Lowering the comm ambient animation rate from max of 120fps to highest known stable rate of 40

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@1886 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/src/sc2code/comm.c

@@ -42,6 +42,18 @@
 
 #include <ctype.h>
 
+// Maximum ambient animation frame rate (actual execution rate)
+// A gfx frame is not always produced during an execution frame,
+// and several animations are combined into one gfx frame.
+// The rate was originally 120fps which allowed for more animation
+// precision which is ultimately wasted on the human eye anyway.
+// The highest known stable animation rate is 40fps, so that's what we use.
+#define AMBIENT_ANIM_RATE   40
+
+// Oscilloscope frame rate
+// Should be <= AMBIENT_ANIM_RATE
+// XXX: was 32 picked experimentally?
+#define OSCILLOSCOPE_RATE   32
 
 static void init_xform_control (void);
 static void uninit_xform_control (void);
@@ -885,7 +897,7 @@ ambient_anim_task (void *data)
 		BOOLEAN Change, CanTalk;
 		DWORD CurTime, ElapsedTicks;
 
-		SleepThreadUntil (LastTime + ONE_SECOND / 120);
+		SleepThreadUntil (LastTime + ONE_SECOND / AMBIENT_ANIM_RATE);
 
 		LockMutex (GraphicsLock);
 		BatchGraphics ();
@@ -1267,7 +1279,7 @@ ambient_anim_task (void *data)
 
 			SetContext (OldContext);
 		}
-		if (LastOscillTime + (ONE_SECOND / 32) < CurTime)
+		if (LastOscillTime + (ONE_SECOND / OSCILLOSCOPE_RATE) < CurTime)
 		{
 			LastOscillTime = CurTime;
 			UpdateSpeechGraphics (FALSE);

sc2/src/sc2code/libs/timelib.h

@@ -23,8 +23,10 @@
 
 /* ONE_SECOND is the LCM of all the fractions of a second the game uses.
  * Battle is 24 FPS, Landers are 35 FPS, most UI-level things are 15 FPS,
- * The Interplanetary flight is 30 FPS.  Thus, the minimum value for
- * ONE_SECOND is 840. */
+ * The Interplanetary flight is 30 FPS, Comm ambient animation is 40 FPS,
+ * (also Comm Oscilloscope is 32 FPS, but it does not require a stable
+ * timer and currently runs within the Comm ambient anim paradigm anyway)
+ * Thus, the minimum value for ONE_SECOND is 840. */
 #if TIMELIB == SDL
 #	define ONE_SECOND 840
 #endif