Fix crashing when we go to low HEAD main

3 files changed, 42 insertions, 10 deletions

diff --git a/TODO.md b/TODO.md
index 482a063..5bdc8d5 100644
--- a/TODO.md
+++ b/TODO.md
@@ -50,9 +50,6 @@
 	It would be cute if the screen did a side-to-side animation on each
 	press as well.
 
-(5) Crash when you try to go below the bottom
-	If you're moving down and you hit the bottom edge, we crash.
-
 (6) Lines with a positive slope draw wrong
 	When you're diagonaling right and up, the line draws almost-inverted
 	and comes out as right and down, but it's more than that. Seemingly,
@@ -87,4 +84,18 @@
 	because i wrote the smallest winit program, none-surface-left-beef, that's only
 	job was to make a winit window. It used 11MB. Our surfaces, assuming that
 	softbuffer holds only one buffer in memory, was ~5.2MB (~5MB for the 640x480 window
-	at a 2x scale, and ~1.2MB for 640x480 (both using u32s for pixels)).
\ No newline at end of file
+	at a 2x scale, and ~1.2MB for 640x480 (both using u32s for pixels)).
+
+(5) Crash when you try to go below the bottom
+	If you're moving down and you hit the bottom edge, we crash.
+
+	DONE
+	this was because in image.rs Image::rect() we do not check that we
+	are only drawing within bounds, and our lines (secretly many rects)
+	were 2 wide. so when we draw the stylus, which is also two-wide, it
+	would try to draw below the image and crash.
+	this also happened on the horizontal but it was wrap back around to
+	the left edge. humorously the in-bounds check used to only be done
+	when we handled the joystick events, which was not every frame. so
+	the keyboard could make it significantly past the right-edge and do
+	a little drawing past that on the left.
\ No newline at end of file
diff --git a/src/image.rs b/src/image.rs
index 177eff2..5b6cb33 100644
--- a/src/image.rs
+++ b/src/image.rs
@@ -73,11 +73,18 @@ impl Image {
 	}
 
 	pub fn rect(&mut self, pos: Vec2<u32>, dim: Vec2<u32>, clr: Color) {
+		if pos.x >= self.width || pos.y >= self.height {
+			// if we're fully over in one of these directions, we shouldn't go further.
+			return;
+		}
+
+		// .min(..) so we only draw what we can see/what's within bounds
 		let x_start = pos.x as usize;
-		let x_end = (pos.x + dim.x) as usize;
+		let x_end = (pos.x + dim.x).min(self.width - 1) as usize;
+		let y_end = (pos.y + dim.y).min(self.height - 1) as usize;
 
 		for idx in x_start..x_end {
-			for idy in pos.y as usize..pos.y as usize + dim.y as usize {
+			for idy in pos.y as usize..y_end {
 				let data_idx = idx + idy * self.width as usize;
 				self.data[data_idx] = clr.into();
 			}
diff --git a/src/main.rs b/src/main.rs
index 59d004f..dc3989a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -132,6 +132,20 @@ impl Etch {
 			gif.save(path).unwrap();
 		}
 	}
+
+	pub fn keep_stylus_inbounds(&mut self) {
+		if self.stylus.x < 0.0 {
+			self.stylus.x = 0.0;
+		} else if self.stylus.x > self.img.width() as f32 - 1.0 {
+			self.stylus.x = self.img.width() as f32 - 1.0;
+		}
+
+		if self.stylus.y < 0.0 {
+			self.stylus.y = 0.0
+		} else if self.stylus.y > self.img.height() as f32 - 1.0 {
+			self.stylus.y = self.img.height() as f32 - 1.0;
+		}
+	}
 }
 
 // Why are my consts HERE of all places
@@ -240,10 +254,8 @@ impl ApplicationHandler for Etch {
 
 					let movement_x = left_delta / DIAL_SENSITIVITY;
 					let movement_y = right_delta / DIAL_SENSITIVITY;
-					self.stylus.x =
-						(self.stylus.x + movement_x).clamp(0.0, self.img.width() as f32);
-					self.stylus.y =
-						(self.stylus.y - movement_y).clamp(0.0, self.img.height() as f32);
+					self.stylus.x = self.stylus.x + movement_x;
+					self.stylus.y = self.stylus.y - movement_y;
 
 					self.next_check = Instant::now();
 				}
@@ -280,6 +292,8 @@ impl ApplicationHandler for Etch {
 					}
 				}
 
+				self.keep_stylus_inbounds();
+
 				// If the stylus moved, we should draw
 				if stylus_prev != self.stylus {
 					self.img.line(