xcompmgr.c optimization

I toyed around with the composite manager and made a little
patch that speeds make_shadow up.

gprof results for make_shadow:
before: self ms/call 146.00
after: self ms/call 28.00

BTW: Is there a way to get a higher refresh rate with the Xvesa server?
-screen 1024x768x32x85 doesn't set the refresh rate to 85hz.

Greetings
 Michael Knorr



--- ../freedesktop/xapps/xcompmgr/xcompmgr.c	2003-11-24 20:41:39.000000000 +0100
+++ xcompmgr_changed/xcompmgr.c	2003-11-30 15:32:52.000000000 +0100
@@ -159,17 +159,17 @@
  */
  
 static unsigned char
-sum_gaussian (conv *map, double opacity, int x, int y, int width, int height)
+sum_gaussian (double opacity, int x, int y, int width, int height)
 {
     int	    fx, fy;
     double  *g_data;
-    double  *g_line = map->data;
-    int	    g_size = map->size;
+    double  *g_line = gaussianMap->data;
+    int	    g_size = gaussianMap->size;
     int	    center = g_size / 2;
     int	    fx_start, fx_end;
     int	    fy_start, fy_end;
     double  v;
-    
+
     /*
      * Compute set of filter values which are "in range",
      * that's the set with:
@@ -195,8 +195,8 @@
 	fy_end = g_size;
 
     g_line = g_line + fy_start * g_size + fx_start;
-    
-    v = 0;
+
+    v = 0.0;
     for (fy = fy_start; fy < fy_end; fy++)
     {
 	g_data = g_line;
@@ -205,10 +205,10 @@
 	for (fx = fx_start; fx < fx_end; fx++)
 	    v += *g_data++;
     }
-    if (v > 1)
-	v = 1;
-    
-    return ((unsigned int) (v * opacity * 255.0));
+    if (v > 1.0)
+	v = 1.0;
+
+    return ((unsigned char) (v * opacity * 255.0));
 }
 
 static XImage *
@@ -223,7 +223,8 @@
     int		    center = gsize / 2;
     int		    x, y;
     unsigned char   d;
-    
+    int x_diff;
+
     data = malloc (swidth * sheight * sizeof (unsigned char));
     ximage = XCreateImage (dpy,
 			   DefaultVisual(dpy, DefaultScreen(dpy)),
@@ -236,6 +237,14 @@
      * Build the gaussian in sections
      */
 
+
+    /*
+     * center (fill the complete data array)
+     */
+
+    d = sum_gaussian (opacity, center, center, width, height);
+    memset(data, d, sheight * swidth);
+
     /*
      * corners
      */
@@ -249,49 +258,41 @@
     for (y = 0; y < ylimit; y++)
 	for (x = 0; x < xlimit; x++)
 	{
-	    d = sum_gaussian (gaussianMap, opacity, x - center, y - center, width, height);
+	    d = sum_gaussian (opacity, x - center, y - center, width, height);
 	    data[y * swidth + x] = d;
 	    data[(sheight - y - 1) * swidth + x] = d;
 	    data[(sheight - y - 1) * swidth + (swidth - x - 1)] = d;
 	    data[y * swidth + (swidth - x - 1)] = d;
 	}
 
+
+    x_diff = swidth - xlimit - xlimit;
+    if(x_diff < 0) x_diff = 0;
+
     /*
      * top/bottom
      */
     for (y = 0; y < ylimit; y++)
     {
-	d = sum_gaussian (gaussianMap, opacity, center, y - center, width, height);
-	for (x = gsize; x < swidth - gsize; x++)
-	{
-	    data[y * swidth + x] = d;
-	    data[(sheight - y - 1) * swidth + x] = d;
-	}
+	d = sum_gaussian (opacity, center, y - center, width, height);
+        memset(data + y * swidth + xlimit, d, x_diff);
+        memset(data + (sheight - y - 1) * swidth + xlimit, d, x_diff);
     }
 
     /*
      * sides
      */
-    
+
     for (x = 0; x < xlimit; x++)
     {
-	d = sum_gaussian (gaussianMap, opacity, x - center, center, width, height);
-	for (y = gsize; y < sheight - gsize; y++)
+	d = sum_gaussian (opacity, x - center, center, width, height);
+	for (y = ylimit; y < sheight - ylimit; y++)
 	{
 	    data[y * swidth + x] = d;
 	    data[y * swidth + (swidth - x - 1)] = d;
 	}
     }
 
-    /*
-     * center
-     */
-
-    d = sum_gaussian (gaussianMap, opacity, center, center, width, height);
-    for (y = ylimit; y < sheight - ylimit; y++)
-	for (x = xlimit; x < swidth - xlimit; x++)
-	    data[y * swidth + x] = d;
-
     return ximage;
 }
 
@@ -299,7 +300,7 @@
 shadow_picture (Display *dpy, double opacity, int width, int height, int *wp, int *hp)
 {
     XImage  *shadowImage = make_shadow (dpy, opacity, width, height);
-    Pixmap  shadowPixmap = XCreatePixmap (dpy, root, 
+    Pixmap  shadowPixmap = XCreatePixmap (dpy, root,
 					  shadowImage->width,
 					  shadowImage->height,
 					  8);
@@ -400,7 +401,7 @@
 win_extents (Display *dpy, win *w)
 {
     XRectangle	    r;
-    
+
     r.x = w->a.x;
     r.y = w->a.y;
     r.width = w->a.width + w->a.border_width * 2;
@@ -408,7 +409,7 @@
     if (w->mode != WINDOW_ARGB)
     {
 	XRectangle  sr;
-	
+
 	if (!w->shadow)
 	{
 	    double	opacity = SHADOW_OPACITY;