From http://www.jwz.org/xscreensaver/xscreensaver-5.23.tar.gz

[xscreensaver] / hacks / interference.c

diff --git a/hacks/interference.c b/hacks/interference.c
index 3a270abe17d86ec3a040bca5eff6dc9d6c234c61..db1513189dcaf45cb195d73935f3ed391cdcd394 100644 (file)
--- a/hacks/interference.c
+++ b/hacks/interference.c
@@ -30,7 +30,7 @@
  * Last modified: Wed May 15 00:04:43 2013,
  *              Dave Odell <dmo2118@gmail.com>
  *              Tuned performance; double-buffering is now off by default.
- *              Made animation speed independant of FPS.
+ *              Made animation speed independent of FPS.
  *              Added cleanup code, fixed a few glitches.
  *              Added gratuitous #ifdefs.
  */
@@ -668,6 +668,44 @@ static void inter_init(Display* dpy, Window win, struct inter_context* c)
  * parallelized, what with all the multi-core hardware nowadays.
  */
 
+#ifdef TEST_PATTERN
+static uint32_t
+_alloc_color(struct inter_context *c, uint16_t r, uint16_t g, uint16_t b)
+{
+       XColor color;
+       color.red = r;
+       color.green = g;
+       color.blue = b;
+       XAllocColor(c->dpy, c->cmap, &color);
+       return color.pixel;
+}
+
+static void _copy_test(Display *dpy, Drawable src, Drawable dst, GC gc, int x, int y, uint32_t cells)
+{
+       XCopyArea(dpy, src, dst, gc, 0, 0, 3, 2, x, y);
+       
+       {
+               XImage *image = XGetImage(dpy, src, 0, 0, 3, 2, cells, ZPixmap);
+               XPutImage(dpy, dst, gc, image, 0, 0, x, y + 2, 3, 2);
+               XDestroyImage(image);
+       }
+}
+
+static void _test_pattern(Display *dpy, Drawable d, GC gc, const uint32_t *rgb)
+{
+       unsigned x;
+       for(x = 0; x != 3; ++x)
+       {
+               XSetForeground(dpy, gc, rgb[x]);
+               XDrawPoint(dpy, d, gc, x, 0);
+               XSetForeground(dpy, gc, rgb[2 - x]);
+               XFillRectangle(dpy, d, gc, x, 1, 1, 1);
+       }
+       
+       _copy_test(dpy, d, d, gc, 0, 2, rgb[0] | rgb[1] | rgb[2]);
+}
+#endif /* TEST_PATTERN */
+
 static unsigned long do_inter(struct inter_context* c)
 {
   int i, j, k;
@@ -857,6 +895,46 @@ static unsigned long do_inter(struct inter_context* c)
   }
 #endif
 
+#ifdef TEST_PATTERN
+       {
+/*             XWindowAttributes xgwa;
+               XGetWindowAttributes(c->dpy, c->win, &xgwa); */
+               
+               // if(xgwa.width >= 9 && xgwa.height >= 10)
+               {
+                       Screen *screen = ScreenOfDisplay(c->dpy, DefaultScreen(c->dpy));
+                       Visual *visual = DefaultVisualOfScreen(screen);
+                       Pixmap pixmap = XCreatePixmap(c->dpy, TARGET(c), 3, 10, visual_depth(screen, visual));
+                       
+                       {
+                               XSetForeground(c->dpy, c->copy_gc, _alloc_color(c, 0xffff, 0x7fff, 0x7fff));
+                               XDrawPoint(c->dpy, TARGET(c), c->copy_gc, 0, c->h - 1);
+                       }
+                       
+                       uint32_t rgb[3], cells;
+                       rgb[0] = _alloc_color(c, 0xffff, 0, 0);
+                       rgb[1] = _alloc_color(c, 0, 0xffff, 0);
+                       rgb[2] = _alloc_color(c, 0, 0, 0xffff);
+                       cells = rgb[0] | rgb[1] | rgb[2];
+                       
+                       _test_pattern(c->dpy, TARGET(c), c->copy_gc, rgb);
+                       _test_pattern(c->dpy, pixmap, c->copy_gc, rgb);
+                       // Here's a good spot to verify that the pixmap contains the right colors at the top. 
+                       _copy_test(c->dpy, TARGET(c), pixmap, c->copy_gc, 0, 6, cells);
+                       
+                       XCopyArea(c->dpy, pixmap, TARGET(c), c->copy_gc, 0, 0, 3, 10, 3, 0);
+                       {
+                               XImage *image = XGetImage(c->dpy, pixmap, 0, 0, 3, 10, cells, ZPixmap);
+                               XPutImage(c->dpy, TARGET(c), c->copy_gc, image, 0, 0, 6, 0, 3, 10);
+                               XDestroyImage(image);
+                       }
+                       
+                       XFreePixmap(c->dpy, pixmap);
+                       XSync(c->dpy, False);
+               }
+       }
+#endif /* TEST_PATTERN */
+
 #ifdef HAVE_DOUBLE_BUFFER_EXTENSION
   if (c->back_buf)
     {