+void game_mkhighlight(frontend *fe, float *ret,
+ int background, int highlight, int lowlight)
+{
+ float max;
+ int i;
+
+ frontend_default_colour(fe, &ret[background * 3]);
+
+ /*
+ * Drop the background colour so that the highlight is
+ * noticeably brighter than it while still being under 1.
+ */
+ max = ret[background*3];
+ for (i = 1; i < 3; i++)
+ if (ret[background*3+i] > max)
+ max = ret[background*3+i];
+ if (max * 1.2F > 1.0F) {
+ for (i = 0; i < 3; i++)
+ ret[background*3+i] /= (max * 1.2F);
+ }
+
+ for (i = 0; i < 3; i++) {
+ ret[highlight * 3 + i] = ret[background * 3 + i] * 1.2F;
+ ret[lowlight * 3 + i] = ret[background * 3 + i] * 0.8F;
+ }
+}
+
+static void memswap(void *av, void *bv, int size)
+{
+ char tmpbuf[512];
+ char *a = av, *b = bv;
+
+ while (size > 0) {
+ int thislen = min(size, sizeof(tmpbuf));
+ memcpy(tmpbuf, a, thislen);
+ memcpy(a, b, thislen);
+ memcpy(b, tmpbuf, thislen);
+ a += thislen;
+ b += thislen;
+ size -= thislen;
+ }
+}
+
+void shuffle(void *array, int nelts, int eltsize, random_state *rs)
+{
+ char *carray = (char *)array;
+ int i;
+
+ for (i = nelts; i-- > 1 ;) {
+ int j = random_upto(rs, i+1);
+ if (j != i)
+ memswap(carray + eltsize * i, carray + eltsize * j, eltsize);
+ }
+}
+
+void draw_rect_outline(frontend *fe, int x, int y, int w, int h, int colour)
+{
+ int x0 = x, x1 = x+w-1, y0 = y, y1 = y+h-1;
+
+ draw_line(fe, x0, y0, x0, y1, colour);
+ draw_line(fe, x0, y1, x1, y1, colour);
+ draw_line(fe, x1, y1, x1, y0, colour);
+ draw_line(fe, x1, y0, x0, y0, colour);
+}
+