sdl: use the same textures for hires/lores

Simpilfies Renderer a bit and only requires minor changes to System::update_texture
32blit · Nov 19, 2023 · eed6738 · eed6738
1 parent e567e97
commit eed6738
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Showing 3 changed files with 14 additions and 27 deletions.
diff --git a/32blit-sdl/Renderer.cpp b/32blit-sdl/Renderer.cpp
@@ -16,7 +16,7 @@ Renderer::Renderer(SDL_Window *window, int width, int height) : sys_width(width)
 		std::cerr << "could not create renderer: " << SDL_GetError() << std::endl;
 	}
 
-	current = fb_hires_texture;
+  current = fb_texture;
 
 	int w, h;
 	SDL_GetWindowSize(window, &w, &h);
@@ -28,17 +28,13 @@ Renderer::Renderer(SDL_Window *window, int width, int height) : sys_width(width)
 	SDL_RenderClear(renderer);
 	SDL_RenderPresent(renderer);
 
-  fb_lores_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, sys_width/2, sys_height/2);
-	fb_hires_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, sys_width, sys_height);
-  fb_lores_565_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_BGR565, SDL_TEXTUREACCESS_STREAMING, sys_width/2, sys_height/2);
-  fb_hires_565_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_BGR565, SDL_TEXTUREACCESS_STREAMING, sys_width, sys_height);
+  fb_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, sys_width, sys_height);
+  fb_565_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_BGR565, SDL_TEXTUREACCESS_STREAMING, sys_width, sys_height);
 }
 
 Renderer::~Renderer() {
-	SDL_DestroyTexture(fb_lores_texture);
-	SDL_DestroyTexture(fb_hires_texture);
-	SDL_DestroyTexture(fb_lores_565_texture);
-	SDL_DestroyTexture(fb_hires_565_texture);
+	SDL_DestroyTexture(fb_texture);
+	SDL_DestroyTexture(fb_565_texture);
 	SDL_DestroyRenderer(renderer);
 }
 
@@ -70,11 +66,7 @@ void Renderer::resize(int width, int height) {
 void Renderer::update(System *sys) {
   auto format = blit::PixelFormat(sys->format());
 
-	if (sys->mode() == 0) {
-		current = format == blit::PixelFormat::RGB565 ? fb_lores_565_texture : fb_lores_texture;
-	} else {
-		current = format == blit::PixelFormat::RGB565 ? fb_hires_565_texture : fb_hires_texture;
-	}
+	current = format == blit::PixelFormat::RGB565 ? fb_565_texture : fb_texture;
 
   if(is_lores != (sys->mode() == 0)) {
     is_lores = sys->mode() == 0;
@@ -98,11 +90,6 @@ void Renderer::present() {
   dest.w = sys_width;
   dest.h = sys_height;
 
-  if (is_lores) {
-    dest.w /= 2;
-    dest.h /= 2;
-  }
-
 	_render(nullptr, &dest);
 	SDL_RenderPresent(renderer);
 }

diff --git a/32blit-sdl/Renderer.hpp b/32blit-sdl/Renderer.hpp
@@ -23,9 +23,7 @@ class Renderer {
 		Mode mode = KeepPixels;
 		SDL_Renderer *renderer = nullptr;
 
-		SDL_Texture *fb_lores_texture = nullptr;
-		SDL_Texture *fb_hires_texture = nullptr;
-		SDL_Texture *fb_lores_565_texture = nullptr;
-		SDL_Texture *fb_hires_565_texture = nullptr;
+		SDL_Texture *fb_texture = nullptr;
+		SDL_Texture *fb_565_texture = nullptr;
 		SDL_Texture *current = nullptr;
 };
diff --git a/32blit-sdl/System.cpp b/32blit-sdl/System.cpp
@@ -346,13 +346,15 @@ Uint32 System::format() {
 
 void System::update_texture(SDL_Texture *texture) {
   bool is_lores = _mode == blit::ScreenMode::lores;
-  auto stride = (is_lores ? width / 2 : width) * blit::pixel_format_stride[int(cur_format)];
+
+  SDL_Rect dest_rect{0, 0, is_lores ? width / 2 : width, is_lores ? height / 2 : height};
+  auto stride = dest_rect.w * blit::pixel_format_stride[int(cur_format)];
 
   if(cur_format == blit::PixelFormat::P) {
     uint8_t col_fb[max_width * max_height * 3];
 
     auto in = framebuffer, out = col_fb;
-    auto size = is_lores ? (width / 2) * (height / 2) : width * height;
+    auto size = dest_rect.w * dest_rect.h;
 
     for(int i = 0; i < size; i++) {
       uint8_t index = *(in++);
@@ -361,9 +363,9 @@ void System::update_texture(SDL_Texture *texture) {
       (*out++) = palette[index].b;
     }
 
-    SDL_UpdateTexture(texture, nullptr, col_fb, stride * 3);
+    SDL_UpdateTexture(texture, &dest_rect, col_fb, stride * 3);
   } else
-    SDL_UpdateTexture(texture, nullptr, framebuffer, stride);
+    SDL_UpdateTexture(texture, &dest_rect, framebuffer, stride);
 }
 
 void System::notify_redraw() {