Added new render mode with reduced tearing.

Available under new option Window->Alternative Rendering.
Issue #29.

SpaceCadetPinball/SpaceCadetPinball.rc

@@ -98,6 +98,7 @@ BEGIN
         POPUP "&Window"
         BEGIN
             MENUITEM "&Uniform Scaling",            Menu1_WindowUniformScale
+            MENUITEM "&Alternative Rendering",      Menu1_AlternativeRender
         END
     END
     POPUP "&Help"

SpaceCadetPinball/options.cpp

@@ -108,6 +108,8 @@ void options::init(HMENU menuHandle)
 	Options.RightTableBumpKey = get_int(nullptr, "Right Table Bump key", Options.RightTableBumpKey);
 	Options.BottomTableBumpKey = get_int(nullptr, "Bottom Table Bump key", Options.BottomTableBumpKey);
 	Options.UniformScaling = get_int(nullptr, "Uniform scaling", true);
+	Options.AlternativeRender = get_int(nullptr, "Alternative Render", false);
+
 	menu_check(Menu1_Sounds, Options.Sounds);
 	Sound::Enable(0, 7, Options.Sounds);
 	menu_check(Menu1_Music, Options.Music);
@@ -117,6 +119,7 @@ void options::init(HMENU menuHandle)
 	menu_check(Menu1_3Players, Options.Players == 3);
 	menu_check(Menu1_4Players, Options.Players == 4);
 	menu_check(Menu1_WindowUniformScale, Options.UniformScaling);
+	menu_check(Menu1_AlternativeRender, Options.AlternativeRender);
 	auto tmpBuf = memory::allocate(0x1F4u);
 	if (tmpBuf)
 	{
@@ -149,6 +152,7 @@ void options::uninit()
 	set_int(nullptr, "Bottom Table Bump key", Options.BottomTableBumpKey);
 	set_int(nullptr, "Screen Resolution", Options.Resolution);
 	set_int(nullptr, "Uniform scaling", Options.UniformScaling);
+	set_int(nullptr, "Alternative Render", Options.AlternativeRender);
 }
 
 void options::path_init(LPCSTR regPath)
@@ -343,6 +347,12 @@ void options::toggle(UINT uIDCheckItem)
 		fullscrn::window_size_changed();
 		fullscrn::paint();
 		break;
+	case Menu1_AlternativeRender:
+		Options.AlternativeRender ^= true;
+		menu_check(Menu1_AlternativeRender, Options.AlternativeRender);
+		fullscrn::window_size_changed();
+		fullscrn::paint();
+		break;
 	default:
 		break;
 	}

SpaceCadetPinball/options.h

@@ -23,6 +23,7 @@ struct optionsStruct
 	int BottomTableBumpKeyDft;
 	int Resolution;
 	bool UniformScaling;
+	bool AlternativeRender;
 };
 
 

SpaceCadetPinball/pb.cpp

@@ -26,7 +26,7 @@
 
 TPinballTable* pb::MainTable = nullptr;
 datFileStruct* pb::record_table = nullptr;
-int pb::time_ticks = 0, pb::demo_mode = 0, pb::game_mode = 2, pb::mode_countdown_, pb::state;
+int pb::time_ticks = 0, pb::demo_mode = 0, pb::game_mode = 2, pb::mode_countdown_, pb::state, pb::frameCounter = 0;
 float pb::time_now, pb::time_next, pb::ball_speed_limit;
 high_score_struct pb::highscore_table[5];
 bool pb::FullTiltMode = false, pb::cheat_mode = false;
@@ -129,9 +129,7 @@ void pb::reset_table()
 
 void pb::firsttime_setup()
 {
-	render::blit = 0;
-	render::update();
-	render::blit = 1;
+	render::update(false);
 }
 
 void pb::paint()
@@ -223,6 +221,8 @@ void pb::ballset(int x, int y)
 
 int pb::frame(int time)
 {
+	static int frameTime = 0;
+
 	if (time > 100)
 		time = 100;
 	float timeMul = time * 0.001f;
@@ -244,7 +244,29 @@ int pb::frame(int time)
 			nudge::nudge_count = nudgeDec;
 		}
 		timer::check();
-		render::update();
+
+		if (!options::Options.AlternativeRender)
+		{
+			render::update(true);
+		}
+		else
+		{
+			// Screen update at UPS > screen refresh rate cause tearing.
+			// Especially noticeable on fast moving ball in scaled up window.
+			// Retained render prevents frame skip. The next best thing - complete refresh at fixed rate. 
+			render::update(false);
+
+			// Frame time at 60 FPS = 16.(6) ms = (16 + 17 + 17) / 3
+			auto targetTime = frameCounter % 3 == 0 ? 16 : 17;
+			frameTime += time;
+			if (frameTime >= targetTime)
+			{
+				frameTime = min(frameTime - targetTime, 100);
+				render::shift(0, 0, 0, 0, MainTable->Width, MainTable->Height);
+				frameCounter++;
+			}
+		}
+
 		score::update(MainTable->CurScoreStruct);
 		if (!MainTable->TiltLockFlag)
 		{
@@ -288,8 +310,8 @@ void pb::timed_frame(float timeNow, float timeDelta, bool drawBalls)
 					ball->Acceleration.Y = ball->Speed * ball->Acceleration.Y;
 					maths::vector_add(&ball->Acceleration, &vec2);
 					ball->Speed = maths::normalize_2d(&ball->Acceleration);
-					ball->InvAcceleration.X = ball->Acceleration.X == 0.0f ? 1000000000.0f : 1.0f / ball->Acceleration.X;
-					ball->InvAcceleration.Y = ball->Acceleration.Y == 0.0f ? 1000000000.0f : 1.0f / ball->Acceleration.Y;
+					ball->InvAcceleration.X = ball->Acceleration.X == 0.0f ? 1.0e9f : 1.0f / ball->Acceleration.X;
+					ball->InvAcceleration.Y = ball->Acceleration.Y == 0.0f ? 1.0e9f : 1.0f / ball->Acceleration.Y;
 				}
 
 				auto timeDelta2 = timeDelta;

SpaceCadetPinball/pb.h

@@ -10,7 +10,7 @@ class pb
 public:
 	static int time_ticks;
 	static float ball_speed_limit, time_now, time_next;
-	static int game_mode;
+	static int game_mode, frameCounter;
 	static bool cheat_mode;
 	static datFileStruct* record_table;
 	static TPinballTable* MainTable;

SpaceCadetPinball/render.cpp

@@ -2,7 +2,6 @@
 #include "render.h"
 #include "memory.h"
 
-int render::blit = 0;
 int render::many_dirty, render::many_sprites, render::many_balls;
 render_sprite_type_struct **render::dirty_list, **render::sprite_list, **render::ball_list;
 zmap_header_type* render::background_zmap;
@@ -60,83 +59,69 @@ void render::uninit()
 	many_balls = 0;
 }
 
-void render::update()
+void render::update(bool blit)
 {
 	rectangle_type overlapRect{};
 
-	auto dirtyPtr = dirty_list;
-	for (int index = 0; index < many_dirty; ++dirtyPtr, ++index)
+	for (int index = 0; index < many_dirty; ++index)
 	{
-		auto curSprite = *dirtyPtr;
-		if ((*dirtyPtr)->VisualType != VisualType::None)
+		auto curSprite = dirty_list[index];
+		bool clearSprite = false;
+		switch (curSprite->VisualType)
 		{
-			if ((*dirtyPtr)->VisualType == VisualType::Sprite)
-			{
-				if (curSprite->BmpRectCopy.Width > 0)
-					maths::enclosing_box(&curSprite->BmpRectCopy, &curSprite->BmpRect, &curSprite->DirtyRect);
-
-				if (!maths::rectangle_clip(&curSprite->DirtyRect, &vscreen_rect, &curSprite->DirtyRect))
-				{
-					curSprite->DirtyRect.Width = -1;
-					continue;
-				}
+		case VisualType::Sprite:
+			if (curSprite->BmpRectCopy.Width > 0)
+				maths::enclosing_box(&curSprite->BmpRectCopy, &curSprite->BmpRect, &curSprite->DirtyRect);
 
-				auto yPos = curSprite->DirtyRect.YPosition;
-				auto width = curSprite->DirtyRect.Width;
-				auto xPos = curSprite->DirtyRect.XPosition;
-				auto height = curSprite->DirtyRect.Height;
-				zdrv::fill(&zscreen, width, height, xPos, yPos, 0xFFFF);
-				if (background_bitmap)
-					gdrv::copy_bitmap(&vscreen, width, height, xPos, yPos, background_bitmap, xPos, yPos);
-				else
-					gdrv::fill_bitmap(&vscreen, width, height, xPos, yPos, 0);
-			}
+			if (maths::rectangle_clip(&curSprite->DirtyRect, &vscreen_rect, &curSprite->DirtyRect))
+				clearSprite = true;
+			else
+				curSprite->DirtyRect.Width = -1;
+			break;
+		case VisualType::None:
+			if (maths::rectangle_clip(&curSprite->BmpRect, &vscreen_rect, &curSprite->DirtyRect))
+				clearSprite = !curSprite->Bmp;
+			else
+				curSprite->DirtyRect.Width = -1;
+			break;
+		default: break;
 		}
-		else
+
+		if (clearSprite)
 		{
-			if (!maths::rectangle_clip(&curSprite->BmpRect, &vscreen_rect, &curSprite->DirtyRect))
-			{
-				curSprite->DirtyRect.Width = -1;
-				continue;
-			}
-			if (!curSprite->Bmp)
-			{
-				auto yPos = curSprite->DirtyRect.YPosition;
-				auto width = curSprite->DirtyRect.Width;
-				auto xPos = curSprite->DirtyRect.XPosition;
-				auto height = curSprite->DirtyRect.Height;
-				zdrv::fill(&zscreen, width, height, xPos, yPos, 0xFFFF);
-				if (background_bitmap)
-					gdrv::copy_bitmap(&vscreen, width, height, xPos, yPos, background_bitmap, xPos, yPos);
-				else
-					gdrv::fill_bitmap(&vscreen, width, height, xPos, yPos, 0);
-			}
+			auto yPos = curSprite->DirtyRect.YPosition;
+			auto width = curSprite->DirtyRect.Width;
+			auto xPos = curSprite->DirtyRect.XPosition;
+			auto height = curSprite->DirtyRect.Height;
+			zdrv::fill(&zscreen, width, height, xPos, yPos, 0xFFFF);
+			if (background_bitmap)
+				gdrv::copy_bitmap(&vscreen, width, height, xPos, yPos, background_bitmap, xPos, yPos);
+			else
+				gdrv::fill_bitmap(&vscreen, width, height, xPos, yPos, 0);
 		}
 	}
 
-	dirtyPtr = dirty_list;
 	for (int index = 0; index < many_dirty; ++index)
 	{
-		auto sprite = *dirtyPtr;
-		if ((*dirtyPtr)->DirtyRect.Width > 0 && (sprite->VisualType == VisualType::None || sprite->VisualType ==
+		auto sprite = dirty_list[index];
+		if (sprite->DirtyRect.Width > 0 && (sprite->VisualType == VisualType::None || sprite->VisualType ==
 			VisualType::Sprite))
-			repaint(*dirtyPtr);
-		++dirtyPtr;
+			repaint(sprite);
 	}
 
-	paint_balls();
 	if (blit)
 	{
+		paint_balls();
 		gdrv::start_blit_sequence();
 
 		auto xPos = vscreen.XPosition + offset_x;
 		auto yPos = vscreen.YPosition + offset_y;
-		dirtyPtr = dirty_list;
-		for (int index = 0; index < many_dirty; ++dirtyPtr, ++index)
+
+		for (int index = 0; index < many_dirty; ++index)
 		{
-			auto sprite = *dirtyPtr;
-			auto dirtyRect = &(*dirtyPtr)->DirtyRect;
-			auto width2 = (*dirtyPtr)->DirtyRect.Width;
+			auto sprite = dirty_list[index];
+			auto dirtyRect = &sprite->DirtyRect;
+			auto width2 = sprite->DirtyRect.Width;
 			if (width2 > 0)
 				gdrv::blit_sequence(
 					&vscreen,
@@ -147,21 +132,16 @@ void render::update()
 					width2,
 					dirtyRect->Height);
 
-			auto rect = &sprite->BmpRectCopy;
-			rect->XPosition = dirtyRect->XPosition;
-			rect->YPosition = dirtyRect->YPosition;
-			rect->Width = dirtyRect->Width;
-			rect->Height = dirtyRect->Height;
-
+			sprite->BmpRectCopy = *dirtyRect;
 			if (sprite->UnknownFlag != 0)
 				remove_sprite(sprite);
 		}
 
-		dirtyPtr = ball_list;
-		for (int index = 0; index < many_balls; ++dirtyPtr, ++index)
+		for (int index = 0; index < many_balls; ++index)
 		{
-			auto rectCopy = &(*dirtyPtr)->BmpRectCopy;
-			auto dirtyRect = &(*dirtyPtr)->DirtyRect;
+			auto sprite = ball_list[index];
+			auto rectCopy = &sprite->BmpRectCopy;
+			auto dirtyRect = &sprite->DirtyRect;
 			if (maths::overlapping_box(dirtyRect, rectCopy, &overlapRect) && dirtyRect->Width > 0)
 			{
 				if (overlapRect.Width > 0)
@@ -198,13 +178,22 @@ void render::update()
 		}
 
 		gdrv::end_blit_sequence();
+		unpaint_balls();
+	}
+	else
+	{
+		for (int index = 0; index < many_dirty; ++index)
+		{
+			auto sprite = dirty_list[index];
+			sprite->BmpRectCopy = sprite->DirtyRect;
+			if (sprite->UnknownFlag != 0)
+				remove_sprite(sprite);
+		}
 	}
 
 	many_dirty = 0;
-	unpaint_balls();
 }
 
-
 void render::paint()
 {
 	paint_balls();
@@ -473,7 +462,7 @@ void render::paint_balls()
 
 void render::unpaint_balls()
 {
-	for (int index = many_balls-1; index >= 0; index--)
+	for (int index = many_balls - 1; index >= 0; index--)
 	{
 		auto curBall = ball_list[index];
 		if (curBall->DirtyRect.Width > 0)

SpaceCadetPinball/render.h

@@ -31,7 +31,6 @@ struct render_sprite_type_struct
 class render
 {
 public:
-	static int blit;
 	static int many_dirty, many_sprites, many_balls;
 	static render_sprite_type_struct **dirty_list, **sprite_list, **ball_list;
 	static zmap_header_type* background_zmap;
@@ -43,7 +42,7 @@ class render
 
 	static void init(gdrv_bitmap8* bmp, float zMin, float zScaler, int width, int height);
 	static void uninit();
-	static void update();
+	static void update(bool blit);
 	static void paint();
 	static void sprite_modified(render_sprite_type_struct* sprite);
 	static render_sprite_type_struct* create_sprite(VisualType visualType, gdrv_bitmap8* bmp,

SpaceCadetPinball/resource.h

@@ -240,6 +240,7 @@
 #define DLG_HIGHSCORES_EditName3        603
 #define DLG_HIGHSCORES_EditName4        604
 #define DLG_HIGHSCORES_EditName5        605
+#define Menu1_AlternativeRender         601
 
 // Next default values for new objects
 // 

SpaceCadetPinball/winmain.cpp

@@ -220,7 +220,16 @@ int winmain::WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLi
 				if (prevTime)
 				{
 					char buf[60];
-					sprintf_s(buf, "Frames/sec = %02.02f", 300.0f / (static_cast<float>(curTime - prevTime) * 0.001f));
+					auto dt = static_cast<float>(curTime - prevTime) * 0.001f;
+					if (!options::Options.AlternativeRender)
+						sprintf_s(buf, "Frames/sec = %02.02f", 300.0f / dt);
+					else 
+					{
+						sprintf_s(buf, "Updates/sec = %02.02f Frames/sec = %02.02f",
+							300.0f / dt, pb::frameCounter / dt);
+						pb::frameCounter = 0;
+					}
+
 					SetWindowTextA(hwnd_frame, buf);
 
 					if (DispGRhistory)
@@ -610,6 +619,7 @@ LRESULT CALLBACK winmain::message_handler(HWND hWnd, UINT Msg, WPARAM wParam, LP
 		case Menu1_800x600:
 		case Menu1_1024x768:
 		case Menu1_WindowUniformScale:
+		case Menu1_AlternativeRender:
 			options::toggle(wParamI);
 			break;
 		case Menu1_Help_Topics: