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
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
//! Module for conveting 2D and 3D camera descriptions into matrices
//! and some helpers like WorkdToCamera/CameraToWorld etc
use crate::{screen_height, screen_width, RenderTarget};
use glam::{vec2, vec3, Mat4, Vec2, Vec3};
pub trait Camera {
fn matrix(&self) -> Mat4;
fn depth_enabled(&self) -> bool;
fn render_pass(&self) -> Option<miniquad::RenderPass>;
}
#[derive(Clone, Copy)]
pub struct Camera2D {
/// Rotation in degrees
pub rotation: f32,
/// Scaling, should be (1.0, 1.0) by default
pub zoom: Vec2,
/// Rotation and zoom origin
pub target: Vec2,
/// Displacement from target
pub offset: Vec2,
/// If "render_target" is set - camera will render to texture
/// otherwise to the screen
pub render_target: Option<RenderTarget>
}
impl Default for Camera2D {
fn default() -> Camera2D {
Camera2D {
zoom: vec2(1., 1.),
offset: vec2(0., 0.),
target: vec2(0., 0.),
rotation: 0.,
render_target: None
}
}
}
impl Camera for Camera2D {
fn matrix(&self) -> Mat4 {
// gleaned from https://github.com/raysan5/raylib/blob/master/src/core.c#L1528
// The camera in world-space is set by
// 1. Move it to target
// 2. Rotate by -rotation and scale by (1/zoom)
// When setting higher scale, it's more intuitive for the world to become bigger (= camera become smaller),
// not for the camera getting bigger, hence the invert. Same deal with rotation.
// 3. Move it by (-offset);
// Offset defines target transform relative to screen, but since we're effectively "moving" screen (camera)
// we need to do it into opposite direction (inverse transform)
// Having camera transform in world-space, inverse of it gives the modelview transform.
// Since (A*B*C)' = C'*B'*A', the modelview is
// 1. Move to offset
// 2. Rotate and Scale
// 3. Move by -target
let mat_origin = Mat4::from_translation(vec3(-self.target.x(), -self.target.y(), 0.0));
let mat_rotation = Mat4::from_axis_angle(vec3(0.0, 0.0, 1.0), self.rotation.to_radians());
let mat_scale = Mat4::from_scale(vec3(self.zoom.x(), self.zoom.y(), 1.0));
let mat_translation = Mat4::from_translation(vec3(self.offset.x(), self.offset.y(), 0.0));
mat_translation * ((mat_rotation * mat_scale) * mat_origin)
}
fn depth_enabled(&self) -> bool {
false
}
fn render_pass(&self) -> Option<miniquad::RenderPass> {
self.render_target.map(|rt| rt.render_pass)
}
}
impl Camera2D {
/// Returns the screen space position for a 2d camera world space position
pub fn world_to_screen(&self, point: Vec2) -> Vec2 {
let mat = self.matrix();
let transform = mat.transform_point3(vec3(point.x(), point.y(), 0.));
vec2(transform.x(), transform.y())
}
// Returns the world space position for a 2d camera screen space position
pub fn screen_to_world(&self, point: Vec2) -> Vec2 {
let inv_mat = self.matrix().inverse();
let transform = inv_mat.transform_point3(vec3(point.x(), point.y(), 0.));
vec2(transform.x(), transform.y())
}
}
#[derive(Debug, Clone, Copy)]
pub enum Projection {
Perspective,
Orthographics,
}
#[derive(Debug, Clone, Copy)]
pub struct Camera3D {
/// Camera position
pub position: Vec3,
/// Camera target it looks-at
pub target: Vec3,
/// Camera up vector (rotation over its axis)
pub up: Vec3,
/// Camera field-of-view apperture in Y (degrees)
/// in perspective, used as near plane width in orthographic
pub fovy: f32,
/// Screen aspect ratio
/// By default aspect is calculated with screen_width() / screen_height() on each frame
pub aspect: Option<f32>,
/// Camera projection type, perspective or orthographics
pub projection: Projection,
}
impl Default for Camera3D {
fn default() -> Camera3D {
Camera3D {
position: vec3(0., -10., 0.),
target: vec3(0., 0., 0.),
aspect: None,
up: vec3(0., 0., 1.),
fovy: 45.,
projection: Projection::Perspective,
}
}
}
impl Camera3D {
const Z_NEAR: f32 = 0.01;
const Z_FAR: f32 = 10000.0;
}
impl Camera for Camera3D {
fn matrix(&self) -> Mat4 {
let aspect = self.aspect.unwrap_or(screen_width() / screen_height());
match self.projection {
Projection::Perspective => {
Mat4::perspective_rh_gl(self.fovy, aspect, Self::Z_NEAR, Self::Z_FAR)
* Mat4::look_at_rh(self.position, self.target, self.up)
}
Projection::Orthographics => {
let top = self.fovy / 2.0;
let right = top * aspect;
Mat4::orthographic_rh_gl(-right, right, -top, top, Self::Z_NEAR, Self::Z_FAR)
* Mat4::look_at_rh(self.position, self.target, self.up)
}
}
}
fn depth_enabled(&self) -> bool {
true
}
fn render_pass(&self) -> Option<miniquad::RenderPass> {
unimplemented!()
}
}