# move camera with keyboard function

• 03-16-2013, 05:57 AM
marito
move camera with keyboard function
Hello! I have two cubes rotating here, and I additionally want to move my camera on a sphere to watch this from different angles. I use keyboard function, but camera doesn't move. I don't know what's wrong... My code is this:

Code :

```#include <stdio.h>   #include <stdlib.h>   #include <glut.h>   #include <math.h>       #define pi 3.14159265       typedef GLfloat point3d[3];   point3d p0={-1,-1,-13}, p1={1,-1,-13}, p2={-1,1,-13}, p3={1,1,-13};   point3d p4={-1,-1,-15}, p5={1,-1,-15}, p6={-1,1,-15}, p7={1,1,-15};   point3d p20={1,1,-13}, p21={1.5,1,-13}, p22={1,1.5,-13}, p23={1.5,1.5,-13};   point3d p24={1,1,-14}, p25={1.5,1,-14}, p26={1,1.5,-14}, p27={1.5,1.5,-14};   int delay=100, angle; //delay in msec   float xe=0., ye=0., ze=0., a=0., b=0., c=0., move=20.;       void InitWindow()   {   GLfloat ambientLight[] = {0.3, 0.3, 0.3, 1};//ambient grey light   GLfloat diffuseLight[] = {0.7, 0.7, 0.7, 1};//diffuse white light   GLfloat lightPos[] = {1, 1, -12, 1};       //ENABLE SPECULAR LIGHT   //GLfloat specularLight[] = {0.8, 0.8, 0.8, 1};   //GLfloat specref[] = {1, 1, 1, 1};//full reflectance   //GLfloat spotDir[]={0, 0, -14};   //glLightfv(GL_LIGHT0,GL_SPECULAR,specularLight);   //glLightfv(GL_LIGHT0,GL_SPOT_DIRECTION, spotDir);   //glLightf(GL_LIGHT0,GL_SPOT_CUTOFF,15);   //glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR,specref);   //glMateriali(GL_FRONT,GL_SHININESS,128);       glLightfv(GL_LIGHT0,GL_AMBIENT,ambientLight);   glLightfv(GL_LIGHT0,GL_DIFFUSE,diffuseLight);   glLightfv(GL_LIGHT0, GL_POSITION, lightPos);       glEnable(GL_LIGHTING);   glEnable(GL_LIGHT0);   glEnable(GL_DEPTH_TEST);   glEnable(GL_COLOR_MATERIAL);   glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE);       glClearColor(0.,0.,40./255.,0); //blue sky   glMatrixMode(GL_PROJECTION);   glFrustum(-2,2,-2,2,10,15000);   // glOrtho(-4,5,-3,5,-13,15000);   glMatrixMode(GL_MODELVIEW);   }       void Stars()   {   float c,d;   glLoadIdentity();   srand(1);   glEnable(GL_POINT_SMOOTH);   glColor3f(1.,1.,0.);   glPointSize(1);   glBegin(GL_POINTS);   for (int i=1;i<=1000;i++){   c=200*rand()/RAND_MAX-100;   d=200*rand()/RAND_MAX-100;   glVertex3i(c,d,-300);   }   glEnd();   glPointSize(4);   glBegin(GL_POINTS);   for (int i=1;i<=100;i++){   c=200*rand()/RAND_MAX-100;   d=200*rand()/RAND_MAX-100;   glVertex3i(c,d,-300);   }   glEnd();   glPointSize(8);   glBegin(GL_POINTS);   for (int i=1;i<=10;i++){   c=200*rand()/RAND_MAX-100;   d=200*rand()/RAND_MAX-100;   glVertex3i(c,d,-300);   }   glEnd();   }       void Cubes()   {   glBegin(GL_QUADS);   glColor3f(0.3,0.3,0.9);//blue   glVertex3fv(p0); glVertex3fv(p1); glVertex3fv(p3); glVertex3fv(p2); //front   glColor3f(0.1,0.6,0.9);   glVertex3fv(p1); glVertex3fv(p5); glVertex3fv(p7); glVertex3fv(p3); //right   glColor3f(0,0.3,0.9);   glVertex3fv(p5); glVertex3fv(p4); glVertex3fv(p6); glVertex3fv(p7); //back   glColor3f(0.3,0,0.9);   glVertex3fv(p4); glVertex3fv(p0); glVertex3fv(p2); glVertex3fv(p6); //left   glColor3f(0.3,0.3,0);   glVertex3fv(p2); glVertex3fv(p3); glVertex3fv(p7); glVertex3fv(p6); //top   glColor3f(1,0.3,1);   glVertex3fv(p1); glVertex3fv(p0); glVertex3fv(p4); glVertex3fv(p5); //bottom   glEnd();   glBegin(GL_QUADS);   glColor3f(0.3,0.3,0.9);//blue   glVertex3fv(p20); glVertex3fv(p21); glVertex3fv(p23); glVertex3fv(p22); //front   glColor3f(0.1,0.6,0.9);   glVertex3fv(p21); glVertex3fv(p25); glVertex3fv(p27); glVertex3fv(p23); //right   glColor3f(0,0.3,0.9);   glVertex3fv(p25); glVertex3fv(p24); glVertex3fv(p26); glVertex3fv(p27); //back   glColor3f(0.3,0,0.9);   glVertex3fv(p24); glVertex3fv(p20); glVertex3fv(p22); glVertex3fv(p26); //left   glColor3f(0.3,0.3,0);   glVertex3fv(p22); glVertex3fv(p23); glVertex3fv(p27); glVertex3fv(p26); //top   glColor3f(1,0.3,1);   glVertex3fv(p21); glVertex3fv(p20); glVertex3fv(p24); glVertex3fv(p25); //bottom   glEnd();   }       void Display(void)   {   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);   glLoadIdentity();   glPushMatrix();   Stars();   glPopMatrix();   xe=(cos(c*pi/180.)*cos(b*pi/180.)*cos(a*pi/180.)-sin(c*pi/180.)*sin(a*pi/180.))*xe+(cos(c*pi/180.)*cos(b*pi/180.)*sin(a*pi/180.)+sin(c*pi/180.)*cos(a*pi/180.))*ye-cos(c*pi/180.)*sin(b*pi/180.)*ze;   ye=-(sin(c*pi/180.)*cos(b*pi/180.)*cos(a*pi/180.)-cos(c*pi/180.)*sin(a*pi/180.))*xe+(-sin(c*pi/180.)*cos(b*pi/180.)*sin(a*pi/180.)+cos(c*pi/180.)*cos(a*pi/180.))*ye+sin(c*pi/180.)*sin(b*pi/180.)*ze;   ze=sin(b*pi/180.)*cos(a*pi/180.)*xe+sin(b*pi/180.)*sin(a*pi/180.)*ye+cos(b*pi/180.)*ze;   gluLookAt(xe,ye,ze,0,0,-14,0,1,0);// (0,1,0) the angle of the camera,(xe,ye,ze) the camera,(0,0,-14) the focus point       glTranslatef(0,0,-14);   glRotatef(angle,0,1,0);   glTranslatef(0,0,14);       Cubes();   glutSwapBuffers();   }       void Camera(unsigned char key, int x, int y)   {   // float move=20.;   switch(key){   case 'q': a+=move; break;   case 'w': a-=move; break;   case 'a': b+=move; break;   case 's': b-=move; break;   case 'z': c+=move; break;   case 'x': c-=move; break;   case '0': a=0.; b=0.; c=0.; //go to the initial state   }   if(key==27) exit(0); //turn off camera   glutPostRedisplay();   }       void Rotate(int n) // the glutTimerFunc   {   n++;   angle+=5;   glutPostRedisplay();   glutTimerFunc(delay,Rotate,n);   }       void main(int argc, char **argv)   {   glutInit(&argc, argv);   glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);   glutInitWindowPosition(200,100);   glutInitWindowSize(400,400);   glutCreateWindow("3D-cubes rotating in space and hit by light");   InitWindow();       glutDisplayFunc(Display);   glutTimerFunc(delay,Rotate,0);   glutKeyboardFunc(Camera);   glutMainLoop();   }```

Thank you for helping :)
• 03-18-2013, 08:50 AM
ClayMontgomery
Re: move camera with keyboard function
Your code is regular OpenGL and not OpenGL ES, but I think you need to switch the matrix mode back to GL_PROJECTION mode before you call gluLookAt().

Try adding this before the gluLookat() call:

glMatrixMode(GL_PROJECTION);

Regards, Clay
• 03-19-2013, 09:28 AM
marito
Re: move camera with keyboard function
Thank you for helping. I tried it but it doesn't work... I think there is problem because I'm using Euler angles to rotate the object, but I'm not sure this is the reason. :|