Replace line_drawing with clipline (#381)

* Replaced `line_drawing` with `clipline`

* Update `clipline` to 0.1.1

examples/conway/Cargo.toml

@@ -14,7 +14,7 @@ byteorder = "1"
 env_logger = "0.10"
 error-iter = "0.4"
 getrandom = "0.2"
-line_drawing = "1"
+clipline = "0.1.1"
 log = "0.4"
 pixels = { path = "../.." }
 randomize = "3"

examples/conway/src/main.rs

@@ -318,19 +318,16 @@ impl ConwayGrid {
         }
     }
 
-    fn set_line(&mut self, x0: isize, y0: isize, x1: isize, y1: isize, alive: bool) {
-        // probably should do sutherland-hodgeman if this were more serious.
-        // instead just clamp the start pos, and draw until moving towards the
-        // end pos takes us out of bounds.
-        let x0 = x0.clamp(0, self.width as isize);
-        let y0 = y0.clamp(0, self.height as isize);
-        for (x, y) in line_drawing::Bresenham::new((x0, y0), (x1, y1)) {
-            if let Some(i) = self.grid_idx(x, y) {
-                self.cells[i].set_alive(alive);
-            } else {
-                break;
-            }
+    fn set_line(&mut self, x0: isize, y0: isize, x1: isize, y1: isize, alive: bool) -> Option<()> {
+        // possible to optimize by matching on Clipline and iterating over its arms
+        for (x, y) in clipline::Clipline::new(
+            ((x0, y0), (x1, y1)),
+            ((0, 0), (self.width as isize - 1, self.height as isize - 1)),
+        )? {
+            let (x, y) = (x as usize, y as usize);
+            self.cells[x + y * self.width].set_alive(alive);
         }
+        Some(())
     }
 
     fn grid_idx<I: std::convert::TryInto<usize>>(&self, x: I, y: I) -> Option<usize> {

examples/invaders/simple-invaders/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Jay Oster <jay@kodewerx.org>"]
 edition = "2018"
 
 [dependencies]
-line_drawing = "1.0"
+clipline = "0.1.1"
 pcx = "0.2"
 randomize = "3.0"
 

examples/invaders/simple-invaders/src/sprites.rs

@@ -3,9 +3,7 @@ use crate::TIME_STEP;
 use crate::{Point, HEIGHT, WIDTH};
 use alloc::rc::Rc;
 use alloc::vec::Vec;
-use core::cmp::min;
 use core::time::Duration;
-use line_drawing::Bresenham;
 
 // This is the type stored in the `Assets` hash map
 pub(crate) type CachedSprite = (usize, usize, Rc<[u8]>);
@@ -215,17 +213,17 @@ where
 }
 
 /// Draw a line to the pixel buffer using Bresenham's algorithm.
-pub(crate) fn line(screen: &mut [u8], p1: &Point, p2: &Point, color: [u8; 4]) {
-    let p1 = (p1.x as i64, p1.y as i64);
-    let p2 = (p2.x as i64, p2.y as i64);
-
-    for (x, y) in Bresenham::new(p1, p2) {
-        let x = min(x as usize, WIDTH - 1);
-        let y = min(y as usize, HEIGHT - 1);
+pub(crate) fn line(screen: &mut [u8], p1: &Point, p2: &Point, color: [u8; 4]) -> Option<()> {
+    let p1 = (p1.x as isize, p1.y as isize);
+    let p2 = (p2.x as isize, p2.y as isize);
+    let clip_max = (WIDTH as isize - 1, HEIGHT as isize - 1);
+    for (x, y) in clipline::Clipline::new((p1, p2), ((0, 0), clip_max))? {
+        let (x, y) = (x as usize, y as usize);
         let i = x * 4 + y * WIDTH * 4;
 
         screen[i..i + 4].copy_from_slice(&color);
     }
+    Some(())
 }
 
 /// Draw a rectangle to the pixel buffer using two points in opposite corners.