#include "myWin.h"
#define BITX 500
#define BITY 500
static HDC hbuf; static HBITMAP hBM;
void initBitMap(HWND hw){
	HDC hdc=GetDC(hw); hBM=CreateCompatibleBitmap(hdc,BITX,BITY);
	hbuf=CreateCompatibleDC(hdc);SelectObject(hbuf,hBM);
	SelectObject(hbuf,GetStockObject(NULL_PEN));
	ReleaseDC(hw, hdc);
}
void clearBitmap(){
	PatBlt(hbuf,0,0,BITX,BITY,BLACKNESS);
}
double a, b, XS, YS;
void initData(){a=1.5; b=0.25;XS=1; YS=1;}
//全体表示用
double SCX=100, SCY=200, X0=220, Y0=200;
//5倍表示用
//double SCX=500, SCY=1000, X0=-200, Y0=200;
//10倍表示用
//double SCX=1000, SCY=2000, X0=-800, Y0=200;
//40倍表示用
//double SCX=4000, SCY=8000, X0=-4400, Y0=300;

int intX(double X) {return (int)(X * SCX +X0);}
int intY(double X) {return (int)(Y0 - X * SCY);}
void cmpIter(){
	clearBitmap();
	double X= XS,Y=YS, XN, YN,IX,IY ;
	for(int i=0;i<100000;i++){
		XN=1-a*X*X+Y;YN=b*X;
		IX=intX(XN); IY=intY(YN);
		SetPixel(hbuf, intX(XN), intY(YN), 0xFFFFFF);
		X=XN; Y=YN;

	}
}
void procLButtonDown(HWND hw, WPARAM wp, LPARAM lp){
	cmpIter();
	InvalidateRect(hw,NULL,FALSE);
}
void procCreate(HWND hw, WPARAM wp, LPARAM lp){
	MoveWindow(hw,0,0,BITX,BITY,NULL);
	SetWindowText(hw,TEXT("Henon Map"));
	initBitMap(hw);
	initData();
	procLButtonDown(hw,wp,lp);
}
void procPaint(HWND hw, WPARAM wp, LPARAM lp){
	PAINTSTRUCT ps; HDC hdc=BeginPaint(hw, &ps);
	BitBlt(hdc,0,0,BITX,BITY,hbuf,0,0,SRCCOPY);
	EndPaint(hw,&ps);
}
LRESULT CALLBACK WndProc(HWND hw, UINT msg, WPARAM wp, LPARAM lp){
	switch(msg){
	case WM_DESTROY : PostQuitMessage(0)    ; return 0;
	case WM_CREATE  : procCreate(hw,wp,lp)  ; return 0;
	case WM_LBUTTONDOWN  : procLButtonDown(hw,wp,lp)  ; return 0;
	case WM_PAINT   : procPaint (hw, wp, lp); return 0;
	}
	return DefWindowProc(hw, msg, wp, lp);
}