Implement a basic Sierpinski Gasket IFS

enkou-shaders/src/camera.rs

@@ -5,6 +5,7 @@ use libm::powf;
 #[derive(Copy, Clone, Pod, Zeroable)]
 #[repr(C)]
 pub struct Camera {
+    dimensions: UVec2,
     transform: Affine2,
 }
 
@@ -39,7 +40,10 @@ impl Camera {
             * zoom_transform
             * ifs_center_transform;
 
-        Camera { transform }
+        Camera {
+            dimensions,
+            transform,
+        }
     }
 
     /// Map a point from IFS coordinates to pixel coordinates.
@@ -62,6 +66,21 @@ impl Camera {
     pub fn transform_point(&self, point: Vec2) -> IVec2 {
         self.transform.transform_point2(point).as_ivec2()
     }
+
+    /// Map a point from IFS coordinates to pixel coordinates (like [`transform_point`]),
+    /// and check that the result is within the provided image dimensions.
+    pub fn transform_point_to_image(&self, point: Vec2) -> Option<UVec2> {
+        let pixel_coordinates = self.transform_point(point);
+        if pixel_coordinates.x < 0
+            || pixel_coordinates.y < 0
+            || (pixel_coordinates.x as u32) >= self.dimensions.x
+            || (pixel_coordinates.y as u32) >= self.dimensions.y
+        {
+            None
+        } else {
+            Some(pixel_coordinates.as_uvec2())
+        }
+    }
 }
 
 #[cfg(test)]