Recognize a few special cases to speed up operations

Fix angular problems in hand position by rotating everything 90 degrees.

4 files changed, 75 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index ac72b23..4e91133 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2004-10-04  Keith Packard  <keithp@keithp.com>
 
+	* twin_primitive.c: (in_over), (over):
+	* twinint.h:
+	Recognize a few special cases to speed up operations
+	
+	* xtwin.c: (twin_clock_set_transform), (twin_clock_minute_angle),
+	(twin_clock_face), (twin_clock):
+	Fix angular problems in hand position by rotating everything 90
+	degrees.
+
+2004-10-04  Keith Packard  <keithp@keithp.com>
+
 	* twin_font.c: (twin_has_ucs4), (twin_path_ucs4):
 	Delete old glyph representation support code.
 	
diff --git a/twin_primitive.c b/twin_primitive.c
index 5c94784..34d75ae 100644
--- a/twin_primitive.c
+++ b/twin_primitive.c
@@ -34,15 +34,38 @@ in_over (twin_argb32_t	dst,
     uint16_t	t1, t2, t3, t4;
     twin_a8_t	a;
 
-    src = (twin_in(src,0,msk,t1) |
-	   twin_in(src,8,msk,t2) |
-	   twin_in(src,16,msk,t3) |
-	   twin_in(src,24,msk,t4));
+    switch (msk) {
+    case 0:
+	return dst;
+    case 0xff:
+	break;
+    default:
+	src = (twin_in(src,0,msk,t1) |
+	       twin_in(src,8,msk,t2) |
+	       twin_in(src,16,msk,t3) |
+	       twin_in(src,24,msk,t4));
+	break;
+    }
+    if (!src)
+	return dst;
     a = ~(src >> 24);
-    return (twin_over (src, dst, 0, a, t1) |
-	    twin_over (src, dst, 8, a, t2) |
-	    twin_over (src, dst, 16, a, t3) |
-	    twin_over (src, dst, 24, a, t4));
+    switch (a) {
+    case 0:
+	return src;
+    case 0xff:
+	dst = (twin_add (src, dst, 0, t1) |
+	       twin_add (src, dst, 8, t2) |
+	       twin_add (src, dst, 16, t3) |
+	       twin_add (src, dst, 24, t4));
+	break;
+    default:
+	dst = (twin_over (src, dst, 0, a, t1) |
+	       twin_over (src, dst, 8, a, t2) |
+	       twin_over (src, dst, 16, a, t3) |
+	       twin_over (src, dst, 24, a, t4));
+	break;
+    }
+    return dst;
 }
     
 static twin_argb32_t __inline
@@ -64,11 +87,26 @@ over (twin_argb32_t	dst,
     uint16_t	t1, t2, t3, t4;
     twin_a8_t	a;
 
+    if (!src)
+	return dst;
     a = ~(src >> 24);
-    return (twin_over (src, dst, 0, a, t1) |
-	    twin_over (src, dst, 8, a, t2) |
-	    twin_over (src, dst, 16, a, t3) |
-	    twin_over (src, dst, 24, a, t4));
+    switch (a) {
+    case 0:
+	return src;
+    case 0xff:
+	dst = (twin_add (src, dst, 0, t1) |
+	       twin_add (src, dst, 8, t2) |
+	       twin_add (src, dst, 16, t3) |
+	       twin_add (src, dst, 24, t4));
+	break;
+    default:
+	dst = (twin_over (src, dst, 0, a, t1) |
+	       twin_over (src, dst, 8, a, t2) |
+	       twin_over (src, dst, 16, a, t3) |
+	       twin_over (src, dst, 24, a, t4));
+	break;
+    }
+    return dst;
 }
 
 static twin_argb32_t __inline
diff --git a/twinint.h b/twinint.h
index 92fe14b..405483c 100644
--- a/twinint.h
+++ b/twinint.h
@@ -82,6 +82,10 @@ typedef signed char	twin_gfixed_t;
     (((t) = twin_int_mult(twin_get_8(d,i),(m),(t)) + twin_get_8(s,i)),\
      (twin_argb32_t) twin_sat (t) << (i))
 
+#define twin_add(s,d,i,t) \
+    (((t) = twin_get_8(d,i) + twin_get_8(s,i)),\
+     (twin_argb32_t) twin_sat (t) << (i))
+
 #define twin_argb32_to_rgb16(s)    ((((s) >> 3) & 0x001f) | \
 				    (((s) >> 5) & 0x07e0) | \
 				    (((s) >> 8) & 0xf800))
diff --git a/xtwin.c b/xtwin.c
index 2ed292f..885a336 100644
--- a/xtwin.c
+++ b/xtwin.c
@@ -61,6 +61,7 @@ twin_clock_set_transform (twin_pixmap_t	*clock,
 
     twin_path_translate (path, D(1) + TWIN_CLOCK_BORDER_WIDTH * 3,
 			 D(1) + TWIN_CLOCK_BORDER_WIDTH * 3);
+    twin_path_rotate (path, -TWIN_ANGLE_90);
 }
 
 static void
@@ -103,7 +104,7 @@ twin_clock_hand (twin_pixmap_t	*clock,
 static twin_angle_t
 twin_clock_minute_angle (int min)
 {
-    return min * TWIN_ANGLE_360 / 60 - TWIN_ANGLE_90;
+    return min * TWIN_ANGLE_360 / 60;
 }
 
 static void
@@ -128,15 +129,15 @@ twin_clock_face (twin_pixmap_t *clock)
 	static char	    *label = "twin";
 
 	twin_path_empty (path);
-	twin_path_rotate (path, twin_degrees_to_angle (-11));
+	twin_path_rotate (path, twin_degrees_to_angle (-11) + TWIN_ANGLE_90);
 	twin_path_set_font_size (path, D(0.5));
 	twin_path_set_font_style (path, TWIN_TEXT_UNHINTED|TWIN_TEXT_OBLIQUE);
 	twin_text_metrics_utf8 (path, label, &metrics);
 	height = metrics.ascent + metrics.descent;
 	width = metrics.right_side_bearing - metrics.left_side_bearing;
 	
-	twin_path_move (path, -width / 2, metrics.ascent - height/2);
-	twin_path_draw (path, width / 2, metrics.ascent - height/2);
+	twin_path_move (path, -width / 2, metrics.ascent - height/2 + D(0.01));
+	twin_path_draw (path, width / 2, metrics.ascent - height/2 + D(0.01));
 	twin_paint_stroke (clock, TWIN_CLOCK_WATER_UNDER, path, D(0.02));
 	twin_path_empty (path);
 	
@@ -205,11 +206,9 @@ twin_clock (twin_screen_t *screen, int x, int y, int w, int h)
 	localtime_r(&tv.tv_sec, &t);
 
 	second_angle = ((t.tm_sec * 100 + tv.tv_usec / 10000) * 
-			TWIN_ANGLE_360) / 6000 - TWIN_ANGLE_90;
+			TWIN_ANGLE_360) / 6000;
 	minute_angle = twin_clock_minute_angle (t.tm_min) + second_angle / 60;
-	hour_angle = (t.tm_hour * TWIN_ANGLE_360 / 12 +
-		      (minute_angle + TWIN_ANGLE_90) / 12 -
-		      TWIN_ANGLE_90);
+	hour_angle = (t.tm_hour * TWIN_ANGLE_360 + minute_angle) / 12;
 	twin_clock_face (clock);
 	twin_clock_hand (clock, hour_angle, D(0.4), D(0.07), D(0.01),
 			 TWIN_CLOCK_HOUR, TWIN_CLOCK_HOUR_OUT);
@@ -222,7 +221,9 @@ twin_clock (twin_screen_t *screen, int x, int y, int w, int h)
 	
 	gettimeofday (&tv, NULL);
 	
-	usleep (1000000 - tv.tv_usec);
+#define INTERVAL    1000000
+	
+	usleep (INTERVAL - (tv.tv_usec % INTERVAL));
     }
     nclock--;
 }