From bce6b05695beb988b607eb1dd82c27c1ed841faa Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Sun, 16 Jan 2011 01:50:12 +0200
Subject: [PATCH 1/1] rewrite frame limiter

the peops one is sometimes sleeping when not needed.
---
 frontend/menu.c       | 12 +++-------
 frontend/menu.h       |  1 +
 frontend/plugin_lib.c | 56 +++++++++++++++++++++++++++++++++----------
 frontend/plugin_lib.h |  2 ++
 4 files changed, 50 insertions(+), 21 deletions(-)

diff --git a/frontend/menu.c b/frontend/menu.c
index e1a3cc00..f2a24fd6 100644
--- a/frontend/menu.c
+++ b/frontend/menu.c
@@ -68,7 +68,6 @@ int g_opts;
 // from softgpu plugin
 extern int iUseDither;
 extern int UseFrameSkip;
-extern int UseFrameLimit;
 extern uint32_t dwActFixes;
 extern float fFrameRateHz;
 extern int dwFrameRateTicks;
@@ -141,13 +140,13 @@ static int emu_save_load_game(int load, int sram)
 
 static void menu_set_defconfig(void)
 {
+	g_opts = 0;
 	scaling = SCALE_4_3;
 
 	Config.Xa = Config.Cdda = Config.Sio =
 	Config.SpuIrq = Config.RCntFix = Config.VSyncWA = 0;
 
 	iUseDither = UseFrameSkip = 0;
-	UseFrameLimit = 1;
 	dwActFixes = 1<<7;
 
 	iUseReverb = 2;
@@ -200,7 +199,6 @@ static const struct {
 	CE_INTVAL(g_opts),
 	CE_INTVAL(iUseDither),
 	CE_INTVAL(UseFrameSkip),
-	CE_INTVAL(UseFrameLimit),
 	CE_INTVAL(dwActFixes),
 	CE_INTVAL(iUseReverb),
 	CE_INTVAL(iUseInterpolation),
@@ -887,7 +885,7 @@ static const char h_cfg_nodrc[]  = "Disable dynamic recompiler and use interpret
 static menu_entry e_menu_adv_options[] =
 {
 	mee_onoff_h   ("Show CPU load",          0, g_opts, OPT_SHOWCPU, h_cfg_cpul),
-	mee_onoff_h   ("Frame Limiter",          0, UseFrameLimit, 1, h_cfg_fl),
+	mee_onoff_h   ("Disable Frame Limiter",  0, g_opts, OPT_NO_FRAMELIM, h_cfg_fl),
 	mee_onoff_h   ("Disable XA Decoding",    0, Config.Xa, 1, h_cfg_xa),
 	mee_onoff_h   ("Disable CD Audio",       0, Config.Cdda, 1, h_cfg_cdda),
 	mee_onoff_h   ("SIO IRQ Always Enabled", 0, Config.Sio, 1, h_cfg_sio),
@@ -1393,11 +1391,7 @@ void menu_prepare_emu(void)
 	if (Config.Cdda)
 		CDR_stop();
 
-	// HACK to set up the frame limiter if softgpu is not used..
-	if (gpu_plugsel != 0) {
-		fFrameRateHz = Config.PsxType ? 50.0f : 59.94f;
-		dwFrameRateTicks = (100000*100 / (unsigned long)(fFrameRateHz*100));
-	}
+	pl_frame_interval = Config.PsxType ? 20000 : 16667;
 
 	if (GPU_open != NULL) {
 		int ret = GPU_open(&gpuDisp, "PCSX", NULL);
diff --git a/frontend/menu.h b/frontend/menu.h
index 7fb85b3e..d8aa8921 100644
--- a/frontend/menu.h
+++ b/frontend/menu.h
@@ -8,6 +8,7 @@ void menu_notify_mode_change(int w, int h, int bpp);
 enum opts {
 	OPT_SHOWFPS = 1 << 0,
 	OPT_SHOWCPU = 1 << 1,
+	OPT_NO_FRAMELIM = 1 << 2,
 };
 
 extern int g_opts;
diff --git a/frontend/plugin_lib.c b/frontend/plugin_lib.c
index dfa2fae1..688bb12b 100644
--- a/frontend/plugin_lib.c
+++ b/frontend/plugin_lib.c
@@ -25,10 +25,11 @@
 #include "../libpcsxcore/new_dynarec/new_dynarec.h"
 
 void *pl_fbdev_buf;
+int pl_frame_interval;
 int keystate;
 static int pl_fbdev_w, pl_fbdev_h, pl_fbdev_bpp;
-static int flip_cnt, flips_per_sec, tick_per_sec;
-extern float fps_cur; // XXX
+static int flip_cnt, vsync_cnt, flips_per_sec, tick_per_sec;
+static float vsps_cur;
 
 static int get_cpu_ticks(void)
 {
@@ -53,7 +54,7 @@ static int get_cpu_ticks(void)
 static void print_fps(void)
 {
 	if (pl_fbdev_bpp == 16)
-		pl_text_out16(2, pl_fbdev_h - 10, "%2d %4.1f", flips_per_sec, fps_cur);
+		pl_text_out16(2, pl_fbdev_h - 10, "%2d %4.1f", flips_per_sec, vsps_cur);
 }
 
 static void print_cpu_usage(void)
@@ -128,36 +129,67 @@ static void update_input(void)
 #endif
 }
 
+#define MAX_LAG_FRAMES 3
+
+#define tvdiff(tv, tv_old) \
+	((tv.tv_sec - tv_old.tv_sec) * 1000000 + tv.tv_usec - tv_old.tv_usec)
+// assumes us < 1000000
+#define tvadd(tv, us) { \
+	tv.tv_usec += us; \
+	if (tv.tv_usec >= 1000000) { \
+		tv.tv_usec -= 1000000; \
+		tv.tv_sec++; \
+	} \
+}
+
 /* called on every vsync */
 void pl_frame_limit(void)
 {
-	extern void CheckFrameRate(void);
-	static int oldsec;
-	struct timeval tv;
+	static struct timeval tv_old, tv_expect;
+	struct timeval now;
+	int diff;
+
+	vsync_cnt++;
 
 	/* doing input here because the pad is polled
 	 * thousands of times per frame for some reason */
 	update_input();
 
 	pcnt_end(PCNT_ALL);
-	gettimeofday(&tv, 0);
+	gettimeofday(&now, 0);
 
-	if (tv.tv_sec != oldsec) {
+	if (now.tv_sec != tv_old.tv_sec) {
+		diff = tvdiff(now, tv_old);
+		vsps_cur = 0.0f;
+		if (0 < diff && diff < 2000000)
+			vsps_cur = 1000000.0f * vsync_cnt / diff;
 		flips_per_sec = flip_cnt;
-		flip_cnt = 0;
-		oldsec = tv.tv_sec;
+		vsync_cnt = flip_cnt = 0;
+		tv_old = now;
 		if (g_opts & OPT_SHOWCPU)
 			tick_per_sec = get_cpu_ticks();
 	}
 #ifdef PCNT
 	static int ya_vsync_count;
 	if (++ya_vsync_count == PCNT_FRAMES) {
-		pcnt_print(fps_cur);
+		pcnt_print(vsps_cur);
 		ya_vsync_count = 0;
 	}
 #endif
 
-	CheckFrameRate();
+	if (!(g_opts & OPT_NO_FRAMELIM)) {
+		tvadd(tv_expect, pl_frame_interval);
+		diff = tvdiff(tv_expect, now);
+		if (diff > MAX_LAG_FRAMES * pl_frame_interval || diff < -MAX_LAG_FRAMES * pl_frame_interval) {
+			//printf("pl_frame_limit reset, diff=%d, iv %d\n", diff, pl_frame_interval);
+			tv_expect = now;
+		}
+		else if (diff > pl_frame_interval) {
+			// yay for working usleep on pandora!
+			//printf("usleep %d\n", diff - pl_frame_interval / 2);
+			usleep(diff - pl_frame_interval / 2);
+		}
+	}
 
 	pcnt_start(PCNT_ALL);
 }
diff --git a/frontend/plugin_lib.h b/frontend/plugin_lib.h
index 53389d2d..22ab285b 100644
--- a/frontend/plugin_lib.h
+++ b/frontend/plugin_lib.h
@@ -39,6 +39,8 @@ struct rearmed_cbs {
 
 extern const struct rearmed_cbs pl_rearmed_cbs;
 
+extern int pl_frame_interval;
+
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 #endif
-- 
2.39.2