blob: 0acab6b7833de61d4b881048d6ef3cc81e0187f3 (
plain)
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
|
#pragma once
#include <string>
inline const std::string FRAGSHADOW = R"#(
precision highp float;
varying vec4 v_color;
varying vec2 v_texcoord;
uniform vec2 topLeft;
uniform vec2 bottomRight;
uniform vec2 fullSize;
uniform float radius;
uniform float range;
uniform float shadowPower;
float pixAlphaRoundedDistance(float distanceToCorner) {
if (distanceToCorner > radius) {
return 0.0;
}
if (distanceToCorner > radius - range) {
return pow((range - (distanceToCorner - radius + range)) / range, shadowPower); // i think?
}
return 1.0;
}
void main() {
vec4 pixColor = v_color;
float originalAlpha = pixColor[3];
bool done = false;
vec2 pixCoord = fullSize * v_texcoord;
// ok, now we check the distance to a border.
if (pixCoord[0] < topLeft[0]) {
if (pixCoord[1] < topLeft[1]) {
// top left
pixColor[3] = pixColor[3] * pixAlphaRoundedDistance(distance(pixCoord, topLeft));
done = true;
} else if (pixCoord[1] > bottomRight[1]) {
// bottom left
pixColor[3] = pixColor[3] * pixAlphaRoundedDistance(distance(pixCoord, vec2(topLeft[0], bottomRight[1])));
done = true;
}
} else if (pixCoord[0] > bottomRight[0]) {
if (pixCoord[1] < topLeft[1]) {
// top right
pixColor[3] = pixColor[3] * pixAlphaRoundedDistance(distance(pixCoord, vec2(bottomRight[0], topLeft[1])));
done = true;
} else if (pixCoord[1] > bottomRight[1]) {
// bottom right
pixColor[3] = pixColor[3] * pixAlphaRoundedDistance(distance(pixCoord, bottomRight));
done = true;
}
}
if (!done) {
// distance to all straight bb borders
float distanceT = pixCoord[1];
float distanceB = fullSize[1] - pixCoord[1];
float distanceL = pixCoord[0];
float distanceR = fullSize[0] - pixCoord[0];
// get the smallest
float smallest = min(min(distanceT, distanceB), min(distanceL, distanceR));
if (smallest < range) {
pixColor[3] = pixColor[3] * pow((smallest / range), shadowPower);
}
}
if (pixColor[3] == 0.0) {
discard; return;
}
// premultiply
pixColor.rgb *= pixColor[3];
gl_FragColor = pixColor;
})#";
|
