src/WSI/FrameBufferDD.cpp - SwiftShader - Git at Google

 // Copyright 2016 The SwiftShader Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "FrameBufferDD.hpp"

 #include "System/Debug.hpp"

 namespace sw
 {
 	extern bool forceWindowed;

 	GUID secondaryDisplay = {0};

 	int __stdcall enumDisplayCallback(GUID* guid, char *driverDescription, char *driverName, void *context, HMONITOR monitor)
 	{
 		if(strcmp(driverName, "\\\\.\\DISPLAY2") == 0)
 		{
 			secondaryDisplay = *guid;
 		}

 		return 1;
 	}

 	FrameBufferDD::FrameBufferDD(HWND windowHandle, int width, int height, bool fullscreen, bool topLeftOrigin) : FrameBufferWin(windowHandle, width, height, fullscreen, topLeftOrigin)
 	{
 		directDraw = 0;
 		frontBuffer = 0;
 		backBuffer = 0;

 		framebuffer = nullptr;

 		ddraw = LoadLibrary("ddraw.dll");
 		DirectDrawCreate = (DIRECTDRAWCREATE)GetProcAddress(ddraw, "DirectDrawCreate");
 		DirectDrawEnumerateExA = (DIRECTDRAWENUMERATEEXA)GetProcAddress(ddraw, "DirectDrawEnumerateExA");

 		if(!windowed)
 		{
 			initFullscreen();
 		}
 		else
 		{
 			initWindowed();
 		}
 	}

 	FrameBufferDD::~FrameBufferDD()
 	{
 		releaseAll();

 		FreeLibrary(ddraw);
 	}

 	void FrameBufferDD::createSurfaces()
 	{
 		if(backBuffer)
 		{
 			backBuffer->Release();
 			backBuffer = 0;
 		}

 		if(frontBuffer)
 		{
 			frontBuffer->Release();
 			frontBuffer = 0;
 		}

 		if(!windowed)
 		{
 			DDSURFACEDESC surfaceDescription = {0};
 			surfaceDescription.dwSize = sizeof(surfaceDescription);
 			surfaceDescription.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT;
 			surfaceDescription.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE | DDSCAPS_FLIP | DDSCAPS_COMPLEX;
 			surfaceDescription.dwBackBufferCount = 1;
 			directDraw->CreateSurface(&surfaceDescription, &frontBuffer, 0);

 			if(frontBuffer)
 			{
 				DDSCAPS surfaceCapabilties = {0};
 				surfaceCapabilties.dwCaps = DDSCAPS_BACKBUFFER;
 				frontBuffer->GetAttachedSurface(&surfaceCapabilties, &backBuffer);
 				backBuffer->AddRef();
 			}
 		}
 		else
 		{
 			IDirectDrawClipper *clipper;

 			DDSURFACEDESC ddsd = {0};
 			ddsd.dwSize = sizeof(ddsd);
 			ddsd.dwFlags = DDSD_CAPS;
 			ddsd.ddsCaps.dwCaps	= DDSCAPS_PRIMARYSURFACE;

 			long result = directDraw->CreateSurface(&ddsd, &frontBuffer, 0);
 			directDraw->GetDisplayMode(&ddsd);

 			switch(ddsd.ddpfPixelFormat.dwRGBBitCount)
 			{
 			case 32: format = VK_FORMAT_B8G8R8A8_UNORM;      break;
 			case 16: format = VK_FORMAT_R5G6B5_UNORM_PACK16; break;
 			default: format = VK_FORMAT_UNDEFINED;           break;
 			}

 			if((result != DD_OK && result != DDERR_PRIMARYSURFACEALREADYEXISTS) || (format == VK_FORMAT_UNDEFINED))
 			{
 				assert(!"Failed to initialize graphics: Incompatible display mode.");
 			}
 			else
 			{
 				ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT;
 				ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
 				ddsd.dwWidth = width;
 				ddsd.dwHeight = height;

 				directDraw->CreateSurface(&ddsd, &backBuffer, 0);

 				directDraw->CreateClipper(0, &clipper, 0);
 				clipper->SetHWnd(0, windowHandle);
 				frontBuffer->SetClipper(clipper);
 				clipper->Release();
 			}
 		}
 	}

 	bool FrameBufferDD::readySurfaces()
 	{
 		if(!frontBuffer || !backBuffer)
 		{
 			createSurfaces();
 		}

 		if(frontBuffer && backBuffer)
 		{
 			if(frontBuffer->IsLost() || backBuffer->IsLost())
 			{
 				restoreSurfaces();
 			}

 			if(frontBuffer && backBuffer)
 			{
 				if(!frontBuffer->IsLost() && !backBuffer->IsLost())
 				{
 					return true;
 				}
 			}
 		}

 		return false;
 	}

 	void FrameBufferDD::updateClipper(HWND windowOverride)
 	{
 		if(windowed)
 		{
 			if(frontBuffer)
 			{
 				HWND window = windowOverride ? windowOverride : windowHandle;

 				IDirectDrawClipper *clipper;
 				frontBuffer->GetClipper(&clipper);
 				clipper->SetHWnd(0, window);
 				clipper->Release();
 			}
 		}
 	}

 	void FrameBufferDD::restoreSurfaces()
 	{
 		long result1 = frontBuffer->Restore();
 		long result2 = backBuffer->Restore();

 		if(result1 != DD_OK || result2 != DD_OK)   // Surfaces could not be restored; recreate them
 		{
 			createSurfaces();
 		}
 	}

 	void FrameBufferDD::initFullscreen()
 	{
 		releaseAll();

 		if(true)   // Render to primary display
 		{
 			DirectDrawCreate(0, &directDraw, 0);
 		}
 		else   // Render to secondary display
 		{
 			DirectDrawEnumerateEx(&enumDisplayCallback, 0, DDENUM_ATTACHEDSECONDARYDEVICES);
 			DirectDrawCreate(&secondaryDisplay, &directDraw, 0);
 		}

 		directDraw->SetCooperativeLevel(windowHandle, DDSCL_EXCLUSIVE | DDSCL_FULLSCREEN);

 		long result = DD_FALSE;

 		do
 		{
 			format = VK_FORMAT_B8G8R8A8_UNORM;
 			result = directDraw->SetDisplayMode(width, height, 32);

 			if(result == DDERR_INVALIDMODE)
 			{
 				format = VK_FORMAT_R5G6B5_UNORM_PACK16;
 				result = directDraw->SetDisplayMode(width, height, 16);

 				if(result == DDERR_INVALIDMODE)
 				{
 					assert(!"Failed to initialize graphics: Display mode not supported.");
 				}
 			}

 			if(result != DD_OK)
 			{
 				Sleep(1);
 			}
 		}
 		while(result != DD_OK);

 		createSurfaces();

 		updateBounds(windowHandle);
 	}

 	void FrameBufferDD::initWindowed()
 	{
 		releaseAll();

 		DirectDrawCreate(0, &directDraw, 0);
 		directDraw->SetCooperativeLevel(windowHandle, DDSCL_NORMAL);

 		createSurfaces();

 		updateBounds(windowHandle);
 	}

 	void FrameBufferDD::flip(sw::Surface *source)
 	{
 		copy(source);

 		if(!readySurfaces())
 		{
 			return;
 		}

 		while(true)
 		{
 			long result;

 			if(windowed)
 			{
 				result = frontBuffer->Blt(&bounds, backBuffer, 0, DDBLT_WAIT, 0);
 			}
 			else
 			{
 				result = frontBuffer->Flip(0, DDFLIP_NOVSYNC);
 			}

 			if(result != DDERR_WASSTILLDRAWING)
 			{
 				break;
 			}

 			Sleep(0);
 		}
 	}

 	void FrameBufferDD::blit(sw::Surface *source, const Rect *sourceRect, const Rect *destRect)
 	{
 		copy(source);

 		if(!readySurfaces())
 		{
 			return;
 		}

 		RECT dRect;

 		if(destRect)
 		{
 			dRect.bottom = bounds.top + destRect->y1;
 			dRect.left = bounds.left + destRect->x0;
 			dRect.right = bounds.left + destRect->x1;
 			dRect.top = bounds.top + destRect->y0;
 		}
 		else
 		{
 			dRect.bottom = bounds.top + height;
 			dRect.left = bounds.left + 0;
 			dRect.right = bounds.left + width;
 			dRect.top = bounds.top + 0;
 		}

 		while(true)
 		{
 			long result = frontBuffer->Blt(&dRect, backBuffer, (LPRECT)sourceRect, DDBLT_WAIT, 0);

 			if(result != DDERR_WASSTILLDRAWING)
 			{
 				break;
 			}

 			Sleep(0);
 		}
 	}

 	void FrameBufferDD::flip(HWND windowOverride, sw::Surface *source)
 	{
 		updateClipper(windowOverride);
 		updateBounds(windowOverride);

 		flip(source);
 	}

 	void FrameBufferDD::blit(HWND windowOverride, sw::Surface *source, const Rect *sourceRect, const Rect *destRect)
 	{
 		updateClipper(windowOverride);
 		updateBounds(windowOverride);

 		blit(source, sourceRect, destRect);
 	}

 	void FrameBufferDD::screenshot(void *destBuffer)
 	{
 		if(!readySurfaces())
 		{
 			return;
 		}

 		DDSURFACEDESC DDSD;
 		DDSD.dwSize = sizeof(DDSD);

 		long result = frontBuffer->Lock(0, &DDSD, DDLOCK_WAIT, 0);

 		if(result == DD_OK)
 		{
 			int width = DDSD.dwWidth;
 			int height = DDSD.dwHeight;
 			int stride = DDSD.lPitch;

 			void *sourceBuffer = DDSD.lpSurface;

 			for(int y = 0; y < height; y++)
 			{
 				memcpy(destBuffer, sourceBuffer, width * 4);   // FIXME: Assumes 32-bit buffer

 				(char*&)sourceBuffer += stride;
 				(char*&)destBuffer += 4 * width;
 			}

 			frontBuffer->Unlock(0);
 		}
 	}

 	void FrameBufferDD::setGammaRamp(GammaRamp *gammaRamp, bool calibrate)
 	{
 		IDirectDrawGammaControl *gammaControl = 0;

 		if(frontBuffer)
 		{
 			frontBuffer->QueryInterface(IID_IDirectDrawGammaControl, (void**)&gammaControl);

 			if(gammaControl)
 			{
 				gammaControl->SetGammaRamp(calibrate ? DDSGR_CALIBRATE : 0, (DDGAMMARAMP*)gammaRamp);

 				gammaControl->Release();
 			}
 		}
 	}

 	void FrameBufferDD::getGammaRamp(GammaRamp *gammaRamp)
 	{
 		IDirectDrawGammaControl *gammaControl = 0;

 		if(frontBuffer)
 		{
 			frontBuffer->QueryInterface(IID_IDirectDrawGammaControl, (void**)&gammaControl);

 			if(gammaControl)
 			{
 				gammaControl->GetGammaRamp(0, (DDGAMMARAMP*)gammaRamp);

 				gammaControl->Release();
 			}
 		}
 	}

 	void *FrameBufferDD::lock()
 	{
 		if(framebuffer)
 		{
 			return framebuffer;
 		}

 		if(!readySurfaces())
 		{
 			return nullptr;
 		}

 		DDSURFACEDESC DDSD;
 		DDSD.dwSize = sizeof(DDSD);

 		long result = backBuffer->Lock(0, &DDSD, DDLOCK_WAIT, 0);

 		if(result == DD_OK)
 		{
 			width = DDSD.dwWidth;
 			height = DDSD.dwHeight;
 			stride = DDSD.lPitch;

 			framebuffer = DDSD.lpSurface;

 			return framebuffer;
 		}

 		return nullptr;
 	}

 	void FrameBufferDD::unlock()
 	{
 		if(!framebuffer || !backBuffer) return;

 		backBuffer->Unlock(0);

 		framebuffer = nullptr;
 	}

 	void FrameBufferDD::drawText(int x, int y, const char *string, ...)
 	{
 		char buffer[256];
 		va_list arglist;

 		va_start(arglist, string);
 		vsprintf(buffer, string, arglist);
 		va_end(arglist);

 		HDC hdc;

 		backBuffer->GetDC(&hdc);

 		SetBkColor(hdc, RGB(0, 0, 255));
 		SetTextColor(hdc, RGB(255, 255, 255));

 		TextOut(hdc, x, y, buffer, lstrlen(buffer));

 		backBuffer->ReleaseDC(hdc);
 	}

 	bool FrameBufferDD::getScanline(bool &inVerticalBlank, unsigned int &scanline)
 	{
 		HRESULT result = directDraw->GetScanLine((unsigned long*)&scanline);

 		if(result == DD_OK)
 		{
 			inVerticalBlank = false;
 		}
 		else if(result == DDERR_VERTICALBLANKINPROGRESS)
 		{
 			inVerticalBlank = true;
 		}
 		else if(result == DDERR_UNSUPPORTED)
 		{
 			return false;
 		}
 		else ASSERT(false);

 		return true;
 	}

 	void FrameBufferDD::releaseAll()
 	{
 		unlock();

 		if(backBuffer)
 		{
 			backBuffer->Release();
 			backBuffer = 0;
 		}

 		if(frontBuffer)
 		{
 			frontBuffer->Release();
 			frontBuffer = 0;
 		}

 		if(directDraw)
 		{
 			directDraw->SetCooperativeLevel(0, DDSCL_NORMAL);
 			directDraw->Release();
 			directDraw = 0;
 		}
 	}
 }
	// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "FrameBufferDD.hpp"

	#include "System/Debug.hpp"

	namespace sw
	{
	extern bool forceWindowed;

	GUID secondaryDisplay = {0};

	int __stdcall enumDisplayCallback(GUID* guid, char driverDescription, char driverName, void *context, HMONITOR monitor)
	{
	if(strcmp(driverName, "\\\\.\\DISPLAY2") == 0)
	{
	secondaryDisplay = *guid;
	}

	return 1;
	}

	FrameBufferDD::FrameBufferDD(HWND windowHandle, int width, int height, bool fullscreen, bool topLeftOrigin) : FrameBufferWin(windowHandle, width, height, fullscreen, topLeftOrigin)
	{
	directDraw = 0;
	frontBuffer = 0;
	backBuffer = 0;

	framebuffer = nullptr;

	ddraw = LoadLibrary("ddraw.dll");
	DirectDrawCreate = (DIRECTDRAWCREATE)GetProcAddress(ddraw, "DirectDrawCreate");
	DirectDrawEnumerateExA = (DIRECTDRAWENUMERATEEXA)GetProcAddress(ddraw, "DirectDrawEnumerateExA");

	if(!windowed)
	{
	initFullscreen();
	}
	else
	{
	initWindowed();
	}
	}

	FrameBufferDD::~FrameBufferDD()
	{
	releaseAll();

	FreeLibrary(ddraw);
	}

	void FrameBufferDD::createSurfaces()
	{
	if(backBuffer)
	{
	backBuffer->Release();
	backBuffer = 0;
	}

	if(frontBuffer)
	{
	frontBuffer->Release();
	frontBuffer = 0;
	}

	if(!windowed)
	{
	DDSURFACEDESC surfaceDescription = {0};
	surfaceDescription.dwSize = sizeof(surfaceDescription);
	surfaceDescription.dwFlags = DDSD_CAPS \| DDSD_BACKBUFFERCOUNT;
	surfaceDescription.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE \| DDSCAPS_FLIP \| DDSCAPS_COMPLEX;
	surfaceDescription.dwBackBufferCount = 1;
	directDraw->CreateSurface(&surfaceDescription, &frontBuffer, 0);

	if(frontBuffer)
	{
	DDSCAPS surfaceCapabilties = {0};
	surfaceCapabilties.dwCaps = DDSCAPS_BACKBUFFER;
	frontBuffer->GetAttachedSurface(&surfaceCapabilties, &backBuffer);
	backBuffer->AddRef();
	}
	}
	else
	{
	IDirectDrawClipper *clipper;

	DDSURFACEDESC ddsd = {0};
	ddsd.dwSize = sizeof(ddsd);
	ddsd.dwFlags = DDSD_CAPS;
	ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;

	long result = directDraw->CreateSurface(&ddsd, &frontBuffer, 0);
	directDraw->GetDisplayMode(&ddsd);

	switch(ddsd.ddpfPixelFormat.dwRGBBitCount)
	{
	case 32: format = VK_FORMAT_B8G8R8A8_UNORM; break;
	case 16: format = VK_FORMAT_R5G6B5_UNORM_PACK16; break;
	default: format = VK_FORMAT_UNDEFINED; break;
	}

	if((result != DD_OK && result != DDERR_PRIMARYSURFACEALREADYEXISTS) \|\| (format == VK_FORMAT_UNDEFINED))
	{
	assert(!"Failed to initialize graphics: Incompatible display mode.");
	}
	else
	{
	ddsd.dwFlags = DDSD_CAPS \| DDSD_WIDTH \| DDSD_HEIGHT;
	ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
	ddsd.dwWidth = width;
	ddsd.dwHeight = height;

	directDraw->CreateSurface(&ddsd, &backBuffer, 0);

	directDraw->CreateClipper(0, &clipper, 0);
	clipper->SetHWnd(0, windowHandle);
	frontBuffer->SetClipper(clipper);
	clipper->Release();
	}
	}
	}

	bool FrameBufferDD::readySurfaces()
	{
	if(!frontBuffer \|\| !backBuffer)
	{
	createSurfaces();
	}

	if(frontBuffer && backBuffer)
	{
	if(frontBuffer->IsLost() \|\| backBuffer->IsLost())
	{
	restoreSurfaces();
	}

	if(frontBuffer && backBuffer)
	{
	if(!frontBuffer->IsLost() && !backBuffer->IsLost())
	{
	return true;
	}
	}
	}

	return false;
	}

	void FrameBufferDD::updateClipper(HWND windowOverride)
	{
	if(windowed)
	{
	if(frontBuffer)
	{
	HWND window = windowOverride ? windowOverride : windowHandle;

	IDirectDrawClipper *clipper;
	frontBuffer->GetClipper(&clipper);
	clipper->SetHWnd(0, window);
	clipper->Release();
	}
	}
	}

	void FrameBufferDD::restoreSurfaces()
	{
	long result1 = frontBuffer->Restore();
	long result2 = backBuffer->Restore();

	if(result1 != DD_OK \|\| result2 != DD_OK) // Surfaces could not be restored; recreate them
	{
	createSurfaces();
	}
	}

	void FrameBufferDD::initFullscreen()
	{
	releaseAll();

	if(true) // Render to primary display
	{
	DirectDrawCreate(0, &directDraw, 0);
	}
	else // Render to secondary display
	{
	DirectDrawEnumerateEx(&enumDisplayCallback, 0, DDENUM_ATTACHEDSECONDARYDEVICES);
	DirectDrawCreate(&secondaryDisplay, &directDraw, 0);
	}

	directDraw->SetCooperativeLevel(windowHandle, DDSCL_EXCLUSIVE \| DDSCL_FULLSCREEN);

	long result = DD_FALSE;

	do
	{
	format = VK_FORMAT_B8G8R8A8_UNORM;
	result = directDraw->SetDisplayMode(width, height, 32);

	if(result == DDERR_INVALIDMODE)
	{
	format = VK_FORMAT_R5G6B5_UNORM_PACK16;
	result = directDraw->SetDisplayMode(width, height, 16);

	if(result == DDERR_INVALIDMODE)
	{
	assert(!"Failed to initialize graphics: Display mode not supported.");
	}
	}

	if(result != DD_OK)
	{
	Sleep(1);
	}
	}
	while(result != DD_OK);

	createSurfaces();

	updateBounds(windowHandle);
	}

	void FrameBufferDD::initWindowed()
	{
	releaseAll();

	DirectDrawCreate(0, &directDraw, 0);
	directDraw->SetCooperativeLevel(windowHandle, DDSCL_NORMAL);

	createSurfaces();

	updateBounds(windowHandle);
	}

	void FrameBufferDD::flip(sw::Surface *source)
	{
	copy(source);

	if(!readySurfaces())
	{
	return;
	}

	while(true)
	{
	long result;

	if(windowed)
	{
	result = frontBuffer->Blt(&bounds, backBuffer, 0, DDBLT_WAIT, 0);
	}
	else
	{
	result = frontBuffer->Flip(0, DDFLIP_NOVSYNC);
	}

	if(result != DDERR_WASSTILLDRAWING)
	{
	break;
	}

	Sleep(0);
	}
	}

	void FrameBufferDD::blit(sw::Surface source, const Rect sourceRect, const Rect *destRect)
	{
	copy(source);

	if(!readySurfaces())
	{
	return;
	}

	RECT dRect;

	if(destRect)
	{
	dRect.bottom = bounds.top + destRect->y1;
	dRect.left = bounds.left + destRect->x0;
	dRect.right = bounds.left + destRect->x1;
	dRect.top = bounds.top + destRect->y0;
	}
	else
	{
	dRect.bottom = bounds.top + height;
	dRect.left = bounds.left + 0;
	dRect.right = bounds.left + width;
	dRect.top = bounds.top + 0;
	}

	while(true)
	{
	long result = frontBuffer->Blt(&dRect, backBuffer, (LPRECT)sourceRect, DDBLT_WAIT, 0);

	if(result != DDERR_WASSTILLDRAWING)
	{
	break;
	}

	Sleep(0);
	}
	}

	void FrameBufferDD::flip(HWND windowOverride, sw::Surface *source)
	{
	updateClipper(windowOverride);
	updateBounds(windowOverride);

	flip(source);
	}

	void FrameBufferDD::blit(HWND windowOverride, sw::Surface source, const Rect sourceRect, const Rect *destRect)
	{
	updateClipper(windowOverride);
	updateBounds(windowOverride);

	blit(source, sourceRect, destRect);
	}

	void FrameBufferDD::screenshot(void *destBuffer)
	{
	if(!readySurfaces())
	{
	return;
	}

	DDSURFACEDESC DDSD;
	DDSD.dwSize = sizeof(DDSD);

	long result = frontBuffer->Lock(0, &DDSD, DDLOCK_WAIT, 0);

	if(result == DD_OK)
	{
	int width = DDSD.dwWidth;
	int height = DDSD.dwHeight;
	int stride = DDSD.lPitch;

	void *sourceBuffer = DDSD.lpSurface;

	for(int y = 0; y < height; y++)
	{
	memcpy(destBuffer, sourceBuffer, width * 4); // FIXME: Assumes 32-bit buffer

	(char*&)sourceBuffer += stride;
	(char&)destBuffer += 4 width;
	}

	frontBuffer->Unlock(0);
	}
	}

	void FrameBufferDD::setGammaRamp(GammaRamp *gammaRamp, bool calibrate)
	{
	IDirectDrawGammaControl *gammaControl = 0;

	if(frontBuffer)
	{
	frontBuffer->QueryInterface(IID_IDirectDrawGammaControl, (void**)&gammaControl);

	if(gammaControl)
	{
	gammaControl->SetGammaRamp(calibrate ? DDSGR_CALIBRATE : 0, (DDGAMMARAMP*)gammaRamp);

	gammaControl->Release();
	}
	}
	}

	void FrameBufferDD::getGammaRamp(GammaRamp *gammaRamp)
	{
	IDirectDrawGammaControl *gammaControl = 0;

	if(frontBuffer)
	{
	frontBuffer->QueryInterface(IID_IDirectDrawGammaControl, (void**)&gammaControl);

	if(gammaControl)
	{
	gammaControl->GetGammaRamp(0, (DDGAMMARAMP*)gammaRamp);

	gammaControl->Release();
	}
	}
	}

	void *FrameBufferDD::lock()
	{
	if(framebuffer)
	{
	return framebuffer;
	}

	if(!readySurfaces())
	{
	return nullptr;
	}

	DDSURFACEDESC DDSD;
	DDSD.dwSize = sizeof(DDSD);

	long result = backBuffer->Lock(0, &DDSD, DDLOCK_WAIT, 0);

	if(result == DD_OK)
	{
	width = DDSD.dwWidth;
	height = DDSD.dwHeight;
	stride = DDSD.lPitch;

	framebuffer = DDSD.lpSurface;

	return framebuffer;
	}

	return nullptr;
	}

	void FrameBufferDD::unlock()
	{
	if(!framebuffer \|\| !backBuffer) return;

	backBuffer->Unlock(0);

	framebuffer = nullptr;
	}

	void FrameBufferDD::drawText(int x, int y, const char *string, ...)
	{
	char buffer[256];
	va_list arglist;

	va_start(arglist, string);
	vsprintf(buffer, string, arglist);
	va_end(arglist);

	HDC hdc;

	backBuffer->GetDC(&hdc);

	SetBkColor(hdc, RGB(0, 0, 255));
	SetTextColor(hdc, RGB(255, 255, 255));

	TextOut(hdc, x, y, buffer, lstrlen(buffer));

	backBuffer->ReleaseDC(hdc);
	}

	bool FrameBufferDD::getScanline(bool &inVerticalBlank, unsigned int &scanline)
	{
	HRESULT result = directDraw->GetScanLine((unsigned long*)&scanline);

	if(result == DD_OK)
	{
	inVerticalBlank = false;
	}
	else if(result == DDERR_VERTICALBLANKINPROGRESS)
	{
	inVerticalBlank = true;
	}
	else if(result == DDERR_UNSUPPORTED)
	{
	return false;
	}
	else ASSERT(false);

	return true;
	}

	void FrameBufferDD::releaseAll()
	{
	unlock();

	if(backBuffer)
	{
	backBuffer->Release();
	backBuffer = 0;
	}

	if(frontBuffer)
	{
	frontBuffer->Release();
	frontBuffer = 0;
	}

	if(directDraw)
	{
	directDraw->SetCooperativeLevel(0, DDSCL_NORMAL);
	directDraw->Release();
	directDraw = 0;
	}
	}
	}