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|
use crate::{
Input,
config::{CAMERA_MOVEMENT_SPEED, CHUNK_SIZE, PIXEL_BUFFER_HEIGHT, PIXEL_BUFFER_WIDTH},
sim::{chunk::Chunk, world::World},
};
pub struct Camera {
// centre coords
pub x: f64,
pub y: f64,
// zoom scale factor, 1.0 = board <-> frame
pub zoom: f64,
}
impl Camera {
pub fn handle_camera_input(&mut self, input: &Input, delta_time: f32) {
// wasd movement
let x: f32 = if input.is_left_pressed {
-1.0
} else if input.is_right_pressed {
1.0
} else {
0.0
};
let y: f32 = if input.is_down_pressed {
1.0
} else if input.is_up_pressed {
-1.0
} else {
0.0
};
if x == 0.0 && y == 0.0 {
return;
}
let magnitude = (x.powi(2) + y.powi(2)).sqrt();
let adjusted_x = x / magnitude * self.zoom as f32 * CAMERA_MOVEMENT_SPEED * delta_time;
let adjusted_y = y / magnitude * self.zoom as f32 * CAMERA_MOVEMENT_SPEED * delta_time;
self.x += adjusted_x as f64;
self.y += adjusted_y as f64;
}
pub fn screen_position_to_world(&self, screen_x: f64, screen_y: f64) -> (f64, f64) {
let camera_width = self.zoom * f64::from(PIXEL_BUFFER_WIDTH);
let camera_height = self.zoom * f64::from(PIXEL_BUFFER_HEIGHT);
let camera_start_x = self.x - camera_width / 2.0;
let camera_start_y = self.y - camera_height / 2.0;
(
(screen_x / PIXEL_BUFFER_WIDTH as f64 * camera_width) + camera_start_x,
(screen_y / PIXEL_BUFFER_HEIGHT as f64 * camera_height) + camera_start_y,
)
}
pub fn write_frame_view(&self, frame: &mut [u8], world: &World) {
puffin::profile_function!();
for i in 0..frame.len() / 4 {
let idx = i * 4;
frame[idx] = 0xFF;
frame[idx + 1] = 0xAA;
frame[idx + 2] = 0xAA;
frame[idx + 3] = 0xFF;
}
return;
const BG: [u8; 4] = [0x00, 0x00, 0x00, 0xFF];
for px in frame.chunks_exact_mut(4) {
px.copy_from_slice(&BG);
}
// world-space rect covered by the screen
let (xl, yl) = self.screen_position_to_world(0.0, 0.0);
let (xu, yu) =
self.screen_position_to_world(PIXEL_BUFFER_WIDTH as f64, PIXEL_BUFFER_HEIGHT as f64);
let c = CHUNK_SIZE as i32;
let cx0 = (xl.floor() as i32).div_euclid(c);
let cx1 = (xu.ceil() as i32).div_euclid(c);
let cy0 = (yl.floor() as i32).div_euclid(c);
let cy1 = (yu.ceil() as i32).div_euclid(c);
let scale = 1.0 / self.zoom; // pixels per cell
for cy in cy0..=cy1 {
for cx in cx0..=cx1 {
let Some(&idx) = world.chunk_position_to_chunk_idx.get(&(cx, cy)) else {
continue;
};
self.write_chunk(frame, &world.chunks[idx], cx, cy, xl, yl, scale);
}
}
}
fn write_chunk(
&self,
frame: &mut [u8],
chunk: &Chunk,
cx: i32,
cy: i32,
xl: f64,
yl: f64,
scale: f64,
) {
let c = CHUNK_SIZE as i32;
let w = PIXEL_BUFFER_WIDTH as i32;
let h = PIXEL_BUFFER_HEIGHT as i32;
for ly in 0..c {
let wy = (cy * c + ly) as f64;
let sy0 = (((wy - yl) * scale).floor() as i32).max(0);
let sy1 = (((wy + 1.0 - yl) * scale).floor() as i32).min(h);
if sy0 >= sy1 {
continue;
}
for lx in 0..c {
let wx = (cx * c + lx) as f64;
let sx0 = (((wx - xl) * scale).floor() as i32).max(0);
let sx1 = (((wx + 1.0 - xl) * scale).floor() as i32).min(w);
if sx0 >= sx1 {
continue;
}
let color = chunk
.get_cell_at_local_position(lx as u8, ly as u8)
.material
.def()
.color;
let rgba = [color.0, color.1, color.2, color.3];
for sy in sy0..sy1 {
let start = (sy * w + sx0) as usize * 4;
let end = (sy * w + sx1) as usize * 4;
for px in frame[start..end].chunks_exact_mut(4) {
px.copy_from_slice(&rgba);
}
}
}
}
}
}
|
