	[x] Posted via EE Mobile
	Search, ask, and monitor your questions on the go with EE Mobile. Visit Experts Exchange from your mobile device and never be out of touch again.

Question

	[x] Attachment Details

[x]

The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

The Grade of the Solution
The Zone Rank of the Expert Providing the Solution
The Number of Author and Expert Comments
The Number of Experts Contributing
The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!

8.6

gluunproject with glut c++

Asked by sassek in 3D Game Programming, C++ Programming Language, OpenGL Graphics & Game Programming

Tags: opengl c++ glu

hi

can anybody explain why the following code for gluunproject will not give the correct coordinates. i am very new to opengl so a good explanation would be useful to me. i want to be able to click on the glut window and see the correct coordinates to be output to the console window.

thankyou

View the Solution FREE for 30 Days

         
           
             1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
61:
62:
63:
64:
65:
66:
67:
68:
69:
70:
71:
72:
73:
74:
75:
76:
77:
78:
79:
80:
81:
82:
83:
84:
85:
86:
87:
88:
89:
90:
91:
92:
93:
94:
95:
96:
97:
98:

           
           
             #include <cstdlib>
#include <iostream>
#include <gl/gl.h>
#include <gl/glu.h>
#include <gl/glut.h>
 
using namespace std;
 
double objx, objy, objz;
 
void processMouse(int button, int state, int x, int y)
{
    double modelview[16], projection[16];
    int viewport[4];
    float z;
    
	//get the modelview matrix		
    glGetDoublev( GL_MODELVIEW_MATRIX, modelview );
    //get the projection matrix
    glGetDoublev( GL_PROJECTION_MATRIX, projection );
	//get the viewport		
    glGetIntegerv( GL_VIEWPORT, viewport );
	
    //Read the window z co-ordinate 
    //(the z value on that point in unit cube)		
    glReadPixels( x, viewport[3]-y, 1, 1,
		 GL_DEPTH_COMPONENT, GL_FLOAT, &z );
 
    //Unproject the window co-ordinates to 
    //find the world co-ordinates.
    gluUnProject( x, viewport[3]-y, z, modelview, 
		projection, viewport, &objx, &objy, &objz );
 
    cout << objx << " , " << objy << " , " << objz << "\n";
}
 
void processNormalKeys(unsigned char key, int x, int y) {
 
	if (key == 27)//escape key ascii value 
		exit(0);
}
 
void processSpecialKeys(int key, int x, int y) {
 
}
 
void changeSize(int w, int h) {
 
	// Prevent a divide by zero, when window is too short
	// (you cant make a window of zero width).
	if(h == 0)
		h = 1;
 
	float ratio = 1.0* w / h;
 
	// Reset the coordinate system before modifying
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	
	// Set the viewport to be the entire window
	glViewport(0, 0, w, h);
 
	// Set the correct perspective.
	gluPerspective(45,ratio,1,1000);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}
 
void renderScene(void) {
	glClear(GL_COLOR_BUFFER_BIT);
	glTranslatef(0,0,-300);
	glBegin(GL_LINES);
		glVertex3f(-100.0,0.0,0.0);
		glVertex3f(100.0,0.0,0.0);
		glVertex3f(0.0,-100.0,0.0);
		glVertex3f(0.0,100.0,0.0);
		glVertex3f(0.0,0.0,-100.0);
		glVertex3f(0.0,0.0,100.0);
	glEnd();
	glFlush();
}
 
 
    int main(int argc, char **argv) {
    glClearColor(0,0,0,0);
    glEnable(GL_DEPTH_TEST);//Enable depth testing
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_SINGLE | GLUT_RGBA);
	glutInitWindowPosition(100,100);
	glutInitWindowSize(320,320);
	glutCreateWindow("glut");
    glutDisplayFunc(renderScene);
    glutReshapeFunc(changeSize);
    glutKeyboardFunc(processNormalKeys);
    glutSpecialFunc(processSpecialKeys);
    glutMouseFunc(processMouse);
    glutMainLoop();
}

           
         

20091021-EE-VQP-81 - Hierarchy / EE_QW_3_20080625

Hall of Fame

1. ikework45,445
2. JoseParrot14,924
3. bham3dman12,000
4. ozo11,440
5. jgordos10,200
6. Interactive...6,600
7. Xcone6,250
8. pepsichris4,000
9. objects3,250
10. satsumo3,000
11. Rh1no2,672
12. NovaDeni...2,368
13. Melange2,000
13. abel2,000
13. yuk992,000
13. rascalpants2,000
13. oobayly2,000
13. Infinity082,000
13. Barthax2,000
13. jamietoner2,000
13. StormSeed2,000
13. darkphotn2,000
13. viju20082,000
13. RPCIT2,000
13. discipline...2,000
13. Christoph...2,000
13. whatisittel...2,000
13. h2g2guy2,000

1. ikework129,149
2. ozo80,051
3. JoseParrot77,371
4. davebytes50,840
5. sunnycoder41,305
6. Interactive...31,500
7. jgordos29,000
8. bham3dman20,000
9. Infinity0818,270
10. NovaDeni...15,368
11. joachimc13,400
12. cybermike3d13,014
13. fl0yd12,581
14. thegilb8,122
15. MASQUE...7,000
15. enkimute7,000
17. Xcone6,250
18. TGGC5,280
19. info_exp...5,250
20. SturmNacht5,105
21. bcladd5,080
22. evilrix4,656
23. nils pipen...4,650
24. shirsoft4,648
25. jkr4,600

gluunproject with glut c++

Asked by sassek in 3D Game Programming, C++ Programming Language, OpenGL Graphics & Game Programming

Tags: opengl c++ glu

About this solution