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#include "exp004mouse.h"
#include "exp004processhits.h"
#include "../view/exp004geometry.h"
#include "../view/exp004state0.h"
#include "../util/check_error.h"
#include <GL/glut.h>
#include <stdio.h>
#define SIZE 500
#define N 3
void
exp004mouse (int button, int state, int x, int y)
{
if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
{
/*
* "Specify the array to be used for the returned hit records
* with glSelectBuffer () [Redbook]."
*/
GLuint select_buf[SIZE];
glSelectBuffer (SIZE, select_buf);
/*
* "Enter selection mode by specifying GL_SELECT with
* glRenderMode () [Redbook]."
*/
glRenderMode (GL_SELECT);
/*
* "Initialize the name stack using glInitNames () and glPush
* Names () [Redbook]."
*/
glInitNames ();
glPushName (0);
/*
* "Define the viewing volume you want to use for selection.
* Usually this is different from the viewing volume you
* originally used to draw the scene, so you probably want to
* save and then restore the current transformation state with
* glPushMatrix () and glPopMatrix () [Redbook]."
*/
glMatrixMode (GL_PROJECTION);
glPushMatrix ();
glLoadIdentity ();
GLint viewport[4];
glGetIntegerv (GL_VIEWPORT, viewport);
gluPickMatrix ((GLdouble) x,
(GLdouble) (viewport[3] - y),
N,
N,
viewport);
gluOrtho2D(exp004state0.ortho.min_x,
exp004state0.ortho.max_x,
exp004state0.ortho.min_y,
exp004state0.ortho.max_y);
/*
* "Alternately issue primitive drawing commands and commands to
* manipulate the name stack so that each primitive of interest
* has appropriate names assigned [Redbook]."
*/
exp004geometry (GL_SELECT);
glMatrixMode (GL_PROJECTION);
glPopMatrix ();
glutSwapBuffers ();
/*
* "Exit selection mode and process the returned selection data
* (the hit records) [Redbook]."
*/
GLint hits = glRenderMode (GL_RENDER);
check_error (__FILE__, __LINE__);
/* "process hits from selection mode rendering [Angel,2008]." */
exp004processhits (hits, select_buf);
/* "normal render [Angel,2008]." */
glutPostRedisplay ();
}
return;
}
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