kicad/common/gal/opengl/shader.frag

76 lines
2.1 KiB
GLSL

/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2013 CERN
* @author Maciej Suminski <maciej.suminski@cern.ch>
*
* Fragment shader
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#version 120
// Shader types
const float SHADER_LINE = 1.0f;
const float SHADER_FILLED_CIRCLE = 2.0f;
const float SHADER_STROKED_CIRCLE = 3.0f;
varying vec4 shaderParams;
varying vec2 circleCoords;
void filledCircle( vec2 aCoord )
{
if( dot( aCoord, aCoord ) < 1.0f )
gl_FragColor = gl_Color;
else
discard;
}
void strokedCircle( vec2 aCoord, float aRadius, float aWidth )
{
float outerRadius = aRadius + ( aWidth / 2 );
float innerRadius = aRadius - ( aWidth / 2 );
float relWidth = innerRadius / outerRadius;
if( ( dot( aCoord, aCoord ) < 1.0f ) &&
( dot( aCoord, aCoord ) > relWidth * relWidth ) )
gl_FragColor = gl_Color;
else
discard;
}
void main()
{
if( shaderParams[0] == SHADER_FILLED_CIRCLE )
{
filledCircle( circleCoords );
}
else if( shaderParams[0] == SHADER_STROKED_CIRCLE )
{
strokedCircle( circleCoords, shaderParams[2], shaderParams[3] );
}
else
{
// Simple pass-through
gl_FragColor = gl_Color;
}
}