From 1525cfae75db3b8532c38eb3295219cd4c50d04e Mon Sep 17 00:00:00 2001
From: MaikelChan <maikelchan88@gmail.com>
Date: Sun, 24 Oct 2021 04:39:22 +0200
Subject: [PATCH] Optimized final blit to the screen render target.

When bumping the table, instead of offseting the table pixels by CPU, just memcpy all the pixels to vScreenTex once, and then render two separate quads from that texture: one for the board and the other for the sidebar. Then change the coordinates of the board quad when bumping.
---
 SpaceCadetPinball/render.cpp | 96 +++++++++++++++---------------------
 1 file changed, 40 insertions(+), 56 deletions(-)

diff --git a/SpaceCadetPinball/render.cpp b/SpaceCadetPinball/render.cpp
index 40d0bb6..ed4d05a 100644
--- a/SpaceCadetPinball/render.cpp
+++ b/SpaceCadetPinball/render.cpp
@@ -1,6 +1,7 @@
 #include "pch.h"
 #include "render.h"
 
+#include "fullscrn.h"
 #include "GroupData.h"
 #include "options.h"
 #include "pb.h"
@@ -538,61 +539,7 @@ void render::BlitVScreen()
 	);
 	assertm(static_cast<unsigned>(pitch) == vscreen->Width * sizeof(ColorRgba), "Padding on vScreen texture");
 
-	if (offset_x == 0 && offset_y == 0)
-	{
-		// No offset - direct copy
-		std::memcpy(lockedPixels, vscreen->BmpBufPtr1, vscreen->Width * vscreen->Height * sizeof(ColorRgba));
-	}
-	else
-	{
-		// Copy offset table and fixed side bar
-		auto tableWidth = pb::MainTable->Width;
-		auto scoreWidth = vscreen->Width - pb::MainTable->Width;
-		auto tableStride = tableWidth * sizeof(ColorRgba);
-		auto scoreStride = scoreWidth * sizeof(ColorRgba);
-		auto srcScorePtr = &vscreen->BmpBufPtr1[tableWidth];
-
-		auto xSrc = 0, ySrc = 0, xDst = offset_x, yDst = offset_y, height = vscreen->Height;
-
-		// Negative dst == positive src offset
-		if (xDst < 0)
-		{
-			xSrc -= xDst;
-			xDst = 0;
-		}
-		if (yDst < 0)
-		{
-			ySrc -= yDst;
-			yDst = 0;
-		}
-
-		if (xSrc)
-		{
-			tableStride -= xSrc * sizeof(ColorRgba);
-		}
-		if (xDst)
-		{
-			tableStride -= xDst * sizeof(ColorRgba);
-			tableWidth -= xDst;
-			scoreWidth += xDst;
-		}
-		if (ySrc)
-			height -= ySrc;
-
-		auto srcBmpPtr = &vscreen->BmpBufPtr1[vscreen->Width * ySrc + xSrc];
-		auto dstPtr = &lockedPixels[vscreen->Width * yDst + xDst];
-		for (int y = height; y > 0; --y)
-		{
-			std::memcpy(dstPtr, srcBmpPtr, tableStride);
-			dstPtr += tableWidth;
-			std::memcpy(dstPtr, srcScorePtr, scoreStride);
-			dstPtr += scoreWidth;
-
-			srcBmpPtr += vscreen->Stride;
-			srcScorePtr += vscreen->Stride;
-		}
-	}
-
+	std::memcpy(lockedPixels, vscreen->BmpBufPtr1, vscreen->Width * vscreen->Height * sizeof(ColorRgba));
 
 	SDL_UnlockTexture(vScreenTex);
 }
@@ -600,5 +547,42 @@ void render::BlitVScreen()
 void render::PresentVScreen()
 {
 	BlitVScreen();
-	SDL_RenderCopy(winmain::Renderer, vScreenTex, nullptr, &DestinationRect);
+
+	if (offset_x == 0 && offset_y == 0)
+	{
+		SDL_RenderCopy(winmain::Renderer, vScreenTex, nullptr, &DestinationRect);
+	}
+	else
+	{
+		int32_t srcSeparationX = static_cast<int32_t>(vscreen->Width * 0.625f);
+
+		SDL_Rect srcBoardRect = SDL_Rect
+		{
+			0, 0,
+			srcSeparationX, vscreen->Height
+		};
+
+		SDL_Rect 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
+		{
+			DestinationRect.x + static_cast<int32_t>(offset_x * fullscrn::ScaleX), DestinationRect.y + static_cast<int32_t>(offset_y * fullscrn::ScaleY),
+			dstSeparationX, DestinationRect.h
+		};
+
+		SDL_Rect dstSidebarRect = SDL_Rect
+		{
+			DestinationRect.x + dstSeparationX, DestinationRect.y,
+			DestinationRect.w - dstSeparationX, DestinationRect.h
+		};
+
+		SDL_RenderCopy(winmain::Renderer, vScreenTex, &srcBoardRect, &dstBoardRect);
+		SDL_RenderCopy(winmain::Renderer, vScreenTex, &srcSidebarRect, &dstSidebarRect);
+	}
 }