Variable font (width and height) - opengl

Question

I'm writing a Level Editor and I'm using the GLUT to display text inside an opengl canvas. However, I would like to scale the text with the canvas instead of staying at the given size (18 at this moment).
How am I able to do this? A friend of mine suggested to create my own font but I think that's a bit much.
This is the code I'm using
public void showCharacters(GL gl, String text) {
final GLUT glut = new GLUT();
System.out.println(text);
if (text != null) {
gl.glColor3f(0.0f, 0.0f, 0.0f);
gl.glRasterPos2f(x + (sizeX / 10), (y - (sizeY)));
glut.glutBitmapString(GLUT.BITMAP_HELVETICA_18, text);
}
}

Answer 1

Use glutStroke*() and GLUT_STROKE_*:
#include <GL/glut.h>
#include <cstring>
int glWidth( void* font, const char* str )
{
int width = 0;
for( size_t i = 0; i < strlen( str ); ++i )
{
width += glutStrokeWidth( font, (int)str[i] );
}
return width;
}
void glPrint( void* font, const char* str )
{
for( size_t i = 0; i < strlen( str ); ++i )
{
glutStrokeCharacter( font, (int)str[i] );
}
}
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
double w = glutGet( GLUT_WINDOW_WIDTH );
double h = glutGet( GLUT_WINDOW_HEIGHT );
double ar = w / h;
glOrtho( -250 * ar, 250 * ar, -250, 250, -1, 1 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
void* font = GLUT_STROKE_MONO_ROMAN;
const char* str = "Hello";
glTranslatef( -glWidth( font, str ) / 2.0f, 0, 0 );
glPrint( font, str );
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMainLoop();
return 0;
}