--- a/render.h	Sun Jul 06 23:33:24 2008 +0300
+++ b/render.h	Mon Jul 07 04:36:03 2008 +0300
@@ -59,6 +59,9 @@
 #define REGION_X2 1.0
 #define REGION_Y2 1.5
 
+#define REGION_W (REGION_X2 - REGION_X1)
+#define REGION_H (REGION_Y2 - REGION_Y1)
+
 int render_region_full (struct render *ctx);
 int render_region_raw (struct render *ctx, double x1, double y1, double x2, double y2);