Only collide with walls from the front
[kaka/rust-sdl-test.git] / src / core / level / mod.rs
1 use core::render::Renderer;
2 use geometry::{Point, Dimension, Intersection, Angle, ToAngle, supercover_line};
3 use sprites::SpriteManager;
4 use std::rc::Rc;
5 use {point, dimen};
6
7 mod lvlgen;
8
9 pub use self::lvlgen::LevelGenerator;
10
11 ////////// LEVEL ///////////////////////////////////////////////////////////////
12
13 #[derive(Default)]
14 pub struct Level {
15     pub gravity: Point<f64>,
16     pub grid: Grid<bool>,
17     walls: Vec<Rc<WallRegion>>,
18     wall_grid: Grid<Vec<Rc<WallEdge>>>,
19 }
20
21 impl Level {
22     pub fn new(gravity: Point<f64>, grid: Grid<bool>, mut walls: Vec<WallRegion>) -> Self {
23         let size = (2560, 1440); // TODO: get actual size from walls or something
24         let wall_grid = Level::build_wall_grid(&mut walls, &size.into());
25         dbg!(&wall_grid.scale);
26         Level {
27             gravity,
28             grid,
29             walls: walls.into_iter().map(|i| Rc::new(i)).collect(),
30             wall_grid,
31         }
32     }
33
34     /// Creates a grid of wall edges for fast lookup
35     fn build_wall_grid(walls: &mut Vec<WallRegion>, lvlsize: &Dimension<usize>) -> Grid<Vec<Rc<WallEdge>>> {
36         let size = dimen!(lvlsize.width / 20, lvlsize.height / 20); // TODO: make sure all walls fit within the grid bounds
37         let cs = point!(lvlsize.width / size.width, lvlsize.height / size.height);
38         //let cs = point!(scale.width as f64, scale.height as f64);
39         let mut grid = Grid {
40             cells: vec!(vec!(vec!(); size.height); size.width),
41             size,
42             scale: dimen!(cs.x as f64, cs.y as f64),
43         };
44
45         for wall in walls {
46             for edge in &wall.edges {
47                 for c in grid.grid_coordinates_on_line(edge.p1, edge.p2) {
48                     grid.cells[c.x][c.y].push(Rc::clone(edge));
49                 }
50             }
51         }
52
53         grid
54     }
55
56     pub fn render(&mut self, renderer: &mut Renderer, _sprites: &SpriteManager, debug_mode: bool) {
57         if debug_mode {
58             // original grid
59             renderer.canvas().set_draw_color((64, 64, 64));
60             let size = &self.grid.scale;
61             for x in 0..self.grid.size.width {
62                 for y in 0..self.grid.size.height {
63                     if self.grid.cells[x][y] {
64                         renderer.canvas().fill_rect(sdl2::rect::Rect::new(
65                             x as i32 * size.width as i32,
66                             y as i32 * size.height as i32,
67                             size.width as u32,
68                             size.height as u32)).unwrap();
69                     }
70                 }
71             }
72
73             // wall grid
74             renderer.canvas().set_draw_color((0, 32, 0));
75             let size = &self.wall_grid.scale;
76             for x in 0..self.wall_grid.size.width {
77                 for y in 0..self.wall_grid.size.height {
78                     if !self.wall_grid.cells[x][y].is_empty() {
79                         let num = self.wall_grid.cells[x][y].len();
80                         renderer.canvas().set_draw_color((0, 32*num as u8, 0));
81                         renderer.canvas().fill_rect(sdl2::rect::Rect::new(
82                             x as i32 * size.width as i32,
83                             y as i32 * size.height as i32,
84                             size.width as u32,
85                             size.height as u32)).unwrap();
86                     }
87                 }
88             }
89
90             // wall normals
91             for wall in &self.walls {
92                 for e in &wall.edges {
93                     let c = (e.p1 + e.p2) / 2.0;
94                     let a = (e.p2 - e.p1).to_angle() + std::f64::consts::FRAC_PI_2.radians();
95
96                     renderer.draw_line(
97                         <(i32, i32)>::from(c.to_i32()),
98                         <(i32, i32)>::from((c + Point::from(a) * 10.0).to_i32()),
99                         (0, 128, 255));
100                 }
101             }
102         }
103
104         // walls
105         for wall in &self.walls {
106             for e in &wall.edges {
107                 if !debug_mode {
108                     let c = (e.p1 + e.p2) / 2.0;
109                     let a = (e.p2 - e.p1).to_angle() - std::f64::consts::FRAC_PI_2.radians();
110
111                     renderer.draw_line(
112                         <(i32, i32)>::from(c.to_i32()),
113                         <(i32, i32)>::from((c + Point::from(a) * 10.0).to_i32()),
114                         (255, 128, 0));
115
116                     renderer.draw_line(
117                         <(i32, i32)>::from(e.p1.to_i32()),
118                         <(i32, i32)>::from((c + Point::from(a) * 20.0).to_i32()),
119                         (96, 48, 0));
120                     renderer.draw_line(
121                         <(i32, i32)>::from(e.p2.to_i32()),
122                         <(i32, i32)>::from((c + Point::from(a) * 20.0).to_i32()),
123                         (96, 48, 0));
124                 }
125
126                 renderer.draw_line(
127                     <(i32, i32)>::from(e.p1.to_i32()),
128                     <(i32, i32)>::from(e.p2.to_i32()),
129                     (255, 255, 0));
130             }
131         }
132     }
133
134     pub fn intersect_walls(&self, p1: Point<f64>, p2: Point<f64>) -> IntersectResult {
135         for c in self.wall_grid.grid_coordinates_on_line(p1, p2) {
136             for w in &self.wall_grid.cells[c.x][c.y] {
137                 if let Intersection::Point(p) = Intersection::lines(p1, p2, w.p1, w.p2) {
138                     if w.point_is_in_front(p1) {
139                         let wall = Wall {
140                             region: Rc::clone(&self.walls[w.region]),
141                             edge: Rc::clone(w),
142                         };
143                         return IntersectResult::Intersection(wall, p)
144                     }
145                 }
146             }
147         }
148         IntersectResult::None
149     }
150 }
151
152 pub enum IntersectResult {
153     Intersection(Wall, Point<f64>),
154     None
155 }
156
157 ////////// GRID ////////////////////////////////////////////////////////////////
158
159 #[derive(Debug, Default)]
160 pub struct Grid<T> {
161     pub size: Dimension<usize>,
162     pub scale: Dimension<f64>,
163     pub cells: Vec<Vec<T>>,
164 }
165
166 impl<T> Grid<T> {
167     // pub fn at<C>(&self, c: C) -> Option<&T>
168     // where C: Into<(isize, isize)>
169     // {
170     //  let c = c.into();
171     //  if c.0 >= 0 && c.0 < self.size.width as isize && c.1 >= 0 && c.1 < self.size.height as isize {
172     //      Some(&self.cells[c.0 as usize][c.1 as usize])
173     //  } else {
174     //      None
175     //  }
176     // }
177
178     pub fn to_grid_coordinate<C>(&self, c: C) -> Option<Point<usize>>
179     where C: Into<(isize, isize)>
180     {
181         let c = c.into();
182         if c.0 >= 0 && c.0 < self.size.width as isize && c.1 >= 0 && c.1 < self.size.height as isize {
183             Some(point!(c.0 as usize, c.1 as usize))
184         } else {
185             None
186         }
187     }
188
189     /// Returns a list of grid coordinates that a line in world coordinates passes through.
190     pub fn grid_coordinates_on_line(&self, p1: Point<f64>, p2: Point<f64>) -> Vec<Point<usize>> {
191         supercover_line(p1 / self.scale, p2 / self.scale)
192             .iter()
193             .map(|c| self.to_grid_coordinate(*c))
194             .flatten()
195             .collect()
196     }
197 }
198
199 ////////// WALL REGION /////////////////////////////////////////////////////////
200
201 #[derive(Debug, Default)]
202 pub struct WallRegion {
203     edges: Vec<Rc<WallEdge>>,
204 }
205
206 impl WallRegion {
207     pub fn new(points: Vec<Point<f64>>) -> Self {
208         let index: RegionIndex = 0; // use as param
209         let mut edges = Vec::with_capacity(points.len());
210
211         for i in 0..points.len() {
212             let edge = Rc::new(WallEdge {
213                 region: index,
214                 id: i,
215                 p1: points[i],
216                 p2: points[(i + 1) % points.len()],
217             });
218             edges.push(edge);
219         }
220
221         WallRegion { edges }
222     }
223
224     fn next(&self, index: EdgeIndex) -> Rc<WallEdge> {
225         let index = (index + 1) % self.edges.len();
226         Rc::clone(&self.edges[index])
227     }
228
229     fn previous(&self, index: EdgeIndex) -> Rc<WallEdge> {
230         let index = (index + self.edges.len() + 1) % self.edges.len();
231         Rc::clone(&self.edges[index])
232     }
233 }
234
235 ////////// WALL EDGE ///////////////////////////////////////////////////////////
236
237 type RegionIndex = usize;
238 type EdgeIndex = usize;
239
240 #[derive(Debug, Default)]
241 struct WallEdge {
242     region: RegionIndex,
243     id: EdgeIndex,
244     pub p1: Point<f64>,
245     pub p2: Point<f64>,
246 }
247
248 impl WallEdge {
249     fn point_is_in_front(&self, p: Point<f64>) -> bool {
250         let cross = (self.p2 - self.p1).cross_product(p - self.p1);
251         cross > 0.0
252     }
253 }
254
255 ////////// WALL ////////////////////////////////////////////////////////////////
256
257 pub struct Wall {
258     region: Rc<WallRegion>,
259     edge: Rc<WallEdge>,
260 }
261
262 impl Wall {
263     #[allow(dead_code)]
264     pub fn next(self) -> Wall {
265         Wall {
266             edge: self.region.next(self.edge.id),
267             region: self.region,
268         }
269     }
270
271     #[allow(dead_code)]
272     pub fn previous(self) -> Wall {
273         Wall {
274             edge: self.region.previous(self.edge.id),
275             region: self.region,
276         }
277     }
278
279     pub fn normal(&self) -> Angle {
280         (self.edge.p2 - self.edge.p1).to_angle() + std::f64::consts::FRAC_PI_2.radians()
281     }
282 }