Sorry, there is an error on the files I have send , please use this new files.
Thanks. On Tue, Sep 2, 2008 at 10:42 AM, christophe loustaunau < [EMAIL PROTECTED]> wrote: > Hi, > > I have found some errors on the example osgGeometryShaders. It's about the > varying in the geometry shader. > take a look at the varying vec4 v_color. > In the vertex shader, v_color is initialized to gl_vertex > then in the geometry shader v_color is initialized to gl_PositionIn[0] > and in the fragment shader v_color is used as the fragment color. > > Try to initialized v_color to vec4(1.0, 0.0, 0.0, 1.0) in the vertex shader > and comment the line : > " v_color = v;\n" in the geometry shader, and you will see the lines as > black ! > > It's because you have to use keywords in and out. > > extract from : > http://www.opengl.org/registry/specs/EXT/geometry_shader4.txt : > > *in - for function parameters passed into a function or for input varying > variables (geometry only) > > out - for function parameters passed back out of a function, but not > initialized for use when passed in. Also for output varying variables > (geometry only).* > > Then for a geometry shader, a varying must be an array : > extract from : > http://www.opengl.org/registry/specs/EXT/geometry_shader4.txt : > > *Since a geometry shader operates on primitives, each input varying > variable needs to be > declared as an array. Each element of such an array corresponds to a > vertex of the primitive being processed. If the varying variable is > declared as a scalar or matrix in the vertex shader, it will be a > one-dimensional array in the geometry shader. Each array can optionally > have a size declared. If a size is not specified, it inferred by the > linker and depends on the value of the input primitive type.* > > > Here is a patch based on the svn version of osg that correct that. > > Regards. > > -- > Christophe Loustaunau. > -- Christophe Loustaunau.
/* OpenSceneGraph example, osgshaders2
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* file: examples/osgshaders2/osgshaders2.cpp
* author: Mike Weiblen 2008-01-03
* copyright: (C) 2008 Zebra Imaging
* license: OpenSceneGraph Public License (OSGPL)
*
* A demo of GLSL geometry shaders using OSG
* Tested on Dell Precision M4300 w/ NVIDIA Quadro FX 360M
*/
#include <osg/Notify>
#include <osg/ref_ptr>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Point>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/Program>
#include <osg/Shader>
#include <osg/Uniform>
#include <osgViewer/Viewer>
// play with these #defines to see their effect
#define ENABLE_GLSL
#define ENABLE_GEOMETRY_SHADER
///////////////////////////////////////////////////////////////////////////
#ifdef ENABLE_GLSL
class SineAnimation: public osg::Uniform::Callback
{
public:
SineAnimation( float rate = 1.0f, float scale = 1.0f, float offset = 0.0f )
:
_rate(rate), _scale(scale), _offset(offset)
{}
void operator()( osg::Uniform* uniform, osg::NodeVisitor* nv )
{
float angle = _rate * nv->getFrameStamp()->getSimulationTime();
float value = sinf( angle ) * _scale + _offset;
uniform->set( value );
}
private:
const float _rate;
const float _scale;
const float _offset;
};
///////////////////////////////////////////////////////////////////////////
static const char* vertSource = {
"#version 120\n"
"#extension GL_EXT_geometry_shader4 : enable\n"
"uniform float u_anim1;\n"
"varying vec4 v_color;\n"
"void main(void)\n"
"{\n"
" v_color = gl_Vertex;\n"
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
"}\n"
};
static const char* geomSource = {
"#version 120\n"
"#extension GL_EXT_geometry_shader4 : enable\n"
"uniform float u_anim1;\n"
"varying in vec4 v_color[];\n"
"varying out vec4 v_color_out;\n"
"void main(void)\n"
"{\n"
" vec4 v = gl_PositionIn[0];\n"
" v_color_out = v + v_color[0];\n"
"\n"
" gl_Position = v + vec4(u_anim1,0.,0.,0.); EmitVertex();\n"
" gl_Position = v - vec4(u_anim1,0.,0.,0.); EmitVertex();\n"
" EndPrimitive();\n"
"\n"
" gl_Position = v + vec4(0.,1.0-u_anim1,0.,0.); EmitVertex();\n"
" gl_Position = v - vec4(0.,1.0-u_anim1,0.,0.); EmitVertex();\n"
" EndPrimitive();\n"
"}\n"
};
static const char* fragSource = {
"#version 120\n"
"#extension GL_EXT_geometry_shader4 : enable\n"
"uniform float u_anim1;\n"
"varying vec4 v_color_out;\n"
"void main(void)\n"
"{\n"
" gl_FragColor = v_color_out;\n"
"}\n"
};
osg::Program* createShader()
{
osg::Program* pgm = new osg::Program;
pgm->setName( "osgshader2 demo" );
pgm->addShader( new osg::Shader( osg::Shader::VERTEX, vertSource ) );
pgm->addShader( new osg::Shader( osg::Shader::FRAGMENT, fragSource ) );
#ifdef ENABLE_GEOMETRY_SHADER
pgm->addShader( new osg::Shader( osg::Shader::GEOMETRY, geomSource ) );
pgm->setParameter( GL_GEOMETRY_VERTICES_OUT_EXT, 4 );
pgm->setParameter( GL_GEOMETRY_INPUT_TYPE_EXT, GL_POINTS );
pgm->setParameter( GL_GEOMETRY_OUTPUT_TYPE_EXT, GL_LINE_STRIP );
#endif
return pgm;
}
#endif
///////////////////////////////////////////////////////////////////////////
class SomePoints : public osg::Geometry
{
public:
SomePoints()
{
osg::Vec4Array* cAry = new osg::Vec4Array;
setColorArray( cAry );
setColorBinding( osg::Geometry::BIND_OVERALL );
cAry->push_back( osg::Vec4(1,1,1,1) );
osg::Vec3Array* vAry = new osg::Vec3Array;
setVertexArray( vAry );
vAry->push_back( osg::Vec3(0,0,0) );
vAry->push_back( osg::Vec3(0,1,0) );
vAry->push_back( osg::Vec3(1,0,0) );
vAry->push_back( osg::Vec3(1,1,0) );
vAry->push_back( osg::Vec3(0,0,1) );
vAry->push_back( osg::Vec3(0,1,1) );
vAry->push_back( osg::Vec3(1,0,1) );
vAry->push_back( osg::Vec3(1,1,1) );
addPrimitiveSet( new osg::DrawArrays( GL_POINTS, 0, vAry->size() ) );
osg::StateSet* sset = getOrCreateStateSet();
sset->setMode( GL_LIGHTING, osg::StateAttribute::OFF );
// if things go wrong, fall back to big points
osg::Point* p = new osg::Point;
p->setSize(6);
sset->setAttribute( p );
#ifdef ENABLE_GLSL
sset->setAttribute( createShader() );
// a generic cyclic animation value
osg::Uniform* u_anim1( new osg::Uniform( "u_anim1", 0.0f ) );
u_anim1->setUpdateCallback( new SineAnimation( 4, 0.5, 0.5 ) );
sset->addUniform( u_anim1 );
#endif
}
};
///////////////////////////////////////////////////////////////////////////
int main( int argc, char *argv[] )
{
osg::Geode* root( new osg::Geode );
root->addDrawable( new SomePoints );
osgViewer::Viewer viewer;
viewer.setSceneData( root );
return viewer.run();
}
// vim: set sw=4 ts=8 et ic ai:
osggeometryshaders.patch
Description: Binary data
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