Hi All, I have been trying to write font out for a while now and it is driving me crazy. I found this neat little font library called GLFT_Font (http://www.cs.rit.edu/~jpt2433/glftfont/). I got to compile the test fine, but when I try to set up a perspective with glFrustum (indead of glOrtho) it doesnt work anymore. Any ideas? I have underestimated the difficulty in displaying simple test in a GL environment!

Thanks for the response.

I wonder what sort of hit performance takes by switching to Ortho, and then back to Frustum each frame. Hmmm, probably not that much?

Thanks again, I will try giving that a shot.

Well lets see... I tried this (I reset all the modelview parameters each time... not sure I have to do this?) It doesnt seem to work.

#include <GL/glfw.h>
#include <GL/gl.h>
#include <cmath>
#include "GLFT_Font.hpp"

const float PI = 3.1415927f;
const double WIDTH = 800;
const double HEIGHT = 600;


#define DELTA 0.001f

void myPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
GLdouble ymax;

ymax = zNear * tan(fovy * PI / 360.0f);
glFrustum(-ymax*aspect, ymax*aspect, -ymax, ymax, zNear, zFar);
}

void drawPoint()
{

glBegin(GL_TRIANGLES);
glNormal3f(0.0f,0.44721359549996f,0.89442719099992f);
glVertex3f(0.0f,1.0f,0.0f);
glVertex3f(0.5f,0.0f,0.5f);
glVertex3f(-0.5f,0.0f,0.5f);

glNormal3f(-0.89442719099992f,0.44721359549996f,0.0f);
glVertex3f(0.0f,1.0f,0.0f);
glVertex3f(-0.5f,0.0f,0.5f);
glVertex3f(-0.5f,0.0f,-0.5f);

glNormal3f(0.0f, 0.44721359549996f,-0.89442719099992f);
glVertex3f(0.0f,1.0f,0.0f);
glVertex3f(-0.5f,0.0f,-0.5f);
glVertex3f(0.5f,0.0f,-0.5f);

glNormal3f(0.89442719099992f,0.44721359549996f,0.0f);
glVertex3f(0.0f,1.0f,0.0f);
glVertex3f(0.5f,0.0f,-0.5f);
glVertex3f(0.5f,0.0f,0.5f);
glEnd();

glBegin(GL_QUADS);
glNormal3f(0.0f, -1.0f, 0.0f);
glVertex3f(0.5f,0.0f,0.5f);
glVertex3f(0.5f,0.0f,-0.5f);
glVertex3f(-0.5f,0.0f,-0.5f);
glVertex3f(-0.5f,0.0f,0.5f);
glEnd();
}

int main(int Arg_N, char ** Arg_V)
{
glfwInit();
glfwOpenWindow(800, 600, 8, 8, 8, 8, 0, 0, GLFW_WINDOW);

GLFT_Font f;
f.open("cour.ttf",12);

float matAmbient[] = {1.0f, 1.0f, 1.0f, 1.0f};
float matDiff[] = {1.0f, 1.0f, 1.0f, 1.0f};
float ambientLight[] = {0.25f, 0.25f, 0.25f, 1.0f};
float diffuseLight[] = {0.25f, 0.25f, 0.25f, 1.0f};
float lightPosition[] = {0.0f, 0.0f, 10.0f, 1.0f};



int j = 0;
do
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 800, 600, 0, -1.0, 1.0);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glDisable(GL_LIGHTING);
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
f.beginDraw(5, 5) << j++ << f.endDraw();

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
myPerspective(75.0f,(GLdouble)WIDTH/(GLdouble)HEIGHT,1.0f,100.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glFrontFace(GL_CW);
glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glMaterialfv(GL_FRONT, GL_AMBIENT, matAmbient);
glMaterialfv(GL_FRONT, GL_DIFFUSE, matDiff);
glLightfv(GL_LIGHT1,GL_AMBIENT,ambientLight);
glLightfv(GL_LIGHT1,GL_DIFFUSE,diffuseLight);
glLightfv(GL_LIGHT1,GL_POSITION,lightPosition);
glEnable(GL_LIGHT1);
glEnable(GL_LINE_SMOOTH);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING);
glLineWidth(3.0f);

glTranslatef(0.0f,0.0f,-5.0f);
drawPoint();

glfwSwapBuffers();
}
while(glfwGetWindowParam(GLFW_OPENED) && glfwGetKey(GLFW_KEY_ESC) != GLFW_PRESS);

glfwCloseWindow();
glfwTerminate();

return(0);
}

Thanks! Worked like a charm.

I wonder though if it is possible to reduce this a little.

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(....);
...

glLoadIdentity();
glFrustum(....);
...

glMatrixMode(GL_MODELVIEW);
//Set things related to model view here...

//And then inside my "game" loop...

do
{
glMatrixMode(GL_PROJECTION);
glOrtho(...);

glMatrixMode(GL_MODELVIEW);
glEnable(GL_BLEND);
f.beginDraw(5, 5) << j++ << f.endDraw();
glDisable(GL_BLEND);

glMatrixMode(GL_PROJECTION);
glFrustum(...);

glMatrixMode(GL_MODELVIEW);
//do everything else.
} while(...);

This doesnt seem to work. I would like for it to "remember" all my settings for glOrtho, and glFrustum so I don't need to set up _everything_ each time. Is this standard and I am complaining about nothing? Something doesnt seem right with code, almost like it is doing way more than it needs to.

Alright, I am _REALLY_ close to making this work. Only one slight problem: the text shows up as a rectangle.

The triangle renders fine, and the text is trying. I am still doing something incorrectly though.

Which opperations act on the modelview matrix? I don't know if any of the setup in my init_gl() function has to be done after switching to GL_MODELVIEW

Thanks for any help!

#include <GL/glfw.h>#include <GL/gl.h>#include <cmath>#include "GLFT_Font.hpp"const float PI = 3.1415927f;const int WIDTH = 800;const int HEIGHT = 600;void myPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar){  GLdouble ymax;  ymax = zNear * tan(fovy * PI / 360.0f);  glFrustum(-ymax*aspect, ymax*aspect, -ymax, ymax, zNear, zFar);}void drawPoint(){  glBegin(GL_TRIANGLES);  glNormal3f(0.0f,0.44721359549996f,0.89442719099992f);  glVertex3f(0.0f,1.0f,0.0f);  glVertex3f(0.5f,0.0f,0.5f);  glVertex3f(-0.5f,0.0f,0.5f);  glNormal3f(-0.89442719099992f,0.44721359549996f,0.0f);  glVertex3f(0.0f,1.0f,0.0f);  glVertex3f(-0.5f,0.0f,0.5f);  glVertex3f(-0.5f,0.0f,-0.5f);  glNormal3f(0.0f, 0.44721359549996f,-0.89442719099992f);  glVertex3f(0.0f,1.0f,0.0f);  glVertex3f(-0.5f,0.0f,-0.5f);  glVertex3f(0.5f,0.0f,-0.5f);  glNormal3f(0.89442719099992f,0.44721359549996f,0.0f);  glVertex3f(0.0f,1.0f,0.0f);  glVertex3f(0.5f,0.0f,-0.5f);  glVertex3f(0.5f,0.0f,0.5f);  glEnd();  glBegin(GL_QUADS);  glNormal3f(0.0f, -1.0f, 0.0f);  glVertex3f(0.5f,0.0f,0.5f);  glVertex3f(0.5f,0.0f,-0.5f);  glVertex3f(-0.5f,0.0f,-0.5f);  glVertex3f(-0.5f,0.0f,0.5f);  glEnd();}void init_gl(void){  float matAmbient[] = {1.0f, 1.0f, 1.0f, 1.0f};  float matDiff[] = {1.0f, 1.0f, 1.0f, 1.0f};  float ambientLight[] = {0.25f, 0.25f, 0.25f, 1.0f};  float diffuseLight[] = {0.25f, 0.25f, 0.25f, 1.0f};  float lightPosition[] = {0.0f, 0.0f, 10.0f, 1.0f};  glEnable(GL_TEXTURE_2D);  glShadeModel(GL_SMOOTH);  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);  glEnable(GL_DEPTH_TEST);  glEnable(GL_CULL_FACE);  glFrontFace(GL_CW);  glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);  glMaterialfv(GL_FRONT, GL_AMBIENT, matAmbient);  glMaterialfv(GL_FRONT, GL_DIFFUSE, matDiff);  glLightfv(GL_LIGHT1,GL_AMBIENT,ambientLight);  glLightfv(GL_LIGHT1,GL_DIFFUSE,diffuseLight);  glLightfv(GL_LIGHT1,GL_POSITION,lightPosition);  glEnable(GL_LIGHT1);  glEnable(GL_LINE_SMOOTH);  glEnable(GL_COLOR_MATERIAL);  glEnable(GL_LIGHTING);  glLineWidth(3.0f);   glMatrixMode(GL_PROJECTION);  glLoadIdentity();  myPerspective(75.0f, WIDTH / (float)HEIGHT, 1.0f, 100.0f);  glMatrixMode(GL_MODELVIEW);  glLoadIdentity();}void enable2d(void){  glMatrixMode(GL_PROJECTION);  glPushMatrix();  glLoadIdentity();  glOrtho(0, WIDTH, HEIGHT, 0, -1.0, 1.0);	  glMatrixMode(GL_MODELVIEW);  glPushMatrix();  glLoadIdentity();}void disable2d(void){  glMatrixMode(GL_PROJECTION);  glPopMatrix();     glMatrixMode(GL_MODELVIEW);  glPopMatrix();		}int main(int Arg_N, char ** Arg_V){  glfwInit();  glfwOpenWindow(WIDTH, HEIGHT, 8, 8, 8, 8, 0, 0, GLFW_WINDOW);    init_gl();    GLFT_Font f;  f.open("cour.ttf",12);  int j = 0;  do  {    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);        glLoadIdentity();    glTranslatef(0.0f,0.0f,-5.0f);    glColor3f(0.0f, 0.0f, 1.0f);     drawPoint();        enable2d();        f.beginDraw(0,0) << j++ << f.endDraw();    disable2d();    glfwSwapBuffers();  }  while ( glfwGetWindowParam(GLFW_OPENED) &&           glfwGetKey(GLFW_KEY_ESC) != GLFW_PRESS);  glfwCloseWindow();  glfwTerminate();  return(0);}