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fix 2d triangle clipping

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Gered 2023-04-03 14:41:14 -04:00
parent 4b91d494d0
commit 39b788c564
1 changed files with 14 additions and 13 deletions
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27
ggdt/src/graphics/bitmap/triangles.rs
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@ -2,6 +2,7 @@ use crate::graphics::bitmap::Bitmap;
use crate::graphics::Pixel;
use crate::math::vector2::Vector2;
use crate::math::NearlyEqual;
use crate::prelude::Rect;
#[inline]
pub fn edge_function(a: Vector2, b: Vector2, c: Vector2) -> f32 {
@ -37,15 +38,15 @@ pub fn per_pixel_triangle_2d<PixelType: Pixel>(
// TODO: implement fill rules, probably using top-left ordering as most 3d APIs do i guess
let min_x = a.x.min(b.x).min(c.x).floor() as i32;
let min_y = a.y.min(b.y).min(c.y).floor() as i32;
let max_x = a.x.max(b.x).max(c.x).ceil() as i32;
let max_y = a.y.max(b.y).max(c.y).ceil() as i32;
let min_x = std::cmp::max(dest.clip_region().x, min_x);
let min_y = std::cmp::max(dest.clip_region().y, min_y);
let max_x = std::cmp::min(dest.clip_region().right(), max_x);
let max_y = std::cmp::min(dest.clip_region().bottom(), max_y);
let mut bounds = Rect::from_coords(
a.x.min(b.x).min(c.x).floor() as i32,
a.y.min(b.y).min(c.y).floor() as i32,
a.x.max(b.x).max(c.x).ceil() as i32,
a.y.max(b.y).max(c.y).ceil() as i32,
);
if !bounds.clamp_to(dest.clip_region()) {
return;
}
let a01 = a.y - b.y;
let b01 = b.x - a.x;
@ -58,16 +59,16 @@ pub fn per_pixel_triangle_2d<PixelType: Pixel>(
let is_ac_bottom_right = is_bottom_right_edge(a, c);
let is_ba_bottom_right = is_bottom_right_edge(b, a);
let p = Vector2::new(min_x as f32 + 0.5, min_y as f32 + 0.5);
let p = Vector2::new(bounds.x as f32 + 0.5, bounds.y as f32 + 0.5);
let mut w0_row = edge_function(b, c, p);
let mut w1_row = edge_function(c, a, p);
let mut w2_row = edge_function(a, b, p);
let draw_width = (max_x - min_x + 1) as usize;
let draw_width = bounds.width as usize;
let next_row_inc = dest.width() as usize;
let mut pixels = unsafe { dest.pixels_at_mut_ptr_unchecked(min_x, min_y) };
let mut pixels = unsafe { dest.pixels_at_mut_ptr_unchecked(bounds.x, bounds.y) };
for _ in min_y..=max_y {
for _ in bounds.y..=bounds.bottom() {
let mut w0 = w0_row;
let mut w1 = w1_row;
let mut w2 = w2_row;