#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)
{
glEnable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_SMOOTH);
glFrontFace(GL_CW);
glEnable(GL_CULL_FACE);
glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
// LIGHTING SETUP
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};
glMaterialfv(GL_FRONT, GL_AMBIENT, matAmbient);
glMaterialfv(GL_FRONT, GL_DIFFUSE, matDiff);
glLightfv(GL_LIGHT0,GL_AMBIENT,ambientLight);
glLightfv(GL_LIGHT0,GL_DIFFUSE,diffuseLight);
glLightfv(GL_LIGHT0,GL_POSITION,lightPosition);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
glEnable(GL_COLOR_MATERIAL);
// END LIGHTING SETUP
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);
GLfloat roty = 0;
GLfloat rotx = 0;
int j = 0;
do
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
if(glfwGetKey(GLFW_KEY_LEFT) == GLFW_PRESS)
roty += 0.2;
if(glfwGetKey(GLFW_KEY_RIGHT) == GLFW_PRESS)
roty -= 0.2;
if(glfwGetKey(GLFW_KEY_UP) == GLFW_PRESS)
rotx += 0.2;
if(glfwGetKey(GLFW_KEY_DOWN) == GLFW_PRESS)
rotx -= 0.2;
glTranslatef(0.0f,0.0f,-5.0f);
glRotatef(roty,0.0f,1.0f,0.0f);
glRotatef(rotx,1.0f,0.0f,0.0f);
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);
}
Font rendering with GLFT_Font and GLFW
Author
I am still a bit of a beginner, but I feel this may a more appropriate category.
I am trying to write text in the top left corner of the viewport while in glOrtho, and then switch back to a glFrustum and draw the rest of my very basic 3D scene. The 3D scene works fine, but the text shows up as a rectangle in the top left corner. It may have something to do with blending, I am not sure. If you can offer any tips please let me know.
Sam.
hey, it's me again :)
you have to have blending enabled for the font to draw because the font is drawn as a texture with alpha transparency, if you look at your earlier post you had the correct blending there when the font worked
you have to have blending enabled for the font to draw because the font is drawn as a texture with alpha transparency, if you look at your earlier post you had the correct blending there when the font worked
Author
Man you are a life saver! Thank you. I don't entirely understand why I need to enable blending and then disable it. Maybe I can find something about it my OpenGL for Game Programmers book. Here is the working version.
p.s. Is there a list of available tag's like source or code? thanks.
#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){ glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_TEXTURE_2D); glEnable(GL_DEPTH_TEST); glShadeModel(GL_SMOOTH); glFrontFace(GL_CW); glEnable(GL_CULL_FACE); glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // LIGHTING SETUP 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}; glMaterialfv(GL_FRONT, GL_AMBIENT, matAmbient); glMaterialfv(GL_FRONT, GL_DIFFUSE, matDiff); glLightfv(GL_LIGHT0,GL_AMBIENT,ambientLight); glLightfv(GL_LIGHT0,GL_DIFFUSE,diffuseLight); glLightfv(GL_LIGHT0,GL_POSITION,lightPosition); glEnable(GL_LIGHT0); glEnable(GL_LIGHTING); glEnable(GL_COLOR_MATERIAL); // END LIGHTING SETUP glMatrixMode(GL_PROJECTION); glLoadIdentity(); myPerspective(45.0f, WIDTH / (float)HEIGHT, 1.0f, 100.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity();}void inline enable2d(void){ glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); glOrtho(0, WIDTH, HEIGHT, 0, -1.0, 1.0); glMatrixMode(GL_MODELVIEW); glPushMatrix(); glLoadIdentity();}void inline 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",18); GLfloat roty = 0; GLfloat rotx = 0; GLfloat rotz = 0; int j = 0; do { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); if(glfwGetKey(GLFW_KEY_LEFT) == GLFW_PRESS) roty += 0.01; if(glfwGetKey(GLFW_KEY_RIGHT) == GLFW_PRESS) roty -= 0.01; if(glfwGetKey(GLFW_KEY_UP) == GLFW_PRESS) rotx += 0.01; if(glfwGetKey(GLFW_KEY_DOWN) == GLFW_PRESS) rotx -= 0.01; if(glfwGetKey(GLFW_KEY_F1) == GLFW_PRESS) rotz += 0.01; if(glfwGetKey(GLFW_KEY_F2) == GLFW_PRESS) rotz -= 0.01; glTranslatef(0.0f,0.0f,-5.0f); glRotatef(180*cos(roty),0.0f,1.0f,0.0f); glRotatef(180*sin(rotx),1.0f,0.0f,0.0f); glRotatef(180*cos(rotz),0.0f,0.0f,1.0f); glColor3f(0.0f, 0.0f, 1.0f); drawPoint(); enable2d(); glColor3f(1.0f,1.0f,1.0f); glEnable(GL_BLEND); f.beginDraw(5,5) << "RotX: " << rotx << ", RotY: " << roty << ", RotZ: " << rotz << f.endDraw(); glDisable(GL_BLEND); disable2d(); glfwSwapBuffers(); } while ( glfwGetWindowParam(GLFW_OPENED) && glfwGetKey(GLFW_KEY_ESC) != GLFW_PRESS); glfwCloseWindow(); glfwTerminate(); return(0);}p.s. Is there a list of available tag's like source or code? thanks.
Quote:Original post by swinchen
p.s. Is there a list of available tag's like source or code? thanks.
yes, see the forum FAQ (icon in the top right of the screen below the menu)
This topic is closed to new replies.
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