Examples/Simple/openglcallback.cpp

   1 // OpenSG example: callback.cpp
   2 //
   3 // This example shows how to establish a callback which is executed once on
   4 // each render traversal. This can be useful for applications which have to
   5 // render native OpenGL code, for various reasons.
   6 //
   7 // To be absolutely clear, this callback technique for native OpenGL rendering
   8 // is not applicable in a cluster setup and it should only be exceptionally
   9 // used at special circumstances.
  10 //
  11 // Especially demonstrated is the use of the following classes:
  12 //      - CallbackAlgorithm
  13 //      - VisitSubTree,
  14 //      - AlgorithmStage
  15 //      - DrawEnv
  16 //
  17 // This examples renders a torus or if no model file is provided at the command
  18 // line.
  19 //
  20 // User interface:
  21 //  a) mouse => standard navigator
  22 //
  23
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string>
  27 #include <sstream>
  28 #include <fstream>
  29 #include <vector>
  30
  31 #ifdef OSG_BUILD_ACTIVE
  32 // Headers
  33 #include <OSGGLUT.h>
  34 #include <OSGConfig.h>
  35 #include <OSGSimpleGeometry.h>
  36 #include <OSGGLUTWindow.h>
  37 #include <OSGSimpleSceneManager.h>
  38 #include <OSGSceneFileHandler.h>
  39 #include <OSGAction.h>
  40 #include <OSGCallbackAlgorithm.h>
  41 #include <OSGAlgorithmStage.h>
  42 #include <OSGVisitSubTree.h>
  43 #include <OSGDrawEnv.h>
  44 #else
  45 // Headers
  46 #include <OpenSG/OSGGLUT.h>
  47 #include <OpenSG/OSGConfig.h>
  48 #include <OpenSG/OSGSimpleGeometry.h>
  49 #include <OpenSG/OSGGLUTWindow.h>
  50 #include <OpenSG/OSGSimpleSceneManager.h>
  51 #include <OpenSG/OSGSceneFileHandler.h>
  52 #include <OpenSG/OSGAction.h>
  53 #include <OpenSG/OSGCallbackAlgorithm.h>
  54 #include <OpenSG/OSGAlgorithmStage.h>
  55 #include <OpenSG/OSGSimpleStage.h>
  56 #include <OpenSG/OSGVisitSubTree.h>
  57 #include <OpenSG/OSGDrawEnv.h>
  58 #endif
  59
  60 using namespace OSG; // just for convenience but not recommended
  61
  62 //
  63 // function forward declarations
  64 //
  65 static void onExit();
  66 static void cleanup(void);
  67 static void display(void);
  68 static void reshape(int w, int h);
  69 static void mouse(int button, int state, int x, int y);
  70 static void motion(int x, int y);
  71 static void keyboard(unsigned char k, int, int);
  72 static int  setupGLUT(int *argc, char *argv[]);
  73 static int  doMain(int argc, char *argv[]);
  74 static void addStage();
  75 static void theCallback(DrawEnv* env);
  76
  77 //
  78 // global state of example
  79 //
  80 SimpleSceneManagerRefPtr mgr;
  81 NodeRefPtr               root;
  82 NodeRefPtr               scene;
  83 GLUTWindowRefPtr         win;
  84
  85
  86 static void onExit()
  87 {
  88     commitChanges();
  89
  90     cleanup();
  91     osgExit();
  92 }
  93
  94 static void cleanup(void)
  95 {
  96     mgr->setWindow(NULL);
  97     mgr->setRoot(NULL);
  98
  99     mgr   = NULL;
 100     root  = NULL;
 101     scene = NULL;
 102     win   = NULL;
 103 }
 104
 105 static void display(void)
 106 {
 107     commitChanges();
 108     mgr->redraw();
 109 }
 110
 111 static void reshape(int w, int h)
 112 {
 113     mgr->resize(w,h);
 114     glutPostRedisplay();
 115 }
 116
 117 static void mouse(int button, int state, int x, int y)
 118 {
 119     if (state)
 120         mgr->mouseButtonRelease(button, x, y);
 121     else
 122         mgr->mouseButtonPress(button, x, y);
 123
 124     glutPostRedisplay();
 125 }
 126
 127 static void motion(int x, int y)
 128 {
 129     mgr->mouseMove(x, y);
 130     glutPostRedisplay();
 131 }
 132
 133 static void keyboard(unsigned char k, int, int)
 134 {
 135     switch(k)
 136     {
 137     case 27:
 138     case 'q':
 139     {
 140         std::exit(EXIT_SUCCESS);
 141     }
 142     break;
 143     }
 144 }
 145
 146 static void addStage()
 147 {
 148     //
 149     // We would like to render the scene but won't detach it from its parent.
 150     // The VisitSubTree allows just that.
 151     //
 152     VisitSubTreeUnrecPtr visitor = VisitSubTree::create();
 153     visitor->setSubTreeRoot(scene);
 154     NodeUnrecPtr visit_node = makeNodeFor(visitor);
 155
 156     //
 157     // Algorithm object: CallbackAlgorithm is kind of Algorithm
 158     //
 159     CallbackAlgorithmUnrecPtr algo = CallbackAlgorithm::create();
 160     algo->setCallback(theCallback, "");
 161     //
 162     // Stage object
 163     //
 164     AlgorithmStageUnrecPtr stage = AlgorithmStage::create();
 165     stage->setAlgorithm(algo);
 166
 167     //
 168     // Give the stage core a place to live
 169     //
 170     NodeUnrecPtr stage_node = makeNodeFor(stage);
 171     stage_node->addChild(visit_node);
 172
 173     root->addChild(stage_node);
 174 }
 175
 176 static void theCallback(DrawEnv* env)
 177 {
 178     //
 179     // Save the current state
 180     //
 181     glMatrixMode(GL_PROJECTION);
 182     glPushMatrix();
 183
 184     glMatrixMode(GL_MODELVIEW);
 185     glPushMatrix();
 186
 187     glPushAttrib(GL_ALL_ATTRIB_BITS);
 188
 189     //
 190     // Setup current viewport
 191     //
 192     glMatrixMode(GL_PROJECTION);
 193     glLoadMatrixf(env->getVPCameraFullProjection().getValues());
 194
 195     glMatrixMode(GL_MODELVIEW);
 196     glLoadMatrixf(env->getVPCameraViewing().getValues());
 197
 198     //
 199     // State initialization
 200     //
 201     glShadeModel(GL_SMOOTH);
 202
 203     glEnable(GL_DEPTH_TEST);
 204     glDepthFunc(GL_LEQUAL);
 205
 206     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 207
 208     //
 209     // Some model geometry
 210     //
 211     glPushMatrix();
 212     glTranslatef(-1.5f,0.0f,-6.0f);
 213     glBegin(GL_TRIANGLES);
 214         glColor3f(1.0f,0.0f,0.0f);
 215         glVertex3f( 0.0f, 1.0f, 0.0f);
 216         glColor3f(0.0f,1.0f,0.0f);
 217         glVertex3f(-1.0f,-1.0f, 1.0f);
 218         glColor3f(0.0f,0.0f,1.0f);
 219         glVertex3f( 1.0f,-1.0f, 1.0f);
 220
 221         glColor3f(1.0f,0.0f,0.0f);
 222         glVertex3f( 0.0f, 1.0f, 0.0f);
 223         glColor3f(0.0f,0.0f,1.0f);
 224         glVertex3f( 1.0f,-1.0f, 1.0f);
 225         glColor3f(0.0f,1.0f,0.0f);
 226         glVertex3f( 1.0f,-1.0f, -1.0f);
 227
 228         glColor3f(1.0f,0.0f,0.0f);
 229         glVertex3f( 0.0f, 1.0f, 0.0f);
 230         glColor3f(0.0f,1.0f,0.0f);
 231         glVertex3f( 1.0f,-1.0f, -1.0f);
 232         glColor3f(0.0f,0.0f,1.0f);
 233         glVertex3f(-1.0f,-1.0f, -1.0f);
 234
 235         glColor3f(1.0f,0.0f,0.0f);
 236         glVertex3f( 0.0f, 1.0f, 0.0f);
 237         glColor3f(0.0f,0.0f,1.0f);
 238         glVertex3f(-1.0f,-1.0f,-1.0f);
 239         glColor3f(0.0f,1.0f,0.0f);
 240         glVertex3f(-1.0f,-1.0f, 1.0f);
 241     glEnd();
 242     glPopMatrix();
 243
 244
 245     glPushMatrix();
 246     glTranslatef(1.5f,0.0f,-7.0f);
 247     glBegin(GL_QUADS);
 248         glColor3f(0.0f,1.0f,0.0f);
 249         glVertex3f( 1.0f, 1.0f,-1.0f);
 250         glVertex3f(-1.0f, 1.0f,-1.0f);
 251         glVertex3f(-1.0f, 1.0f, 1.0f);
 252         glVertex3f( 1.0f, 1.0f, 1.0f);
 253
 254         glColor3f(1.0f,0.5f,0.0f);
 255         glVertex3f( 1.0f,-1.0f, 1.0f);
 256         glVertex3f(-1.0f,-1.0f, 1.0f);
 257         glVertex3f(-1.0f,-1.0f,-1.0f);
 258         glVertex3f( 1.0f,-1.0f,-1.0f);
 259
 260         glColor3f(1.0f,0.0f,0.0f);
 261         glVertex3f( 1.0f, 1.0f, 1.0f);
 262         glVertex3f(-1.0f, 1.0f, 1.0f);
 263         glVertex3f(-1.0f,-1.0f, 1.0f);
 264         glVertex3f( 1.0f,-1.0f, 1.0f);
 265
 266         glColor3f(1.0f,1.0f,0.0f);
 267         glVertex3f( 1.0f,-1.0f,-1.0f);
 268         glVertex3f(-1.0f,-1.0f,-1.0f);
 269         glVertex3f(-1.0f, 1.0f,-1.0f);
 270         glVertex3f( 1.0f, 1.0f,-1.0f);
 271
 272         glColor3f(0.0f,0.0f,1.0f);
 273         glVertex3f(-1.0f, 1.0f, 1.0f);
 274         glVertex3f(-1.0f, 1.0f,-1.0f);
 275         glVertex3f(-1.0f,-1.0f,-1.0f);
 276         glVertex3f(-1.0f,-1.0f, 1.0f);
 277
 278         glColor3f(1.0f,0.0f,1.0f);
 279         glVertex3f( 1.0f, 1.0f,-1.0f);
 280         glVertex3f( 1.0f, 1.0f, 1.0f);
 281         glVertex3f( 1.0f,-1.0f, 1.0f);
 282         glVertex3f( 1.0f,-1.0f,-1.0f);
 283     glEnd();
 284     glPopMatrix();
 285
 286     //
 287     // Restore the state
 288     //
 289     glPopAttrib();
 290
 291     glMatrixMode(GL_PROJECTION);
 292     glPopMatrix();
 293
 294     glMatrixMode(GL_MODELVIEW);
 295     glPopMatrix();
 296 }
 297
 298 //
 299 // initialize GLUT
 300 //
 301 static int setupGLUT(int *argc, char *argv[])
 302 {
 303     glutInit(argc, argv);
 304
 305     glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_STENCIL | GLUT_DOUBLE);
 306
 307     int winid = glutCreateWindow("OpenSG");
 308
 309     glutReshapeFunc(reshape);
 310     glutDisplayFunc(display);
 311     glutIdleFunc(display);
 312     glutMouseFunc(mouse);
 313     glutMotionFunc(motion);
 314     glutKeyboardFunc(keyboard);
 315
 316     return winid;
 317 }
 318
 319 //
 320 // setup scene
 321 //
 322 static int doMain(int argc, char *argv[])
 323 {
 324     preloadSharedObject("OSGFileIO");
 325     preloadSharedObject("OSGImageFileIO");
 326     preloadSharedObject("OSGContribPLY");
 327
 328     osgInit(argc,argv);
 329
 330     int winid = setupGLUT(&argc, argv);
 331
 332     win = GLUTWindow::create();
 333     win->setGlutId(winid);
 334     win->init();
 335
 336     root = Node::create();
 337     root->setCore(Group::create());
 338
 339     if(argc < 2)
 340     {
 341         FWARNING(("No file given!\n"));
 342         FWARNING(("Supported file formats:\n"));
 343
 344         std::list<const char*> suffixes;
 345         SceneFileHandler::the()->getSuffixList(suffixes);
 346
 347         for(std::list<const char*>::iterator it  = suffixes.begin();
 348                                             it != suffixes.end();
 349                                         ++it)
 350         {
 351             FWARNING(("%s\n", *it));
 352         }
 353
 354         scene = makeTorus(.5, 2, 16, 16);
 355     }
 356     else
 357     {
 358         scene = SceneFileHandler::the()->read(argv[1]);
 359     }
 360
 361     root->addChild(scene);
 362
 363     addStage();
 364
 365     commitChanges();
 366
 367     mgr = SimpleSceneManager::create();
 368
 369     mgr->setWindow(win);
 370     mgr->setRoot  (root);
 371
 372     mgr->showAll();
 373
 374     return 0;
 375 }
 376
 377 //
 378 // main entry point
 379 //
 380 int main(int argc, char *argv[])
 381 {
 382     int ret = doMain(argc, argv);
 383
 384     atexit(onExit);
 385
 386     glutMainLoop();
 387
 388     cleanup();
 389
 390     osgExit();
 391
 392     return ret;
 393 }
 394
 395