GTK and Windows appear to handle timers very differently:

specifically, the elapsed time between calls varies much more with
GTK than it does under Windows. Therefore, I now take my own time
readings on every timer call, and this appears to have made the
animations run at closer to the same speed between platforms. Having
done that, I decided some of them were at the _wrong_ speed, and
fiddled with each game's timings as well.

[originally from svn r4189]

cube.c

@@ -160,7 +160,7 @@ enum {
 enum { LEFT, RIGHT, UP, DOWN, UP_LEFT, UP_RIGHT, DOWN_LEFT, DOWN_RIGHT };
 
 #define GRID_SCALE 48.0F
-#define ROLLTIME 0.1F
+#define ROLLTIME 0.13F
 
 #define SQ(x) ( (x) * (x) )
 

fifteen.c

@@ -19,8 +19,8 @@ const int game_can_configure = TRUE;
 #define COORD(x)  ( (x) * TILE_SIZE + BORDER )
 #define FROMCOORD(x)  ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
 
-#define ANIM_TIME 0.1F
+#define ANIM_TIME 0.13F
-#define FLASH_FRAME 0.1F
+#define FLASH_FRAME 0.13F
 
 #define X(state, i) ( (i) % (state)->w )
 #define Y(state, i) ( (i) / (state)->w )

gtk.c

@@ -9,6 +9,8 @@
 #include <stdarg.h>
 #include <string.h>
 
+#include <sys/time.h>
+
 #include <gtk/gtk.h>
 #include <gdk/gdkkeysyms.h>
 
@@ -63,6 +65,7 @@ struct frontend {
     GdkGC *gc;
     int bbox_l, bbox_r, bbox_u, bbox_d;
     int timer_active, timer_id;
+    struct timeval last_time;
     struct font *fonts;
     int nfonts, fontsize;
     config_item *cfg;
@@ -354,8 +357,15 @@ static gint timer_func(gpointer data)
 {
     frontend *fe = (frontend *)data;
 
-    if (fe->timer_active)
+    if (fe->timer_active) {
-        midend_timer(fe->me, 0.02);    /* may clear timer_active */
+	struct timeval now;
+	float elapsed;
+	gettimeofday(&now, NULL);
+	elapsed = ((now.tv_usec - fe->last_time.tv_usec) * 0.000001F +
+		   (now.tv_sec - fe->last_time.tv_sec));
+        midend_timer(fe->me, elapsed);	/* may clear timer_active */
+	fe->last_time = now;
+    }
 
     return fe->timer_active;
 }
@@ -369,8 +379,10 @@ void deactivate_timer(frontend *fe)
 
 void activate_timer(frontend *fe)
 {
-    if (!fe->timer_active)
+    if (!fe->timer_active) {
         fe->timer_id = gtk_timeout_add(20, timer_func, fe);
+	gettimeofday(&fe->last_time, NULL);
+    }
     fe->timer_active = TRUE;
 }
 

net.c

@@ -56,8 +56,8 @@ const int game_can_configure = TRUE;
 #define TILE_BORDER 1
 #define WINDOW_OFFSET 16
 
-#define ROTATE_TIME 0.1F
+#define ROTATE_TIME 0.13F
-#define FLASH_FRAME 0.05F
+#define FLASH_FRAME 0.07F
 
 enum {
     COL_BACKGROUND,

sixteen.c

@@ -21,8 +21,8 @@ const int game_can_configure = TRUE;
 #define COORD(x)  ( (x) * TILE_SIZE + BORDER )
 #define FROMCOORD(x)  ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )
 
-#define ANIM_TIME 0.1F
+#define ANIM_TIME 0.13F
-#define FLASH_FRAME 0.1F
+#define FLASH_FRAME 0.13F
 
 #define X(state, i) ( (i) % (state)->w )
 #define Y(state, i) ( (i) / (state)->w )

windows.c

@@ -88,6 +88,7 @@ struct frontend {
     HPEN *pens;
     HRGN clip;
     UINT timer;
+    DWORD timer_last_tickcount;
     int npresets;
     game_params **presets;
     struct font *fonts;
@@ -302,7 +303,10 @@ void deactivate_timer(frontend *fe)
 
 void activate_timer(frontend *fe)
 {
+    if (!fe->timer) {
 	fe->timer = SetTimer(fe->hwnd, fe->timer, 20, NULL);
+	fe->timer_last_tickcount = GetTickCount();
+    }
 }
 
 static frontend *new_window(HINSTANCE inst)
@@ -942,8 +946,12 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
 	    PostQuitMessage(0);
 	return 0;
       case WM_TIMER:
-	if (fe->timer)
+	if (fe->timer) {
-	    midend_timer(fe->me, (float)0.02);
+	    DWORD now = GetTickCount();
+	    float elapsed = (float) (now - fe->timer_last_tickcount) * 0.001F;
+	    midend_timer(fe->me, elapsed);
+	    fe->timer_last_tickcount = now;
+	}
 	return 0;
     }