blob: c0a982d4ee5391b207a81973f06f6af530bc381f (
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
|
/* -*- 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/.
*/
/*precision mediump float;*/
varying vec2 tex_coord;
uniform sampler2D texture; /* white background */
uniform sampler2D mask; /* black background */
void main() {
float alpha;
vec4 texel0, texel1;
texel0 = texture2D(texture, tex_coord);
texel1 = texture2D(mask, tex_coord);
alpha = 1.0 - abs(texel0.r - texel1.r);
if(alpha > 0.0)
gl_FragColor = texel1 / alpha;
gl_FragColor.a = alpha;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
