Subversion Repositories gelsvn

#ifdef WIN32
#include <windows.h>
#endif
#include <GL/gl.h>
#include <GL/glu.h>
#include "SimpleTrackBall.h"

using namespace std;
using namespace CGLA;

namespace Graphics
{

                void SimpleTrackBall::roll_x(float dx)
                {
                                float mouse_sign = ((dx<0)?-1.0f:1.0f);
                                phi += mouse_sign * da;
                }

                void SimpleTrackBall::roll_y(float dy)
                {
                                float sgn = (dy<0)?1.0f:-1.0f;
                                theta += sgn * da;
                                theta = min(float(M_PI)-0.001f, max(0.0001f, theta));
                }

                void SimpleTrackBall::up_axis(char up)
                {
                                switch(up)
                                {
                                                case 'x':
                                                case 'X':
                                                                X=1;
                                                                Y=2;
                                                                Z=0;
                                                                break;
                                                case 'y':
                                                case 'Y':
                                                                X=0;
                                                                Y=1;
                                                                Z=2;
                                                                break;
                                                case 'z':
                                                case 'Z':
                                                                X=2;
                                                                Y=0;
                                                                Z=1;
                                                                break;
                                }
                                theta = M_PI/2.0f;
                                phi = 0;
                }

/** Call this to set up OpenGL viewing matrix. It will also 
                clear the view matrix. */
                void SimpleTrackBall::gl_view() const
                {
                                const Vec3f up(0,1,0);
                                float x = r * sin(theta) * cos(phi);
                                float y = r * cos(theta);
                                float z = r * sin(theta) * sin(phi);
                                Vec3f dir(x,y,z);
                                Vec3f e = center + Vec3f(dir[X], dir[Y], dir[Z]);
                                glLoadIdentity();
                                gluLookAt(e[0],e[1],e[2],
                                                                        center[0],center[1],center[2],
                                                                        up[X], up[Y], up[Z]);
                }

/** Roll ball. Call with the x,y coordinates. This function is typically
                called from GLUT's mouse motion callback. */
                void SimpleTrackBall::roll(int x, int y)
                {
                                if(firsttime) 
                                                firsttime=false;
                                else
                                {
                                                float dx = x - oldx;
                                                float dy = y - oldy;
                                        
                                                if(dx*dx>dy*dy)
                                                                roll_x(dx);
                                                else
                                                                roll_y(dy);
                                        
                                }
                                oldx = x;
                                oldy = y;
                }

}