#include "myWin.h"
#include "stdio.h"
#include "math.h"
#define swap(type, X,Y) do{type T; T=X;X=Y; Y=T;}while(0)
static HDC hBuff; static HBITMAP hBM;
static int X, Y ;static int XDT[5], YDT[5];
int IMS=0;double MAT[5][6];
void clearBitmap(){//ビットマップのクリア
	SelectObject(hBuff,GetStockObject(NULL_PEN));
	PatBlt(hBuff,0,0,1000,600,WHITENESS);
}
void setData(){
	for(int i=0;i<4;i++)for(int j=4;j>i;j--)//X座標の小さい順にソート
		if(XDT[j-1]>XDT[j]){
			swap(int, XDT[j-1],XDT[j]);swap(int, YDT[j-1],YDT[j]);
		}
}
void initData(){//初期値設定
	for(int i=0; i<5;i++){ XDT[i] = YDT[i] = 64*i;}
	setData(); //matSolve();
}
double difference(int i1,int i2){//■微分値（X方向は256で除した値とする）
	return ((double)(YDT[i2 ]-YDT[i1]))/((double)(XDT[i2]-XDT[i1]))*256.0;
}
int spline(double X, int i){//■スプライン補間
	int i1=i, i2=i+1;double DY1, DY2,DD=256;      //X方向の値をそのまま使うと
	if(abs(X-XDT[i1])<0.1) return (int) YDT[i1];  //誤差が大きくなるので256で除した
	if(abs(X-XDT[i2])<0.1) return (int) YDT[i2];  //値を用いる
	if(i1==0) DY1=difference(1,0); else DY1=difference(i2, i-1);
	if(i2==4) DY2=difference(4,3); else DY2=difference(i2+1,i1);
	double SG=(double)(XDT[i2]-XDT[i1])/DD, SG2=SG*SG, SG3=SG2*SG;
	double A1=2.0*((double)(YDT[i1]-YDT[i2]))/SG3+(DY1+DY2)/SG2;
	double A2=3.0*((double)(YDT[i2]-YDT[i1]))/SG2-(2.0*DY1+DY2)/SG;
	double A3=DY1, A4=YDT[i1];
	double T= (X-(double)XDT[i1])/DD; double T2=T*T; double T3=T2*T;
	int R=(int) A1*T3+A2*T2+A3*T+A4;if(R<0) R=0; if(R>255)R=255;
	return R;
}
int setValue(double X){//カラートーン値を求める関数
    if(X<=XDT[0])return 0; if(X>=XDT[4])return 255;//範囲外を除く
	for(int i=0;i<4;i++) if(X>=XDT[i] && X<XDT[i+1]) return spline(X, i);
	return 0;//最初、範囲外を除いているのでありえない。
}
void drawFig(HWND hw){
	clearBitmap();
	HPEN pen = CreatePen(PS_SOLID,1,0);SelectObject(hBuff,pen);
	Rectangle(hBuff,10,10,266,266);
	MoveToEx(hBuff,10,265,NULL);
	for(int k=1;k<256; k++)	LineTo(hBuff,k+10,265-(int)setValue((double)k));
	for(int j=1;j<=3;j++){
		int k=XDT[j], A=YDT[j]; //setValue(XDT[j]);
		Rectangle(hBuff,k+7,262-(int)A, k+13,268-(int)A);
	}
	DeleteObject(pen);
	InvalidateRect(hw,NULL,TRUE);
}
void viewChange(HWND hw, int X, int Y){//座標値の変更
	int MinDT = 9999999, ID=0; 
	for(int i=1;i<=3; i++){
		int DX = X-XDT[i],DY=Y-YDT[i], RR=DX*DX+DY*DY;
		if(RR<MinDT){ MinDT=RR; ID=i;}
	}
	if(MinDT<20){
		if(X<=0) X=1; if(X>=255) X=254;
		if(Y<=0) Y=0; if(Y>=255) Y=255;
		IMS=ID;	XDT[IMS]=X; YDT[IMS]=Y;setData(); drawFig(hw);
	}
}
void procCreate(HWND hw, WPARAM wp,LPARAM lp){
	initData();MoveWindow(hw,0,0,320,320,TRUE);
	SetWindowText(hw,TEXT("スプライン補間によるトーンカーブ"));
	HDC hdc=GetDC(hw); hBM=CreateCompatibleBitmap(hdc,1000,600);
	hBuff=CreateCompatibleDC(hdc); SelectObject(hBuff,hBM);
	viewChange(hw,127,127);	drawFig(hw);
	ReleaseDC(hw,hdc);
}
void procLButtonDown(HWND hw, WPARAM wp,LPARAM lp){
	X=LOWORD(lp)-10; Y=265-HIWORD(lp); viewChange(hw,X,Y);
}
void procLButtonUp(HWND hw, WPARAM wp,LPARAM lp){ IMS=0;}
void procMouseMove(HWND hw, WPARAM wp,LPARAM lp){
	if(GetKeyState(VK_LBUTTON)<0 && IMS!=0){
		X=LOWORD(lp)-10; Y=265-HIWORD(lp); viewChange(hw,X, Y);
	}
}
void procPaint(HWND hw,WPARAM wp,LPARAM lp){
	PAINTSTRUCT ps;	HDC hdc=BeginPaint(hw,&ps);
	BitBlt(hdc,0,0,1000,600,hBuff,0,0,SRCCOPY);
	EndPaint(hw,&ps);
}
LRESULT CALLBACK WndProc(HWND hw, UINT msg, WPARAM wp,LPARAM lp){
	switch(msg){
 	case WM_DESTROY    : DeleteDC(hBuff);DeleteObject(hBM); 
						 PostQuitMessage(0)     ; return 0;
	case WM_CREATE     : procCreate     (hw,wp,lp); return 0;
	case WM_LBUTTONDOWN: procLButtonDown(hw,wp,lp); return 0;	
	case WM_LBUTTONUP  : procLButtonUp  (hw,wp,lp); return 0;	
	case WM_MOUSEMOVE  : procMouseMove  (hw,wp,lp); return 0;	
	case WM_PAINT      : procPaint      (hw,wp,lp); return 0;
	}
	return DefWindowProc(hw,msg,wp,lp);
}