Thread: opengl model transformations

The gameobjects are currently not translated at all. As far as I can tell the translations are performed on the ModelView matrix it is the last thing set in the reshape function.

Here is my current code It is a long way from complete and is basicly an adaptation of the double.c program from the redbook.

Code:

#include <iostream>
#include <GL/glut.h>
#include <stdlib.h>
#include <list>
#include <functional>
#include <algorithm>
#include <time.h>

#include "gobject.h"
#include "ship.h"
#include "astroid.h"

using namespace std;
extern const int SCREENWIDTH = 450;
extern const int SCREENHEIGHT = 450;

static GLfloat spin = 0.0;
list<GObject*> gameObjects;
list<Astroid*> astroids;
Ship* spaceShip = new Ship();

void display()
{
   
   glClear(GL_COLOR_BUFFER_BIT);
   glColor3f(1.0, 1.0, 1.0);
   for_each(gameObjects.begin(),gameObjects.end(),mem_fun(&GObject::translate));
   glutSwapBuffers();
   
}

void moveAstroids(void)
{ 
 
  // for_each(astroids.begin(),astroids.end(),mem_fun(&Astroid::translate));
  glutPostRedisplay();
 
}


void idleGameLoop(void)
{ 
  
  moveAstroids();
  glutPostRedisplay();
}


void init(void)
{
  srand(time(NULL));
  glClearColor (0.0, 0.0, 0.0, 0.0);
  glShadeModel (GL_FLAT);
  gameObjects.push_front(spaceShip);
  for (int i = 0; i<10; i++){
   Astroid* sharedTempAstroid = new Astroid();
     gameObjects.push_back(sharedTempAstroid);
     astroids.push_back(sharedTempAstroid);

  }
}

void reshape(int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   gluOrtho2D(-SCREENWIDTH/2,SCREENWIDTH/2,-SCREENHEIGHT/2,SCREENHEIGHT/2);
  
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

/* ARGSUSED2 */
void mouse(int button, int state, int x, int y)
{
   switch (button) {
      case GLUT_RIGHT_BUTTON:
         if (state == GLUT_DOWN)
	    glutIdleFunc(idleGameLoop);
         break;
      case GLUT_MIDDLE_BUTTON:
         if (state == GLUT_DOWN)
            glutIdleFunc(NULL);
         break;
      default:
         break;
   }
}

		    

static void
key(unsigned char k, int x, int y)
{
  switch (k) {
  case 27:  /* Escape */
    exit(0);
    break;
  case 65:
  case 97:
    spin = (int)spin % 360 + 2.0;
    glutIdleFunc(idleGameLoop);
    break;
  case 68:
  case 100:
    spin = (int)spin % 360 - 2.0;
    glutIdleFunc(idleGameLoop);
    break;
  default:
    return;
  }
  glutPostRedisplay();
}

/*
 *  Request double buffer display mode.
 *  Register mouse input callback functions
 */
int main(int argc, char** argv)
{
  
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
   glutInitWindowSize (SCREENWIDTH, SCREENHEIGHT);
   glutInitWindowPosition (10, 10);
   glutCreateWindow (argv[0]);
   init ();
  
   glutDisplayFunc(display);
   glutReshapeFunc(reshape);
   glutMouseFunc(mouse);
   glutKeyboardFunc(key);
   glutMainLoop();
   return 0;   /* ANSI C requires main to return int. */
}

Code:

#include "astroid.h"

extern const int SCREENWIDTH;
extern const int SCREENHEIGHT;

Astroid::Astroid()
{
 
  xcoord=rand()%(SCREENWIDTH/2)+1;
  ycoord=rand()%(SCREENHEIGHT/2)+1;
  velocity = 1*(rand()%4);
 
}

void Astroid::draw(){
  glColor3f(256.0, 0.0 , 0.0);
 
  glRectf(xcoord, ycoord,xcoord+10,ycoord+10);
 
}

void Astroid::rotate(){}
void Astroid::translate(){
  glPushMatrix();
  glTranslatef(velocity,velocity,0);
  Astroid::draw();
  glPopMatrix();
}

Astroid::~Astroid(){}