OpenSceneGraph/examples/osgshadermultiviewport/osgshadermultiviewport.cpp

183 lines
7.0 KiB
C++

/* OpenSceneGraph example, osgshadermultiviewport.
*
* 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.
*/
#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osg/StateSet>
#include <osg/Texture2D>
#include <osg/ViewportIndexed>
void createShaderCompositionStateSet(osg::StateSet *stateSet) {
stateSet->setDefine("LIGHTING");
stateSet->setDefine("TEXTURE_2D");
//add a global (dummy) texture, to fill in for missing textures.
osg::Image* image = new osg::Image;
unsigned char* imageData = new unsigned char[4];
*((int *)(imageData)) = 0xFFFF0000;//blue
image->setImage(1, 1, 1, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, imageData, osg::Image::USE_NEW_DELETE, 1);
osg::Texture2D* texture = new osg::Texture2D(image);
stateSet->setTextureAttributeAndModes(0, texture, osg::StateAttribute::ON);
//handle the alpha values
stateSet->setDefine("ALPHA_FUNC(a)", "if (a < 0.5) discard;");
osg::ref_ptr<osg::Program> program = new osg::Program;
stateSet->setAttribute(program.get());
stateSet->addUniform(new osg::Uniform("texture0", 0));
//////////////////////////
osg::ref_ptr<osg::Shader> ts =
new osg::Shader(osg::Shader::GEOMETRY,
"#version 330 core\n"
"#extension GL_ARB_gpu_shader5 : enable\n"
"#extension GL_NV_viewport_array : enable\n"
"layout (triangles, invocations = 2) in;\n"
"layout (triangle_strip, max_vertices = 3) out;\n"
"uniform mat4 transform_block[2];\n"
"in vec4 vbasecolor[];\n"
"in vec2 vtexcoord[];\n"
"out vec4 basecolor;\n"
"out vec2 texcoord;\n"
"out int gl_Layer;\n"
"void main(void) {\n"
" for (int i = 0; i < gl_in.length(); i++)\n"
" {"
" basecolor = vec4(1,1,1,1);"
" texcoord = vtexcoord[i];\n"
" gl_ViewportIndex = gl_InvocationID;\n"
" gl_Position = transform_block[gl_InvocationID] * gl_in[i].gl_Position;\n"
" EmitVertex();\n"
" }\n"
" EndPrimitive();\n"
"}\n"
);
program->addShader(ts.get());
osg::ref_ptr<osg::Shader> vertex_shader =
new osg::Shader(osg::Shader::VERTEX,
"#version 120\n"
"#pragma import_defines ( LIGHTING )\n"
"#ifdef LIGHTING\n"
"void directionalLight( int lightNum, vec3 normal, inout vec4 color )"
"{"
" vec3 n = normalize(gl_NormalMatrix * normal);"
" float NdotL = dot( n, normalize(gl_LightSource[lightNum].position.xyz) );"
" NdotL = max( 0.0, NdotL );"
" float NdotHV = dot( n, gl_LightSource[lightNum].halfVector.xyz );"
" NdotHV = max( 0.0, NdotHV );"
" color *= gl_LightSource[lightNum].ambient +"
" gl_LightSource[lightNum].diffuse * NdotL;"
"}\n"
"#endif\n"
"varying vec2 vtexcoord;"
"varying vec4 vbasecolor;"
"void main(void)"
"{"
" vbasecolor = gl_Color;\n"
"#ifdef LIGHTING\n"
" directionalLight( 0, gl_Normal.xyz, vbasecolor);\n"
"#endif\n"
" vtexcoord = gl_MultiTexCoord0.xy;"
#if 1
" gl_Position = gl_ModelViewMatrix * gl_Vertex;"
#else
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;"
#endif
"}");
program->addShader(vertex_shader.get());
osg::ref_ptr<osg::Shader> fragment_shader =
new osg::Shader(osg::Shader::FRAGMENT,
"#pragma import_defines ( TEXTURE_2D )\n"
"#pragma import_defines ( ALPHA_FUNC )\n"
"#ifdef TEXTURE_2D\n"
"uniform sampler2D texture0;\n"
"varying vec2 texcoord;\n"
"#endif\n"
"varying vec4 basecolor;\n"
"void main(void)\n"
"{\n"
"#ifdef TEXTURE_2D\n"
" gl_FragColor = texture2D( texture0, texcoord) * basecolor;\n"
"#ifdef ALPHA_FUNC\n"
" ALPHA_FUNC(gl_FragColor.a)\n"
"#endif \n"
"#else\n"
" gl_FragColor = basecolor;\n"
"#endif\n"
"}\n");
program->addShader(fragment_shader.get());
}
osg::Node* createNewShaderCompositionScene(osg::ArgumentParser& arguments)
{
osg::ref_ptr<osg::Node> node = osgDB::readRefNodeFiles(arguments);
if (!node) return 0;
osg::ref_ptr<osg::Group> group = new osg::Group;
osg::ref_ptr<osg::StateSet> stateset = group->getOrCreateStateSet();
createShaderCompositionStateSet(stateset.get());
group->addChild(node.get());
return group.release();
}
int main( int argc, char **argv )
{
osg::ArgumentParser arguments(&argc,argv);
osgViewer::Viewer viewer(arguments);
viewer.setThreadingModel(osgViewer::Viewer::SingleThreaded);
// use new #pragma(tic) shader composition.
osg::ref_ptr<osg::Node> scenegraph = createNewShaderCompositionScene(arguments);
if (!scenegraph) return 1;
osg::ref_ptr<osg::StateSet> stateSet = scenegraph->getOrCreateStateSet();
osg::Uniform* LRuniform = stateSet->getUniform("transform_block");
if (!LRuniform) {
LRuniform = new osg::Uniform(osg::Uniform::FLOAT_MAT4, "transform_block", 2);
stateSet->addUniform(LRuniform);
}
viewer.setSceneData(scenegraph.get());
viewer.realize();
double width = viewer.getCamera()->getViewport()->width();
double height = viewer.getCamera()->getViewport()->height();
stateSet->setAttribute(new osg::ViewportIndexed(0, 0.0, 0.0, width * 0.5, height)); // left
stateSet->setAttribute(new osg::ViewportIndexed(1, width * 0.5, 0.0, width * 0.5, height)); // right
osg::Camera *cam = viewer.getCamera();
osg::Matrix matrixL = cam->getProjectionMatrix();
LRuniform->setElement(0, matrixL);
double l, r, b, t, n, f;
matrixL.getFrustum(l, r, b, t, n, f);
osg::Matrix matrixR;
matrixR.makeFrustum(l * 2.0, r* 2.0, b* 2.0, t* 2.0, n, f);
LRuniform->setElement(1, matrixR);
return viewer.run();
}