inochi2d.math.camera source code

1 /*
2     Inochi2D Camera
3 
4     Copyright © 2020, Inochi2D Project
5     Distributed under the 2-Clause BSD License, see LICENSE file.
6     
7     Authors: Luna Nielsen
8 */
9 module inochi2d.math.camera;
10 import inochi2d.math;
11 import inochi2d;
12 import std.math : isFinite;
13 
14 /**
15     An orthographic camera
16 */
17 class Camera {
18 private:
19     mat4 projection;
20 
21 public:
22 
23     /**
24         Position of camera
25     */
26     vec2 position = vec2(0, 0);
27 
28     /**
29         Rotation of the camera
30     */
31     float rotation = 0f;
32 
33     /**
34         Size of the camera
35     */
36     vec2 scale = vec2(1, 1);
37 
38     vec2 getRealSize() {
39         int width, height;
40         inGetViewport(width, height);
41 
42         return vec2(cast(float)width/scale.x, cast(float)height/scale.y);
43     }
44 
45     vec2 getCenterOffset() {
46         vec2 realSize = getRealSize();
47         return realSize/2;
48     }
49 
50     /**
51         Matrix for this camera
52 
53         width = width of camera area
54         height = height of camera area
55     */
56     mat4 matrix() {
57         if(!position.isFinite) position = vec2(0);
58         if(!scale.isFinite) scale = vec2(1);
59         if(!rotation.isFinite) rotation = 0;
60 
61         vec2 realSize = getRealSize();
62         if(!realSize.isFinite) return mat4.identity;
63         
64         vec2 origin = vec2(realSize.x/2, realSize.y/2);
65         vec3 pos = vec3(position.x, position.y, -(ushort.max/2));
66 
67         return 
68             mat4.orthographic(0f, realSize.x, realSize.y, 0, 0, ushort.max) * 
69             mat4.translation(origin.x, origin.y, 0) *
70             mat4.zRotation(rotation) *
71             mat4.translation(pos);
72     }
73 }