isf 0.1.0

Parsing, Deserialization and Serialization of the Interactive Shader Format.
Documentation 
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

/*{
    "CATEGORIES": [
        "Wipe",
        "Distortion"
    ],
    "CREDIT": "Automatically converted from https://www.github.com/gl-transitions/gl-transitions/tree/master/cube.glsl",
    "DESCRIPTION": "",
    "INPUTS": [
        {
            "NAME": "startImage",
            "TYPE": "image"
        },
        {
            "NAME": "endImage",
            "TYPE": "image"
        },
        {
            "DEFAULT": 0,
            "MAX": 1,
            "MIN": 0,
            "NAME": "progress",
            "TYPE": "float"
        },
        {
            "DEFAULT": 0.4,
            "MAX": 1,
            "MIN": 0,
            "NAME": "reflection",
            "TYPE": "float"
        },
        {
            "DEFAULT": 0.7,
            "MAX": 1,
            "MIN": 0,
            "NAME": "persp",
            "TYPE": "float"
        },
        {
            "DEFAULT": 0.3,
            "MAX": 1,
            "MIN": 0,
            "NAME": "unzoom",
            "TYPE": "float"
        },
        {
            "DEFAULT": 3,
            "MAX": 10,
            "MIN": 0,
            "NAME": "floating",
            "TYPE": "float"
        }
    ],
    "ISFVSN": "2"
}
*/



vec4 getFromColor(vec2 inUV)	{
	return IMG_NORM_PIXEL(startImage, inUV);
}
vec4 getToColor(vec2 inUV)	{
	return IMG_NORM_PIXEL(endImage, inUV);
}



// Author: gre
// License: MIT

vec2 project (vec2 p) {
  return p * vec2(1.0, -1.2) + vec2(0.0, -floating/100.);
}

bool inBounds (vec2 p) {
  return all(lessThan(vec2(0.0), p)) && all(lessThan(p, vec2(1.0)));
}

vec4 bgColor (vec2 p, vec2 pfr, vec2 pto) {
  vec4 c = vec4(0.0, 0.0, 0.0, 1.0);
  pfr = project(pfr);
  // FIXME avoid branching might help perf!
  if (inBounds(pfr)) {
    c += mix(vec4(0.0), getFromColor(pfr), reflection * mix(1.0, 0.0, pfr.y));
  }
  pto = project(pto);
  if (inBounds(pto)) {
    c += mix(vec4(0.0), getToColor(pto), reflection * mix(1.0, 0.0, pto.y));
  }
  return c;
}

// p : the position
// persp : the perspective in [ 0, 1 ]
// center : the xcenter in [0, 1] \ 0.5 excluded
vec2 xskew (vec2 p, float persp, float center) {
  float x = mix(p.x, 1.0-p.x, center);
  return (
    (
      vec2( x, (p.y - 0.5*(1.0-persp) * x) / (1.0+(persp-1.0)*x) )
      - vec2(0.5-distance(center, 0.5), 0.0)
    )
    * vec2(0.5 / distance(center, 0.5) * (center<0.5 ? 1.0 : -1.0), 1.0)
    + vec2(center<0.5 ? 0.0 : 1.0, 0.0)
  );
}

vec4 transition(vec2 op) {
  float uz = unzoom * 2.0*(0.5-distance(0.5, progress));
  vec2 p = -uz*0.5+(1.0+uz) * op;
  vec2 fromP = xskew(
    (p - vec2(progress, 0.0)) / vec2(1.0-progress, 1.0),
    1.0-mix(progress, 0.0, persp),
    0.0
  );
  vec2 toP = xskew(
    p / vec2(progress, 1.0),
    mix(pow(progress, 2.0), 1.0, persp),
    1.0
  );
  // FIXME avoid branching might help perf!
  if (inBounds(fromP)) {
    return getFromColor(fromP);
  }
  else if (inBounds(toP)) {
    return getToColor(toP);
  }
  return bgColor(op, fromP, toP);
}



void main()	{
	gl_FragColor = transition(isf_FragNormCoord.xy);
}