i have a dialog that has a variable m_length of float type. When i tried to draw a polygon using this variable, i encounter assetion error, where is the problem?
void Dialog::OnOK()
{
UpdateData(TRUE);
float length=m_length;
CPaintDC dc(this);
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_POLYGON);
glColor3ub(0,40,230);
glVertex2f(100.0f, 100.0f);
glColor3ub(0,40,230);
glVertex2f(100.0f, length);
glColor3ub(0,40,230);
glVertex2f(400.0f, length);
glColor3ub(0,40,230);
glVertex2f(400.0f, 100.0f);
glEnd();
glFlush();
CDialog::OnOK();
}