From b2ec53525ded322cfbaae865fdb5d9e7f7d41cbe Mon Sep 17 00:00:00 2001
From: Jon Janzen <jonjanzen@me.com>
Date: Sun, 3 Oct 2021 16:19:44 -0600
Subject: [PATCH] added draw cross

---
 src/main.rs | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 09c5c2c..ee7a673 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -74,6 +74,11 @@ fn write_canvas_to_file(canvas: Canvas, file_path: &str) {
 
 }
 
+fn write_point(canvas: &mut Canvas, point: &Tuple, color: Color) {
+    canvas.write_pixel(point.x() as usize, point.y() as usize, color);
+}
+
+
 fn before_clock() {
     let env = init_env();
 
@@ -151,6 +156,19 @@ fn main() {
     clock();
 }
 
+fn draw_cross(canvas: &mut Canvas, start: &Tuple, color: Color) {
+    canvas.write_pixel(start.x() as usize, start.y() as usize, color);
+
+    let top = start * &Matrix::translation(1.0, 0.0, 0.0);
+    write_point(canvas, &top, color);
+    let right = start * &Matrix::translation(0.0, 1.0, 0.0);
+    write_point(canvas, &right, color);
+    let bottom = start * &Matrix::translation(-1.0, 0.0, 0.0);
+    write_point(canvas, &bottom, color);
+    let left = start * &Matrix::translation(0.0, -1.0, 0.0);
+    write_point(canvas, &left, color);
+}
+
 fn clock() {
     println!("Starting clock!");
 
@@ -158,17 +176,18 @@ fn clock() {
     let color = Color::new(1.0, 0.0, 0.0);
     let middle = 1024.0 / 2.0;
     canvas.write_pixel(middle as usize, middle as usize, Color::new(0.0, 1.0, 0.0));
+    let middle_point = &Tuple::point_zero() * &Matrix::translation(middle, middle, 0.0);
+    draw_cross(&mut canvas, &middle_point, Color::new(0.0, 1.0, 0.0));
 
     for i in 1..13 {
-        let twelve = Tuple::point_zero();
+        let center = Tuple::point_zero();
 
-        let twelve = &Matrix::translation(0.0, -24.0, 0.0) * &twelve;
-        let twelve = &Matrix::scaling(0.0, 10.0, 0.0) * &twelve;
-        let twelve = &Matrix::rotation_z((i as f32 / 12.0) * (2.0 * PI)) * &twelve;
-        let twelve = &Matrix::translation(middle, middle, 0.0) * &twelve;
-
-        canvas.write_pixel(twelve.x() as usize, twelve.y() as usize, color);
+        let center = &Matrix::translation(0.0, -24.0, 0.0) * &center;
+        let center = &Matrix::scaling(0.0, 10.0, 0.0) * &center;
+        let center = &Matrix::rotation_z((i as f32 / 12.0) * (2.0 * PI)) * &center;
+        let center = &Matrix::translation(middle, middle, 0.0) * &center;
 
+        draw_cross(&mut canvas, &center, color);
     }
 
     write_canvas_to_file(canvas, "clock.ppm");