FGFS-4.1/OpenSceneGraph
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Removed use of ints and reading from gl_FragColor in shader

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This commit is contained in:
Robert Osfield 2008-09-12 15:41:30 +00:00
parent dc1b52aa7c
commit b000198cc4
1 changed files with 139 additions and 23 deletions
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156
examples/osgvolume/osgvolume.cpp
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@ -34,6 +34,7 @@
#include <osg/Endian>
#include <osg/BlendFunc>
#include <osg/BlendEquation>
#include <osg/TransferFunction>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
@ -420,7 +421,8 @@ osg::Image* createTexture3D(ImageList& imageList, ProcessRow& processRow,
unsigned int numComponentsDesired,
int s_maximumTextureSize,
int t_maximumTextureSize,
int r_maximumTextureSize )
int r_maximumTextureSize,
bool resizeToPowerOfTwo)
{
int max_s = 0;
int max_t = 0;
@ -475,19 +477,27 @@ osg::Image* createTexture3D(ImageList& imageList, ProcessRow& processRow,
if (desiredPixelFormat==0) return 0;
// compute nearest powers of two for each axis.
int s_nearestPowerOfTwo = 1;
while(s_nearestPowerOfTwo<max_s && s_nearestPowerOfTwo<s_maximumTextureSize) s_nearestPowerOfTwo*=2;
int t_nearestPowerOfTwo = 1;
while(t_nearestPowerOfTwo<max_t && t_nearestPowerOfTwo<t_maximumTextureSize) t_nearestPowerOfTwo*=2;
int r_nearestPowerOfTwo = 1;
while(r_nearestPowerOfTwo<total_r && r_nearestPowerOfTwo<r_maximumTextureSize) r_nearestPowerOfTwo*=2;
if (resizeToPowerOfTwo)
{
while(s_nearestPowerOfTwo<max_s && s_nearestPowerOfTwo<s_maximumTextureSize) s_nearestPowerOfTwo*=2;
while(t_nearestPowerOfTwo<max_t && t_nearestPowerOfTwo<t_maximumTextureSize) t_nearestPowerOfTwo*=2;
while(r_nearestPowerOfTwo<total_r && r_nearestPowerOfTwo<r_maximumTextureSize) r_nearestPowerOfTwo*=2;
osg::notify(osg::NOTICE)<<"max image width = "<<max_s<<" nearest power of two = "<<s_nearestPowerOfTwo<<std::endl;
osg::notify(osg::NOTICE)<<"max image height = "<<max_t<<" nearest power of two = "<<t_nearestPowerOfTwo<<std::endl;
osg::notify(osg::NOTICE)<<"max image depth = "<<total_r<<" nearest power of two = "<<r_nearestPowerOfTwo<<std::endl;
}
else
{
s_nearestPowerOfTwo = max_s;
t_nearestPowerOfTwo = max_t;
r_nearestPowerOfTwo = total_r;
}
// now allocate the 3d texture;
osg::ref_ptr<osg::Image> image_3d = new osg::Image;
@ -828,6 +838,7 @@ osg::Node* createShaderModel(osg::ref_ptr<osg::Image>& image_3d, osg::ref_ptr<os
else
{
char vertexShaderSource[] =
"#version 110\n"
"varying vec4 cameraPos;\n"
"varying vec4 vertexPos;\n"
"varying mat4 texgen;\n"
@ -920,33 +931,34 @@ osg::Node* createShaderModel(osg::ref_ptr<osg::Image>& image_3d, osg::ref_ptr<os
" }\n"
" }\n"
"\n"
" const int max_iteratrions = 256;\n"
" int num_iterations = length(te-t0)/sampleDensity;\n"
" const float max_iteratrions = 256.0;\n"
" float num_iterations = length(te-t0)/sampleDensity;\n"
" if (num_iterations>max_iteratrions) \n"
" {\n"
" num_iterations = max_iteratrions;\n"
" }\n"
"\n"
" vec3 deltaTexCoord=(te-t0)/float(num_iterations-1);\n"
" vec3 deltaTexCoord=(te-t0)/float(num_iterations-1.0);\n"
" vec3 texcoord = t0;\n"
"\n"
" gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0); \n"
" while(num_iterations>0)\n"
" vec4 fragColor = vec4(0.0, 0.0, 0.0, 0.0); \n"
" while(num_iterations>0.0)\n"
" {\n"
" vec4 color = texture3D( baseTexture, texcoord);\n"
" float r = color[3]*transparency;\n"
" if (r>alphaCutOff)\n"
" {\n"
" gl_FragColor.xyz = gl_FragColor.xyz*(1.0-r)+color.xyz*r;\n"
" gl_FragColor.w += r;\n"
" fragColor.xyz = fragColor.xyz*(1.0-r)+color.xyz*r;\n"
" fragColor.w += r;\n"
" }\n"
" texcoord += deltaTexCoord; \n"
"\n"
" --num_iterations;\n"
" }\n"
"\n"
" if (gl_FragColor.w>1.0) gl_FragColor.w = 1.0; \n"
" if (gl_FragColor.w==0.0) discard;\n"
" if (fragColor.w>1.0) fragColor.w = 1.0; \n"
" if (fragColor.w==0.0) discard;\n"
" gl_FragColor = fragColor;\n"
"}\n";
osg::Shader* fragment_shader = new osg::Shader(osg::Shader::FRAGMENT, fragmentShaderSource);
@ -1040,7 +1052,8 @@ osg::Node* createShaderModel(osg::ref_ptr<osg::Image>& image_3d, osg::ref_ptr<os
return root;
}
osg::Node* createModel(osg::ref_ptr<osg::Image>& image_3d, osg::ref_ptr<osg::Image>& normalmap_3d,
osg::Node* createModel(osg::ref_ptr<osg::Image>& image_3d,
osg::ref_ptr<osg::Image>& normalmap_3d,
osg::Texture::InternalFormatMode internalFormatMode,
float xSize, float ySize, float zSize,
float xMultiplier, float yMultiplier, float zMultiplier,
@ -1540,6 +1553,95 @@ void doColourSpaceConversion(ColourSpaceOperation op, osg::Image* image, osg::Ve
}
}
struct ApplyTransferFunctionOperator
{
ApplyTransferFunctionOperator(osg::TransferFunction1D* tf, unsigned char* data):
_tf(tf),
_data(data) {}
inline void luminance(float l) const
{
osg::Vec4 c = _tf->getInterpolatedValue(l);
//std::cout<<"l = "<<l<<" c="<<c<<std::endl;
*(_data++) = (unsigned char)(c[0]*255.0f + 0.5f);
*(_data++) = (unsigned char)(c[1]*255.0f + 0.5f);
*(_data++) = (unsigned char)(c[2]*255.0f + 0.5f);
*(_data++) = (unsigned char)(c[3]*255.0f + 0.5f);
}
inline void alpha(float a) const
{
luminance(a);
}
inline void luminance_alpha(float l,float a) const
{
luminance(l);
}
inline void rgb(float r,float g,float b) const
{
luminance((r+g+b)*0.3333333);
}
inline void rgba(float r,float g,float b,float a) const
{
luminance(a);
}
mutable osg::ref_ptr<osg::TransferFunction1D> _tf;
mutable unsigned char* _data;
};
osg::Image* applyTransferFunction(osg::Image* image, osg::TransferFunction1D* transferFunction)
{
std::cout<<"Applying transfer function"<<std::endl;
osg::Image* output_image = new osg::Image;
output_image->allocateImage(image->s(),image->t(), image->r(), GL_RGBA, GL_UNSIGNED_BYTE);
readImage(image,ApplyTransferFunctionOperator(transferFunction, output_image->data()));
return output_image;
}
osg::TransferFunction1D* readTransferFunctionFile(const std::string& filename)
{
std::string foundFile = osgDB::findDataFile(filename);
if (foundFile.empty())
{
std::cout<<"Error: could not find transfer function file : "<<filename<<std::endl;
return 0;
}
std::cout<<"Reading transfer function "<<filename<<std::endl;
osg::TransferFunction1D::ValueMap valueMap;
std::ifstream fin(foundFile.c_str());
while(fin)
{
float value, red, green, blue, alpha;
fin >> value >> red >> green >> blue >> alpha;
if (fin)
{
std::cout<<"value = "<<value<<" ("<<red<<", "<<green<<", "<<blue<<", "<<alpha<<")"<<std::endl;
valueMap[value] = osg::Vec4(red,green,blue,alpha);
}
}
if (valueMap.empty())
{
std::cout<<"Error: No values read from transfer function file: "<<filename<<std::endl;
return 0;
}
osg::TransferFunction1D* tf = new osg::TransferFunction1D;
tf->assign(valueMap, true);
return tf;
}
class TestSupportOperation: public osg::GraphicsOperation
{
public:
@ -1624,6 +1726,14 @@ int main( int argc, char **argv )
while (arguments.read("-o",outputFile)) {}
osg::ref_ptr<osg::TransferFunction1D> transferFunction;
std::string tranferFunctionFile;
while (arguments.read("--tf",tranferFunctionFile))
{
transferFunction = readTransferFunctionFile(tranferFunctionFile);
}
unsigned int numSlices=500;
while (arguments.read("-s",numSlices)) {}
@ -1657,9 +1767,9 @@ int main( int argc, char **argv )
viewer.realize();
int maximumTextureSize = testSupportOperation->maximumTextureSize;
int s_maximumTextureSize = 256;
int t_maximumTextureSize = 256;
int r_maximumTextureSize = 256;
int s_maximumTextureSize = maximumTextureSize;
int t_maximumTextureSize = maximumTextureSize;
int r_maximumTextureSize = maximumTextureSize;
while(arguments.read("--maxTextureSize",maximumTextureSize))
{
s_maximumTextureSize = maximumTextureSize;
@ -1685,6 +1795,7 @@ int main( int argc, char **argv )
while(arguments.read("--modulate-alpha-by-colour", colourModulate.x(),colourModulate.y(),colourModulate.z(),colourModulate.w() )) { colourSpaceOperation = MODULATE_ALPHA_BY_COLOUR; }
while(arguments.read("--replace-alpha-with-luminance")) { colourSpaceOperation = REPLACE_ALPHA_WITH_LUMINACE; }
bool resizeToPowerOfTwo = false;
unsigned int numComponentsDesired = 0;
while(arguments.read("--num-components", numComponentsDesired)) {}
@ -1717,7 +1828,7 @@ int main( int argc, char **argv )
// pack the textures into a single texture.
ProcessRow processRow;
image_3d = createTexture3D(imageList, processRow, numComponentsDesired, s_maximumTextureSize, t_maximumTextureSize, r_maximumTextureSize);
image_3d = createTexture3D(imageList, processRow, numComponentsDesired, s_maximumTextureSize, t_maximumTextureSize, r_maximumTextureSize, resizeToPowerOfTwo);
}
@ -1752,6 +1863,11 @@ int main( int argc, char **argv )
doColourSpaceConversion(colourSpaceOperation, image_3d.get(), colourModulate);
}
if (transferFunction.valid())
{
image_3d = applyTransferFunction(image_3d.get(), transferFunction.get());
}
osg::ref_ptr<osg::Image> normalmap_3d = createNormalMap ? createNormalMapTexture(image_3d.get()) : 0;