205 lines
6.8 KiB
C++
205 lines
6.8 KiB
C++
#include <iostream>
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#include <osg/Array>
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#include <osg/BoundingSphere>
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#include <osg/BufferIndexBinding>
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#include <osg/BufferObject>
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#include <osg/Group>
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#include <osg/Math>
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#include <osg/MatrixTransform>
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#include <osg/Program>
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#include <osg/Shader>
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#include <osgDB/ReadFile>
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#include <osgDB/WriteFile>
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#include <osgUtil/Optimizer>
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#include <osgViewer/Viewer>
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#include <osgViewer/ViewerEventHandlers>
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using namespace std;
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using namespace osg;
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// This example is based on the sample code in the
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// ARB_uniform_buffer_object extension specification.
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GLfloat colors1[] = {
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// block
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0.45,0.45,1,1,
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0.45,0.45,1,1,
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0.75,0.75,0.75,1,
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0.0,0.0,1.0,1,
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0.0,1.0,0.0,1
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};
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GLfloat colors2[] = {
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// block
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0.45,0.45,1,1,
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0.45,0.45,1,1,
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0.75,0.75,0.75,1,
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1.0,0.0,0.0,1,
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0.0,1.0,0.0,1,
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};
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char vertexShaderSource[] =
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"// Vertex shader for Gooch shading\n"
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"// Author: Randi Rost\n"
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"// Copyright (c) 2002-2006 3Dlabs Inc. Ltd.\n"
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"// See 3Dlabs-License.txt for license information\n"
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"vec3 LightPosition = vec3(0.0, 10.0, 4.0); \n"
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"varying float NdotL;\n"
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"varying vec3 ReflectVec;\n"
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"varying vec3 ViewVec;\n"
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"void main(void)\n"
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"{\n"
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"vec3 ecPos = vec3 (gl_ModelViewMatrix * gl_Vertex);\n"
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"vec3 tnorm = normalize(gl_NormalMatrix * gl_Normal);\n"
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"vec3 lightVec = normalize(LightPosition - ecPos);\n"
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"ReflectVec = normalize(reflect(-lightVec, tnorm));\n"
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"ViewVec = normalize(-ecPos);\n"
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"NdotL = (dot(lightVec, tnorm) + 1.0) * 0.5;\n"
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"gl_Position = ftransform();\n"
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"}\n";
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char fragmentShaderSource[] =
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"// Fragment shader for Gooch shading, adapted for ARB_uniform_buffer_object\n"
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"#extension GL_ARB_uniform_buffer_object : enable\n"
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"layout(std140) uniform colors0\n"
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"{\n"
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"float DiffuseCool;\n"
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"float DiffuseWarm;\n"
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"vec3 SurfaceColor;\n"
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"vec3 WarmColor;\n"
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"vec3 CoolColor;\n"
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"};\n"
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"varying float NdotL;\n"
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"varying vec3 ReflectVec;\n"
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"varying vec3 ViewVec;\n"
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"void main (void)\n"
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"{\n"
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"vec3 kcool = min(CoolColor + DiffuseCool * SurfaceColor, 1.0);\n"
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"vec3 kwarm = min(WarmColor + DiffuseWarm * SurfaceColor, 1.0); \n"
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"vec3 kfinal = mix(kcool, kwarm, NdotL);\n"
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"vec3 nreflect = normalize(ReflectVec);\n"
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"vec3 nview = normalize(ViewVec);\n"
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"float spec = max(dot(nreflect, nview), 0.0);\n"
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"spec = pow(spec, 32.0);\n"
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"gl_FragColor = vec4 (min(kfinal + spec, 1.0), 1.0);\n"
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"}\n";
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// Callback for animating the WarmColor
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class UniformBufferCallback : public StateAttributeCallback
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{
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public:
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void operator() (StateAttribute* attr, NodeVisitor* nv)
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{
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UniformBufferBinding* ubb = static_cast<UniformBufferBinding*>(attr);
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FloatArray* array = static_cast<FloatArray*>(ubb->getBufferData());
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double time = nv->getFrameStamp()->getSimulationTime();
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double frac = fmod(time, 1.0);
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Vec4f warmColor = (Vec4f(0.0, 0.0, 1.0 ,1) * frac
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+ Vec4f(1.0, 0.0, 0.0, 1) * (1 - frac));
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// Since we're using the std140 layout, we know where the
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// warmColor variable is located in the buffer.
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for (int i = 0; i < 4; ++i)
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(*array)[12 + i] = warmColor[i];
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array->dirty();
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}
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};
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int main(int argc, char** argv)
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{
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osg::ArgumentParser arguments(&argc,argv);
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osgViewer::Viewer viewer(arguments);
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if (arguments.argc() <= 1) {
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cerr << "Need a scene.\n";
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return 1;
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}
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osg::ref_ptr<osg::Node> loadedModel = osgDB::readRefNodeFiles(arguments);
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if (!loadedModel) {
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cerr << "couldn't load " << argv[1] << "\n";
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return 1;
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}
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osgUtil::Optimizer optimizer;
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optimizer.optimize(loadedModel.get());
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const BoundingSphere bound = loadedModel->getBound();
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const float displacement = 2.25 * bound.radius();
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Group* scene = new Group;
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StateSet* rootSS = scene->getOrCreateStateSet();
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Shader* vertexShader = new Shader(Shader::VERTEX);
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vertexShader->setShaderSource(vertexShaderSource);
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Shader* fragmentShader = new Shader(Shader::FRAGMENT);
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fragmentShader->setShaderSource(fragmentShaderSource);
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Program* prog = new Program;
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prog->addShader(vertexShader);
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prog->addShader(fragmentShader);
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prog->addBindUniformBlock("colors0", 0);
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rootSS->setAttributeAndModes(prog, StateAttribute::ON);
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// Place 3 instances of the loaded model with different uniform
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// blocks for each.
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//
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// The blocksize is known because of the std140 format.
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const unsigned blockSize = 20 * sizeof(GLfloat);
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ref_ptr<FloatArray> colorArray
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= new FloatArray(&colors1[0],
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&colors1[sizeof(colors1) / sizeof(GLfloat)]);
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ref_ptr<UniformBufferObject> ubo = new UniformBufferObject;
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colorArray->setBufferObject(ubo.get());
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Group* group1 = new Group;
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StateSet* ss1 = group1->getOrCreateStateSet();
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group1->addChild(loadedModel.get());
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scene->addChild(group1);
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ref_ptr<UniformBufferBinding> ubb1
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= new UniformBufferBinding(0, colorArray.get(), 0, blockSize);
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ss1->setAttributeAndModes(ubb1.get(), StateAttribute::ON);
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ref_ptr<FloatArray> colorArray2
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= new FloatArray(&colors2[0],
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&colors2[sizeof(colors2) / sizeof(GLfloat)]);
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ref_ptr<UniformBufferObject> ubo2 = new UniformBufferObject;
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colorArray2->setBufferObject(ubo2.get());
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MatrixTransform* group2 = new MatrixTransform;
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Matrix mat2 = Matrix::translate(-displacement, 0.0, 0.0);
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group2->setMatrix(mat2);
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StateSet* ss2 = group2->getOrCreateStateSet();
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group2->addChild(loadedModel.get());
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scene->addChild(group2);
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ref_ptr<UniformBufferBinding> ubb2
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= new UniformBufferBinding(0, colorArray2.get(), 0, blockSize);
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ss2->setAttributeAndModes(ubb2.get(), StateAttribute::ON);
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ref_ptr<FloatArray> colorArray3
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= new FloatArray(&colors2[0],
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&colors2[sizeof(colors2) / sizeof(GLfloat)]);
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ref_ptr<UniformBufferObject> ubo3 = new UniformBufferObject;
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colorArray3->setBufferObject(ubo3.get());
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MatrixTransform* group3 = new MatrixTransform;
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Matrix mat3 = Matrix::translate(displacement, 0.0, 0.0);
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group3->setMatrix(mat3);
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StateSet* ss3 = group3->getOrCreateStateSet();
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group3->addChild(loadedModel.get());
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scene->addChild(group3);
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ref_ptr<UniformBufferBinding> ubb3
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= new UniformBufferBinding(0, colorArray3.get(), 0, blockSize);
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ubb3->setUpdateCallback(new UniformBufferCallback);
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ubb3->setDataVariance(Object::DYNAMIC);
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ss3->setAttributeAndModes(ubb3.get(), StateAttribute::ON);
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viewer.setSceneData(scene);
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viewer.realize();
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return viewer.run();
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}
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