Hello, I'm writing a game code, but my triangles don't get drawn. This is the display function. Please help me find the error.

Code:
static void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glRasterPos2i(0,0);//pozisyon
    glDrawPixels(myGame.getTemsilResmi()->getWidth(), myGame.getTemsilResmi()->getHeight(), GL_RGB, GL_UNSIGNED_BYTE, myGame.getTemsilResmi()->getDataRGB());

    glRasterPos2f(-0.6,-0.8);//pozisyon
    //glDrawPixels(myGame2.getTemsilResmi()->getWidth(), myGame2.getTemsilResmi()->getHeight(), GL_RGB, GL_UNSIGNED_BYTE, myGame2.getTemsilResmi()->getDataRGB());

    glColor3f( 1,0,1);
//    glRasterPos2f(0,0.3);
//    const char *text = mesaj.c_str();
//        for(int j=0; j<(int)mesaj.length(); j++)
//        {
//            glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, (int)text[j]);
//        }


    for(int k=0;k<3;k++)
    {
        rand_n=(rand()%5)+1;
        mat[5][12]=rand_n;
        int h=0;
        bool m=1;
        while(m==1)
        {
            while(h!=11)
            {
                y1-=5;
                time_mod=GetTickCount()%10;
                while(time_mod!=0)
                {
                    Sleep(1);
                    time_mod=GetTickCount()%10;
                }
                h++;
            }
            if(mat[row][col-1]==0) col-=1;
            else
            {
                mat[row][col]=rand_n;
                m=0;
            }
        }


    }
    for(col=0;col<12;col++)
    {
        for(row=0;row<9;row++)
        {
            switch(mat[row][col])
            {
                case 0:
                    break;
                case 1:
                    //glLoadIdentity();
                    glBegin(GL_TRIANGLES);

                    glVertex2i(x1+25,y1);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
                case 2:
                    //glLoadIdentity();
                    glBegin(GL_QUADS);

                    glVertex2i(x1,y1);
                    glVertex2i(x1+50,y1);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
                case 3:
                    glBegin(GL_TRIANGLES);

                    glVertex2i(x1+25,y1);
                    glVertex2i(x1+50,y1-25);
                    glVertex2i(x1,y1-25);

                    glEnd();

                    glBegin(GL_QUADS);

                    glVertex2i(x1,y1-25);
                    glVertex2i(x1+50,y1-25);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
                case 4:
                    glColor3f(1,0,0);
                    glBegin(GL_TRIANGLES);

                    glVertex2i(x1+25,y1);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
                case 5:
                    glColor3f(1,0,0);
                    glBegin(GL_QUADS);

                    glVertex2i(x1,y1);
                    glVertex2i(x1+50,y1);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
                case 6:
                    glColor3f(1,0,0);
                    glBegin(GL_TRIANGLES);

                    glVertex2i(x1+25,y1);
                    glVertex2i(x1+50,y1-25);
                    glVertex2i(x1,y1-25);

                    glEnd();

                    glBegin(GL_QUADS);

                    glVertex2i(x1,y1-25);
                    glVertex2i(x1+50,y1-25);
                    glVertex2i(x1+50,y1-50);
                    glVertex2i(x1,y1-50);

                    glEnd();
                    //glutSwapBuffers();
                    break;
            }
        }
    }
    glColor3f(0.0,1.0,0.0);
                    glBegin(GL_LINES);

                    glVertex2i(100,200);
                    glVertex2i(100,400);

                    glEnd();
    glFlush();
    //glutSwapBuffers();
}