Performance improvements for runtime icon generation.

[rrace.git] / src / icon.c

diff --git a/src/icon.c b/src/icon.c
index 4970694c1abca950ebdc4da91029e2a5e8585c4d..4ea355b49e2c8c630ba43410396712546f2a82a9 100644 (file)
--- a/src/icon.c
+++ b/src/icon.c
@@ -1,6 +1,6 @@
 /*
  * Icon generation 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
@@ -22,17 +22,29 @@
 #include "colour.h"
 #include "icon.h"
 
-static void format_row(unsigned char *row, unsigned long c,
-                       unsigned s, unsigned y, unsigned w, unsigned h)
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+#define primary(c) (((c) >> 8*COLOUR_PRIMARY) & 0xff)
+#define dark(c)    (((c) >> 8*COLOUR_DARK) & 0xff)
+#define light(c)   (((c) >> 8*COLOUR_LIGHT) & 0xff)
+
+static void format_row(unsigned char *row, unsigned long c, unsigned s,
+                       unsigned y, unsigned w, unsigned h)
+{
+       memset(row, dark(c), w);
+       memset(row, primary(c), y+s < h ? w-s : 0);
+       memset(row, light(c), y >= s ? MIN(s, h-y) : w-y);
+}
+
+static void format_row2(unsigned char *row, unsigned long c, unsigned s,
+                        unsigned y, unsigned w, unsigned h, unsigned stride)
 {
-       unsigned x;
-
-       for (x = 0; x < w; x++) {
-               row[x] = (c >> 8*COLOUR_PRIMARY) & 0xff;
-               if (x < s || y < s)
-                       row[x] = (c >> 8*COLOUR_LIGHT) & 0xff;
-               if ((x+s >= w && x+y >= w) || (y+s >= h && x+y >= h))
-                       row[x] = (c >> 8*COLOUR_DARK) & 0xff;
+       row += stride*y;
+       if (y > s && y+s < h) {
+               if (stride)
+                       memcpy(row, row-stride, w);
+       } else {
+               format_row(row, c, s, y, w, h);
        }
 }
 
@@ -42,16 +54,15 @@ static void format_row(unsigned char *row, unsigned long c,
  */
 void icon_tile16(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
 {
-       int out_x, out_y, out_w, y;
        unsigned char row[6];
+       unsigned y, w;
 
-       out_x = tile_x * 11 / 2;
-       out_y = tile_y * 11 / 2;
-       out_w = (5 + (tile_x == 1)) * sizeof row[0];
+       icon += 16*(11u*tile_y / 2) + (11u*tile_x / 2);
 
-       for (y = 0+(tile_y == 0); y < 6-(tile_y == 2); y++) {
-               format_row(row, c, 1, y, 6, 6);
-               memcpy(&icon[16 * out_y++ + out_x], &row[tile_x == 0], out_w);
+       w = 5+(tile_x&1u);
+       for (y = !tile_y; y < 6-(tile_y==2); y++) {
+               format_row2(row, c, 1, y, 6, 6, 0);
+               memcpy(&icon[16*(y-!tile_y)], &row[!tile_x], w);
        }
 }
 
@@ -60,13 +71,12 @@ void icon_tile16(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
  */
 void icon_tile24(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
 {
-       int out_x, out_y, y;
+       unsigned y;
 
-       out_x = tile_x * 8;
-       out_y = tile_y * 8;
+       icon += 8*(24u*tile_y + tile_x);
 
        for (y = 0; y < 8; y++) {
-               format_row(&icon[24 * out_y++ + out_x], c, 1, y, 8, 8);
+               format_row2(icon, c, 1, y, 8, 8, 24);
        }
 }
 
@@ -76,15 +86,14 @@ void icon_tile24(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
  */
 void icon_tile32(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
 {
-       int out_x, out_y, out_w, out_h, y;
+       unsigned y, w, h;
 
-       out_x = 10*tile_x + (tile_x > 0);
-       out_y = 10*tile_y + (tile_y > 0);
-       out_w = 10 + (tile_x != 1);
-       out_h = 10 + (tile_y != 1);
+       icon += 32*(10u*tile_y + !!tile_y) + (10u*tile_x + !!tile_x);
 
-       for (y = 0; y < out_h; y++) {
-               format_row(&icon[32 * out_y++ + out_x], c, 1, y, out_w, out_h);
+       w = 10u + (tile_x != 1);
+       h = 10u + (tile_y != 1);
+       for (y = 0; y < h; y++) {
+               format_row2(icon, c, 1, y, w, h, 32);
        }
 }
 
@@ -93,12 +102,11 @@ void icon_tile32(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
  */
 void icon_tile48(unsigned char *icon, unsigned long c, int tile_x, int tile_y)
 {
-       int out_x, out_y, y;
+       unsigned y;
 
-       out_x = tile_x * 16;
-       out_y = tile_y * 16;
+       icon += 16*(48u*tile_y + tile_x);
 
        for (y = 0; y < 16; y++) {
-               format_row(&icon[48 * out_y++ + out_x], c, 2, y, 16, 16);
+               format_row2(icon, c, 2, y, 16, 16, 48);
        }
 }