From 997d5021ed3e269908d993386c59edeac10ddea9 Mon Sep 17 00:00:00 2001
From: erysdren <contact@erysdren.me>
Date: Mon, 14 Oct 2024 15:16:22 -0500
Subject: [PATCH] remove several blit operations, should be faster now

---
 platform/sdl3/main.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/platform/sdl3/main.c b/platform/sdl3/main.c
index e545066..ae6c254 100644
--- a/platform/sdl3/main.c
+++ b/platform/sdl3/main.c
@@ -15,8 +15,6 @@ static u16 backbuffer[YETI_FRAMEBUFFER_WIDTH * YETI_FRAMEBUFFER_HEIGHT];
 static SDL_Window *window = NULL;
 static SDL_Renderer *renderer = NULL;
 static SDL_Texture *texture = NULL;
-static SDL_Surface *front = NULL;
-static SDL_Surface *back = NULL;
 
 static bool focused = true;
 
@@ -67,17 +65,7 @@ SDL_AppResult SDL_AppInit(void **appstate, int argc, char **argv)
 	SDL_RenderClear(renderer);
 	SDL_RenderPresent(renderer);
 
-	back = SDL_CreateSurfaceFrom(YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, SDL_PIXELFORMAT_XBGR1555, backbuffer, YETI_FRAMEBUFFER_WIDTH * sizeof(u16));
-	if (!back)
-		die(SDL_GetError());
-
-	format = SDL_GetWindowPixelFormat(window);
-
-	front = SDL_CreateSurface(YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, format);
-	if (!front)
-		die(SDL_GetError());
-
-	texture = SDL_CreateTexture(renderer, format, SDL_TEXTUREACCESS_STREAMING, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT);
+	texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_XBGR1555, SDL_TEXTUREACCESS_STREAMING, YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT);
 	if (!texture)
 		die(SDL_GetError());
 
@@ -133,13 +121,20 @@ void do_frame(Sint64 dt)
 
 SDL_AppResult SDL_AppIterate(void *appstate)
 {
+	void *pixels;
+	int pitch;
+
 	/* speed limiter */
 	now = SDL_GetTicks();
 	do_frame(now - then);
 	then = now;
 
-	SDL_BlitSurface(back, NULL, front, NULL);
-	SDL_UpdateTexture(texture, NULL, front->pixels, front->pitch);
+	if (SDL_LockTexture(texture, NULL, &pixels, &pitch))
+	{
+		SDL_memcpy(pixels, backbuffer, sizeof(backbuffer));
+		SDL_UnlockTexture(texture);
+	}
+
 	SDL_RenderClear(renderer);
 	SDL_RenderTexture(renderer, texture, NULL, NULL);
 	SDL_RenderPresent(renderer);
@@ -175,12 +170,21 @@ SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
 			}
 			else if (event->key.scancode == SDL_SCANCODE_F12)
 			{
+				SDL_Surface *screen;
 				char filename[256];
+
+				screen = SDL_CreateSurfaceFrom(YETI_FRAMEBUFFER_WIDTH, YETI_FRAMEBUFFER_HEIGHT, SDL_PIXELFORMAT_XBGR1555, backbuffer, YETI_FRAMEBUFFER_WIDTH * sizeof(u16));
+				if (!screen)
+					die("%s", SDL_GetError());
+
 				SDL_snprintf(filename, sizeof(filename), "yeti%03d.bmp", screenshot_idx++);
 				while (file_exists(filename))
 					SDL_snprintf(filename, sizeof(filename), "yeti%03d.bmp", screenshot_idx++);
-				SDL_SaveBMP(back, filename);
+
+				SDL_SaveBMP(screen, filename);
 				SDL_Log("Saved screenshot %s", filename);
+
+				SDL_DestroySurface(screen);
 			}
 			break;
 
@@ -200,8 +204,6 @@ void SDL_AppQuit(void *appstate, SDL_AppResult result)
 {
 	if (window) SDL_DestroyWindow(window);
 	if (renderer) SDL_DestroyRenderer(renderer);
-	if (back) SDL_DestroySurface(back);
-	if (front) SDL_DestroySurface(front);
 	if (texture) SDL_DestroyTexture(texture);
 
 	SDL_Quit();