* Added bitmap invert routine. It doesn't work well, so don't use it right now. Sam is working hard to correct the strange behaviour.

cucul/bitmap.c

@@ -149,6 +149,7 @@ struct cucul_bitmap
     int red[256], green[256], blue[256], alpha[256];
     float gamma;
     int gammatab[4097];
+    unsigned char invert;
 };
 #endif
 
@@ -313,6 +314,9 @@ struct cucul_bitmap *cucul_create_bitmap(unsigned int bpp, unsigned int w,
     for(i = 0; i < 4096; i++)
         bitmap->gammatab[i] = i;
 
+    /* No color inversion by default */
+    bitmap->invert = 0;
+
     return bitmap;
 }
 
@@ -379,6 +383,22 @@ void cucul_set_bitmap_gamma(struct cucul_bitmap *bitmap, float gamma)
         bitmap->gammatab[i] = 4096.0 * gammapow((float)i / 4096.0, 1.0 / gamma);
 }
 
+
+/**
+ * \brief Invert colors of bitmap
+ *
+ * Invert colors of bitmap
+ *
+ * \param bitmap Bitmap object.
+ * \param value 0 for normal behaviour, 1 for invert
+ */
+void cucul_set_bitmap_invert(struct cucul_bitmap *bitmap, unsigned char value)
+{
+    bitmap->invert = (value==0)?0:1;
+}
+
+
+
 /**
  * \brief Free the memory associated with a bitmap.
  *
@@ -781,6 +801,11 @@ void cucul_draw_bitmap(cucul_t *qq, int x1, int y1, int x2, int y2,
             fs_b[x+1] = 1 * error[2] / 16;
         }
 
+        if(bitmap->invert) {
+            outfg = 15-outfg;
+            outbg = 15-outfg;
+        }
+
         /* Now output the character */
         cucul_set_color(qq, outfg, outbg);
         cucul_putstr(qq, x, y, outch);

cucul/cucul.h

@@ -223,6 +223,7 @@ void cucul_set_bitmap_palette(struct cucul_bitmap *,
                               unsigned int b[], unsigned int a[]);
 void cucul_set_bitmap_gamma(struct cucul_bitmap *, float);
 void cucul_draw_bitmap(cucul_t *, int, int, int, int, struct cucul_bitmap const *, void *);
+void cucul_set_bitmap_invert(struct cucul_bitmap *, unsigned char);
 void cucul_free_bitmap(struct cucul_bitmap *);
 /*  @} */
 

test/demo.c

@@ -493,7 +493,7 @@ static void demo_render(void)
         //*dest++ = ((x >> 3) << 11) | ((y >> 2) << 5) | ((z >> 3));
         *dest++ = (x << 16) | (y << 8) | (z);
     }
-
+    cucul_set_bitmap_invert(bitmap, 1);
     //bitmap = cucul_create_bitmap(16, 256, 256, 2 * 256, 0xf800, 0x07e0, 0x001f, 0x0000);
     bitmap = cucul_create_bitmap(32, 256, 256, 4 * 256, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
     cucul_draw_bitmap(qq, 0, 0, cucul_get_width(qq) - 1, cucul_get_height(qq) - 1,
@@ -540,6 +540,7 @@ static void demo_render(void)
         draw_circle(buffer, xo, yo, z, 0x000000ff, 200);
 
     bitmap = cucul_create_bitmap(32, 256, 256, 4 * 256, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
+ cucul_set_bitmap_invert(bitmap, 1);
     cucul_draw_bitmap(qq, 0, 0, cucul_get_width(qq) - 1, cucul_get_height(qq) - 1, bitmap, (char *)buffer);
     cucul_free_bitmap(bitmap);
 }