From 7647062619228de43625f3a292dde1011ba7abec Mon Sep 17 00:00:00 2001
From: fgsfds <derp.primus@gmail.com>
Date: Wed, 6 Dec 2023 17:11:21 +0100
Subject: [PATCH] port: hard cap FPS to 200 for now

---
 port/fast3d/gfx_sdl2.cpp             | 12 ++++++++----
 port/fast3d/gfx_window_manager_api.h |  2 +-
 port/include/video.h                 |  3 +++
 port/src/video.c                     | 12 ++++++++++--
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/port/fast3d/gfx_sdl2.cpp b/port/fast3d/gfx_sdl2.cpp
index 274bf1230..07128bfcf 100644
--- a/port/fast3d/gfx_sdl2.cpp
+++ b/port/fast3d/gfx_sdl2.cpp
@@ -291,7 +291,7 @@ static void gfx_sdl_set_target_fps(int fps) {
 }
 
 static bool gfx_sdl_can_disable_vsync(void) {
-    return false;
+    return true;
 }
 
 static void *gfx_sdl_get_window_handle(void) {
@@ -302,9 +302,13 @@ static void gfx_sdl_set_window_title(const char *title) {
     SDL_SetWindowTitle(wnd, title);
 }
 
-static void gfx_sdl_set_swap_interval(int interval) {
-    SDL_GL_SetSwapInterval(interval);
-    vsync_enabled = (interval != 0);
+static bool gfx_sdl_set_swap_interval(int interval) {
+    const bool success = SDL_GL_SetSwapInterval(interval) >= 0;
+    vsync_enabled = success && (interval != 0);
+    if (!success) {
+        sysLogPrintf(LOG_WARNING, "SDL: failed to set vsync %d: %s", interval, SDL_GetError());
+    }
+    return success;
 }
 
 struct GfxWindowManagerAPI gfx_sdl = { 
diff --git a/port/fast3d/gfx_window_manager_api.h b/port/fast3d/gfx_window_manager_api.h
index f4070f782..71886547e 100644
--- a/port/fast3d/gfx_window_manager_api.h
+++ b/port/fast3d/gfx_window_manager_api.h
@@ -22,7 +22,7 @@ struct GfxWindowManagerAPI {
     bool (*can_disable_vsync)(void);
     void *(*get_window_handle)(void);
     void (*set_window_title)(const char *);
-    void (*set_swap_interval)(int);
+    bool (*set_swap_interval)(int);
 };
 
 #endif
diff --git a/port/include/video.h b/port/include/video.h
index ffd2c6728..2ebeda21e 100644
--- a/port/include/video.h
+++ b/port/include/video.h
@@ -4,6 +4,9 @@
 #include <PR/ultratypes.h>
 #include <PR/gbi.h>
 
+// maximum framerate; if the game runs faster than this, things will break
+#define VIDEO_MAX_FPS 200
+
 s32 videoInit(void);
 void videoStartFrame(void);
 void videoSubmitCommands(Gfx *cmds);
diff --git a/port/src/video.c b/port/src/video.c
index 075546218..c0c2fb642 100644
--- a/port/src/video.c
+++ b/port/src/video.c
@@ -46,7 +46,15 @@ s32 videoInit(void)
 
 	gfx_init(wmAPI, renderingAPI, "PD", vidFullscreen, vidWidth, vidHeight, 100, 100);
 
-	wmAPI->set_swap_interval(vidVsync);
+	if (!wmAPI->set_swap_interval(vidVsync)) {
+		vidVsync = 0;
+	}
+
+	if (vidVsync == 0 && vidFramerateLimit == 0) {
+		// cap FPS if there's no vsync to prevent the game from exploding
+		vidFramerateLimit = VIDEO_MAX_FPS;
+	}
+
 	wmAPI->set_target_fps(vidFramerateLimit); // disabled because vsync is on
 	renderingAPI->set_texture_filter((enum FilteringMode)texFilter);
 
@@ -228,7 +236,7 @@ PD_CONSTRUCTOR static void videoConfigInit(void)
 	configRegisterInt("Video.DefaultHeight", &vidHeight, 0, 32767);
 	configRegisterInt("Video.VSync", &vidVsync, -1, 10);
 	configRegisterInt("Video.FramebufferEffects", &vidFramebuffers, 0, 1);
-	configRegisterInt("Video.FramerateLimit", &vidFramerateLimit, 0, 10000);
+	configRegisterInt("Video.FramerateLimit", &vidFramerateLimit, 0, VIDEO_MAX_FPS);
 	configRegisterInt("Video.MSAA", &vidMSAA, 1, 16);
 	configRegisterInt("Video.TextureFilter", &texFilter, 0, 2);
 	configRegisterInt("Video.TextureFilter2D", &texFilter2D, 0, 1);