use core::fmt::Debug;
use embedded_graphics_core::draw_target::DrawTarget;
use embedded_graphics_core::pixelcolor::{Rgb565, RgbColor};
use embedded_graphics_core::prelude::Point;
use crate::pipeline::rasterize::draw::blend::fast_blend_rgb565;
#[inline(always)]
pub(super) fn fill_triangle_zbuffered_translucent<D: DrawTarget<Color = Rgb565>>(
p1: nalgebra::Point2<i32>,
p2: nalgebra::Point2<i32>,
p3: nalgebra::Point2<i32>,
z1: f32,
z2: f32,
z3: f32,
color: Rgb565,
alpha: u8,
fb: &mut D,
zbuffer: &mut [crate::ZDepth],
width: usize,
) where
<D as DrawTarget>::Error: Debug,
{
let p1_eg = Point::new(p1.x, p1.y);
let p2_eg = Point::new(p2.x, p2.y);
let p3_eg = Point::new(p3.x, p3.y);
let z1_int = (z1 * 65536.0) as u32;
let z2_int = (z2 * 65536.0) as u32;
let z3_int = (z3 * 65536.0) as u32;
if p2_eg.y == p3_eg.y {
fill_bottom_flat_translucent(
p1_eg, p2_eg, p3_eg, z1_int, z2_int, z3_int, color, alpha, fb, zbuffer, width,
);
} else if p1_eg.y == p2_eg.y {
fill_top_flat_translucent(
p1_eg, p2_eg, p3_eg, z1_int, z2_int, z3_int, color, alpha, fb, zbuffer, width,
);
} else {
let t = (p2_eg.y - p1_eg.y) as f32 / (p3_eg.y - p1_eg.y) as f32;
let p4 = Point::new(
(p1_eg.x as f32 + t * (p3_eg.x - p1_eg.x) as f32) as i32,
p2_eg.y,
);
let z4_int = (z1_int as i64 + (t * (z3_int as i64 - z1_int as i64) as f32) as i64) as u32;
fill_bottom_flat_translucent(
p1_eg, p2_eg, p4, z1_int, z2_int, z4_int, color, alpha, fb, zbuffer, width,
);
fill_top_flat_translucent(
p2_eg, p4, p3_eg, z2_int, z4_int, z3_int, color, alpha, fb, zbuffer, width,
);
}
}
#[inline(always)]
pub(super) fn fill_bottom_flat_translucent<D: DrawTarget<Color = Rgb565>>(
p1: Point,
p2: Point,
p3: Point,
z1: u32,
z2: u32,
z3: u32,
color: Rgb565,
alpha: u8,
fb: &mut D,
zbuffer: &mut [crate::ZDepth],
width: usize,
) where
<D as DrawTarget>::Error: Debug,
{
let height = p2.y - p1.y;
if height == 0 {
return;
}
let invslope1 = ((p2.x - p1.x) << 16) / height;
let invslope2 = ((p3.x - p1.x) << 16) / height;
let mut curx1 = (p1.x << 16) + (1 << 15);
let mut curx2 = (p1.x << 16) + (1 << 15);
for scanline_y in p1.y..=p2.y {
let dy = scanline_y - p1.y;
let z_left = (z1 as i64 + ((z2 as i64 - z1 as i64) * dy as i64 / height as i64)) as u32;
let z_right = (z1 as i64 + ((z3 as i64 - z1 as i64) * dy as i64 / height as i64)) as u32;
let (left_x, right_x, z_l, z_r) = if curx1 <= curx2 {
(curx1 >> 16, curx2 >> 16, z_left, z_right)
} else {
(curx2 >> 16, curx1 >> 16, z_right, z_left)
};
let span = right_x - left_x;
for x in left_x..=right_x {
if x < 0 || scanline_y < 0 || x >= width as i32 {
continue;
}
let idx = (scanline_y as usize) * width + (x as usize);
if idx >= zbuffer.len() {
continue;
}
let z = if span > 0 {
let t = (x - left_x) as f32 / span as f32;
(z_l as f32 + t * (z_r as f32 - z_l as f32)) as u32
} else {
z_l
};
let z_depth = crate::to_zdepth(z);
if z_depth < zbuffer[idx] {
zbuffer[idx] = z_depth;
let draw_color = fast_blend_rgb565(Rgb565::BLACK, color, alpha);
let _ = fb.draw_iter([embedded_graphics_core::Pixel(
Point::new(x, scanline_y),
draw_color,
)]);
}
}
curx1 += invslope1;
curx2 += invslope2;
}
}
#[inline(always)]
pub(super) fn fill_top_flat_translucent<D: DrawTarget<Color = Rgb565>>(
p1: Point,
p2: Point,
p3: Point,
z1: u32,
z2: u32,
z3: u32,
color: Rgb565,
alpha: u8,
fb: &mut D,
zbuffer: &mut [crate::ZDepth],
width: usize,
) where
<D as DrawTarget>::Error: Debug,
{
let height = p3.y - p1.y;
if height == 0 {
return;
}
let invslope1 = ((p3.x - p1.x) << 16) / height;
let invslope2 = ((p3.x - p2.x) << 16) / height;
let mut curx1 = (p3.x << 16) + (1 << 15);
let mut curx2 = (p3.x << 16) + (1 << 15);
for scanline_y in (p1.y..=p3.y).rev() {
let dy = scanline_y - p1.y;
let z_left = (z1 as i64 + ((z3 as i64 - z1 as i64) * dy as i64 / height as i64)) as u32;
let z_right = (z2 as i64 + ((z3 as i64 - z2 as i64) * dy as i64 / height as i64)) as u32;
let (left_x, right_x, z_l, z_r) = if curx1 <= curx2 {
(curx1 >> 16, curx2 >> 16, z_left, z_right)
} else {
(curx2 >> 16, curx1 >> 16, z_right, z_left)
};
let span = right_x - left_x;
for x in left_x..=right_x {
if x < 0 || scanline_y < 0 || x >= width as i32 {
continue;
}
let idx = (scanline_y as usize) * width + (x as usize);
if idx >= zbuffer.len() {
continue;
}
let z = if span > 0 {
let t = (x - left_x) as f32 / span as f32;
(z_l as f32 + t * (z_r as f32 - z_l as f32)) as u32
} else {
z_l
};
let z_depth = crate::to_zdepth(z);
if z_depth < zbuffer[idx] {
zbuffer[idx] = z_depth;
let draw_color = fast_blend_rgb565(Rgb565::BLACK, color, alpha);
let _ = fb.draw_iter([embedded_graphics_core::Pixel(
Point::new(x, scanline_y),
draw_color,
)]);
}
}
curx1 -= invslope1;
curx2 -= invslope2;
}
}