feat(screenshot): Add threaded JPEG/PNG screenshots without game stalls

CMakeLists.txt

@@ -65,6 +65,7 @@ endif()
 include(cmake/config.cmake)
 include(cmake/gamespy.cmake)
 include(cmake/lzhl.cmake)
+include(cmake/stb.cmake)
 
 if (IS_VS6_BUILD)
     # The original max sdk does not compile against a modern compiler.

Core/GameEngine/Include/Common/UserPreferences.h

@@ -93,6 +93,7 @@ class OptionPreferences : public UserPreferences
 	Bool getAlternateMouseModeEnabled(void);	// convenience function
 	Bool getRetaliationModeEnabled();					// convenience function
 	Bool getDoubleClickAttackMoveEnabled(void);	// convenience function
+	Int getJPEGQuality(void);									// convenience function
 	Real getScrollFactor(void);								// convenience function
 	Bool getDrawScrollAnchor(void);
 	Bool getMoveScrollAnchor(void);

Core/GameEngineDevice/CMakeLists.txt

@@ -72,6 +72,7 @@ set(GAMEENGINEDEVICE_SRC
     Include/W3DDevice/GameClient/W3DTreeBuffer.h
     Include/W3DDevice/GameClient/W3DVideoBuffer.h
     Include/W3DDevice/GameClient/W3DView.h
+    Include/W3DDevice/GameClient/W3DScreenshot.h
 #    Include/W3DDevice/GameClient/W3DVolumetricShadow.h
     Include/W3DDevice/GameClient/W3DWater.h
     Include/W3DDevice/GameClient/W3DWaterTracks.h
@@ -173,6 +174,8 @@ set(GAMEENGINEDEVICE_SRC
     Source/W3DDevice/GameClient/W3DTreeBuffer.cpp
     Source/W3DDevice/GameClient/W3DVideoBuffer.cpp
     Source/W3DDevice/GameClient/W3DView.cpp
+#    Source/W3DDevice/GameClient/W3DScreenshot.cpp
+    Source/W3DDevice/GameClient/stb_image_write_impl.cpp
 #    Source/W3DDevice/GameClient/W3dWaypointBuffer.cpp
 #    Source/W3DDevice/GameClient/W3DWebBrowser.cpp
     Source/W3DDevice/GameClient/Water/W3DWater.cpp
@@ -218,6 +221,7 @@ target_include_directories(corei_gameenginedevice_public INTERFACE
 target_link_libraries(corei_gameenginedevice_private INTERFACE
     corei_always
     corei_main
+    stb
 )
 
 target_link_libraries(corei_gameenginedevice_public INTERFACE

Core/GameEngineDevice/Include/W3DDevice/GameClient/W3DScreenshot.h

@@ -0,0 +1,24 @@
+/*
+**	Command & Conquer Generals Zero Hour(tm)
+**	Copyright 2025 TheSuperHackers
+**
+**	This program is free software: you can redistribute it and/or modify
+**	it under the terms of the GNU General Public License as published by
+**	the Free Software Foundation, either version 3 of the License, or
+**	(at your option) any later version.
+**
+**	This program is distributed in the hope that it will be useful,
+**	but WITHOUT ANY WARRANTY; without even the implied warranty of
+**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**	GNU General Public License for more details.
+**
+**	You should have received a copy of the GNU General Public License
+**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include "GameClient/Display.h"
+
+void W3D_TakeCompressedScreenshot(ScreenshotFormat format, int quality = 0);
+

Core/GameEngineDevice/Source/W3DDevice/GameClient/stb_image_write_impl.cpp

@@ -0,0 +1,21 @@
+/*
+**	Command & Conquer Generals(tm)
+**	Copyright 2025 TheSuperHackers
+**
+**	This program is free software: you can redistribute it and/or modify
+**	it under the terms of the GNU General Public License as published by
+**	the Free Software Foundation, either version 3 of the License, or
+**	(at your option) any later version.
+**
+**	This program is distributed in the hope that it will be useful,
+**	but WITHOUT ANY WARRANTY; without even the implied warranty of
+**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**	GNU General Public License for more details.
+**
+**	You should have received a copy of the GNU General Public License
+**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include <stb_image_write.h>
+

Generals/Code/GameEngine/Include/Common/GlobalData.h

@@ -142,6 +142,7 @@ class GlobalData : public SubsystemInterface
 	Bool m_clientRetaliationModeEnabled;
 	Bool m_doubleClickAttackMove;
 	Bool m_rightMouseAlwaysScrolls;
+	Int m_jpegQuality;
 	Bool m_useWaterPlane;
 	Bool m_useCloudPlane;
 	Bool m_useShadowVolumes;

Generals/Code/GameEngine/Include/Common/MessageStream.h

@@ -257,7 +257,8 @@ class GameMessage : public MemoryPoolObject
 		MSG_META_BEGIN_PREFER_SELECTION,						///< The Shift key has been depressed alone
 		MSG_META_END_PREFER_SELECTION,							///< The Shift key has been released.
 
-		MSG_META_TAKE_SCREENSHOT,										///< take screenshot
+		MSG_META_TAKE_SCREENSHOT,										///< take JPEG screenshot (F12)
+		MSG_META_TAKE_SCREENSHOT_PNG,							///< take PNG screenshot (CTRL+F12, lossless)
 		MSG_META_ALL_CHEER,													///< Yay! :)
 		MSG_META_TOGGLE_ATTACKMOVE,									///< enter attack-move mode
 

Generals/Code/GameEngine/Include/GameClient/Display.h

@@ -33,6 +33,12 @@
 #include "GameClient/GameFont.h"
 #include "GameClient/View.h"
 
+enum ScreenshotFormat
+{
+	SCREENSHOT_JPEG,
+	SCREENSHOT_PNG
+};
+
 struct ShroudLevel
 {
 	Short m_currentShroud;		///< A Value of 1 means shrouded.  0 is not.  Negative is the count of people looking.
@@ -166,7 +172,7 @@ class Display : public SubsystemInterface
 	virtual void preloadModelAssets( AsciiString model ) = 0;	///< preload model asset
 	virtual void preloadTextureAssets( AsciiString texture ) = 0;	///< preload texture asset
 
-	virtual void takeScreenShot(void) = 0;										///< saves screenshot to a file
+	virtual void takeScreenShot(ScreenshotFormat format) = 0;			///< saves screenshot in specified format
 	virtual void toggleMovieCapture(void) = 0;							///< starts saving frames to an avi or frame sequence
 	virtual void toggleLetterBox(void) = 0;										///< enabled letter-boxed display
 	virtual void enableLetterBox(Bool enable) = 0;						///< forces letter-boxed display on/off

Generals/Code/GameEngine/Source/Common/GlobalData.cpp

@@ -645,6 +645,7 @@ GlobalData::GlobalData()
 	m_enableDynamicLOD = TRUE;
 	m_enableStaticLOD = TRUE;
 	m_rightMouseAlwaysScrolls = FALSE;
+	m_jpegQuality = 80;
 	m_useWaterPlane = FALSE;
 	m_useCloudPlane = FALSE;
 	m_downwindAngle = ( -0.785f );//Northeast!
@@ -1189,6 +1190,7 @@ void GlobalData::parseGameDataDefinition( INI* ini )
 	TheWritableGlobalData->m_useAlternateMouse = optionPref.getAlternateMouseModeEnabled();
 	TheWritableGlobalData->m_clientRetaliationModeEnabled = optionPref.getRetaliationModeEnabled();
 	TheWritableGlobalData->m_doubleClickAttackMove = optionPref.getDoubleClickAttackMoveEnabled();
+	TheWritableGlobalData->m_jpegQuality = optionPref.getJPEGQuality();
 	TheWritableGlobalData->m_keyboardScrollFactor = optionPref.getScrollFactor();
 	TheWritableGlobalData->m_drawScrollAnchor = optionPref.getDrawScrollAnchor();
 	TheWritableGlobalData->m_moveScrollAnchor = optionPref.getMoveScrollAnchor();

Generals/Code/GameEngine/Source/Common/MessageStream.cpp

@@ -364,6 +364,7 @@ const char *GameMessage::getCommandTypeAsString(GameMessage::Type t)
 	CASE_LABEL(MSG_META_BEGIN_PREFER_SELECTION)
 	CASE_LABEL(MSG_META_END_PREFER_SELECTION)
 	CASE_LABEL(MSG_META_TAKE_SCREENSHOT)
+	CASE_LABEL(MSG_META_TAKE_SCREENSHOT_PNG)
 	CASE_LABEL(MSG_META_ALL_CHEER)
 	CASE_LABEL(MSG_META_TOGGLE_ATTACKMOVE)
 	CASE_LABEL(MSG_META_BEGIN_CAMERA_ROTATE_LEFT)

Generals/Code/GameEngine/Source/GameClient/GUI/GUICallbacks/Menus/OptionsMenu.cpp

@@ -354,6 +354,18 @@ Bool OptionPreferences::getDoubleClickAttackMoveEnabled(void)
 	return FALSE;
 }
 
+Int OptionPreferences::getJPEGQuality(void)
+{
+	OptionPreferences::const_iterator it = find("JPEGQuality");
+	if (it == end())
+		return 80;
+
+	Int quality = atoi(it->second.str());
+	if (quality < 1) quality = 1;
+	if (quality > 100) quality = 100;
+	return quality;
+}
+
 Real OptionPreferences::getScrollFactor(void)
 {
 	OptionPreferences::const_iterator it = find("ScrollFactor");

Generals/Code/GameEngine/Source/GameClient/MessageStream/CommandXlat.cpp

@@ -3418,7 +3418,15 @@ GameMessageDisposition CommandTranslator::translateGameMessage(const GameMessage
 		case GameMessage::MSG_META_TAKE_SCREENSHOT:
 		{
 			if (TheDisplay)
-				TheDisplay->takeScreenShot();
+				TheDisplay->takeScreenShot(SCREENSHOT_JPEG);
+			disp = DESTROY_MESSAGE;
+			break;
+		}
+
+		case GameMessage::MSG_META_TAKE_SCREENSHOT_PNG:
+		{
+			if (TheDisplay)
+				TheDisplay->takeScreenShot(SCREENSHOT_PNG);
 			disp = DESTROY_MESSAGE;
 			break;
 		}

Generals/Code/GameEngine/Source/GameClient/MessageStream/MetaEvent.cpp

@@ -163,6 +163,7 @@ static const LookupListRec GameMessageMetaTypeNames[] =
 	{ "END_PREFER_SELECTION",											GameMessage::MSG_META_END_PREFER_SELECTION },
 
 	{ "TAKE_SCREENSHOT",													GameMessage::MSG_META_TAKE_SCREENSHOT },
+	{ "TAKE_SCREENSHOT_PNG",											GameMessage::MSG_META_TAKE_SCREENSHOT_PNG },
 	{ "ALL_CHEER",																GameMessage::MSG_META_ALL_CHEER },
 
 	{ "BEGIN_CAMERA_ROTATE_LEFT",									GameMessage::MSG_META_BEGIN_CAMERA_ROTATE_LEFT },
@@ -813,6 +814,26 @@ MetaMapRec *MetaMap::getMetaMapRec(GameMessage::Type t)
 			map->m_usableIn = COMMANDUSABLE_GAME;
 		}
 	}
+	{
+		MetaMapRec *map = TheMetaMap->getMetaMapRec(GameMessage::MSG_META_TAKE_SCREENSHOT);
+		if (map->m_key == MK_NONE)
+		{
+			map->m_key = MK_F12;
+			map->m_transition = DOWN;
+			map->m_modState = NONE;
+			map->m_usableIn = COMMANDUSABLE_EVERYWHERE;
+		}
+	}
+	{
+		MetaMapRec *map = TheMetaMap->getMetaMapRec(GameMessage::MSG_META_TAKE_SCREENSHOT_PNG);
+		if (map->m_key == MK_NONE)
+		{
+			map->m_key = MK_F12;
+			map->m_transition = DOWN;
+			map->m_modState = CTRL;
+			map->m_usableIn = COMMANDUSABLE_EVERYWHERE;
+		}
+	}
 
 #if defined(RTS_DEBUG)
 	{

Generals/Code/GameEngineDevice/CMakeLists.txt

@@ -139,6 +139,7 @@ set(GAMEENGINEDEVICE_SRC
     Source/W3DDevice/GameClient/W3DDebugDisplay.cpp
     Source/W3DDevice/GameClient/W3DDebugIcons.cpp
     Source/W3DDevice/GameClient/W3DDisplay.cpp
+    Source/W3DDevice/GameClient/W3DScreenshot.cpp
     Source/W3DDevice/GameClient/W3DDisplayString.cpp
     Source/W3DDevice/GameClient/W3DDisplayStringManager.cpp
     Source/W3DDevice/GameClient/W3DDynamicLight.cpp
@@ -200,6 +201,7 @@ target_link_libraries(g_gameenginedevice PRIVATE
     corei_gameenginedevice_private
     gi_always
     gi_main
+    stb
 )
 
 target_link_libraries(g_gameenginedevice PUBLIC

Generals/Code/GameEngineDevice/Include/W3DDevice/GameClient/W3DDisplay.h

@@ -120,7 +120,7 @@ class W3DDisplay : public Display
 
 	virtual VideoBuffer*	createVideoBuffer( void ) ;							///< Create a video buffer that can be used for this display
 
-	virtual void takeScreenShot(void);						//save screenshot to file
+	virtual void takeScreenShot(ScreenshotFormat format);	//save screenshot in specified format
 	virtual void toggleMovieCapture(void);			//enable AVI or frame capture mode.
 
 	virtual void toggleLetterBox(void);	///<enabled letter-boxed display

Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DDisplay.cpp

@@ -41,6 +41,7 @@ static void drawFramerateBar(void);
 #include <time.h>
 
 // USER INCLUDES //////////////////////////////////////////////////////////////
+#include "W3DDevice/GameClient/W3DScreenshot.h"
 #include "Common/FramePacer.h"
 #include "Common/ThingFactory.h"
 #include "Common/GlobalData.h"
@@ -2879,142 +2880,6 @@ static void CreateBMPFile(LPTSTR pszFile, char *image, Int width, Int height)
 }
 
 ///Save Screen Capture to a file
-void W3DDisplay::takeScreenShot(void)
-{
-	char leafname[256];
-	char pathname[1024];
-
-	static int frame_number = 1;
-
-	Bool done = false;
-	while (!done) {
-#ifdef CAPTURE_TO_TARGA
-		sprintf( leafname, "%s%.3d.tga", "sshot", frame_number++);
-#else
-		sprintf( leafname, "%s%.3d.bmp", "sshot", frame_number++);
-#endif
-		strlcpy(pathname, TheGlobalData->getPath_UserData().str(), ARRAY_SIZE(pathname));
-		strlcat(pathname, leafname, ARRAY_SIZE(pathname));
-		if (_access( pathname, 0 ) == -1)
-			done = true;
-	}
-
-	// TheSuperHackers @bugfix xezon 21/05/2025 Get the back buffer and create a copy of the surface.
-	// Originally this code took the front buffer and tried to lock it. This does not work when the
-	// render view clips outside the desktop boundaries. It crashed the game.
-	SurfaceClass* surface = DX8Wrapper::_Get_DX8_Back_Buffer();
-
-	SurfaceClass::SurfaceDescription surfaceDesc;
-	surface->Get_Description(surfaceDesc);
-
-	SurfaceClass* surfaceCopy = NEW_REF(SurfaceClass, (DX8Wrapper::_Create_DX8_Surface(surfaceDesc.Width, surfaceDesc.Height, surfaceDesc.Format)));
-	DX8Wrapper::_Copy_DX8_Rects(surface->Peek_D3D_Surface(), nullptr, 0, surfaceCopy->Peek_D3D_Surface(), nullptr);
-
-	surface->Release_Ref();
-	surface = nullptr;
-
-	struct Rect
-	{
-		int Pitch;
-		void* pBits;
-	} lrect;
-
-	lrect.pBits = surfaceCopy->Lock(&lrect.Pitch);
-	if (lrect.pBits == nullptr)
-	{
-		surfaceCopy->Release_Ref();
-		return;
-	}
-
-	unsigned int x,y,index,index2,width,height;
-
-	width = surfaceDesc.Width;
-	height = surfaceDesc.Height;
-
-	char *image=NEW char[3*width*height];
-#ifdef CAPTURE_TO_TARGA
-	//bytes are mixed in targa files, not rgb order.
-	for (y=0; y<height; y++)
-	{
-		for (x=0; x<width; x++)
-		{
-			// index for image
-			index=3*(x+y*width);
-			// index for fb
-			index2=y*lrect.Pitch+4*x;
-
-			image[index]=*((char *) lrect.pBits + index2+2);
-			image[index+1]=*((char *) lrect.pBits + index2+1);
-			image[index+2]=*((char *) lrect.pBits + index2+0);
-		}
-	}
-
-	surfaceCopy->Unlock();
-	surfaceCopy->Release_Ref();
-	surfaceCopy = nullptr;
-
-	Targa targ;
-	memset(&targ.Header,0,sizeof(targ.Header));
-	targ.Header.Width=width;
-	targ.Header.Height=height;
-	targ.Header.PixelDepth=24;
-	targ.Header.ImageType=TGA_TRUECOLOR;
-	targ.SetImage(image);
-	targ.YFlip();
-
-	targ.Save(pathname,TGAF_IMAGE,false);
-#else	//capturing to bmp file
-	//bmp is same byte order
-	for (y=0; y<height; y++)
-	{
-		for (x=0; x<width; x++)
-		{
-			// index for image
-			index=3*(x+y*width);
-			// index for fb
-			index2=y*lrect.Pitch+4*x;
-
-			image[index]=*((char *) lrect.pBits + index2+0);
-			image[index+1]=*((char *) lrect.pBits + index2+1);
-			image[index+2]=*((char *) lrect.pBits + index2+2);
-		}
-	}
-
-	surfaceCopy->Unlock();
-	surfaceCopy->Release_Ref();
-	surfaceCopy = nullptr;
-
-	//Flip the image
-	char *ptr,*ptr1;
-	char  v,v1;
-
-	for (y = 0; y < (height >> 1); y++)
-	{
-		/* Compute address of lines to exchange. */
-		ptr = (image + ((width * y) * 3));
-		ptr1 = (image + ((width * (height - 1)) * 3));
-		ptr1 -= ((width * y) * 3);
-
-		/* Exchange all the pixels on this scan line. */
-		for (x = 0; x < (width * 3); x++)
-			{
-			v = *ptr;
-			v1 = *ptr1;
-			*ptr = v1;
-			*ptr1 = v;
-			ptr++;
-			ptr1++;
-			}
-	}
-	CreateBMPFile(pathname, image, width, height);
-#endif
-
-	delete [] image;
-
-	UnicodeString ufileName;
-	ufileName.translate(leafname);
-	TheInGameUI->message(TheGameText->fetch("GUI:ScreenCapture"), ufileName.str());
-}
 
 /** Start/Stop capturing an AVI movie*/
 void W3DDisplay::toggleMovieCapture(void)