#include "myWin.h"
#include "math.h"
#define ORDER    5 // 次数
#define INIT_H   5 // Hの初期値
#define SX      20 // 画面左上端座標（XY共通とする）
#define RSC      2 // 画面表示倍率の逆数

int cX, cY, ID, H;
void pos(int X, int Y){ cX = X; cY = Y;}
int ScXY(int X){ return SX + X/RSC; }
void rLine(HDC hdc, int X, int Y){//相対描画
	int nX = cX + X, nY = cY + Y;
	MoveToEx(hdc, ScXY(cX), ScXY(cY), NULL);
	LineTo  (hdc, ScXY(nX), ScXY(nY));
	cX=nX; cY=nY;
}
void URD(HDC hdc); void LUR(HDC hdc); void DLU(HDC hdc);
void RDL(HDC hdc){
	if(ID<=0) return;
	ID--;
	RDL(hdc); rLine(hdc,  H, -H); URD(hdc); rLine(hdc,  0, -2*H);
	DLU(hdc); rLine(hdc, -H, -H); RDL(hdc);
	ID++;
}
void DLU(HDC hdc){
	if(ID<=0) return;
	ID--; 
	DLU(hdc); rLine(hdc,   -H, -H);	RDL(hdc); rLine(hdc, -2*H,  0);
	LUR(hdc); rLine(hdc,   -H,  H);	DLU(hdc);
	ID++;
}
void LUR(HDC hdc){
	if(ID<=0) return;
	ID--; 
	LUR(hdc); rLine(hdc, -H,   H);	DLU(hdc); rLine(hdc,  0, 2*H);
	URD(hdc); rLine(hdc,  H,   H);	LUR(hdc);
	ID++;
}
void URD(HDC hdc){
	if(ID<=0) return;
	ID--; 
	URD(hdc); rLine(hdc,   H,  H);	LUR(hdc); rLine(hdc, 2*H,  0);
	RDL(hdc); rLine(hdc,   H, -H);	URD(hdc);
	ID++;
}
void procPaint(HWND hw, WPARAM wp,LPARAM lp){
	PAINTSTRUCT ps;	HDC hdc=BeginPaint(hw, &ps);
	ID = ORDER; H = INIT_H; pos(H,0);
	URD(hdc); rLine(hdc, H, H);	LUR(hdc); rLine(hdc,-H, H); 
	DLU(hdc); rLine(hdc,-H,-H);	RDL(hdc); rLine(hdc, H,-H);
	EndPaint(hw,&ps);
}
void procCreate(HWND hw, WPARAM wp,LPARAM lp){
	SetWindowText(hw,TEXT("シェルピンスキ曲線(Sierpinski Curve)"));
	MoveWindow(hw,0,0,380,400,TRUE);
}
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_PAINT   : procPaint(hw,wp,lp)  ; return 0;
	}
	return DefWindowProc(hw,msg,wp,lp);
}