61 lines
1.4 KiB
GLSL
61 lines
1.4 KiB
GLSL
// Copyright (C) 2023 The Qt Company Ltd.
|
|
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
|
|
|
|
//! [1]
|
|
#version 440
|
|
|
|
layout(location = 0) in vec2 vTexCoord;
|
|
|
|
layout(location = 0) out vec4 fragColor;
|
|
|
|
//! [2]
|
|
// uniform block: 84 bytes
|
|
layout(std140, binding = 0) uniform buf {
|
|
mat4 qt_Matrix; // offset 0
|
|
float qt_Opacity; // offset 64
|
|
float zoom; // offset 68
|
|
vec2 center; // offset 72
|
|
int limit; // offset 80
|
|
} ubuf;
|
|
//! [2]
|
|
|
|
void main()
|
|
{
|
|
vec4 color1 = vec4(1.0, 0.85, 0.55, 1);
|
|
vec4 color2 = vec4(0.226, 0.0, 0.615, 1);
|
|
|
|
float aspect_ratio = -ubuf.qt_Matrix[0][0]/ubuf.qt_Matrix[1][1];
|
|
vec2 z, c;
|
|
|
|
c.x = (vTexCoord.x - 0.5) / ubuf.zoom + ubuf.center.x;
|
|
c.y = aspect_ratio * (vTexCoord.y - 0.5) / ubuf.zoom + ubuf.center.y;
|
|
|
|
int iLast;
|
|
z = c;
|
|
for (int i = 0; i < 1000000; i++) {
|
|
if (i >= ubuf.limit)
|
|
{
|
|
iLast = i;
|
|
break;
|
|
}
|
|
float x = (z.x * z.x - z.y * z.y) + c.x;
|
|
float y = (z.y * z.x + z.x * z.y) + c.y;
|
|
|
|
if ((x * x + y * y) > 4.0)
|
|
{
|
|
iLast = i;
|
|
break;
|
|
}
|
|
z.x = x;
|
|
z.y = y;
|
|
}
|
|
|
|
if (iLast == ubuf.limit) {
|
|
fragColor = vec4(0.0, 0.0, 0.0, 1.0);
|
|
} else {
|
|
float f = (iLast * 1.0) / ubuf.limit;
|
|
fragColor = mix(color1, color2, sqrt(f));
|
|
}
|
|
}
|
|
//! [1]
|