//===========================================================================
//                                    CLASS OVERLOADED 2000 WANDERING SQUARES
//                                                               26 July 2009
//
//   As an illustration of class construction, probably too much code has
//                    been added to the class declaration and definition.
//   Note:  The rectangle method runs 10 times as fast as the ellipse method.
//===========================================================================

#include <vcl.h>
#include <math.h>
#pragma hdrstop

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;

#define POP 2000

// ====================================================== VARIABLES & CLASSES

bool stop = true;
TColor back = 0X79BBD7;
TColor fore = 0X4080FF;

class shapes {
	public:
		double x, y ;
		double direction;
		double dx, dy;
		float height, width;
		void erase (void) {
			Form1->Canvas->Pen->Color = back;
			Form1->Canvas->Brush->Color = back;
			Form1->Canvas->Rectangle(x, y, x + width, y + height);
		}
		void draw (void) {
			Form1->Canvas->Pen->Color = clBlack;
			Form1->Canvas->Brush->Color = fore;
			Form1->Canvas->Rectangle(x, y, x + width, y + height);
        }
		void shrink (void) {
			erase();
			height *= .9; width *= .9;
			draw();
		}
		void grow (void) {
			erase();
			height *= 1.1; width *= 1.1;
			draw();
		}
		void move (void) {
			if (Form1->RadioGroupTrail->ItemIndex == 0) {
				Form1->Canvas->Pen->Color = back;
				Form1->Canvas->Brush->Color = back;
				Form1->Canvas->Rectangle(x, y, x + width, y + height);
			}
			x += dx;
			y += dy;
			if (x > 480 || x < 0) {
				dx = -dx;
			}
			if (y > 480 || y < 0) {
                dy = -dy;
			}
			draw();
        }
} shape[POP];

// ================================================================ FUNCTIONS

void initialize (void) {

	for (int i = 0; i < POP; i++) {
		shape[i].erase();
		shape[i].height = 10;
		shape[i].width = 10;
		shape[i].direction =  double(i) / 3;
		shape[i].x = random(480);
		shape[i].y = random(480);
		shape[i].dy = double(random(100) - 50) / 25.00;
		shape[i].dx = double(random(100) - 50) / 25.00;
		Form1->Canvas->Pen->Color = clBlack;
		Form1->Canvas->Brush->Color = fore;
		Form1->Canvas->Rectangle(shape[i].x, shape[i].y,
			shape[i].x + shape[i].width, shape[i].y + shape[i].height);
	}
}

void step (void) {
		for (int i = 0; i < POP; i++) {
			shape[i].move();
		}
}

// =========================================================== EVENT HANDLERS

//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
	: TForm(Owner)
{
	DoubleBuffered = true;
	randomize();
	initialize();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ButtonShrinkClick(TObject *Sender)
{
	for (int i = 0; i < POP; i++) {
		shape[i].shrink();
	}
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ButtonGrowClick(TObject *Sender)
{
	for (int i = 0; i < POP; i++) {
		shape[i].grow();
	}
}
//---------------------------------------------------------------------------

void __fastcall TForm1::FormPaint(TObject *Sender)
{
	for (int i = 0; i < POP; i++) {
		Form1->Canvas->Rectangle(shape[i].x, shape[i].y,
			shape[i].x + shape[i].width, shape[i].y + shape[i].height);
	}
}
//---------------------------------------------------------------------------


void __fastcall TForm1::RadioGroupTrailClick(TObject *Sender)
{
	Form1->Refresh();	
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ButtonStepClick(TObject *Sender)
{
	stop = true;
	step();
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ButtonRunClick(TObject *Sender)
{
	stop = false;
	while (stop == false) {
		Application->ProcessMessages();
		step();
	}
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ButtonStopClick(TObject *Sender)
{
	stop = true;
}
//---------------------------------------------------------------------------

void __fastcall TForm1::ButtonResetClick(TObject *Sender)
{
	initialize();
	Form1->Paint();
}
//---------------------------------------------------------------------------