glReadPixels로 찾은 깊이값을 수정?
I want to take depth_valuew with glReadPixels.
I exhaust some days about this.
As you see below, I coded program.
First, i draw rectangle with z_value=-1.
and i clicked with mouse_pointer in rectangle.
So print its pixel_value_depth.
I think this print -2.
But …
92559604281399047000000000000000000000000000000000000000000000.000000
these string of numbers was printed.
What’s the problem?
How Can i fix it…?
Give me correct code.!!!
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_FLAT);
glDepthRange(0.0, 1.0);
}
void drawRects()
{
glPushMatrix();
glTranslatef(0,0, -7);
glBegin(GL_QUADS);
glColor3f(1.0, 0.0, 1.0);
glVertex3i(0, 2, -2);
glVertex3i(0, 7, -2);
glVertex3i(5, 7, -2);
glVertex3i(5, 2, -2);
glEnd();
glPopMatrix();
}
void PickObject(int button, int state, int x, int y)
{
int m_iView[4];
glGetIntegerv(GL_VIEWPORT, m_iView);
GLdouble depth;
glReadPixels (x, m_iView[3]-y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &depth);
printf("
depth=%f
", depth);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
drawRects();
glFlush();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//glOrtho(0.0, 8.0, 0.0, 8.0, -0.5, 2.5);
gluPerspective( 90, 1, 0.1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 27:
exit(0);
break;
}
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize (200, 200);
glutInitWindowPosition (100, 100);
glutCreateWindow(argv[0]);
init();
glutReshapeFunc(reshape);
glutDisplayFunc(display);
glutMouseFunc(PickObject);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}