91 lines
4.4 KiB
C++
91 lines
4.4 KiB
C++
/* -*-c++-*- OpenSceneGraph example, osgcomputeshaders.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
// Written by Wang Rui
|
|
// This example can work only if GL version is 4.3 or greater
|
|
|
|
#include <osg/Texture2D>
|
|
#include <osg/ComputeDispatch>
|
|
#include <osg/Geode>
|
|
#include <osgDB/ReadFile>
|
|
#include <osgGA/StateSetManipulator>
|
|
#include <osgViewer/Viewer>
|
|
#include <osgViewer/ViewerEventHandlers>
|
|
|
|
static const char* computeSrc = {
|
|
"#version 430\n"
|
|
"uniform float osg_FrameTime;\n"
|
|
"layout (r32f, binding =0) uniform image2D targetTex;\n"
|
|
"layout (local_size_x = 16, local_size_y = 16) in;\n"
|
|
"void main() {\n"
|
|
" ivec2 storePos = ivec2(gl_GlobalInvocationID.xy);\n"
|
|
" float coeffcient = 0.5*sin(float(gl_WorkGroupID.x + gl_WorkGroupID.y)*0.1 + osg_FrameTime);\n"
|
|
" coeffcient *= length(vec2(ivec2(gl_LocalInvocationID.xy) - ivec2(8)) / vec2(8.0));\n"
|
|
" imageStore(targetTex, storePos, vec4(1.0-coeffcient, 0.0, 0.0, 0.0));\n"
|
|
"}\n"
|
|
};
|
|
|
|
int main( int argc, char** argv )
|
|
{
|
|
osg::ArgumentParser arguments( &argc, argv );
|
|
|
|
// Create the texture as both the output of compute shader and the input of a normal quad
|
|
osg::ref_ptr<osg::Texture2D> tex2D = new osg::Texture2D;
|
|
tex2D->setTextureSize( 512, 512 );
|
|
tex2D->setFilter( osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR );
|
|
tex2D->setFilter( osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR );
|
|
tex2D->setInternalFormat( GL_R32F );
|
|
tex2D->setSourceFormat( GL_RED );
|
|
tex2D->setSourceType( GL_FLOAT );
|
|
tex2D->bindToImageUnit( 0, osg::Texture::WRITE_ONLY ); // So we can use 'image2D' in the compute shader
|
|
|
|
// The compute shader can't work with other kinds of shaders
|
|
// It also requires the work group numbers. Setting them to 0 will disable the compute shader
|
|
osg::ref_ptr<osg::Program> computeProg = new osg::Program;
|
|
computeProg->addShader( new osg::Shader(osg::Shader::COMPUTE, computeSrc) );
|
|
|
|
// Create a node for outputting to the texture.
|
|
// It is OK to have just an empty node here, but seems inbuilt uniforms like osg_FrameTime won't work then.
|
|
// TODO: maybe we can have a custom drawable which also will implement glMemoryBarrier?
|
|
osg::ref_ptr<osg::Node> sourceNode = new osg::ComputeDispatch(512/16, 512/16, 1 );
|
|
sourceNode->setDataVariance( osg::Object::DYNAMIC );
|
|
sourceNode->getOrCreateStateSet()->setAttributeAndModes( computeProg.get() );
|
|
sourceNode->getOrCreateStateSet()->addUniform( new osg::Uniform("targetTex", (int)0) );
|
|
sourceNode->getOrCreateStateSet()->setTextureAttributeAndModes( 0, tex2D.get() );
|
|
|
|
// Display the texture on a quad. We will also be able to operate on the data if reading back to CPU side
|
|
osg::Geometry* geom = osg::createTexturedQuadGeometry(
|
|
osg::Vec3(), osg::Vec3(1.0f,0.0f,0.0f), osg::Vec3(0.0f,0.0f,1.0f) );
|
|
osg::ref_ptr<osg::Geode> quad = new osg::Geode;
|
|
quad->addDrawable( geom );
|
|
quad->getOrCreateStateSet()->setMode( GL_LIGHTING, osg::StateAttribute::OFF );
|
|
quad->getOrCreateStateSet()->setTextureAttributeAndModes( 0, tex2D.get() );
|
|
|
|
// Create the scene graph and start the viewer
|
|
osg::ref_ptr<osg::Group> scene = new osg::Group;
|
|
scene->addChild( sourceNode );
|
|
scene->addChild( quad.get() );
|
|
|
|
osgViewer::Viewer viewer;
|
|
viewer.addEventHandler( new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );
|
|
viewer.addEventHandler( new osgViewer::StatsHandler );
|
|
viewer.addEventHandler( new osgViewer::WindowSizeHandler );
|
|
viewer.setSceneData( scene.get() );
|
|
return viewer.run();
|
|
}
|