flake-engine 0.1.1

Immediate-mode game framework built on wgpu + winit
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

use crate::camera::Camera;
use cgmath::{Vector2, Zero};
use crate::camera::render_target::RenderTarget;

#[derive(Clone)]
pub struct Camera2D {
    pub position: Vector2<f32>,
    pub width: f32,
    pub height: f32,
    pub zoom: f32,
    pub render_target: Option<RenderTarget>
}

impl Camera for Camera2D {
    fn matrix(&self) -> cgmath::Matrix4<f32> {
        let left = self.position.x;
        let right = self.position.x + self.width / self.zoom;
        let top = self.position.y;
        let bottom = self.position.y + self.height / self.zoom;

        let (near, far) = (-1000.0, 1000.0);
        let proj = cgmath::ortho(left, right, bottom, top, near, far);

        // OpenGL clip z [-1,1] -> wgpu clip z [0,1]
        #[rustfmt::skip]
        let opengl_to_wgpu = cgmath::Matrix4::new(
            1.0, 0.0, 0.0, 0.0,
            0.0, 1.0, 0.0, 0.0,
            0.0, 0.0, 0.5, 0.0,
            0.0, 0.0, 0.5, 1.0,
        );

        opengl_to_wgpu * proj
    }
}

impl Default for Camera2D {
    fn default() -> Self {
        Self {
            position: Vector2::zero(),
            width: 800.0,
            height: 600.0,
            zoom: 1.0,
            render_target: None,
        }
    }
}