Added timer routine to throttle game.

3 files changed, 65 insertions, 41 deletions

diff --git a/Makefile b/Makefile
index 8927c67..c469232 100644
--- a/Makefile
+++ b/Makefile
@@ -5,10 +5,6 @@ OPTIM=-g
 OBJ=dash
 CC=cc
 
-# Uncomment the following line if your system does not support usleep()
-#
-# USLEEP=-DNOUSLEEP
-
 # For Suns - edit if your system is awkward too
 #
 INCLUDE_PATH=-I/usr/openwin/include -I/usr/5include
@@ -16,7 +12,7 @@ LIB_PATH=-L/usr/openwin/lib -L/usr/5lib
 
 # Shouldn't need to edit below here
 #
-OPTS=$(OPTIM) $(USLEEP)
+OPTS=$(OPTIM)
 
 ALL=dash spred
 
diff --git a/README b/README
index 6eed935..f3e577b 100644
--- a/README
+++ b/README
@@ -43,7 +43,6 @@ USAGE
 dash [switches]
 -s          		Use small version
 -b          		Use black and white sprites
--d delay    		usleep() by delay for fast servers (eg, 90000 on Sun4)
 -l lev      		start from level lev
 -c          		use curses on tty (not yet perfect)
 -h          		Dump hi-score table
diff --git a/dash.c b/dash.c
index 4fd2ca8..67aa496 100644
--- a/dash.c
+++ b/dash.c
@@ -43,13 +43,8 @@
 
 #define RND(x)  ((rand())%(x))
 
-/* Slightly roundabout, but allows us to test the op
-*/
-#ifdef NOUSLEEP
-#	define USLEEP(x)	LocalUsleep(x)
-#else
-#	define USLEEP(x)	usleep(x)
-#endif
+#define PLAY_HERTZ	10
+#define OTHER_HERTZ	25
 
 static XSizeHints	size_hints;
 static ulong		black,white;
@@ -293,6 +288,8 @@ static int	cursesmode=False;
 static double	si[360];
 static double	co[360];
 
+static struct timespec frame_start;
+
 static int	level=1;
 static int	score=0;
 static int	no_levels=0;
@@ -365,6 +362,8 @@ static void	EnterHiscore(void);
 static void	DrawMess(const char *s);
 static void	Gravity(void);
 static void	DoPause(void);
+static void	StartFrame(void);
+static void	EndFrame(int hertz);
 
 
 /* ------------------------------------------------------------ MAIN
@@ -392,11 +391,6 @@ int main(int argc, char *argv[])
             chsz=8;
             f++;
             }
-        else if (!strcmp(argv[f],"-d"))
-            {
-            slp=atoi(argv[f+1]);
-            f+=2;
-            }
         else if (!strcmp(argv[f],"-l"))
             {
             startlev=atoi(argv[f+1]);
@@ -1062,8 +1056,8 @@ static void DoTillPress(void (*f)(void),int s,int qf)
 
     while(1)
         {
-        if ((slp>-1)&&(s))
-            USLEEP(slp);
+	if (s)
+	    StartFrame();
 
         if(XPending(disp))
             {
@@ -1100,6 +1094,9 @@ static void DoTillPress(void (*f)(void),int s,int qf)
             }
 
         (*f)();
+
+	if (s)
+	    EndFrame(OTHER_HERTZ);
         }
 }
 
@@ -1175,6 +1172,8 @@ static void XTitle(void)
     char s[128];
     int f;
 
+    StartFrame();
+
     if (title_fr)
         {
         x=title_bl[0].x;
@@ -1239,6 +1238,7 @@ static void XTitle(void)
         }
 
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 /* --------------------------------------------------------------------- */
@@ -1267,6 +1267,7 @@ static void XIntroLevel(void)
         fr=False;
         }
 
+    StartFrame();
     (*Cls)(black);
 
     for(f=0;f<INTROSPR;f++)
@@ -1288,9 +1289,8 @@ static void XIntroLevel(void)
 
     (*Centre)("Press Space to continue",Y(SCRY-2),white);
 
-    USLEEP(10000);
-
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 /* --------------------------------------------------------------------- */
@@ -2387,8 +2387,7 @@ static int XPlayLevel(void)
 
     while(dt)
         {
-        if (slp>-1)
-            USLEEP(slp);
+	StartFrame();
 
 	for(f=0;f<4;f++)
 	    if (released[f])
@@ -2582,6 +2581,7 @@ static int XPlayLevel(void)
         (*Repaint)(False);
         DrawScore();
         (*Update)();
+	EndFrame(PLAY_HERTZ);
 
         if (!ok)
             {
@@ -2762,6 +2762,7 @@ static void DoXGameOverWonSmallScale(void)
     double dy;
     int f;
 
+    StartFrame();
     (*Cls)(black);
 
     (*Centre)(gw_text[gw_text_no],Y(3),white);
@@ -2802,9 +2803,8 @@ static void DoXGameOverWonSmallScale(void)
             gw_cast_no=0;
         }
 
-    USLEEP(10000);
-
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 
@@ -2816,6 +2816,8 @@ static void DoXGameOverWonLargeScale(void)
     double dx,dy;
     int f;
 
+    StartFrame();
+
     XFillBox(0,Y(2),X(SCRX),Y(2),black);
     XFillBox(0,Y(SCRY-2),X(SCRX),Y(2),black);
 
@@ -2869,9 +2871,8 @@ static void DoXGameOverWonLargeScale(void)
             gw_cast_no=0;
         }
 
-    USLEEP(10000);
-
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 
@@ -3065,8 +3066,7 @@ static int CursesPlayLevel(void)
 
     while(dt)
         {
-        if (slp>-1)
-            USLEEP(slp);
+	StartFrame();
 
 	shiftmode=False;
 
@@ -3185,6 +3185,7 @@ static int CursesPlayLevel(void)
         (*Repaint)(False);
         DrawScore();
         (*Update)();
+	EndFrame(PLAY_HERTZ);
 
         if (!ok)
             {
@@ -3220,6 +3221,7 @@ static void SubCursesGameOverWon(void)
 {
     static unsigned int c;
 
+    StartFrame();
     (*Cls)(black);
 
     c++;
@@ -3230,12 +3232,13 @@ static void SubCursesGameOverWon(void)
 
     (*Centre)("A feat I never thought possible...",Y(12),white);
     (*Centre)("Noddybox salutes you!",Y(13),white);
-    (*Centre)("www.noddybox.demon.co.uk",Y(15),white);
+    (*Centre)("noddybox.co.uk",Y(15),white);
 
     if ((c/10)%2)
         (*Centre)("Press Space to continue",Y(SCRY-2),white);
 
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 
@@ -3249,6 +3252,7 @@ static void SubCursesGameOverLost(void)
 {
     static unsigned int c;
 
+    StartFrame();
     (*Cls)(black);
 
     c++;
@@ -3259,6 +3263,7 @@ static void SubCursesGameOverLost(void)
         (*Centre)("Press Space to continue",Y(SCRY-2),white);
 
     (*Update)();
+    EndFrame(OTHER_HERTZ);
 }
 
 
@@ -3274,6 +3279,8 @@ static void CursesDoTillPress(void (*f)(void), int s, int q)
 
     while(1)
         {
+	StartFrame();
+
         switch(getch())
             {
             case ' ':
@@ -3289,8 +3296,7 @@ static void CursesDoTillPress(void (*f)(void), int s, int q)
 
         (*f)();
 
-        if /* (s) */ (True)
-            USLEEP(slp);
+	EndFrame(OTHER_HERTZ);
         }
 }
 
@@ -3314,16 +3320,39 @@ static void Exit(int n)
 
 /* --------------------------------------------------------------------- */
 
-#ifdef NOUSLEEP
+static void StartFrame(void)
+{
+    clock_gettime(CLOCK_REALTIME, &frame_start);
+}
+
 
-LocalUsleep(int u)
+static void EndFrame(int hertz)
 {
-    struct timeval tv;
+    long FRAME = 1000000000 / hertz;
+    struct timespec now;
+    struct timespec diff;
 
-    tv.tv_sec=0;
-    tv.tv_usec=u;
+    clock_gettime(CLOCK_REALTIME, &now);
 
-    (void)select(0,NULL,NULL,NULL,&tv);
-}
+    diff.tv_sec = now.tv_sec - frame_start.tv_sec;
+    diff.tv_nsec = now.tv_nsec - frame_start.tv_nsec;
+
+    if (diff.tv_sec > 0)
+    {
+    	diff.tv_sec--;
+	diff.tv_nsec += 1000000000;
+    }
 
-#endif	/* NOUSLEEP */
+    if (diff.tv_nsec >= 1000000000)
+    {
+    	diff.tv_sec++;
+	diff.tv_nsec -= 1000000000;
+    }
+
+    if (diff.tv_sec == 0 && diff.tv_nsec < FRAME)
+    {
+	diff.tv_nsec = FRAME - diff.tv_nsec;
+
+	nanosleep(&diff, NULL);
+    }
+}