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//VTK::System::Dec
// ============================================================================
//
// Program: Visualization Toolkit
// Module: vtkPointFillPassFS.glsl
//
// Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// All rights reserved.
// See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
//
// This software is distributed WITHOUT ANY WARRANTY; without even
// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the above copyright notice for more information.
//
// ============================================================================
// Fragment shader used by the DOF render pass.
varying vec2 tcoordVC;
uniform sampler2D source;
uniform sampler2D depth;
uniform float nearC;
uniform float farC;
uniform float MinimumCandidateAngle;
uniform float CandidatePointRatio;
uniform vec2 pixelToTCoord;
// the output of this shader
//VTK::Output::Dec
void main(void)
{
// original pixel
float fbdepth = texture2D(depth,tcoordVC).r;
fbdepth = 2.0*nearC/(farC + nearC -fbdepth*(farC - nearC));
vec4 fbcolor = texture2D(source,tcoordVC);
vec4 closestColor = vec4(0.0,0.0,0.0,0.0);
float closestDepth = 0.0;
int count = 0;
// we track the theta range twice
// the original values and a shifted by pi version
// this is to deal with the cyclic nature of atan2
// e.g. 1 degree and 359 degrees are really only 2
// degrees apart. have to handle that.
float minTheta = 4.0;
float maxTheta = -4.0;
float minTheta2 = 4.0;
float maxTheta2 = -4.0;
// loop over pixels
for (int i = -3; i <= 3; i++)
{
for (int j = -3; j <= 3; j++)
{
float adepth = texture2D(depth,tcoordVC + pixelToTCoord*vec2(i,j)).r;
float mdepth = 2.0*nearC/(farC + nearC -adepth*(farC - nearC));
if (mdepth < fbdepth*CandidatePointRatio && (i != 0 || j != 0))
{
float theta = atan(float(j),float(i));
minTheta = min(minTheta,theta);
maxTheta = max(maxTheta,theta);
if (theta > 0)
{
theta -= 3.1415926;
}
else
{
theta += 3.1415926;
}
minTheta2 = min(minTheta2,theta);
maxTheta2 = max(maxTheta2,theta);
count = count + 1;
closestColor += texture2D(source,tcoordVC + pixelToTCoord*vec2(i,j));
closestDepth += adepth;
}
}
}
// must be at least the candidate angle of support
if (min(maxTheta-minTheta, maxTheta2-minTheta2) > MinimumCandidateAngle)
{
gl_FragData[0] = closestColor/count;
gl_FragDepth = closestDepth/count;
}
else
{
gl_FragData[0] = fbcolor;
gl_FragDepth = fbdepth;
}
}
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