render_agnostic/renderers/
image.rs

1use std::{
2    f64::consts::{FRAC_PI_2, PI},
3    iter::once,
4};
5
6use ab_glyph::FontArc;
7use anchor2d::{Anchor2D, HorizontalAnchor, VerticalAnchorContext, VerticalAnchorValue};
8use glam::{DVec2, IVec2, dvec2, ivec2};
9use image::{
10    Rgba, RgbaImage,
11    imageops::{FilterType, overlay, resize},
12};
13use imageproc::{
14    drawing::{
15        draw_filled_circle_mut, draw_filled_rect_mut, draw_polygon_mut, draw_text_mut, text_size,
16    },
17    point::Point,
18    rect::Rect,
19};
20use itertools::Itertools;
21use palette::Srgba;
22
23use crate::Renderer;
24
25fn srgba_to_rgba8(color: Srgba) -> Rgba<u8> {
26    let red = (color.red * 255.0).round().clamp(0.0, 255.0) as u8;
27    let green = (color.green * 255.0).round().clamp(0.0, 255.0) as u8;
28    let blue = (color.blue * 255.0).round().clamp(0.0, 255.0) as u8;
29    let alpha = (color.alpha * 255.0).round().clamp(0.0, 255.0) as u8;
30    Rgba([red, green, blue, alpha])
31}
32
33#[derive(Clone)]
34pub struct ImageRenderer {
35    virtual_width: u32,
36    virtual_height: u32,
37    image: RgbaImage,
38    scale: f64,
39    scaling_target: DVec2,
40    supersampling: u32,
41    font: FontArc,
42}
43
44impl ImageRenderer {
45    pub fn new(
46        width: u32,
47        height: u32,
48        scale: f64,
49        scaling_target: DVec2,
50        supersampling: u32,
51        font: FontArc,
52    ) -> Self {
53        Self {
54            virtual_width: width,
55            virtual_height: height,
56            image: RgbaImage::new(width * supersampling, height * supersampling),
57            scale,
58            scaling_target,
59            supersampling,
60            font,
61        }
62    }
63
64    pub fn get_font(&self) -> &FontArc {
65        &self.font
66    }
67
68    pub fn set_font(&mut self, font: FontArc) {
69        self.font = font;
70    }
71
72    fn get_supersampled_width(&self) -> u32 {
73        self.virtual_width * self.supersampling
74    }
75
76    fn get_supersampled_height(&self) -> u32 {
77        self.virtual_height * self.supersampling
78    }
79
80    fn map_value(&self, value: f64) -> f64 {
81        value * self.scale * self.supersampling as f64
82    }
83
84    fn map_x(&self, x: f64) -> f64 {
85        let target_x = self.get_supersampled_width() as f64 * self.scaling_target.x;
86        (x * self.supersampling as f64 - target_x) * self.scale + target_x
87    }
88
89    fn map_y(&self, y: f64) -> f64 {
90        let target_y = self.get_supersampled_height() as f64 * self.scaling_target.y;
91        (y * self.supersampling as f64 - target_y) * self.scale + target_y
92    }
93
94    fn map_dvec2(&self, v: DVec2) -> DVec2 {
95        dvec2(self.map_x(v.x), self.map_y(v.y))
96    }
97
98    pub fn reset(&mut self) {
99        self.image = self.transparent();
100    }
101
102    pub fn get_image(&self) -> &RgbaImage {
103        &self.image
104    }
105
106    pub fn render_image_onto(&self, mut image: RgbaImage) -> RgbaImage {
107        overlay(&mut image, &self.image, 0, 0);
108
109        resize(
110            &image,
111            self.virtual_width,
112            self.virtual_height,
113            FilterType::Lanczos3,
114        )
115    }
116
117    pub fn transparent(&self) -> RgbaImage {
118        RgbaImage::new(
119            self.get_supersampled_width(),
120            self.get_supersampled_height(),
121        )
122    }
123
124    pub fn black(&self) -> RgbaImage {
125        RgbaImage::from_pixel(
126            self.get_supersampled_width(),
127            self.get_supersampled_height(),
128            Rgba([0, 0, 0, 255]),
129        )
130    }
131
132    fn get_base_points(&self, position: DVec2, width: f64, height: f64) -> Vec<DVec2> {
133        vec![
134            position,
135            position + DVec2::X * width,
136            position + DVec2::X * width + DVec2::Y * height,
137            position + DVec2::Y * height,
138        ]
139    }
140
141    fn get_offset_vec(&self, width: f64, height: f64, offset: DVec2) -> DVec2 {
142        let offset_width = width * offset.x;
143        let offset_height = height * offset.y;
144
145        dvec2(offset_width, offset_height)
146    }
147
148    fn get_offset_points(&self, points: &[DVec2], offset_vec: DVec2) -> Vec<DVec2> {
149        points
150            .iter()
151            .copied()
152            .map(|base_point| base_point - offset_vec)
153            .collect::<Vec<DVec2>>()
154    }
155
156    fn get_rotated_points(&self, points: &[DVec2], axis: DVec2, rotation: f64) -> Vec<DVec2> {
157        points
158            .iter()
159            .copied()
160            .map(|point| rotate_point_around(point, axis, rotation))
161            .collect::<Vec<DVec2>>()
162    }
163
164    fn get_unique_integer_points(&self, points: &[DVec2]) -> Vec<IVec2> {
165        points
166            .iter()
167            .map(|point| point.round().as_ivec2())
168            .unique()
169            .collect::<Vec<IVec2>>()
170    }
171}
172
173impl Renderer for ImageRenderer {
174    fn render_point(&mut self, position: DVec2, color: Srgba) {
175        let position = self.map_dvec2(position);
176        let width = self.map_value(1.0);
177        let height = self.map_value(1.0);
178
179        let integer_position = position.round().as_ivec2();
180
181        draw_filled_rect_mut(
182            &mut self.image,
183            Rect::at(integer_position.x, integer_position.y)
184                .of_size(width.round() as u32, height.round() as u32),
185            srgba_to_rgba8(color),
186        );
187    }
188
189    fn render_line(&mut self, start: DVec2, end: DVec2, thickness: f64, color: Srgba) {
190        let start = self.map_dvec2(start);
191        let end = self.map_dvec2(end);
192
193        let thickness = self.map_value(thickness);
194        let offset = thickness / 2.0;
195        let normal = DVec2::from_angle((end - start).to_angle() + FRAC_PI_2);
196
197        let points = vec![
198            start + normal * offset,
199            start - normal * offset,
200            end - normal * offset,
201            end + normal * offset,
202        ];
203
204        let integer_points = self
205            .get_unique_integer_points(&points)
206            .iter()
207            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
208            .collect::<Vec<Point<i32>>>();
209
210        if integer_points.len() == 1 {
211            let integer_point = integer_points.first().unwrap();
212
213            self.render_point(dvec2(integer_point.x as f64, integer_point.y as f64), color);
214        } else {
215            draw_polygon_mut(&mut self.image, &integer_points, srgba_to_rgba8(color));
216        }
217    }
218
219    fn render_circle(&mut self, position: DVec2, radius: f64, color: Srgba) {
220        let position = self.map_dvec2(position).round().as_ivec2();
221        let radius = (radius * self.scale * self.supersampling as f64).round() as u32;
222
223        draw_filled_circle_mut(
224            &mut self.image,
225            position.into(),
226            radius as i32,
227            srgba_to_rgba8(color),
228        );
229    }
230
231    fn render_circle_lines(&mut self, position: DVec2, radius: f64, thickness: f64, color: Srgba) {
232        let position = self.map_dvec2(position).round().as_ivec2();
233        let radius = (radius * self.scale * self.supersampling as f64).round();
234        let thickness = (thickness * self.scale * self.supersampling as f64).round();
235
236        let mut circle_renderer = ImageRenderer::new(
237            2 * radius as u32 + 1,
238            2 * radius as u32 + 1,
239            self.scale,
240            self.scaling_target,
241            self.supersampling,
242            self.font.clone(),
243        );
244
245        circle_renderer.render_circle(dvec2(radius, radius), radius, color);
246
247        circle_renderer.render_circle(
248            dvec2(radius, radius),
249            radius - thickness,
250            Srgba::new(0.0, 0.0, 0.0, 0.0),
251        );
252
253        overlay(
254            &mut self.image,
255            &circle_renderer.render_image_onto(circle_renderer.transparent()),
256            (position.x - radius as i32) as i64,
257            (position.y - radius as i32) as i64,
258        );
259    }
260
261    fn render_arc(&mut self, position: DVec2, radius: f64, rotation: f64, arc: f64, color: Srgba) {
262        let position = self.map_dvec2(position);
263        let radius = self.map_value(radius);
264
265        let points =
266            once(position)
267                .chain((0..32).map(|i| {
268                    position + radius * DVec2::from_angle(rotation + arc * i as f64 / 31.0)
269                }))
270                .collect::<Vec<DVec2>>();
271
272        let integer_points = self
273            .get_unique_integer_points(&points)
274            .iter()
275            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
276            .collect::<Vec<Point<i32>>>();
277
278        if integer_points.len() == 1 {
279            let integer_point = integer_points.first().unwrap();
280
281            self.render_point(dvec2(integer_point.x as f64, integer_point.y as f64), color);
282        } else {
283            draw_polygon_mut(&mut self.image, &integer_points, srgba_to_rgba8(color));
284        }
285    }
286
287    fn render_arc_lines(
288        &mut self,
289        position: DVec2,
290        radius: f64,
291        rotation: f64,
292        arc: f64,
293        thickness: f64,
294        color: Srgba,
295    ) {
296        let position = self.map_dvec2(position).round().as_ivec2();
297        let radius = (radius * self.scale * self.supersampling as f64).round();
298        let thickness = (thickness * self.scale * self.supersampling as f64).round();
299
300        let mut circle_renderer = ImageRenderer::new(
301            2 * radius as u32 + 1,
302            2 * radius as u32 + 1,
303            self.scale,
304            self.scaling_target,
305            self.supersampling,
306            self.font.clone(),
307        );
308
309        circle_renderer.render_arc(dvec2(radius, radius), radius, rotation, arc, color);
310
311        circle_renderer.render_circle(
312            dvec2(radius, radius),
313            radius - thickness,
314            Srgba::new(0.0, 0.0, 0.0, 0.0),
315        );
316
317        overlay(
318            &mut self.image,
319            &circle_renderer.render_image_onto(circle_renderer.transparent()),
320            (position.x - radius as i32) as i64,
321            (position.y - radius as i32) as i64,
322        );
323    }
324
325    fn render_text(
326        &mut self,
327        text: &str,
328        position: DVec2,
329        anchor: Anchor2D,
330        size: f64,
331        color: Srgba,
332    ) {
333        let position = self.map_dvec2(position);
334        let size = size * self.scale * self.supersampling as f64;
335
336        let (text_width, _) = text_size(size as f32, &self.font, text);
337
338        let x = match anchor.get_horizontal() {
339            HorizontalAnchor::Left => position.x,
340            HorizontalAnchor::Center => position.x - text_width as f64 / 2.0,
341            HorizontalAnchor::Right => position.x - text_width as f64,
342        };
343
344        let vertical_anchor = anchor.get_vertical();
345
346        let y = match (vertical_anchor.get_context(), vertical_anchor.get_value()) {
347            (VerticalAnchorContext::Graphics, VerticalAnchorValue::Bottom) => {
348                position.y - size / 1.25
349            }
350            (VerticalAnchorContext::Math, VerticalAnchorValue::Bottom) => position.y,
351            (_, VerticalAnchorValue::Center) => position.y - size / 1.25 / 2.0,
352            (VerticalAnchorContext::Graphics, VerticalAnchorValue::Top) => position.y,
353            (VerticalAnchorContext::Math, VerticalAnchorValue::Top) => position.y - size / 1.25,
354        };
355
356        draw_text_mut(
357            &mut self.image,
358            srgba_to_rgba8(color),
359            x as i32,
360            y as i32,
361            size as f32,
362            &self.font,
363            text,
364        );
365    }
366
367    fn render_rectangle(
368        &mut self,
369        position: DVec2,
370        width: f64,
371        height: f64,
372        offset: DVec2,
373        rotation: f64,
374        color: Srgba,
375    ) {
376        let position = self.map_dvec2(position);
377        let width = self.map_value(width) - 1.0;
378        let height = self.map_value(height) - 1.0;
379
380        let base_points = self.get_base_points(position, width, height);
381        let offset_vec = self.get_offset_vec(width, height, offset);
382        let offset_points = self.get_offset_points(&base_points, offset_vec);
383        let rotated_points = self.get_rotated_points(&offset_points, position, rotation);
384
385        let integer_points = self
386            .get_unique_integer_points(&rotated_points)
387            .iter()
388            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
389            .collect::<Vec<Point<i32>>>();
390
391        if integer_points.len() == 1 {
392            let integer_point = integer_points.first().unwrap();
393
394            self.render_point(dvec2(integer_point.x as f64, integer_point.y as f64), color);
395        } else {
396            draw_polygon_mut(&mut self.image, &integer_points, srgba_to_rgba8(color));
397        }
398    }
399
400    fn render_rectangle_lines(
401        &mut self,
402        position: DVec2,
403        width: f64,
404        height: f64,
405        offset: DVec2,
406        rotation: f64,
407        thickness: f64,
408        color: Srgba,
409    ) {
410        let position = self.map_dvec2(position);
411        let width = self.map_value(width) - 1.0;
412        let height = self.map_value(height) - 1.0;
413        let thickness = self.map_value(thickness);
414
415        let base_points = self.get_base_points(position, width, height);
416        let offset_vec = self.get_offset_vec(width, height, offset);
417        let offset_points = self.get_offset_points(&base_points, offset_vec);
418        let rotated_points = self.get_rotated_points(&offset_points, position, rotation);
419
420        let integer_points = self
421            .get_unique_integer_points(&rotated_points)
422            .iter()
423            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
424            .collect::<Vec<Point<i32>>>();
425
426        let min_x = integer_points
427            .iter()
428            .map(|integer_point| integer_point.x)
429            .min()
430            .unwrap();
431        let max_x = integer_points
432            .iter()
433            .map(|integer_point| integer_point.x)
434            .max()
435            .unwrap();
436
437        let min_y = integer_points
438            .iter()
439            .map(|integer_point| integer_point.y)
440            .min()
441            .unwrap();
442        let max_y = integer_points
443            .iter()
444            .map(|integer_point| integer_point.y)
445            .max()
446            .unwrap();
447
448        let min_vec = ivec2(min_x, min_y).as_dvec2();
449
450        let renderer_width = max_x - min_x + 1;
451        let renderer_height = max_y - min_y + 1;
452
453        let mut rectangle_renderer = ImageRenderer::new(
454            renderer_width as u32,
455            renderer_height as u32,
456            1.0,
457            DVec2::ZERO,
458            1,
459            self.font.clone(),
460        );
461
462        rectangle_renderer.render_rectangle(
463            position - min_vec,
464            width + 1.0,
465            height + 1.0,
466            offset,
467            rotation,
468            color,
469        );
470
471        let midpoint = rotated_points
472            .iter()
473            .copied()
474            .map(|rotated_point| rotated_point - min_vec)
475            .sum::<DVec2>()
476            / 4.0;
477
478        rectangle_renderer.render_rectangle(
479            midpoint,
480            width + 1.0 - 2.0 * thickness,
481            height + 1.0 - 2.0 * thickness,
482            DVec2::splat(0.5),
483            rotation,
484            Srgba::new(0.0, 0.0, 0.0, 0.0),
485        );
486
487        overlay(
488            &mut self.image,
489            &rectangle_renderer.render_image_onto(rectangle_renderer.transparent()),
490            min_x as i64,
491            min_y as i64,
492        );
493    }
494
495    fn render_equilateral_triangle(
496        &mut self,
497        position: DVec2,
498        radius: f64,
499        rotation: f64,
500        color: Srgba,
501    ) {
502        let position = self.map_dvec2(position);
503        let radius = self.map_value(radius);
504
505        let points = (0..3)
506            .map(|i| position + radius * DVec2::from_angle(i as f64 * 2.0 * PI / 3.0 + rotation))
507            .collect::<Vec<DVec2>>();
508
509        let integer_points = self
510            .get_unique_integer_points(&points)
511            .iter()
512            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
513            .collect::<Vec<Point<i32>>>();
514
515        if integer_points.len() == 1 {
516            let integer_point = integer_points.first().unwrap();
517
518            self.render_point(dvec2(integer_point.x as f64, integer_point.y as f64), color);
519        } else {
520            draw_polygon_mut(&mut self.image, &integer_points, srgba_to_rgba8(color));
521        }
522    }
523
524    fn render_equilateral_triangle_lines(
525        &mut self,
526        position: DVec2,
527        radius: f64,
528        rotation: f64,
529        thickness: f64,
530        color: Srgba,
531    ) {
532        let position = self.map_dvec2(position);
533        let radius = self.map_value(radius);
534        let thickness = self.map_value(thickness);
535
536        let points = (0..3)
537            .map(|i| position + radius * DVec2::from_angle(i as f64 * 2.0 * PI / 3.0 + rotation))
538            .collect::<Vec<DVec2>>();
539
540        let integer_points = self
541            .get_unique_integer_points(&points)
542            .iter()
543            .map(|integer_point| Point::new(integer_point.x, integer_point.y))
544            .collect::<Vec<Point<i32>>>();
545
546        let min_x = integer_points
547            .iter()
548            .map(|integer_point| integer_point.x)
549            .min()
550            .expect("triangles have more than 0 points");
551        let max_x = integer_points
552            .iter()
553            .map(|integer_point| integer_point.x)
554            .max()
555            .expect("triangles have more than 0 points");
556        let min_y = integer_points
557            .iter()
558            .map(|integer_point| integer_point.y)
559            .min()
560            .expect("triangles have more than 0 points");
561        let max_y = integer_points
562            .iter()
563            .map(|integer_point| integer_point.y)
564            .max()
565            .expect("triangles have more than 0 points");
566
567        let min_point = ivec2(min_x, min_y);
568
569        let renderer_width = (max_x - min_x + 1) as u32;
570        let renderer_height = (max_y - min_y + 1) as u32;
571
572        let mut triangle_renderer = ImageRenderer::new(
573            renderer_width,
574            renderer_height,
575            1.0,
576            DVec2::ZERO,
577            1,
578            self.font.clone(),
579        );
580
581        triangle_renderer.render_equilateral_triangle(
582            (position - min_point.as_dvec2()).round(),
583            radius,
584            rotation,
585            color,
586        );
587
588        triangle_renderer.render_equilateral_triangle(
589            (position - min_point.as_dvec2()).round(),
590            radius - thickness,
591            rotation,
592            Srgba::new(0.0, 0.0, 0.0, 0.0),
593        );
594
595        overlay(
596            &mut self.image,
597            &triangle_renderer.render_image_onto(triangle_renderer.transparent()),
598            min_x as i64,
599            min_y as i64,
600        );
601    }
602}
603
604fn rotate_point_around(point: DVec2, axis: DVec2, theta: f64) -> DVec2 {
605    if theta == 0.0 {
606        return point;
607    }
608
609    let relative = point - axis;
610    let relative_theta = relative.to_angle();
611    let new_relative_theta = relative_theta + theta;
612    let new_relative = DVec2::from_angle(new_relative_theta) * relative.length();
613    new_relative + axis
614}