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class PushButton {
  public:

    // constructor

    PushButton(int x, int y, int w, int h,
               char *text,
               float r = 0.5, float g = 0.5, float b = 0.5);

    // destructor

    ~PushButton();

    // void methods

    void Draw();
    void Depress();

    // value-returning methods

    bool WasClicked(int mouse_x, int mouse_y);

  private:

    int LeftX, BotY, Width, Height;
    char * Label;
    float Red, Green, Blue;

}; // end of class PushButton



PushButton::PushButton(int x, int y, int w, int h,
                       char *text,
                       float r, float g, float b)
{
    LeftX = x;  BotY = y;   Width = w;  Height = h;
    Red = r;    Green = g;  Blue = b;
    Label = new char[strlen(text)+1];
    strcpy(Label, text);
} // end of PushButton::PushButton

PushButton::~PushButton()
{
    delete [] Label;
} // end of PushButton::~PushButton

void PushButton::Draw()
{
    // draw button
    glBegin(GL_POLYGON);
        glColor3f(Red, Green, Blue);
        glVertex2i(LeftX, BotY);
        glVertex2i(LeftX + Width, BotY);
        glVertex2i(LeftX + Width, BotY + Height);
        glVertex2i(LeftX, BotY + Height);
    glEnd();

    // place text in center of button
    int textwidth = 0;
	for (unsigned k=0; k<strlen(Label); k++)
		textwidth += glutBitmapWidth(GLUT_BITMAP_HELVETICA_12, Label[k]);
	glColor3f(0.0, 0.0, 0.0);
	glRasterPos2i((Width - textwidth)/2 + LeftX,  Height/2 + BotY - 3);
	for (k=0; k<strlen(Label); k++)
		glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, Label[k]);
    
    // draw shadow lines:  top and left in WHITE
    glBegin(GL_LINE_STRIP);
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(LeftX - 1, BotY - 1);
        glVertex2i(LeftX - 1, BotY + Height + 1);
        glVertex2i(LeftX + Width - 1, BotY + Height + 1);
    glEnd(); 

    // draw shadow lines:  bottom and right in DARK GREY
    glBegin(GL_LINE_STRIP);
        glColor3f(0.3, 0.3, 0.3);
        glVertex2i(LeftX, BotY - 1);
        glVertex2i(LeftX + Width + 1, BotY - 1);
        glVertex2i(LeftX + Width + 1, BotY + Height + 1);
    glEnd(); 
	glFlush();
} // end of PushButton::Draw()

void PushButton::Depress()
{
    // draw button
    glBegin(GL_POLYGON);
        glColor3f(Red, Green, Blue);
        glVertex2i(LeftX, BotY);
        glVertex2i(LeftX + Width, BotY);
        glVertex2i(LeftX + Width, BotY + Height);
        glVertex2i(LeftX, BotY + Height);
    glEnd();

    // place text in center of button
    int textwidth = 0;
	for (unsigned k=0; k<strlen(Label); k++)
		textwidth += glutBitmapWidth(GLUT_BITMAP_HELVETICA_12, Label[k]);
	glColor3f(0.0, 0.0, 0.0);
	glRasterPos2i((Width - textwidth)/2 + LeftX + 1,  Height/2 + BotY - 4);
	for (k=0; k<strlen(Label); k++)
		glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, Label[k]);

    // draw shadow lines:  top and left in DARK GREY
    glBegin(GL_LINE_STRIP);
        glColor3f(0.3, 0.3, 0.3);
        glVertex2i(LeftX - 1, BotY - 1);
        glVertex2i(LeftX - 1, BotY + Height + 1);
        glVertex2i(LeftX + Width - 1, BotY + Height + 1);
    glEnd(); 

    // draw shadow lines:  bottom and right in WHITE
    glBegin(GL_LINE_STRIP);
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(LeftX, BotY - 1);
        glVertex2i(LeftX + Width + 1, BotY - 1);
        glVertex2i(LeftX + Width + 1, BotY + Height + 1);
    glEnd(); 
	glFlush();
} // end of PushButton::Depress()

bool PushButton::WasClicked(int mouse_x, int mouse_y)
{
    int window_height = glutGet(GLUT_WINDOW_HEIGHT);
	mouse_y = window_height - mouse_y;
    if (LeftX <= mouse_x && mouse_x <= LeftX + Width &&
        BotY  <= mouse_y && mouse_y <= BotY + Height)
            return true;
    else
            return false;
} // end of PushButton::WasClicked()

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