Fix issues when drawing frames with crop fit. (#32)

divoom/src/animation/animation_builder.rs

@@ -453,14 +453,29 @@ mod tests {
         );
     }
 
+    #[test]
+    fn divoom_animation_builder_can_crop_animation() {
+        let frames = DivoomAnimationResourceLoader::from_gif_file(
+            "test_data/animation_builder_tests/input/logo.gif",
+        )
+            .unwrap();
+
+        let builder = DivoomAnimationBuilder::new(32, Duration::from_millis(100)).unwrap();
+        let animation = builder.draw_frames(&frames, 0).build();
+        test_utils::assert_animation_equal_with_baseline(
+            &animation,
+            "test_data/animation_builder_tests/expected_cropped_animation.gif",
+        );
+    }
+
     #[test]
     fn divoom_animation_builder_can_downscale_animation() {
         let frames = DivoomAnimationResourceLoader::from_gif_file(
             "test_data/animation_builder_tests/input/logo.gif",
         )
         .unwrap();
 
-        let builder = DivoomAnimationBuilder::new(64, Duration::from_millis(100)).unwrap();
+        let builder = DivoomAnimationBuilder::new(32, Duration::from_millis(100)).unwrap();
         let animation = builder
             .draw_frames_fit(
                 &frames,

divoom/src/animation/animation_frame_builder.rs

@@ -68,8 +68,8 @@ impl DivoomAnimationFrameBuilder<'_> {
 
         match fit {
             DivoomDrawFitMode::Center => {
-                x = ((self.frame.width() - draw_width) / 2) as i32;
-                y = ((self.frame.height() - draw_height) / 2) as i32;
+                x = (self.frame.width() as i32 - draw_width as i32) / 2;
+                y = (self.frame.height() as i32 - draw_height as i32) / 2;
             }
 
             DivoomDrawFitMode::FitX => {
@@ -81,7 +81,7 @@ impl DivoomAnimationFrameBuilder<'_> {
             DivoomDrawFitMode::FitY => {
                 draw_height = self.frame.height();
                 draw_width = (draw_height as f32 * frame_ratio).round() as u32;
-                x = ((self.frame.width() - draw_width) / 2) as i32;
+                x = (self.frame.width() as i32 - draw_width as i32) / 2;
             }
 
             DivoomDrawFitMode::Stretch => {