Monday, 21 January 2013

OpenGL:


I'm using OpenGL and QT creator in Ubuntu environment. I will constantly make short notes about problems and solutions in programming.

Adding OpenGL Library


To add external library, right click on the project or .pro file then click >>Add new library >>External library >>Browse "usr/lib/libGLEW.so"

Or edit the *.pro file by adding "LIBS += -L$$PWD/../../../../../../usr/lib/ -lglut -lGLEW"

A good OpenGL tutorial can be found here or here.

Create a simple project

1. Firstly, open QT Creator and create a empty project.
2. Add libraries (see above). After adding two libraries you can see the "-lglut -lGLEW" in the *.pro file.
3. Add the main source file (main.cpp)
4. Finally build and execute the project.

------------------------------------main.cpp----------------------------------------
#include <GL/glut.h>
void display(){
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_POLYGON);
    glVertex2f(-0.5, -0.5);
    glVertex2f(-0.5, 0.5);
    glVertex2f(0.5, 0.5);
    glVertex2f(0.5, -0.5);
    glEnd();
    glFlush();
}
void init(){
    glClearColor (0.0, 0.0, 0.0, 0.0);
    glColor3f(1.0, 1.0, 1.0);
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity();
    glOrtho (-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
}
int main(int argc, char** argv){
    glutInit(&argc,argv);
    glutCreateWindow("simple");
    glutDisplayFunc(display);
    init();
    glutMainLoop();
}
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Another useful material click here.