Source/System/State/Shader/SHL/testSHLGeometryShader.cpp

   1 // OpenSG example: testSHL
   2 //
   3 // Demonstrates the use of the SHLChunk
   4 // Implements a simple bumpmapping via vertex and fragment shader.
   5
   6 // Headers
   7 #include "OSGConfig.h"
   8 #include "OSGSimpleGeometry.h"
   9 #include "OSGGLUT.h"
  10 #include "OSGGLEXT.h"
  11 #include "OSGGLUTWindow.h"
  12 #include "OSGSimpleSceneManager.h"
  13 #include "OSGAction.h"
  14 #include "OSGSceneFileHandler.h"
  15 #include "OSGBaseFunctions.h"
  16
  17 #include "OSGNode.h"
  18 #include "OSGGroup.h"
  19 #include "OSGTransform.h"
  20 #include "OSGPointLight.h"
  21
  22 #include "OSGImage.h"
  23 #include "OSGChunkMaterial.h"
  24 #include "OSGMaterialChunk.h"
  25 #include "OSGSimpleSHLChunk.h"
  26
  27
  28
  29 // ------------------- global vars ----------------------
  30 //
  31 // The SimpleSceneManager to manage simple applications
  32 static OSG::SimpleSceneManagerRefPtr _mgr;
  33 // The scene
  34 static OSG::NodeRecPtr _scene;
  35
  36 // forward declaration so we can have the interesting stuff upfront
  37 int setupGLUT( int *argc, char *argv[] );
  38
  39 static std::string _vertex_shader =
  40 "void main(void)\n"
  41 "{\n"
  42 "    gl_Position = gl_Vertex;\n"
  43 "    gl_TexCoord[0] = vec4(abs(gl_Normal), 0.0);\n"
  44 "}\n"
  45 "\n";
  46
  47 static std::string _fragment_shader =
  48 "void main (void)\n"
  49 "{\n"
  50 "    gl_FragColor = gl_Color;\n"
  51 "\n"
  52 "}\n";
  53
  54 // ok we create some triangles to draw the face normals.
  55 static std::string _geometry_shader =
  56 "#version 120\n"
  57 "#extension GL_EXT_geometry_shader4 : enable\n"
  58 "\n"
  59 "void main(void)\n"
  60 "{\n"
  61 "    vec4 v1 = gl_PositionIn[0];\n"
  62 "    vec4 v2 = gl_PositionIn[1];\n"
  63 "    vec4 v3 = gl_PositionIn[2];\n"
  64 "\n"
  65 "    vec4 l1 = v2 - v1;\n"
  66 "    vec4 l2 = v3 - v1;\n"
  67 "\n"
  68 "    gl_Position = gl_ModelViewProjectionMatrix * v1;\n"
  69 "    gl_FrontColor = vec4(0.0, 1.0, 0.0, 0.0);\n"
  70 "    EmitVertex();\n"
  71 "    gl_Position = gl_ModelViewProjectionMatrix * v2;\n"
  72 "    gl_FrontColor = vec4(0.0, 1.0, 0.0, 0.0);\n"
  73 "    EmitVertex();\n"
  74 "    gl_Position = gl_ModelViewProjectionMatrix * v3;\n"
  75 "    gl_FrontColor = vec4(0.0, 1.0, 0.0, 0.0);\n"
  76 "    EmitVertex();\n"
  77 "    EndPrimitive();\n"
  78 "\n"
  79 "    vec3 l1n = l1.xyz;\n"
  80 "    vec3 l2n = l2.xyz;\n"
  81 "\n"
  82 "    vec3 N = cross(l1n.xyz, l2n.xyz);\n"
  83 "    N = normalize(N);\n"
  84 "    vec4 middle = v1 + 0.333 * l1 + 0.333 * l2;\n"
  85 "    gl_Position = gl_ModelViewProjectionMatrix * middle;\n"
  86 "    gl_FrontColor = gl_TexCoordIn[0][0];\n"
  87 "    EmitVertex();\n"
  88 "    gl_FrontColor = gl_TexCoordIn[0][0];\n"
  89 "    gl_Position = gl_ModelViewProjectionMatrix * (middle + 0.1 * vec4(N, 0.0));\n"
  90 "    EmitVertex();\n"
  91 "    gl_FrontColor = gl_TexCoordIn[0][0];\n"
  92 "    gl_Position = gl_ModelViewProjectionMatrix * (middle + vec4(0.01,0.01,0.01,0.0));\n"
  93 "    EmitVertex();\n"
  94 "    EndPrimitive();\n"
  95 "\n"
  96 "}\n";
  97
  98 // Initialize GLUT & OpenSG and set up the scene
  99 int doMain(int argc, char **argv)
 100 {
 101     // OSG init
 102     OSG::osgInit(argc,argv);
 103
 104     // GLUT init
 105     int winid = setupGLUT(&argc, argv);
 106
 107     // the connection between GLUT and OpenSG
 108     OSG::GLUTWindowUnrecPtr gwin= OSG::GLUTWindow::create();
 109     gwin->setGlutId(winid);
 110     gwin->setSize( 800, 800 );
 111     gwin->init();
 112
 113     // Create the shader material
 114     OSG::ChunkMaterialUnrecPtr cmat = OSG::ChunkMaterial::create();
 115
 116     OSG::SimpleSHLChunkUnrecPtr shl = OSG::SimpleSHLChunk::create();
 117
 118     shl->setProgramParameter(GL_GEOMETRY_INPUT_TYPE_EXT,
 119                              GL_TRIANGLES);
 120     shl->setProgramParameter(GL_GEOMETRY_OUTPUT_TYPE_EXT,
 121                              GL_TRIANGLE_STRIP);
 122     shl->setProgramParameter(GL_GEOMETRY_VERTICES_OUT_EXT, 6);
 123
 124     shl->setVertexProgram(_vertex_shader);
 125     shl->setFragmentProgram(_fragment_shader);
 126     shl->setGeometryProgram(_geometry_shader);
 127
 128     cmat->addChunk(shl);
 129
 130     // create root node
 131     _scene = OSG::Node::create();
 132
 133     // create torus
 134     OSG::GeometryUnrecPtr geo = OSG::makeTorusGeo(.8f, 1.8f, 128, 128);
 135
 136     geo->setMaterial(cmat);
 137
 138     OSG::NodeUnrecPtr torus = OSG::Node::create();
 139
 140     torus->setCore(geo);
 141
 142     // add torus to scene
 143     OSG::GroupUnrecPtr group = OSG::Group::create();
 144
 145     _scene->setCore(group);
 146     _scene->addChild(torus);
 147
 148     // create the SimpleSceneManager helper
 149     _mgr = OSG::SimpleSceneManager::create();
 150
 151     // tell the manager what to manage
 152     _mgr->setWindow(gwin );
 153     _mgr->setRoot(_scene);
 154
 155     // show the whole scene
 156     _mgr->showAll();
 157
 158     return 0;
 159 }
 160
 161 // Initialize GLUT & OpenSG and set up the scene
 162 int main(int argc, char **argv)
 163 {
 164     if(doMain(argc, argv) != 0)
 165         return 1;
 166
 167     // GLUT main loop
 168     glutMainLoop();
 169
 170     return 0;
 171 }
 172 //
 173 // GLUT callback functions
 174 //
 175
 176 // redraw the window
 177 void display(void)
 178 {
 179   // render scene
 180   _mgr->redraw();
 181 }
 182
 183 // react to size changes
 184 void reshape(int w, int h)
 185 {
 186     _mgr->resize(w, h);
 187     glutPostRedisplay();
 188 }
 189
 190 // react to mouse button presses
 191 void mouse(int button, int state, int x, int y)
 192 {
 193     if (state)
 194         _mgr->mouseButtonRelease(button, x, y);
 195     else
 196         _mgr->mouseButtonPress(button, x, y);
 197
 198     glutPostRedisplay();
 199 }
 200
 201 // react to mouse motions with pressed buttons
 202 void motion(int x, int y)
 203 {
 204     _mgr->mouseMove(x, y);
 205     glutPostRedisplay();
 206 }
 207
 208 // react to keys
 209 void keyboard(unsigned char k, int x, int y)
 210 {
 211     switch(k)
 212     {
 213         case 27:
 214         case 'q':
 215
 216             _scene = NULL;
 217             _mgr   = NULL;
 218
 219             exit(1);
 220         break;
 221         case 'w':
 222             OSG::SceneFileHandler::the()->write(_scene, "scene.osb.gz", true);
 223             printf("wrote scene.osb.gz\n");
 224         break;
 225     }
 226
 227     glutPostRedisplay();
 228 }
 229
 230 // setup the GLUT library which handles the windows for us
 231 int setupGLUT(int *argc, char *argv[])
 232 {
 233     glutInit(argc, argv);
 234     glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
 235
 236     int winid = glutCreateWindow("OpenSG GLSL Geometry Shader");
 237
 238     glutReshapeFunc(reshape);
 239     glutDisplayFunc(display);
 240     glutMouseFunc(mouse);
 241     glutMotionFunc(motion);
 242     glutKeyboardFunc(keyboard);
 243
 244     return winid;
 245 }
 246
 247