scale sdl window

1 files changed, 69 insertions, 3 deletions

diff --git a/inc/lzy.h b/inc/lzy.h
index cfbef1c..1ec1fc9 100644
--- a/inc/lzy.h
+++ b/inc/lzy.h
@@ -160,6 +160,7 @@ const char *LZY_GetError(void) {
 static const char *error = NULL;
 static SDL_Window *window = NULL;
 static SDL_Renderer *renderer = NULL;
+static SDL_Texture *target = NULL;
 static int should_quit = 0;
 static int input[LZYK_COUNT] = {0};
 static int fps_limiter = 0;
@@ -176,7 +177,7 @@ int LZY_Init(const char *title, int target_fps) {
 
 	window = SDL_CreateWindow(title, SDL_WINDOWPOS_UNDEFINED,
 	                          SDL_WINDOWPOS_UNDEFINED, LZY_DISPLAY_WIDTH,
-	                          LZY_DISPLAY_HEIGHT, SDL_WINDOW_SHOWN);
+	                          LZY_DISPLAY_HEIGHT, SDL_WINDOW_RESIZABLE);
 	if (window == NULL) {
 		error = SDL_GetError();
 		return -2;
@@ -190,6 +191,14 @@ int LZY_Init(const char *title, int target_fps) {
 		return -3;
 	}
 
+	target = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB888,
+	                           SDL_TEXTUREACCESS_TARGET, LZY_DISPLAY_WIDTH,
+	                           LZY_DISPLAY_HEIGHT);
+	if (target == NULL) {
+		error = SDL_GetError();
+		return -4;
+	}
+
 	fps_limiter = target_fps > 0;
 	if (fps_limiter) {
 		min_dt = 1000 / target_fps;
@@ -200,6 +209,11 @@ int LZY_Init(const char *title, int target_fps) {
 }
 
 void LZY_Quit(void) {
+	if (target != NULL) {
+		SDL_DestroyTexture(target);
+		target = NULL;
+	}
+
 	if (renderer != NULL) {
 		SDL_DestroyRenderer(renderer);
 		renderer = NULL;
@@ -216,10 +230,50 @@ void LZY_Quit(void) {
 int LZY_DrawBegin(void) {
 	if (fps_limiter)
 		next_time += min_dt;
+
+	if (SDL_SetRenderTarget(renderer, target) < 0) {
+		error = SDL_GetError();
+		return -1;
+	}
 	return 0;
 }
 
 int LZY_DrawEnd(void) {
+	int win_w, win_h, off_x, off_y;
+	float ratio_w, ratio_h, scale;
+	SDL_Rect src, dst;
+
+	if (SDL_SetRenderTarget(renderer, NULL)) {
+		error = SDL_GetError();
+		return -1;
+	}
+
+	LZY_DrawSetColor(0x00, 0x00, 0x00);
+	if (LZY_DrawClear())
+		return -2;
+
+	SDL_GetWindowSize(window, &win_w, &win_h);
+	ratio_w = (float)win_w / LZY_DISPLAY_WIDTH;
+	ratio_h = (float)win_h / LZY_DISPLAY_HEIGHT;
+	scale = (ratio_w < ratio_h) ? (ratio_w) : (ratio_h);
+	off_x = (win_w - LZY_DISPLAY_WIDTH * scale) / 2;
+	off_y = (win_h - LZY_DISPLAY_HEIGHT * scale) / 2;
+
+	src.x = 0;
+	src.y = 0;
+	src.w = LZY_DISPLAY_WIDTH;
+	src.h = LZY_DISPLAY_HEIGHT;
+
+	dst.x = off_x;
+	dst.y = off_y;
+	dst.w = LZY_DISPLAY_WIDTH * scale;
+	dst.h = LZY_DISPLAY_HEIGHT * scale;
+
+	if (SDL_RenderCopy(renderer, target, &src, &dst) < 0) {
+		error = SDL_GetError();
+		return -3;
+	}
+
 	SDL_RenderPresent(renderer);
 
 	if (fps_limiter) {
@@ -250,18 +304,30 @@ int LZY_DrawClear(void) {
 
 int LZY_DrawRect(int x, int y, unsigned int w, unsigned int h) {
 	const SDL_Rect rect = {x, y, w, h};
+
+	if (w == 0 || h == 0) {
+		error = "rectangle dimensions cannot be 0";
+		return -1;
+	}
+
 	if (SDL_RenderDrawRect(renderer, &rect) < 0) {
 		error = SDL_GetError();
-		return -1;
+		return -2;
 	}
 	return 0;
 }
 
 int LZY_DrawFillRect(int x, int y, unsigned int w, unsigned int h) {
 	const SDL_Rect rect = {x, y, w, h};
+
+	if (w == 0 || h == 0) {
+		error = "rectangle dimensions cannot be 0";
+		return -1;
+	}
+
 	if (SDL_RenderFillRect(renderer, &rect) < 0) {
 		error = SDL_GetError();
-		return -1;
+		return -2;
 	}
 	return 0;
 }