uxn

commit 156ef01226c069ad5930c2655a10f22380a387a8
parent 87465a40baf315e32213fbd100fee20d7d97c371
Author: John Yates <jyates65@gmail.com>
Date:   Wed, 12 Nov 2025 13:43:36 -0500

fix framerate delay calculation to account for screen vector execution time

Diffstat:
M
src/uxnemu.c
 | 
21
++++++++++-----------

1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/src/uxnemu.c b/src/uxnemu.c
@@ -42,7 +42,6 @@ WITH REGARD TO THIS SOFTWARE.
 
 #define WIDTH 64 * 8
 #define HEIGHT 40 * 8
-#define TIMEOUT_MS 334
 
 Uxn uxn;
 int console_vector;
@@ -58,7 +57,6 @@ static SDL_Thread *stdin_thread;
 
 static int window_created, fullscreen, borderless;
 static Uint32 stdin_event, audio0_event, zoom = 1;
-static Uint64 exec_deadline, deadline_interval, ms_interval;
 
 static Uint8
 audio_dei(int instance, Uint8 *d, Uint8 port)
@@ -269,9 +267,6 @@ emu_init(void)
 	SDL_ShowCursor(SDL_DISABLE);
 	SDL_EventState(SDL_DROPFILE, SDL_ENABLE);
 	SDL_SetRenderDrawColor(emu_renderer, 0x00, 0x00, 0x00, 0xff);
-	ms_interval = SDL_GetPerformanceFrequency() / 1000;
-	deadline_interval = ms_interval * TIMEOUT_MS;
-	exec_deadline = SDL_GetPerformanceCounter() + deadline_interval;
 	screen_resize(WIDTH, HEIGHT, 1);
 	return 1;
 }
@@ -421,10 +416,12 @@ static int
 emu_run(void)
 {
 	Uint64 next_refresh = 0;
-	Uint64 frame_interval = SDL_GetPerformanceFrequency() / 60;
+	Uint64 perf_freq = SDL_GetPerformanceFrequency();
+	Uint64 frame_interval = perf_freq / 60;
+	Uint64 ms_interval = perf_freq / 1000;
 	Uint32 window_flags = SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI;
 	char *rom_name = metadata_read_name();
-	window_created = 1;
+	window_created = 0;
 	if(fullscreen)
 		window_flags = window_flags | SDL_WINDOW_FULLSCREEN_DESKTOP;
 	emu_window = SDL_CreateWindow(rom_name,
@@ -435,6 +432,7 @@ emu_run(void)
 		window_flags);
 	if(emu_window == NULL)
 		return system_error("sdl_window", SDL_GetError());
+	window_created = 1;
 	emu_renderer = SDL_CreateRenderer(emu_window, -1, SDL_RENDERER_ACCELERATED);
 	if(emu_renderer == NULL)
 		return system_error("sdl_renderer", SDL_GetError());
@@ -445,19 +443,20 @@ emu_run(void)
 		/* .System/halt */
 		if(uxn.dev[0x0f])
 			return system_error("Run", "Ended.");
-		exec_deadline = now + deadline_interval;
 		if(!handle_events())
 			return 0;
 		if(now >= next_refresh) {
-			now = SDL_GetPerformanceCounter();
 			next_refresh = now + frame_interval;
 			uxn_eval(uxn_screen.vector);
 			if(uxn_screen.x2 && uxn_screen.y2 && screen_changed())
 				screen_redraw(), emu_redraw();
 		}
 		if(uxn_screen.vector) {
-			Uint64 delay_ms = (next_refresh - now) / ms_interval;
-			if(delay_ms > 0) SDL_Delay(delay_ms);
+			now = SDL_GetPerformanceCounter();
+			if(now < next_refresh) {
+				Uint64 delay_ms = (next_refresh - now) / ms_interval;
+				if (delay_ms > 0) SDL_Delay(delay_ms);
+			}
 		} else
 			SDL_WaitEvent(NULL);
 	}