blob: b2006010896592f7164384d2207a4a811e1a211c (
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
|
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
varying float fade_factor; // 0->1 fade factor used for AA
#ifdef USE_VERTEX_COLORS
varying vec4 vertex_color;
#endif
uniform vec4 color;
uniform float line_width;
uniform float feather;
#define TYPE_NORMAL 0
#define TYPE_LINE 1
uniform int type;
void main()
{
float alpha = 1.0;
#ifdef USE_VERTEX_COLORS
vec4 result = vertex_color;
#else
vec4 result = color;
#endif
if (type == TYPE_LINE)
{
float start = (line_width / 2.0) - feather; // where we start to apply alpha
float end = (line_width / 2.0) + feather; // where we end to apply alpha
// Calculate the multiplier so we can transform the 0->1 fade factor
// to take feather and line width into account.
float multiplied = start == end ? 1.0 : 1.0 / (1.0 - (start / end));
float dist = (1.0 - abs(fade_factor)) * multiplied;
alpha = clamp(dist, 0.0, 1.0);
}
result.a = result.a * alpha;
gl_FragColor = result;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|