaders can be compiled.
*/
static void PlatformInitOpenGL(void*& ContextPtr, void*& PrevContextPtr, int InMajorVersion, int InMinorVersion)
{
static FPlatformOpenGLContext ShaderCompileContext = {0};
ContextPtr = (void*)wglGetCurrentDC();
PrevContextPtr = (void*)wglGetCurrentContext();
if (ShaderCompileContext.OpenGLContext == NULL && InMajorVersion && InMinorVersion)
{
PlatformCreateDummyGLWindow(&ShaderCompileContext);
// Disable warning C4191: 'type cast' : unsafe conversion from 'PROC' to 'XXX' while getting GL entry points.
#pragma warning(push)
#pragma warning(disable:4191)
if (wglCreateContextAttribsARB == NULL)
{
// Create a dummy context so that wglCreateContextAttribsARB can be initialized.
ShaderCompileContext.OpenGLContext = wglCreateContext(ShaderCompileContext.DeviceContext);
check(ShaderCompileContext.OpenGLContext);
PlatformMakeGLContextCurrent(&ShaderCompileContext);
wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC)wglGetProcAddress("wglCreateContextAttribsARB");
check(wglCreateContextAttribsARB);
wglDeleteContext(ShaderCompileContext.OpenGLContext);
}
// Create a context so that remaining GL function pointers can be initialized.
PlatformCreateOpenGLContextCore(&ShaderCompileContext, InMajorVersion, InMinorVersion, /*InParentContext=*/ NULL);
check(ShaderCompileContext.OpenGLContext);
PlatformMakeGLContextCurrent(&ShaderCompileContext);
if (glCreateShader == NULL)
{
// Initialize all entry points.
#define GET_GL_ENTRYPOINTS(Type,Func) Func = (Type)wglGetProcAddress(#Func);
ENUM_GL_ENTRYPOINTS(GET_GL_ENTRYPOINTS);
// Check that all of the entry points have been initialized.
bool bFoundAllEntryPoints = true;
#define CHECK_GL_ENTRYPOINTS(Type,Func) if (Func == NULL) { bFoundAllEntryPoints = false; UE_LOG(LogOpenGLShaderCompiler, Warning, TEXT("Failed to find entry point for %s"), TEXT(#Func)); }
ENUM_GL_ENTRYPOINTS(CHECK_GL_ENTRYPOINTS);
checkf(bFoundAllEntryPoints, TEXT("Failed to find all OpenGL entry points."));
}
// Restore warning C4191.
#pragma warning(pop)
}
PlatformMakeGLContextCurrent(&ShaderCompileContext);
}
bool PlatformInitOpenGL()
{
static bool bInitialized = false;
static bool bOpenGLSupported = false;
if (!bInitialized)
{
// Disable warning C4191: 'type cast' : unsafe conversion from 'PROC' to 'XXX' while getting GL entry points.
#pragma warning(push)
#pragma warning(disable:4191)
// Create a dummy context so that wglCreateContextAttribsARB can be initialized.
FPlatformOpenGLContext DummyContext;
PlatformCreateDummyGLWindow(&DummyContext);
DummyContext.OpenGLContext = wglCreateContext(DummyContext.DeviceContext);
check(DummyContext.OpenGLContext);
ContextMakeCurrent(DummyContext.DeviceContext, DummyContext.OpenGLContext);
wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC)wglGetProcAddress("wglCreateContextAttribsARB");
if (wglCreateContextAttribsARB)
{
int MajorVersion = 0;
int MinorVersion = 0;
ContextMakeCurrent(NULL,NULL);
wglDeleteContext(DummyContext.OpenGLContext);
PlatformOpenGLVersionFromCommandLine(MajorVersion, MinorVersion);
PlatformCreateOpenGLContextCore(&DummyContext, MajorVersion, MinorVersion, NULL);
if (DummyContext.OpenGLContext)
{
bOpenGLSupported = true;
ContextMakeCurrent(DummyContext.DeviceContext, DummyContext.OpenGLContext);
}
else
{
UE_LOG(LogRHI,Error,TEXT("OpenGL %d.%d not supported by driver"),MajorVersion,MinorVersion);
}
}
if (bOpenGLSupported)
{
// Retrieve the OpenGL DLL.
void* OpenGLDLL = FPlatformProcess::GetDllHandle(TEXT("opengl32.dll"));
if (!OpenGLDLL)
{
UE_LOG(LogRHI,Fatal,TEXT("Couldn't load opengl32.dll"));
}
// Initialize entry points required by Unreal from opengl32.dll
#define GET_GL_ENTRYPOINTS_DLL(Type,Func) Func = (Type)FPlatformProcess::GetDllExport(OpenGLDLL,TEXT(#Func));
ENUM_GL_ENTRYPOINTS_DLL(GET_GL_ENTRYPOINTS_DLL);
// Release the OpenGL DLL.
FPlatformProcess::FreeDllHandle(OpenGLDLL);
// Initialize all entry points required by Unreal.
#define GET_GL_ENTRYPOINTS(Type,Func) Func = (Type)wglGetProcAddress(#Func);
ENUM_GL_ENTRYPOINTS(GET_GL_ENTRYPOINTS);
ENUM_GL_ENTRYPOINTS_OPTIONAL(GET_GL_ENTRYPOINTS);
// Restore warning C4191.
#pragma warning(pop)
// Check that all of the entry points have been initialized.
bool bFoundAllEntryPoints = true;
#define CHECK_GL_ENTRYPOINTS(Type,Func) if (Func == NULL) { bFoundAllEntryPoints = false; UE_LOG(LogRHI, Warning, TEXT("Failed to find entry point for %s"), TEXT(#Func)); }
ENUM_GL_ENTRYPOINTS_DLL(CHECK_GL_ENTRYPOINTS);
ENUM_GL_ENTRYPOINTS(CHECK_GL_ENTRYPOINTS);
checkf(bFoundAllEntryPoints, TEXT("Failed to find all OpenGL entry points."));
FString VendorName( ANSI_TO_TCHAR((const ANSICHAR*)glGetString(GL_VENDOR) ) );
if ( VendorName.Contains(TEXT("ATI ")) )
{
// Workaround for AMD driver not handling GL_SRGB8_ALPHA8 in glTexStorage2D() properly (gets treated as non-sRGB)
glTexStorage1D = NULL;
glTexStorage2D = NULL;
glTexStorage3D = NULL;
}
}
// The dummy context can now be released.
if (DummyContext.OpenGLContext)
{
ContextMakeCurrent(NULL,NULL);
wglDeleteContext(DummyContext.OpenGLContext);
}
ReleaseDC(DummyContext.WindowHandle, DummyContext.DeviceContext);
check(DummyContext.bReleaseWindowOnDestroy);
DestroyWindow(DummyContext.WindowHandle);
}
return bOpenGLSupported;
}
