kicad/common/gal/opengl/gl_builtin_shaders.cpp

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#include "gl_builtin_shaders.h"
namespace KIGFX {
namespace BUILTIN_SHADERS {
/*
*
* KiCad shaders
*
*/
const char kicad_vertex_shader[] = R"SHADER_SOURCE(
/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2013-2016 CERN
* @author Maciej Suminski <maciej.suminski@cern.ch>
*
* Vertex 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 = 1.0;
const float SHADER_FILLED_CIRCLE = 2.0;
const float SHADER_STROKED_CIRCLE = 3.0;
const float SHADER_FONT = 4.0;
// Minimum line width
const float MIN_WIDTH = 1.0;
attribute vec4 attrShaderParams;
varying vec4 shaderParams;
varying vec2 circleCoords;
void main()
{
// Pass attributes to the fragment shader
shaderParams = attrShaderParams;
if( shaderParams[0] == SHADER_LINE )
{
float lineWidth = shaderParams[3];
float worldScale = abs( gl_ModelViewMatrix[0][0] );
// Make lines appear to be at least 1 pixel wide
if( worldScale * lineWidth < MIN_WIDTH )
gl_Position = gl_ModelViewProjectionMatrix *
( gl_Vertex + vec4( shaderParams.yz * MIN_WIDTH / ( worldScale * lineWidth ), 0.0, 0.0 ) );
else
gl_Position = gl_ModelViewProjectionMatrix *
( gl_Vertex + vec4( shaderParams.yz, 0.0, 0.0 ) );
}
else if( ( shaderParams[0] == SHADER_STROKED_CIRCLE ) ||
( shaderParams[0] == SHADER_FILLED_CIRCLE ) )
{
// Compute relative circle coordinates basing on indices
// Circle
if( shaderParams[1] == 1.0 )
circleCoords = vec2( -sqrt( 3.0 ), -1.0 );
else if( shaderParams[1] == 2.0 )
circleCoords = vec2( sqrt( 3.0 ), -1.0 );
else if( shaderParams[1] == 3.0 )
circleCoords = vec2( 0.0, 2.0 );
// Semicircle
else if( shaderParams[1] == 4.0 )
circleCoords = vec2( -3.0 / sqrt( 3.0 ), 0.0 );
else if( shaderParams[1] == 5.0 )
circleCoords = vec2( 3.0 / sqrt( 3.0 ), 0.0 );
else if( shaderParams[1] == 6.0 )
circleCoords = vec2( 0.0, 2.0 );
// Make the line appear to be at least 1 pixel wide
float lineWidth = shaderParams[3];
float worldScale = abs( gl_ModelViewMatrix[0][0] );
if( worldScale * lineWidth < MIN_WIDTH )
shaderParams[3] = shaderParams[3] / ( worldScale * lineWidth );
gl_Position = ftransform();
}
else
{
// Pass through the coordinates like in the fixed pipeline
gl_Position = ftransform();
}
gl_FrontColor = gl_Color;
}
)SHADER_SOURCE";
const char kicad_fragment_shader[] = R"SHADER_SOURCE(
/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2013-2016 CERN
* Copyright (C) 2016 Kicad Developers, see authors.txt for contributors.
* @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
// Multi-channel signed distance field
#define USE_MSDF
// Shader types
const float SHADER_LINE = 1.0;
const float SHADER_FILLED_CIRCLE = 2.0;
const float SHADER_STROKED_CIRCLE = 3.0;
const float SHADER_FONT = 4.0;
varying vec4 shaderParams;
varying vec2 circleCoords;
uniform sampler2D fontTexture;
// Needed to reconstruct the mipmap level / texel derivative
uniform int fontTextureWidth;
void filledCircle( vec2 aCoord )
{
if( dot( aCoord, aCoord ) < 1.0 )
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 ) < 1.0 ) &&
( dot( aCoord, aCoord ) > relWidth * relWidth ) )
gl_FragColor = gl_Color;
else
discard;
}
#ifdef USE_MSDF
float median( vec3 v )
{
return max( min( v.r, v.g ), min( max( v.r, v.g ), v.b ) );
}
#endif
void main()
{
if( shaderParams[0] == SHADER_FILLED_CIRCLE )
{
filledCircle( circleCoords );
}
else if( shaderParams[0] == SHADER_STROKED_CIRCLE )
{
strokedCircle( circleCoords, shaderParams[2], shaderParams[3] );
}
else if( shaderParams[0] == SHADER_FONT )
{
vec2 tex = shaderParams.yz;
// Unless we're streching chars it is okay to consider
// one derivative for filtering
float derivative = length( dFdx( tex ) ) * fontTextureWidth / 4;
#ifdef USE_MSDF
float dist = median( texture2D( fontTexture, tex ).rgb );
#else
float dist = texture2D( fontTexture, tex ).r;
#endif
// use the derivative for zoom-adaptive filtering
float alpha = smoothstep( 0.5 - derivative, 0.5 + derivative, dist );
gl_FragColor = vec4( gl_Color.rgb, alpha );
}
else
{
// Simple pass-through
gl_FragColor = gl_Color;
}
}
)SHADER_SOURCE";
}
}