Add color mapping to planes

src/object/plane.rs

@@ -4,28 +4,38 @@ use na::*;
 use na::geometry::Point3;
 
 use crate::types::*;
-use super::base::*;
+use super::Surface;
 
 pub struct Plane {
     pub center: Point3<f32>,
     pub normal: Unit<Vector3<f32>>,
 
-    pub texture: Box<dyn Fn(f32, f32) -> Color>
+    x_axis: Vector3<f32>,
+    y_axis: Vector3<f32>,
+    texture: Box<dyn Fn(f32, f32) -> Color>
 }
 
 impl Plane {
-    pub fn new<F: 'static>(center: Point3<f32>, normal: Vector3<f32>, texture: F) -> Self
+    pub fn new<F: 'static>(center: Point3<f32>, x_axis: Vector3<f32>, y_axis: Vector3<f32>, texture: F) -> Self
         where F: Fn(f32, f32) -> Color
     {
         Plane {
             center: center,
-            normal: Unit::new_normalize(normal),
+            normal: Unit::new_normalize(x_axis.cross(&y_axis)),
+            x_axis: x_axis,
+            y_axis: y_axis,
             texture: Box::new(texture)
         }
     }
 
-    pub fn new_solid(center: Point3<f32>, normal: Vector3<f32>, color: Color) -> Self
-        { Plane::new(center, normal, move |_, _| color) }
+    pub fn new_solid(center: Point3<f32>, x_axis: Vector3<f32>, y_axis: Vector3<f32>, color: Color) -> Self
+        { Plane::new(center, x_axis, y_axis, move |_, _| color) }
+
+    pub fn xy<F: 'static + Fn(f32, f32) -> Color>(texture: F) -> Self
+        { Plane::new(Point3::origin(), Vector3::x(), Vector3::y(), texture) }
+
+    pub fn xz<F: 'static + Fn(f32, f32) -> Color>(texture: F) -> Self
+        { Plane::new(Point3::origin(), Vector3::x(), Vector3::z(), texture) }
 }
 
 impl Surface for Plane {
@@ -43,6 +53,45 @@ impl Surface for Plane {
     fn normal(&self, _point: Point3<f32>) -> Unit<Vector3<f32>> { self.normal }
 
     fn getcolor(&self, point: Point3<f32>) -> Color {
-        unimplemented!()
+        let rel_pos = point - self.center;
+        let proj_point3 = rel_pos - (*self.normal * self.normal.dot(&rel_pos));
+
+        let x = proj_point3.dot(&self.x_axis);
+        let y = proj_point3.dot(&self.y_axis);
+
+        (*self.texture)(x, y)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn plane_new() {
+        let plane = Plane::xy(|_, _| Color::black());
+
+        assert_eq!(plane.center, Point3::new(0.0, 0.0, 0.0));
+        assert_eq!(plane.normal, Unit::new_unchecked(Vector3::z()));
+    }
+
+    #[test]
+    fn plane_intersect() {
+        const N: f32 = 5.0;
+        let plane = Plane::xz(|_, _| Color::black());
+
+        let ray = Ray::new(Point3::new(0.0, N, 0.0), Vector3::new(0.0, -1.0, 0.0));
+
+        assert_eq!(plane.intersect(ray), Some(N));
+    }
+
+    #[test]
+    fn plane_getcolor() {
+        const N: f32 = 5.0;
+        let plane = Plane::xz(|x, y| Color::new(x, y, 0.0));
+
+        let point = Point3::new(5.0, 7.0, 6.0);
+
+        assert_eq!(plane.getcolor(point), Color::new(5.0, 6.0, 0.0));
     }
 }