From 4c9c479ddc80d245d1ae7424cc3dd775f9ee3eef Mon Sep 17 00:00:00 2001
From: gennyble <gen@nyble.dev>
Date: Sat, 30 Nov 2024 02:24:20 -0600
Subject: Make the line solid

---
 src/image.rs | 36 ++++++++++++++++++++++++++++++++++--
 src/main.rs  | 13 ++++++++++---
 2 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/src/image.rs b/src/image.rs
index 66ca858..0ce41d9 100644
--- a/src/image.rs
+++ b/src/image.rs
@@ -36,11 +36,43 @@ impl Image {
 		self.height
 	}
 
-	pub fn rect(&mut self, x: u32, y: u32, width: u32, height: u32) {
-		todo!()
+	pub fn rect(&mut self, x: u32, y: u32, width: u32, height: u32, clr: Color) {
+		let x_start = x as usize;
+		let x_end = (x + width) as usize;
+
+		for idx in x_start..x_end {
+			for idy in y as usize..y as usize + height as usize {
+				let data_idx = idx + idy * self.width as usize;
+				self.data[data_idx] = clr.into();
+			}
+		}
+	}
+
+	/// Primitive, naive line drawing funciton. lerps the points together and
+	/// draws a rect of the specified width at that location.
+	pub fn line(&mut self, x1: u32, y1: u32, x2: u32, y2: u32, width: u32, clr: Color) {
+		let start_x = x1.min(x2) as f32;
+		let start_y = y1.min(y2) as f32;
+		let end_x = x1.max(x2) as f32;
+		let end_y = y1.max(y2) as f32;
+
+		tracing::trace!("start_x = {start_x} / end_x = {end_x}");
+		tracing::trace!("start_y = {start_y} / end_y = {end_y}");
+
+		let dx = end_x - start_x;
+		let dy = end_y - start_y;
+		let long = dx.max(dy);
+
+		for idx in 0..long as usize {
+			let x = start_x + dx * (idx as f32 / long);
+			let y = start_y + dy * (idx as f32 / long);
+
+			self.rect(x as u32, y as u32, width, width, clr);
+		}
 	}
 }
 
+#[derive(Copy, Clone, Debug)]
 pub struct Color {
 	pub r: u8,
 	pub g: u8,
diff --git a/src/main.rs b/src/main.rs
index 9aed460..6d07411 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -169,6 +169,7 @@ impl ApplicationHandler for Etch {
 						"ANGLE {left_angle} // {left_delta}v -=- {right_angle} // {right_delta}v"
 					);
 
+					let stylus_prev = self.stylus;
 					let movement_x = left_delta / 10.0;
 					let movement_y = right_delta / 10.0;
 					self.stylus.x =
@@ -176,9 +177,14 @@ impl ApplicationHandler for Etch {
 					self.stylus.y =
 						(self.stylus.y - movement_y).clamp(0.0, self.img.height() as f32);
 
-					let w = self.img.width();
-					self.img.data_mut()
-						[w as usize * self.stylus.y as usize + self.stylus.x as usize] = LINE_COLOUR;
+					self.img.line(
+						self.stylus.x as u32,
+						self.stylus.y as u32,
+						stylus_prev.x as u32,
+						stylus_prev.y as u32,
+						2,
+						LINE_COLOUR.into(),
+					);
 
 					tracing::info!("STYLUS: ({},{})", self.stylus.x, self.stylus.y);
 
@@ -257,6 +263,7 @@ fn angle_delta(lhs: f32, rhs: f32) -> f32 {
 	}
 }
 
+#[derive(Copy, Clone, Debug)]
 pub struct Vec2 {
 	x: f32,
 	y: f32,
-- 
cgit 1.4.1-3-g733a5