-
-
Notifications
You must be signed in to change notification settings - Fork 46
/
parallax.lisp
75 lines (64 loc) · 2.8 KB
/
parallax.lisp
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
(in-package #:org.shirakumo.fraf.trial)
(define-gl-struct parallax
(parallax :vec2 :accessor parallax)
(scaling :vec2 :accessor scaling)
(offset :vec2 :accessor offset)
(view-size :vec2 :accessor view-size))
(define-asset (trial parallax) uniform-block
'parallax)
(define-shader-entity parallax-background (renderable listener)
((name :initform 'parallax-background)
(texture :initform NIL :accessor texture)
(default-background :initarg :default-background :initform () :accessor default-background))
(:buffers (trial parallax)))
(defmethod render ((parallax-background parallax-background) (program shader-program))
(unless (texture parallax-background)
;; Set up default here, I guess.
(apply #'change-background
(append (default-background parallax-background)
(list :unit parallax-background
:scaling (vec 1 1)
:offset (vec 0 0)
:parallax (vec 2 2)))))
(setf (uniform program "view_matrix") (minv *view-matrix*))
(bind (texture parallax-background) :texture0)
(render-array (// 'trial 'empty-vertex-array) :vertex-form :triangle-strip :vertex-count 4))
(defmethod handle ((ev resize) (parallax-background parallax-background))
(with-buffer-tx (bg (// 'trial 'parallax))
(setf (view-size bg) (vec2 (max 1 (width ev)) (max 1 (height ev))))))
(defmethod stage :after ((entity parallax-background) (area staging-area))
(stage (// 'trial:trial 'trial::empty-vertex-array) area)
(when (texture entity)
(stage (texture entity) area)))
(defun change-background (&key texture scaling parallax offset unit)
(when texture
(setf (texture (or unit (node 'parallax-background (scene +main+)))) texture))
(when (or parallax scaling offset)
(with-buffer-tx (bg (// 'trial 'parallax))
(when parallax
(setf (parallax bg) parallax))
(when scaling
(setf (scaling bg) scaling))
(when offset
(setf (offset bg) offset)))))
(define-class-shader (parallax-background :vertex-shader)
(gl-source (asset 'trial 'parallax))
"const vec2 quad_vertices[4] = vec2[4](vec2(-1.0, -1.0), vec2(1.0, -1.0), vec2(-1.0, 1.0), vec2(1.0, 1.0));
uniform sampler2D tex_image;
uniform mat4 view_matrix;
out vec2 map_coord;
void main(){
gl_Position = vec4(quad_vertices[gl_VertexID], 0, 1);
vec2 vertex_uv = (quad_vertices[gl_VertexID]+1)*0.5;
vec2 tex_size = textureSize(tex_image, 0).xy;
map_coord = (view_matrix * vec4(vertex_uv*parallax.view_size*parallax.parallax, 0, 1)).xy;
map_coord += tex_size/2 + parallax.offset;
map_coord /= parallax.parallax * parallax.scaling * tex_size;
}")
(define-class-shader (parallax-background :fragment-shader)
"uniform sampler2D tex_image;
in vec2 map_coord;
out vec4 color;
void main(){
color = texture(tex_image, map_coord);
}")