Я хотел бы скомпилировать этот файл в Qt Creator (4.7)

Я новичок в использовании Qt и OpenGl, и я хотел бы скомпилировать этот файл, но не могу. Я действительно хотел бы попробовать этот пример, потому что я хочу понять, как работает «функция выбора». Что я должен делать?

Это код: (Вы можете найти его здесь:http://www.et.byu.edu/~merk/me570/qtRedExamples.html)

//          picksquare.cpp
//   Use of multiple names and picking are demonstrated.
//   A 3x3 grid of squares is drawn.  When the left mouse
//   button is pressed, all squares under the cursor position
//   have their color changed.
//   Author  Travis Astle
//   Oct 19, 2001

#include <qgl.h>
#include <qapplication.h>
#include <qkeycode.h>

int board[3][3];   /*  amount of color for each square  */

GLuint ii =0, jj=0, names, *ptr;

// Picksquare class declaration

class Picksquare : public QGLWidget
{
public:
Picksquare( QWidget *parent=0, const char *name=0 ) :
QGLWidget(parent, name) {};
protected:
void initializeGL(void);
void resizeGL( int w, int h );
void paintGL();
void drawSquares(GLenum mode);
void keyPressEvent( QKeyEvent *e);
void processHits (GLint hits, GLuint buffer[]);
void mousePressEvent(QMouseEvent *e);

};

// Initialize function adapted from existing init function code

void Picksquare::initializeGL(void)
{
int i, j;
for (i = 0; i < 3; i++)
for (j = 0; j < 3; j ++)
board[i][j] = 0;
glClearColor (0.0, 0.0, 0.0, 0.0);
}

// Paint function to replace the display function

void Picksquare::paintGL(void)
{
glClear(GL_COLOR_BUFFER_BIT);
drawSquares (GL_RENDER);
glFlush();
}

/*  The nine squares are drawn.  In selection mode, each
*  square is given two names:  one for the row and the
*  other for the column on the grid.  The color of each
*  square is determined by its position on the grid, and
*  the value in the board[][] array.
*/

void Picksquare::drawSquares(GLenum mode)
{
GLuint i, j;
for (i = 0; i < 3; i++) {
if (mode == GL_SELECT)
glLoadName (i);
for (j = 0; j < 3; j ++) {
if (mode == GL_SELECT)
glPushName (j);
glColor3f ((GLfloat) i/3.0, (GLfloat) j/3.0,
(GLfloat) board[i][j]/3.0);
glRecti (i, j, i+1, j+1);
if (mode == GL_SELECT)
glPopName ();
}
}
}

// Resize function adapted from reshape function code

void Picksquare::resizeGL(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D (0.0, 3.0, 0.0, 3.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

//  processHits changes color of selected boxes

void Picksquare::processHits (GLint hits, GLuint buffer[])
{
unsigned int i, j;
GLuint ii, jj, names, *ptr;

printf ("hits = %d\n", hits);
ptr = (GLuint *) buffer;
for (i = 0; i < hits; i++) { /*  for each hit  */
names = *ptr;
printf (" number of names for this hit = %d\n", names); ptr++;
printf("  z1 is %g;", (float) *ptr/0x7fffffff); ptr++;
printf(" z2 is %g\n", (float) *ptr/0x7fffffff); ptr++;
printf ("   names are ");
for (j = 0; j < names; j++) { /*  for each name */
printf ("%d ", *ptr);
if (j == 0)  /*  set row and column  */
ii = *ptr;
else if (j == 1)
jj = *ptr;
ptr++;
}
printf ("\n");
board[ii][jj] = (board[ii][jj] + 1) % 3;
}
}/*  pickSquares() sets up selection mode, name stack,
*  and projection matrix for picking.  Then the
*  objects are drawn.
*/
#define BUFSIZE 512

void Picksquare::mousePressEvent(QMouseEvent *e)

{
GLuint selectBuf[BUFSIZE];
GLint hits;
GLint viewport[4];

if (e-> button() != LeftButton) //|| state != GLUT_DOWN)
return;

glGetIntegerv (GL_VIEWPORT, viewport);

glSelectBuffer (BUFSIZE, selectBuf);
(void) glRenderMode (GL_SELECT);

glInitNames();
glPushName(0);

glMatrixMode (GL_PROJECTION);
glPushMatrix ();
glLoadIdentity ();

//  create 5x5 pixel picking region near cursor location

gluPickMatrix ((GLdouble) e->x(), (GLdouble) (viewport[3] - e->y()),
5.0, 5.0, viewport);
gluOrtho2D (0.0, 3.0, 0.0, 3.0);
drawSquares (GL_SELECT);

glMatrixMode (GL_PROJECTION);
glPopMatrix ();
glFlush ();

hits = glRenderMode (GL_RENDER);
processHits (hits, selectBuf);
update();
}

// Picksquare function adaped from keyboard function.  This function has
// been modified to accept one argument (the keyboard input), instaed of three
// arguments as is was done in the keyboard function.

void Picksquare::keyPressEvent(QKeyEvent *e)
{
switch (e -> key()) {
case 27:
exit(0);
break;
}
}
/*  Main Loop
*  Open window with initial window size, title bar,
*  color index display mode, and handle input events.
*/
int main( int argc, char **argv )
{
QApplication::setColorSpec( QApplication::CustomColor );
QApplication a( argc, argv );

if ( !QGLFormat::hasOpenGL() ) {
qWarning( "This system has no OpenGL support. Exiting." );
return -1;
}

Picksquare w;
a.setMainWidget( &w );
w.show();
return a.exec();
}