diff options
Diffstat (limited to 'src/framebuffer.rs')
| -rw-r--r-- | src/framebuffer.rs | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/src/framebuffer.rs b/src/framebuffer.rs new file mode 100644 index 0000000..5a250d7 --- /dev/null +++ b/src/framebuffer.rs @@ -0,0 +1,234 @@ +use crate::texture::Font; +use crate::map::{MapCell, Map}; +use crate::camera::{Ray, Camera}; +use crate::util::{Side, Sprite}; +use crate::vec2::Vec2; + +pub struct Framebuffer { + pub height: usize, + pub width: usize, + pub pixels: Vec<u32>, + pub z_buffer: Vec<f64>, +} + +impl Framebuffer { + pub fn new(height: usize, width: usize) -> Framebuffer { + Framebuffer { + height, + width, + pixels: vec![0; height * width], + z_buffer: vec![f64::INFINITY; height * width], + } + } + + pub fn clear(&mut self) { + for pixel in &mut self.pixels { + *pixel = 0; + } + } + + pub fn clear_z_buffer(&mut self) { + for pixel in &mut self.z_buffer { + *pixel = f64::INFINITY; + } + } + + pub fn draw_vertical_line(&mut self, x: usize, start: usize, stop: usize, color: u32) { + for row in start..stop { + self.pixels[row * self.width + x] = color; + } + } + + pub fn write_ascii_string(&mut self, x: usize, y: usize, string: &Vec<u8>, font: &Font, color: u32) { + for char_index in 0..string.len() { + for glyph_x in 0..font.glyph_size { + for glyph_y in 0..font.glyph_size { + if font.glyphs[(font.glyph_size - 1 - glyph_y) * (font.charset_length * font.glyph_size) + glyph_x + font.glyph_size * (string[char_index] as usize)] { + self.pixels[((y + glyph_y) * self.width) + x + (char_index * font.glyph_size) + glyph_x] = color; + } + } + } + } + } + + pub fn set_pixel(&mut self, x: usize, y: usize, color: u32) { + if let Some(pixel) = self.pixels.get_mut(y * self.width + x) { + *pixel = color; + } + } + + pub fn draw_wall(&mut self, camera: &Camera, x: usize, perp_wall_dist: f64, cell: &MapCell, side: &Side, ray: &Ray, world: &Map) { + let line_height = (self.height as f64 / perp_wall_dist) as i32; + if line_height < 0 { + self.draw_vertical_line(x, 0, self.height, 0x00FF0000); + return; + } + let draw_start = ((-line_height / 2 + (self.height as i32) / 2) - 1 + ((camera.height / perp_wall_dist) as i32)).max(0); + let draw_end = ((line_height / 2 + (self.height as i32) / 2) + 1 + ((camera.height / perp_wall_dist) as i32)).min(self.height as i32); + + match cell { + MapCell::Wall { texture } | MapCell::ThinWall { texture, orientation: _, offset_into_cell: _, ceiling_texture: _, floor_texture: _ } => { + let wall_x = match &side { + Side::X => camera.position.y + perp_wall_dist * ray.direction.y, + Side::Y=> camera.position.x + perp_wall_dist * ray.direction.x, + }.fract(); + + let mut tex_x = (wall_x * (texture.width as f64)) as usize; + if let Side::X = side { + if ray.direction.x > 0.0 { + tex_x = texture.width - tex_x - 1; + } + } else { + if ray.direction.y < 0.0 { + tex_x = texture.width - tex_x - 1; + } + } + let step = (texture.height as f64) / (line_height as f64); + let mut tex_position = ((draw_start as f64) - (camera.height / perp_wall_dist) - (self.height as f64) / 2.0 + (line_height as f64) / 2.0) * step; + for y in draw_start..draw_end { + let tex_y = (tex_position as usize) & (texture.height - 1); + tex_position += step; + if perp_wall_dist < self.z_buffer[y as usize * self.width + x as usize] { + let mut color = texture.data[texture.height * tex_y + tex_x]; + if (color & 0x00FFFFFF) != 0 { + if let Side::Y = side { + color = (color >> 1) & 8355711; + } + if let Some(MapCell::Empty { ceiling_texture: _, floor_texture: _, fog, fog_color }) = world.at(&camera.position.as_usize()) { + let fog_prop = (perp_wall_dist * fog).min(1.0); + if fog_prop > 0.0 { + let mut color_bytes = color.to_le_bytes(); + let fog_bytes = fog_color.to_le_bytes(); + color_bytes[0] = (fog_bytes[0] as f64 * fog_prop + color_bytes[0] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[1] = (fog_bytes[1] as f64 * fog_prop + color_bytes[1] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[2] = (fog_bytes[2] as f64 * fog_prop + color_bytes[2] as f64 * (1.0 - fog_prop)) as u8; + color = u32::from_le_bytes(color_bytes); + } + } + self.set_pixel(x, y as usize, color); + self.z_buffer[y as usize * self.width + x as usize] = perp_wall_dist; + } + } + } + }, + MapCell::Empty { ceiling_texture: _, floor_texture: _, fog: _, fog_color: _ } => {}, + } + } + + pub fn draw_sprites(&mut self, camera: &Camera, sprites: &mut Vec<Sprite>, world: &Map) { + for sprite in sprites.into_iter() { + sprite.distance_from_camera = (&camera.position - &sprite.position).length(); + } + for sprite in sprites { + let rel_position = &sprite.position - &camera.position; + let inverse_det = 1.0 / (camera.plane.x * camera.direction.y - camera.direction.x * camera.plane.y); + let transform = Vec2 { + x: inverse_det * (camera.direction.y * rel_position.x - camera.direction.x * rel_position.y), + y: inverse_det * (-camera.plane.y * rel_position.x + camera.plane.x * rel_position.y) + }; + if transform.y == 0.0 { + continue; + } + let vertical_offset = ((sprite.vertical_offset / transform.y) + (camera.height / transform.y)) as i32; + let sprite_screen_x = ((self.width as f64 / 2.0) * (1.0 + transform.x / transform.y)) as i32; + let sprite_height = (((self.height as f64 / transform.y) as i32).abs() as f64 * sprite.scale_factor.y) as i32; + let sprite_width = (((self.height as f64 / transform.y) as i32).abs() as f64 * sprite.scale_factor.x) as i32; + let draw_start = Vec2 { + x: ((-sprite_width / 2) + sprite_screen_x).max(0), + y: ((-sprite_height / 2 + (self.height as i32) / 2) + vertical_offset).max(0), + }; + let draw_end = Vec2 { + x: ((sprite_width / 2) + sprite_screen_x).min(self.width as i32), + y: ((sprite_height / 2 + (self.height as i32) / 2) + vertical_offset).min(self.height as i32), + }; + for column in draw_start.x..draw_end.x { + let tex_x = (256 * (column - (-sprite_width / 2 + (sprite_screen_x))) * sprite.texture.width as i32 / sprite_width) as i32 / 256; + if transform.y > 0.0 && column >= 0 && column < self.width as i32 { + for y in draw_start.y..draw_end.y { + let d = (y - vertical_offset) * 256 - self.height as i32 * 128 + sprite_height * 128; + let tex_y = ((d * sprite.texture.height as i32) / sprite_height) / 256; + if (tex_x as usize) < sprite.texture.width && (tex_y as usize) < sprite.texture.height { + let mut color = sprite.texture.data[sprite.texture.width * tex_y as usize + tex_x as usize]; + if (color & 0x00FFFFFF) != 0 { + if let Some(&depth) = self.z_buffer.get(y as usize * self.width + column as usize) { + if sprite.distance_from_camera < depth { + if let Some(MapCell::Empty { ceiling_texture: _, floor_texture: _, fog, fog_color }) = world.at(&camera.position.as_usize()) { + let fog_prop = (sprite.distance_from_camera * fog).min(1.0); + if fog_prop > 0.0 { + let mut color_bytes = color.to_le_bytes(); + let fog_bytes = fog_color.to_le_bytes(); + color_bytes[0] = (fog_bytes[0] as f64 * fog_prop + color_bytes[0] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[1] = (fog_bytes[1] as f64 * fog_prop + color_bytes[1] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[2] = (fog_bytes[2] as f64 * fog_prop + color_bytes[2] as f64 * (1.0 - fog_prop)) as u8; + color = u32::from_le_bytes(color_bytes); + } + } + self.set_pixel(column as usize, y as usize, color); + self.z_buffer[y as usize * self.width + column as usize] = sprite.distance_from_camera; + } + } + } + } + } + } + } + } + } + + pub fn draw_floor_and_ceiling(&mut self, camera: &Camera, world: &Map) { + for y in 0..self.height { + let is_floor = y > self.height / 2; + let ray_dir_0 = &camera.direction - &camera.plane; + let ray_dir_1 = &camera.direction + &camera.plane; + + let current_position = if is_floor { + (y as i32) - (self.height as i32) / 2 + } else { + (self.height as i32) / 2 - (y as i32) + }; + let camera_z = if is_floor { + 0.5 * self.height as f64 + camera.height + } else { + 0.5 * self.height as f64 - camera.height + }; + let row_distance = camera_z / current_position as f64; + + let floor_step = row_distance * (&ray_dir_1 - &ray_dir_0) / self.width as f64; + let mut floor = &camera.position + row_distance * &ray_dir_0; + + for x in 0..self.width { + let cell = floor.as_usize(); + floor += &floor_step; + match world.at(&cell) { + Some(MapCell::Empty { ceiling_texture, floor_texture, fog: _, fog_color: _ }) | Some(MapCell::ThinWall { texture: _, orientation: _, offset_into_cell: _, ceiling_texture, floor_texture }) => { + let texture_coords = Vec2 { + // this is also the ceiling size, but we only check the floor size + x: ((floor_texture.width as f64 * (floor.x - cell.x as f64)) as usize & (floor_texture.width - 1)) as i32, + y: ((floor_texture.height as f64 * (floor.y - cell.y as f64)) as usize & (floor_texture.height - 1)) as i32, + }; + + let mut color = if is_floor { + (floor_texture.data[(floor_texture.width as i32 * texture_coords.y + texture_coords.x) as usize] >> 1) & 8355711 + } else { + (ceiling_texture.data[(ceiling_texture.width as i32 * texture_coords.y + texture_coords.x) as usize] >> 1) & 8355711 + }; + if let Some(MapCell::Empty { ceiling_texture: _, floor_texture: _, fog, fog_color }) = world.at(&camera.position.as_usize()) { + let fog_prop = ((&floor - &camera.position).length() * fog).min(1.0); + if fog_prop > 0.0 { + let mut color_bytes = color.to_le_bytes(); + let fog_bytes = fog_color.to_le_bytes(); + color_bytes[0] = (fog_bytes[0] as f64 * fog_prop + color_bytes[0] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[1] = (fog_bytes[1] as f64 * fog_prop + color_bytes[1] as f64 * (1.0 - fog_prop)) as u8; + color_bytes[2] = (fog_bytes[2] as f64 * fog_prop + color_bytes[2] as f64 * (1.0 - fog_prop)) as u8; + color = u32::from_le_bytes(color_bytes); + } + } + self.pixels[y * self.width + x] = color; + }, + Some(MapCell::Wall { texture: _ }) => {}, + None => {}, + } + } + } + } +} |