Performance improvements for runtime icon generation.

[rrace.git] / src / ewmhicon.c

diff --git a/src/ewmhicon.c b/src/ewmhicon.c
index 319ed3ac548e746c9df3e92f9a850cf3774a78ae..7e69ec883f5c36317c900abff0a947e03b149d8c 100644 (file)
--- a/src/ewmhicon.c
+++ b/src/ewmhicon.c
@@ -1,6 +1,6 @@
 /*
  * _NET_WM_ICON helpers for slide puzzle game
- * Copyright © 2022 Nick Bowler
+ * Copyright © 2022-2023 Nick Bowler
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -32,41 +32,6 @@
 
 enum { ICON_16x16, ICON_24x24, ICON_32x32, ICON_48x48, ICON_MAX };
 
-/*
- * Allocate storage for the EWMH _NET_WM_ICON array.  The sizes array is
- * populated with pointers to the beginning of each icon's pixel data.  For
- * example, sizes[ICON_24x24] points to the first pixel of the 24x24 image.
- *
- * The returned value can then be passed to XChangeProperty to set the icon,
- * (use EWMH_ICON_NELEM for the number of elements) and must be freed by the
- * caller.
- */
-static void *ewmh_icon_alloc(unsigned long **sizes)
-{
-       unsigned long *buf;
-
-       buf = calloc(sizeof *buf, EWMH_ICON_NELEM);
-       if (buf) {
-               sizes[ICON_16x16] = buf;
-               *sizes[ICON_16x16]++ = 16;
-               *sizes[ICON_16x16]++ = 16;
-
-               sizes[ICON_24x24] = sizes[ICON_16x16] + 16*16;
-               *sizes[ICON_24x24]++ = 24;
-               *sizes[ICON_24x24]++ = 24;
-
-               sizes[ICON_32x32] = sizes[ICON_24x24] + 24*24;
-               *sizes[ICON_32x32]++ = 32;
-               *sizes[ICON_32x32]++ = 32;
-
-               sizes[ICON_48x48] = sizes[ICON_32x32] + 32*32;
-               *sizes[ICON_48x48]++ = 48;
-               *sizes[ICON_48x48]++ = 48;
-       }
-
-       return buf;
-}
-
 static unsigned long scale16to8(unsigned x)
 {
        return x*0xfful / 0xffff;
@@ -80,43 +45,51 @@ static unsigned long wm_pixel(const XColor *c)
             | scale16to8(c->blue);
 }
 
-static void do_remap(void *icon, unsigned size, const XColor *map)
+static void do_remap(void *icon, unsigned area, const XColor *map)
 {
        unsigned char *index = icon;
        unsigned long *argb = icon;
-       unsigned i, count = size*size;
+       unsigned i;
 
-       for (i = 0; i < count; i++) {
-               argb[count-i-1] = wm_pixel(map + index[count-i-1]);
+       area--;
+       for (i = 0; i <= area; i++) {
+               argb[area-i] = wm_pixel(map + index[area-i]);
        }
 }
 
 void *ewmh_icon_generate(const unsigned long *seq, const XColor *map)
 {
-       unsigned long *buf, *sizes[ICON_MAX];
-       unsigned i, j;
+       static const unsigned char dims[ICON_MAX] = { 16, 24, 32, 48 };
+       unsigned long *work, *ret;
+       unsigned i, j, fullsize, size;
 
-       buf = ewmh_icon_alloc(sizes);
-       if (!buf)
+       work = ret = malloc(sizeof *work * EWMH_ICON_NELEM);
+       if (!work)
                return NULL;
 
-       for (i = 0; i < 9; i++) {
-               unsigned x = i%3, y = i/3;
+       for (i = fullsize = 0; i < ICON_MAX; i++) {
+               work += fullsize;
 
-               icon_tile16((void *)sizes[ICON_16x16], seq[i], x, y);
-               icon_tile24((void *)sizes[ICON_24x24], seq[i], x, y);
-               icon_tile32((void *)sizes[ICON_32x32], seq[i], x, y);
-               icon_tile48((void *)sizes[ICON_48x48], seq[i], x, y);
-       }
+               size = dims[i];
+               *work++ = size;
+               *work++ = size;
+
+               for (j = 0; j < 9; j++) {
+                       unsigned x = j%3, y = j/3;
 
-       for (i = 0; i < ICON_MAX; i++) {
-               /* Produces the sequence 16, 24, 32, 48 */
-               unsigned size = 16 + (1u<<i)/2 * 8;
+                       switch (i) {
+                       case 0: icon_tile16((void *)work, seq[j], x, y); break;
+                       case 1: icon_tile24((void *)work, seq[j], x, y); break;
+                       case 2: icon_tile32((void *)work, seq[j], x, y); break;
+                       case 3: icon_tile48((void *)work, seq[j], x, y); break;
+                       }
+               }
 
-               do_remap(sizes[i], size, map);
+               fullsize = size*size;
+               do_remap(work, fullsize, map);
        }
 
-       return buf;
+       return ret;
 }
 
 #if !X_DISPLAY_MISSING