New feature: Flood-fill

src/drawing/fill.rs

@@ -1,12 +1,23 @@
-use image::{GenericImage, Pixel};
+use crate::definitions::Image;
+use image::Pixel;
 
 /// Equivalent to bucket tool in MS-PAINT
 /// Performs 4-way flood-fill based on this algorithm: https://en.wikipedia.org/wiki/Flood_fill#Span_filling
-pub fn flood_fill<I>(image: &mut I, x: u32, y: u32, fill_with: I::Pixel)
+pub fn flood_fill<P>(image: &Image<P>, x: u32, y: u32, fill_with: P) -> Image<P>
 where
-    I: GenericImage,
+    P: Pixel + PartialEq,
 {
-    let target = image.get_pixel(x, y);
+    let mut filled_image = image.clone();
+    flood_fill_mut(&mut filled_image, x, y, fill_with);
+    filled_image
+}
+
+#[doc=generate_mut_doc_comment!("draw_line_segment")]
+pub fn flood_fill_mut<P>(image: &mut Image<P>, x: u32, y: u32, fill_with: P)
+where
+    P: Pixel + PartialEq,
+{
+    let target = image.get_pixel(x, y).clone();
 
     let mut stack = Vec::new();
 
@@ -47,9 +58,9 @@ where
 }
 
 /// Determines whether (x,y) is within the image bounds and if the pixel there is equal to target_color
-fn inside<I>(image: &I, x: i32, y: i32, target_color: I::Pixel) -> bool
+fn inside<P>(image: &Image<P>, x: i32, y: i32, target_pixel: P) -> bool
 where
-    I: GenericImage,
+    P: Pixel + PartialEq,
 {
     if x < 0 || y < 0 {
         return false;
@@ -58,5 +69,5 @@ where
     let y = y as u32;
     let (width, height) = image.dimensions();
     //TODO: Compare pixel equality without conversion to rgba
-    x < width && y < height && image.get_pixel(x, y).to_rgba() == target_color.to_rgba()
+    x < width && y < height && *image.get_pixel(x, y) == target_pixel
 }

src/drawing/mod.rs

@@ -36,7 +36,7 @@ mod text;
 pub use self::text::{draw_text, draw_text_mut, text_size};
 
 mod fill;
-pub use self::fill::flood_fill;
+pub use self::fill::{flood_fill, flood_fill_mut};
 
 // Set pixel at (x, y) to color if this point lies within image bounds,
 // otherwise do nothing.

tests/regression.rs

@@ -23,7 +23,6 @@ use image::{
 
 use imageproc::contrast::ThresholdType;
 use imageproc::definitions::Image;
-use imageproc::drawing::flood_fill;
 use imageproc::filter::bilateral::GaussianEuclideanColorDistance;
 use imageproc::filter::bilateral_filter;
 use imageproc::kernel::{self};
@@ -751,7 +750,7 @@ fn test_draw_filled_ellipse() {
 
 #[test]
 fn test_draw_flood_filled_shape() {
-    use imageproc::drawing::{draw_hollow_ellipse_mut, flood_fill};
+    use imageproc::drawing::{draw_hollow_ellipse_mut, flood_fill, flood_fill_mut};
 
     let red = Rgb([255, 0, 0]);
     let green = Rgb([0, 255, 0]);
@@ -763,8 +762,10 @@ fn test_draw_flood_filled_shape() {
     draw_hollow_ellipse_mut(&mut image, (100, 150), 80, 30, green);
     draw_hollow_ellipse_mut(&mut image, (150, 150), 100, 60, blue);
 
-    flood_fill(&mut image, 120, 120, red);
+    let filled_image = flood_fill(&image, 120, 120, red);
+    compare_to_truth_image(&filled_image, "flood_filled_shape.png");
 
+    flood_fill_mut(&mut image, 120, 120, red);
     compare_to_truth_image(&image, "flood_filled_shape.png");
 }