text in openGL

[esash28]

Hi everyone..

I am a new programmer to OpenGL using C++. I have an nxn grid having numbers in each cell of the grid.. I have to swap the content of two cells.. ie., the numbers in 2 cells selected, have to be swapped. I am not knowing how to do this. Please help me.

Thanks a lot in advance.
Esash

[daviddoria]

I'm not sure which grid/cells you are talking about?

To your title, here is how to draw text in opengl:

#include <iostream>
#include <cstdio>
#include <string>
#include <cstdlib>

#include <GL/glut.h>

using namespace std;

void display(void);
void polygon(int a, int b, int c , int d);
void DrawCube();

int WindowHeight = 1000;
int WindowWidth = 1000;

void printtext(int x, int y, string String)
{
//(x,y) is from the bottom left of the window
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    glOrtho(0, WindowWidth, 0, WindowHeight, -1.0f, 1.0f);
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();
    glPushAttrib(GL_DEPTH_TEST);
    glDisable(GL_DEPTH_TEST);
    glRasterPos2i(x,y);
    for (int i=0; i<String.size(); i++)
    {
        glutBitmapCharacter(GLUT_BITMAP_9_BY_15, String[i]);
    }
    glPopAttrib();
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    glMatrixMode(GL_MODELVIEW);
    glPopMatrix();
}


int main(int argc, char *argv[])
{	
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutInitWindowSize(WindowWidth, WindowHeight);
	glutInitWindowPosition(0, 0);
	
	glutCreateWindow("OpenGL Text Example");
	
	glutDisplayFunc(display);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(70, 1, 1, 100);
	
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	
	gluLookAt(2, 2, 10, 2, 0, 0, 0, 1, 0);

	glutMainLoop();
	return 0;
}

void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glEnable(GL_DEPTH_TEST);
	
    char string[64];
    sprintf(string, "something");
    printtext(10,10,string);

	glutSwapBuffers();
}