1 files changed, 34 insertions, 0 deletions
diff --git a/src/lib/algo/flood_fill.c b/src/lib/algo/flood_fill.c
new file mode 100644
index 0000000..91f94ad
--- /dev/null
+++ b/src/lib/algo/flood_fill.c
@@ -0,0 +1,34 @@
+#include <lib/algo/flood_fill.h>
+
+//-----------------------------------------------
+// Flood
+// Floods a mask from a given set of image to determine the contiguous regions
+//  1. Check that the (x,y) is within the picture
+//  2. Check if the (x,y) coordinate in the mask is unused
+//  3. Check if the (x,y) coordinate in the image is non-background
+//  4. Check if the (x,y) coordinate in the image is the same color as the fill color
+//  5. If all hold, set the label for the pixel, and check each neighbor
+//     Otherwise, stop flooding
+bool_t flood(uint8_t* image, uint16_t* mask, size_t width, size_t height, size_t channels, size_t x, size_t y, uint8_t* fill_color, uint16_t label)
+{
+  if ((x >= width) | (y >= height)) {
+    return FALSE;
+  }
+  size_t coord = x + y*width;
+  if (mask[coord] != 0) {
+    return FALSE;
+  }
+  if (color_zero(&(image[coord*channels]), channels)) {
+    return FALSE;
+  }
+  if (color_equal(&(image[coord*channels]), fill_color, channels)) {
+    mask[coord] = label;
+    flood(image, mask, width, height, channels, x, y+1, fill_color, label);
+    flood(image, mask, width, height, channels, x, y-1, fill_color, label);
+    flood(image, mask, width, height, channels, x+1, y, fill_color, label);
+    flood(image, mask, width, height, channels, x-1, y, fill_color, label);
+    return TRUE;
+  }
+  return FALSE;
+}
+