blob: 60d2cca63b22e80d1b4352ffcb31ef45c3f04d92 (
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
|
/*
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
*/
attribute vec4 gtf_Vertex;
attribute vec4 gtf_Color;
uniform mat4 gtf_ModelViewProjectionMatrix;
varying vec4 color;
void main (void)
{
const float M_PI = 3.14159265358979323846;
vec3 x = 2.0 * (gtf_Color.ggg - 0.5);
vec3 y = 2.0 * (gtf_Color.bbb - 0.5);
const float epsilon = 1.0e-4;
color = vec4(0.0, 0.0, 0.0, 1.0);
// Avoid evaluating atan(0, x) for x < epsilon because it's implementation-dependent
if(x[0] > epsilon || abs(y[0]) > epsilon)
{
color[0] = atan(y[0], x[0]) / (2.0 * M_PI) + 0.5;
}
if(x[1] > epsilon || abs(y[1]) > epsilon)
{
color[1] = atan(y[1], x[1]) / (2.0 * M_PI) + 0.5;
}
if(x[2] > epsilon || abs(y[2]) > epsilon)
{
color[2] = atan(y[2], x[2]) / (2.0 * M_PI) + 0.5;
}
gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex;
}
|
