Rename Point -> Vec2 to distinguish it clearly from any 3d object

src/render.rs

@@ -1,5 +1,5 @@
 use ansi_term::Color::RGB;
-use crate::geom::Point;
+use crate::geom::Vec2;
 use crate::{flt::{Flt, Real}, Material as _};
 use crate::mat;
 use crate::sim::{Cell, GenericSim};
@@ -48,7 +48,7 @@ fn scale_unsigned_to_u8(x: Flt, typ: Flt) -> u8 {
 }
 
 /// Scale a vector to have magnitude between [0, 1).
-fn scale_vector(x: Point, typical_mag: Flt) -> Point {
+fn scale_vector(x: Vec2, typical_mag: Flt) -> Vec2 {
     let new_mag = scale_unsigned(x.mag(), typical_mag);
     x.with_mag(new_mag)
 }
@@ -112,7 +112,7 @@ impl<'a> RenderSteps<'a> {
         self.render_vector_field(Rgb([0xff, 0xff, 0xff]), 1.0e-9, |cell| cell.b().xy());
     }
 
-    fn render_vector_field<F: Fn(&Cell<mat::Static>) -> Point>(&mut self, color: Rgb<u8>, typical: Flt, measure: F) {
+    fn render_vector_field<F: Fn(&Cell<mat::Static>) -> Vec2>(&mut self, color: Rgb<u8>, typical: Flt, measure: F) {
         let w = self.im.width();
         let h = self.im.height();
         let vec_spacing = 10;
@@ -123,7 +123,7 @@ impl<'a> RenderSteps<'a> {
                     let norm_vec = scale_vector(vec, typical);
                     let alpha = 0.7*scale_unsigned(vec.mag_sq(), typical * 5.0);
                     let vec = norm_vec * (vec_spacing as Flt);
-                    let center = Point::new(x as _, y as _) + Point::new(vec_spacing as _, vec_spacing as _)*0.5;
+                    let center = Vec2::new(x as _, y as _) + Vec2::new(vec_spacing as _, vec_spacing as _)*0.5;
                     self.im.draw_field_arrow(center, vec, color, alpha as f32);
                 }
             }
@@ -169,8 +169,8 @@ impl<'a> RenderSteps<'a> {
         }
     }
 
-    fn field_vector<F: Fn(&Cell<mat::Static>) -> Point>(&self, xidx: u32, yidx: u32, size: u32, measure: &F) -> Point {
-        let mut field = Point::default();
+    fn field_vector<F: Fn(&Cell<mat::Static>) -> Vec2>(&self, xidx: u32, yidx: u32, size: u32, measure: &F) -> Vec2 {
+        let mut field = Vec2::default();
         let w = self.im.width();
         let h = self.im.height();
         let xstart = xidx.min(w);
@@ -186,7 +186,7 @@ impl<'a> RenderSteps<'a> {
         let yw = yend - ystart;
         if xw == 0 || yw == 0 {
             // avoid division by zero
-            Point::new(0.0, 0.0)
+            Vec2::new(0.0, 0.0)
         } else {
             field * (1.0 / ((xw*yw) as Flt))
         }
@@ -194,11 +194,11 @@ impl<'a> RenderSteps<'a> {
 }
 
 trait ImageRenderExt {
-    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>, alpha: f32);
+    fn draw_field_arrow(&mut self, center: Vec2, rel: Vec2, color: Rgb<u8>, alpha: f32);
 }
 
 impl ImageRenderExt for RgbImage {
-    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>, alpha: f32) {
+    fn draw_field_arrow(&mut self, center: Vec2, rel: Vec2, color: Rgb<u8>, alpha: f32) {
         let start = (center - rel * 0.5).round();
         let end = (center + rel * 0.5).round();
         let i_start = (start.x() as _, start.y() as _);