PresentVScreen: fixed sub pixel offset.

SDL<2.0.10 uses crude approximation.

SpaceCadetPinball/options.cpp

@@ -3,6 +3,7 @@
 
 #include "fullscrn.h"
 #include "midi.h"
+#include "render.h"
 #include "Sound.h"
 #include "winmain.h"
 
@@ -246,7 +247,7 @@ void options::toggle(Menu1 uIDCheckItem)
 		break;
 	case Menu1::WindowLinearFilter:
 		Options.LinearFiltering ^= true;
-		winmain::Restart();
+		render::recreate_screen_texture();
 		break;
 	default:
 		break;

SpaceCadetPinball/pch.h

@@ -77,4 +77,10 @@ inline float RandFloat()
 	return static_cast<float>(std::rand() / static_cast<double>(RAND_MAX));
 }
 
+template <typename T> constexpr
+int Sign(T val)
+{
+	return (T(0) < val) - (val < T(0));
+}
+
 #endif //PCH_H

SpaceCadetPinball/render.cpp

@@ -42,17 +42,7 @@ void render::init(gdrv_bitmap8* bmp, float zMin, float zScaler, int width, int h
 	else
 		gdrv::fill_bitmap(vscreen, vscreen->Width, vscreen->Height, 0, 0, 0);
 
-	{
-		UsingSdlHint hint{SDL_HINT_RENDER_SCALE_QUALITY, options::Options.LinearFiltering ? "linear" : "nearest"};
-		vScreenTex = SDL_CreateTexture
-		(
-			winmain::Renderer,
-			SDL_PIXELFORMAT_ARGB8888,
-			SDL_TEXTUREACCESS_STREAMING,
-			width, height
-		);
-		SDL_SetTextureBlendMode(vScreenTex, SDL_BLENDMODE_NONE);
-	}
+	recreate_screen_texture();
 }
 
 void render::uninit()
@@ -69,6 +59,25 @@ void render::uninit()
 	dirty_list.clear();
 	sprite_list.clear();
 	SDL_DestroyTexture(vScreenTex);
+	vScreenTex = nullptr;
+}
+
+void render::recreate_screen_texture()
+{
+	if (vScreenTex != nullptr)
+	{
+		SDL_DestroyTexture(vScreenTex);
+	}
+
+	UsingSdlHint hint{ SDL_HINT_RENDER_SCALE_QUALITY, options::Options.LinearFiltering ? "linear" : "nearest" };
+	vScreenTex = SDL_CreateTexture
+	(
+		winmain::Renderer,
+		SDL_PIXELFORMAT_ARGB8888,
+		SDL_TEXTUREACCESS_STREAMING,
+		vscreen_rect.Width, vscreen_rect.Height
+	);
+	SDL_SetTextureBlendMode(vScreenTex, SDL_BLENDMODE_NONE);
 }
 
 void render::update()
@@ -554,29 +563,53 @@ void render::PresentVScreen()
 	}
 	else
 	{
-		int32_t srcSeparationX = static_cast<int32_t>(vscreen->Width * 0.625f);
-
-		SDL_Rect srcBoardRect = SDL_Rect
+		auto tableWidthCoef = static_cast<float>(pb::MainTable->Width) / vscreen->Width;
+		auto srcSeparationX = static_cast<int>(round(vscreen->Width * tableWidthCoef));
+		auto srcBoardRect = SDL_Rect
 		{
 			0, 0,
 			srcSeparationX, vscreen->Height
 		};
-
-		SDL_Rect srcSidebarRect = SDL_Rect
+		auto srcSidebarRect = SDL_Rect
 		{
 			srcSeparationX, 0,
 			vscreen->Width - srcSeparationX, vscreen->Height
 		};
 
-		int32_t dstSeparationX = static_cast<int32_t>(DestinationRect.w * 0.625f);
-
-		SDL_Rect dstBoardRect = SDL_Rect
+#if SDL_VERSION_ATLEAST(2, 0, 10)
+		// SDL_RenderCopyF was added in 2.0.10
+		auto dstSeparationX = DestinationRect.w * tableWidthCoef;
+		auto dstBoardRect = SDL_FRect
 		{
-			DestinationRect.x + static_cast<int32_t>(offset_x * fullscrn::ScaleX), DestinationRect.y + static_cast<int32_t>(offset_y * fullscrn::ScaleY),
-			dstSeparationX, DestinationRect.h
+			DestinationRect.x + offset_x * fullscrn::ScaleX,
+			DestinationRect.y + offset_y * fullscrn::ScaleY,
+			dstSeparationX, static_cast<float>(DestinationRect.h)
+		};
+		auto dstSidebarRect = SDL_FRect
+		{
+			DestinationRect.x + dstSeparationX, static_cast<float>(DestinationRect.y),
+			DestinationRect.w - dstSeparationX, static_cast<float>(DestinationRect.h)
 		};
 
-		SDL_Rect dstSidebarRect = SDL_Rect
+		SDL_RenderCopyF(winmain::Renderer, vScreenTex, &srcBoardRect, &dstBoardRect);
+		SDL_RenderCopyF(winmain::Renderer, vScreenTex, &srcSidebarRect, &dstSidebarRect);
+#else
+		// SDL_RenderCopy cannot express sub pixel offset.
+		// Vscreen shift is required for that.
+		auto dstSeparationX = static_cast<int>(DestinationRect.w * tableWidthCoef);
+		auto scaledOffX = static_cast<int>(round(offset_x * fullscrn::ScaleX));
+		if (offset_x != 0 && scaledOffX == 0)
+			scaledOffX = Sign(offset_x);
+		auto scaledOffY = static_cast<int>(round(offset_y * fullscrn::ScaleY));
+		if (offset_y != 0 && scaledOffX == 0)
+			scaledOffY = Sign(offset_y);
+
+		auto dstBoardRect = SDL_Rect
+		{
+			DestinationRect.x + scaledOffX, DestinationRect.y + scaledOffY,
+			dstSeparationX, DestinationRect.h
+		};
+		auto dstSidebarRect = SDL_Rect
 		{
 			DestinationRect.x + dstSeparationX, DestinationRect.y,
 			DestinationRect.w - dstSeparationX, DestinationRect.h
@@ -584,5 +617,6 @@ void render::PresentVScreen()
 
 		SDL_RenderCopy(winmain::Renderer, vScreenTex, &srcBoardRect, &dstBoardRect);
 		SDL_RenderCopy(winmain::Renderer, vScreenTex, &srcSidebarRect, &dstSidebarRect);
+#endif
 	}
 }

SpaceCadetPinball/render.h

@@ -35,6 +35,7 @@ public:
 
 	static void init(gdrv_bitmap8* bmp, float zMin, float zScaler, int width, int height);
 	static void uninit();
+	static void recreate_screen_texture();
 	static void update();
 	static void sprite_modified(render_sprite_type_struct* sprite);
 	static render_sprite_type_struct* create_sprite(VisualTypes visualType, gdrv_bitmap8* bmp,