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Rimher

[SFML] Can't draw anything in OpenGL

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Rimher    132
Hello there! I've just recently started learning OpenGL, and I'm trying to use SFML as a working environment.
But I'm having my first problems.
I'm following Nehe's tutorial on how to get started in OpenGL, and I was trying to draw some simple shapes. The problem is, they do not appear on the screen! I clearly remember doing this on Windows at the time, but since I switched to Mac, everything seems much harder.

Anyway, here's the code...if anyone can help me, it'd be really appreciated.

[source lang="cpp"]#include <SFML/Graphics.hpp>
#include <SFML/Audio.hpp>
#include <SFML/Network.hpp>
#include <SFML/Window.hpp>
#include <SFML/OpenGL.hpp>
#include "ResourcePath.hpp"
// Include standard headers
#include <stdio.h>
#include <stdlib.h>

using namespace glm;

GLfloat rtri, rquad;

GLfloat xrot, yrot, zrot;
int draw(){

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(-1.5f, 0.0f, -6.0f);

glRotatef(rtri, 0.0f, 1.0f, 0.0f);

glBegin(GL_TRIANGLES);
glColor3f(1.0f,0.0f,0.0f); // Red
glVertex3f( 0.0f, 1.0f, 0.0f); // Top Of Triangle (Front)
glColor3f(0.0f,1.0f,0.0f); // Green
glVertex3f(-1.0f,-1.0f, 1.0f); // Left Of Triangle (Front)
glColor3f(0.0f,0.0f,1.0f); // Blue
glVertex3f( 1.0f,-1.0f, 1.0f); // Right Of Triangle (Front)
glColor3f(1.0f,0.0f,0.0f); // Red
glVertex3f( 0.0f, 1.0f, 0.0f); // Top Of Triangle (Right)
glColor3f(0.0f,0.0f,1.0f); // Blue
glVertex3f( 1.0f,-1.0f, 1.0f); // Left Of Triangle (Right)
glColor3f(0.0f,1.0f,0.0f); // Green
glVertex3f( 1.0f,-1.0f, -1.0f); // Right Of Triangle (Right)
glColor3f(1.0f,0.0f,0.0f); // Red
glVertex3f( 0.0f, 1.0f, 0.0f); // Top Of Triangle (Back)
glColor3f(0.0f,1.0f,0.0f); // Green
glVertex3f( 1.0f,-1.0f, -1.0f); // Left Of Triangle (Back)
glColor3f(0.0f,0.0f,1.0f); // Blue
glVertex3f(-1.0f,-1.0f, -1.0f); // Right Of Triangle (Back)
glColor3f(1.0f,0.0f,0.0f); // Red
glVertex3f( 0.0f, 1.0f, 0.0f); // Top Of Triangle (Left)
glColor3f(0.0f,0.0f,1.0f); // Blue
glVertex3f(-1.0f,-1.0f,-1.0f); // Left Of Triangle (Left)
glColor3f(0.0f,1.0f,0.0f); // Green
glVertex3f(-1.0f,-1.0f, 1.0f); // Right Of Triangle (Left)
glEnd();

glLoadIdentity();
glTranslatef(1.5f,0.0f,-7.0f); // Move Right And Into The Screen

glRotatef(rquad,1.0f,1.0f,1.0f); // Rotate The Cube On X, Y & Z

glBegin(GL_QUADS);
glColor3f(0.0f,1.0f,0.0f); // Set The Color To Green
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Top)
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Top)
glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Quad (Top)
glVertex3f( 1.0f, 1.0f, 1.0f); // Bottom Right Of The Quad (Top)
glColor3f(1.0f,0.5f,0.0f); // Set The Color To Orange
glVertex3f( 1.0f,-1.0f, 1.0f); // Top Right Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f, 1.0f); // Top Left Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Bottom)
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Bottom)
glColor3f(1.0f,0.0f,0.0f); // Set The Color To Red
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Front)
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Front)
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Front)
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Front)
glColor3f(1.0f,1.0f,0.0f); // Set The Color To Yellow
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Back)
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Back)
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Back)
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Back)
glColor3f(0.0f,0.0f,1.0f); // Set The Color To Blue
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Left)
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Left)
glColor3f(1.0f,0.0f,1.0f); // Set The Color To Violet
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Right)
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Right)
glEnd(); // Done Drawing The Quad

rtri+=0.2f; // Increase The Rotation Variable For The Triangle
rquad-=0.15f; // Decrease The Rotation Variable For The Quad

return true;
}

int initGL(){

glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 0.3f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);

glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

return true;
}

int main (int argc, const char * argv[])
{
sf::Window window(sf::VideoMode(800, 600), "OpenGL window");

initGL();

do
{
// Process events
sf::Event event;
while (window.pollEvent(event))
{
if(event.type == sf::Event::Resized){
glViewport(0, 0, event.size.width, event.size.height);
}
// Close window : exit
if (event.type == sf::Event::Closed)
window.close();

// Escape pressed : exit
if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape)
window.close();
}

draw();


// Update the window
window.display();

}while(window.isOpen());


return EXIT_SUCCESS;
}
[/source]

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RulerOfNothing    1466
The tutorial in question has these lines of code:[CODE]
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glLoadIdentity(); // Reset The Projection Matrix
// Calculate The Aspect Ratio Of The Window
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
glLoadIdentity(); // Reset The Modelview Matrix
[/CODE]
in its window resizing code after the call to glViewport which are missing from your code. Maybe this is causing the problem? Edited by RulerOfNothing

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Rimher    132
[quote name='RulerOfNothing' timestamp='1348928437' post='4985059']
The tutorial in question has these lines of code:[CODE]
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glLoadIdentity(); // Reset The Projection Matrix
// Calculate The Aspect Ratio Of The Window
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
glLoadIdentity(); // Reset The Modelview Matrix
[/CODE]
in its window resizing code after the call to glViewport which are missing from your code. Maybe this is causing the problem?
[/quote]Such a rookie mistake! Thanks a lot, I had a different perspective in my inizialization!

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