1/* Notice to anyone that wants to repurpose the raster for your library:
2 * Please don't reuse this raster. Fontdue's raster is very unsafe, with nuanced invariants that
3 * need to be accounted for. Fontdue sanitizes the input that the raster will consume to ensure it
4 * is safe. Please be aware of this.
5 */
6
7use crate::math::Line;
8use crate::platform::{abs, as_i32, copysign, f32x4, fract};
9use crate::Glyph;
10use alloc::vec;
11use alloc::vec::*;
12
13pub struct Raster {
14 w: usize,
15 h: usize,
16 a: Vec<f32>,
17}
18
19impl Raster {
20 pub fn new(w: usize, h: usize) -> Raster {
21 Raster {
22 w,
23 h,
24 a: vec![0.0; w * h + 3],
25 }
26 }
27
28 pub(crate) fn draw(&mut self, glyph: &Glyph, scale_x: f32, scale_y: f32, offset_x: f32, offset_y: f32) {
29 let params = f32x4::new(1.0 / scale_x, 1.0 / scale_y, scale_x, scale_y);
30 let scale = f32x4::new(scale_x, scale_y, scale_x, scale_y);
31 let offset = f32x4::new(offset_x, offset_y, offset_x, offset_y);
32 for line in &glyph.v_lines {
33 self.v_line(line, line.coords * scale + offset);
34 }
35 for line in &glyph.m_lines {
36 self.m_line(line, line.coords * scale + offset, line.params * params);
37 }
38 }
39
40 #[inline(always)]
41 fn add(&mut self, index: usize, height: f32, mid_x: f32) {
42 // This is fast and hip.
43 unsafe {
44 let m = height * mid_x;
45 *self.a.get_unchecked_mut(index) += height - m;
46 *self.a.get_unchecked_mut(index + 1) += m;
47 }
48
49 // This is safe but slow.
50 // let m = height * mid_x;
51 // self.a[index] += height - m;
52 // self.a[index + 1] += m;
53 }
54
55 #[inline(always)]
56 fn v_line(&mut self, line: &Line, coords: f32x4) {
57 let (x0, y0, _, y1) = coords.copied();
58 let temp = coords.sub_integer(line.nudge).trunc();
59 let (start_x, start_y, end_x, end_y) = temp.copied();
60 let (_, mut target_y, _, _) = (temp + line.adjustment).copied();
61 let sy = copysign(1f32, y1 - y0);
62 let mut y_prev = y0;
63 let mut index = as_i32(start_x + start_y * self.w as f32);
64 let index_y_inc = as_i32(copysign(self.w as f32, sy));
65 let mut dist = as_i32(abs(start_y - end_y));
66 let mid_x = fract(x0);
67 while dist > 0 {
68 dist -= 1;
69 self.add(index as usize, y_prev - target_y, mid_x);
70 index += index_y_inc;
71 y_prev = target_y;
72 target_y += sy;
73 }
74 self.add(as_i32(end_x + end_y * self.w as f32) as usize, y_prev - y1, mid_x);
75 }
76
77 #[inline(always)]
78 fn m_line(&mut self, line: &Line, coords: f32x4, params: f32x4) {
79 let (x0, y0, x1, y1) = coords.copied();
80 let temp = coords.sub_integer(line.nudge).trunc();
81 let (start_x, start_y, end_x, end_y) = temp.copied();
82 let (tdx, tdy, dx, dy) = params.copied();
83 let (mut target_x, mut target_y, _, _) = (temp + line.adjustment).copied();
84 let sx = copysign(1f32, tdx);
85 let sy = copysign(1f32, tdy);
86 let mut tmx = tdx * (target_x - x0);
87 let mut tmy = tdy * (target_y - y0);
88 let tdx = abs(tdx);
89 let tdy = abs(tdy);
90 let mut x_prev = x0;
91 let mut y_prev = y0;
92 let mut index = as_i32(start_x + start_y * self.w as f32);
93 let index_x_inc = as_i32(sx);
94 let index_y_inc = as_i32(copysign(self.w as f32, sy));
95 let mut dist = as_i32(abs(start_x - end_x) + abs(start_y - end_y));
96 while dist > 0 {
97 dist -= 1;
98 let prev_index = index;
99 let y_next: f32;
100 let x_next: f32;
101 if tmx < tmy {
102 y_next = tmx * dy + y0; // FMA is not faster.
103 x_next = target_x;
104 tmx += tdx;
105 target_x += sx;
106 index += index_x_inc;
107 } else {
108 y_next = target_y;
109 x_next = tmy * dx + x0;
110 tmy += tdy;
111 target_y += sy;
112 index += index_y_inc;
113 }
114 self.add(prev_index as usize, y_prev - y_next, fract((x_prev + x_next) / 2.0));
115 x_prev = x_next;
116 y_prev = y_next;
117 }
118 self.add(as_i32(end_x + end_y * self.w as f32) as usize, y_prev - y1, fract((x_prev + x1) / 2.0));
119 }
120
121 #[inline(always)]
122 pub fn get_bitmap(&self) -> Vec<u8> {
123 crate::platform::get_bitmap(&self.a, self.w * self.h)
124 }
125}
126