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#include "performzoom.h"
#include "exp004reshape.h"
#include "../util/check_error.h"
#include "../view/exp004state0.h"
#include <GL/glut.h>
#include <math.h>
/*
* A simple alias to make the code more readable.
*/
#define S exp004state0
void
performzoom (int x1, int y1, int x2, int y2)
{
/*
* Convert the selection boundary from window coordinates to
* world coordinates.
*/
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
GLdouble model[16];
glGetDoublev (GL_MODELVIEW_MATRIX, model);
GLdouble projection[16];
glGetDoublev (GL_PROJECTION_MATRIX, projection);
GLint viewport[4];
glGetIntegerv (GL_VIEWPORT, viewport);
check_error (__FILE__, __LINE__);
GLdouble start_position[3];
gluUnProject (x1,
y1,
0,
model,
projection,
viewport,
&start_position[0],
&start_position[1], &start_position[2]);
check_error (__FILE__, __LINE__);
GLdouble end_position[3];
gluUnProject (x2,
y2,
0,
model,
projection,
viewport,
&end_position[0], &end_position[1], &end_position[2]);
check_error (__FILE__, __LINE__);
S.zoom.active = true;
S.zoom.coords[0] = fmin (start_position[0], end_position[0]);
S.zoom.coords[1] = fmax (start_position[0], end_position[0]);
S.zoom.coords[2] = fmin (start_position[1], end_position[1]);
S.zoom.coords[3] = fmax (start_position[1], end_position[1]);
exp004reshape (S.viewport.w, S.viewport.h);
glutPostRedisplay ();
return;
}
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