// blend1.cpp : DLL アプリケーションのエントリ ポイントを定義します。
//

#include "stdafx.h"
#include <math.h>


#ifdef _MANAGED
#pragma managed(push, off)
#endif



extern "C" {
typedef unsigned char n_byte;

int __stdcall get_blend_func_count();
char* __stdcall get_blend_func_key(int no);
char* __stdcall get_blend_func_name(int no);
void __stdcall blend(unsigned char* dst,const unsigned char* col,const unsigned char* alpha,int col_step
								 ,int alpha_step,int num_channel,int num_pixel,int no);



//追加する合成方法の数を返す。
int __stdcall get_blend_func_count()
{
    return 1;
}


//psdファイルに保存するときのkeyを返す。
/*
'norm' = normal
'dark' = darken
'lite' = lighten
'hue ' = hue
'sat ' = saturation
'colr' = color
'lum ' = luminosity
'mul ' = multiply
'scrn' = screen
'diss' = dissolve
'over' = overlay
'hLit' = hard light
'sLit' = soft light
'diff' = difference
'smud' = exlusion
'div ' = color dodge
'idiv' = color burn
*/
char* __stdcall get_blend_func_key(int no) 
{
	if (no == 0) {
		return "hueh";
	}
	return 0;
}

//合成方法の名前を返す。
char* __stdcall get_blend_func_name(int no)
{
	if (no == 0) {
		return "色相変更スライダー";
	}
	return "";
}


//合成を行う関数。
//num_channel チャンネル数。グレーモードの場合は１、カラーモードの場合は３

void __stdcall blend(unsigned char* dst,const unsigned char* col,const unsigned char* alpha,int col_step,int alpha_step
					,int num_channel,int num_pixel,int no)
{
	if (no == 0) {//色相変更スライダー
		if (num_channel == 1) {// 表示・グレスケ用
			const unsigned char* col_end = col + num_pixel * col_step;
			while (col < col_end) {
				*dst = *dst;

				alpha += alpha_step;
				col += col_step;
				dst += col_step;
			}
		}
		else if (num_channel == 3) {// 表示・カラー用
			const unsigned char* col_end = col + num_pixel * col_step;
			while (col < col_end) {

		if  (*dst == *(dst + 1) && *dst == *(dst + 2)){
				// RGB一致のグレーは変更しない
				*dst = *dst;
				*(dst + 1) = *(dst + 1);
				*(dst + 2) = *(dst + 2);
		}
		else {
				// RGBをHSVに変換
				double hsv_h = 0 ;
				double hsv_s = 0 ;
				double hsv_v = 0 ;
				double a1 = *alpha / 255.0 * 359 ;
				double rgb_max = max(*(dst + 2), max(*(dst + 1), *dst));
		        double rgb_min = min(*(dst + 2), min(*(dst + 1), *dst));

       // h
        if(rgb_max == *(dst + 2)){ // 赤が一番高いとき
            hsv_h = (int)(60 * (*(dst + 1) - *dst) / (rgb_max - rgb_min) + 360) % 360;
       }
        else if(rgb_max == *(dst + 1)){ // 緑が一番高いとき
            hsv_h = (60 * (*dst - *(dst + 2)) / (rgb_max - rgb_min)) + 120;
        }
        else if(rgb_max == *dst){ // 青が一番高いとき
            hsv_h = (60 * (*(dst + 2) - *(dst + 1)) / (rgb_max - rgb_min)) + 240;   
        }
            hsv_h = (int)(hsv_h + a1 +360) % 360;
        
        // s
            hsv_s = (255 * ((rgb_max - rgb_min) / rgb_max));
        
        // v
	        hsv_v = rgb_max;

				// HSVをRGBに戻す

		  int hi = 0;
		  double f, p, q, t;

		  hi = ((int)(hsv_h / 60)) % 6;
		  f = hsv_h / 60 - hi;
		  p = hsv_v * (1 - (hsv_s / 255));
		  q = hsv_v * (1 - f * (hsv_s / 255));
		  t = hsv_v * (1 - (1 - f) * (hsv_s / 255));

		  if (hi == 0){
		      *(dst + 2) = (int)hsv_v;
			  *(dst + 1) = (int)t;
			  *dst = (int)p;
		  }
	      else if (hi == 1){
		      *(dst + 2) = (int)q;
			  *(dst + 1) = (int)hsv_v;
			  *dst = (int)p;
		  }
	      else if (hi == 2){
		      *(dst + 2) = (int)p;
			  *(dst + 1) = (int)hsv_v;
			  *dst = (int)t;
		  }
	      else if (hi == 3){
		      *(dst + 2) = (int)p;
			  *(dst + 1) = (int)q;
			  *dst = (int)hsv_v;
		  }
	      else if (hi == 4){
 		      *(dst + 2) = (int)t;
			  *(dst + 1) = (int)p;
			  *dst = (int)hsv_v;
		  }
	      else if (hi == 5){
 		      *(dst + 2) = (int)hsv_v;
			  *(dst + 1) = (int)p;
			  *dst = (int)q;
		  }

		}

				alpha += alpha_step;
				col += col_step;
				dst += col_step;
			}
		}
	}

}

//下のレイヤーと結合で使用される
void __stdcall merge(n_byte* dst,const n_byte* col,const n_byte* base_col,const n_byte* alpha,const n_byte* base_alpha
					 ,int col_step,int alpha_step,int base_alpha_step,int num_channel,int num_pixel,int no)
{
	if (no == 0) {
		if (num_channel == 1) {
			const unsigned char* col_end = col + num_pixel * col_step;
			while (col < col_end) {
				unsigned int a0 = *base_alpha;
				unsigned int a1 = *alpha;

				if (a1 != 0) {
					*dst = *base_col;
					*(dst + 1) = *base_alpha;
				}
				else {
					*dst = *base_col;
					*(dst + 1) = *base_alpha;
				}

				dst += 2;
				col += col_step;
				base_col += col_step;
				alpha += alpha_step;
				base_alpha += alpha_step;
			}
		}
		else if (num_channel == 3) {
			const unsigned char* col_end = col + num_pixel * col_step;
			while (col < col_end) {
		if  (*base_col == *(base_col + 1) && *base_col == *(base_col + 2)){
				// RGB一致のグレーは変更しない
					*dst = *base_col;
					*(dst + 1) = *(base_col + 1);
					*(dst + 2) = *(base_col + 2);
					*(dst + 3) = *base_alpha;
		}
		else {
				// RGBをHSVに変換
				double hsv_h = 0 ;
				double hsv_s = 0 ;
				double hsv_v = 0 ;
				double a1 = *alpha / 255.0 * 359 ;
				double rgb_max = max(*(base_col + 2), max(*(base_col + 1), *base_col));
		        double rgb_min = min(*(base_col + 2), min(*(base_col + 1), *base_col));

       // h
        if(rgb_max == *(base_col + 2)){ // 赤が一番高いとき
            hsv_h = (int)(60 * (*(base_col + 1) - *base_col) / (rgb_max - rgb_min) + 360) % 360;
       }
        else if(rgb_max == *(base_col + 1)){ // 緑が一番高いとき
            hsv_h = (60 * (*base_col - *(base_col + 2)) / (rgb_max - rgb_min)) + 120;
        }
        else if(rgb_max == *base_col){ // 青が一番高いとき
            hsv_h = (60 * (*(base_col + 2) - *(base_col + 1)) / (rgb_max - rgb_min)) + 240;   
        }
            hsv_h = (int)(hsv_h + a1 +360) % 360;
        
        // s
            hsv_s = (255 * ((rgb_max - rgb_min) / rgb_max));
        
        // v
	        hsv_v = rgb_max;

				// HSVをRGBに戻す

		  int hi = 0;
		  double f, p, q, t;

		  hi = ((int)(hsv_h / 60)) % 6;
		  f = hsv_h / 60 - hi;
		  p = hsv_v * (1 - (hsv_s / 255));
		  q = hsv_v * (1 - f * (hsv_s / 255));
		  t = hsv_v * (1 - (1 - f) * (hsv_s / 255));

		  if (hi == 0){
		      *(dst + 2) = (int)hsv_v;
			  *(dst + 1) = (int)t;
			  *dst = (int)p;
			  *(dst + 3) = *base_alpha;
		  }
	      else if (hi == 1){
		      *(dst + 2) = (int)q;
			  *(dst + 1) = (int)hsv_v;
			  *dst = (int)p;
			  *(dst + 3) = *base_alpha;
		  }
	      else if (hi == 2){
		      *(dst + 2) = (int)p;
			  *(dst + 1) = (int)hsv_v;
			  *dst = (int)t;
			  *(dst + 3) = *base_alpha;
		  }
	      else if (hi == 3){
		      *(dst + 2) = (int)p;
			  *(dst + 1) = (int)q;
			  *dst = (int)hsv_v;
			  *(dst + 3) = *base_alpha;
		  }
	      else if (hi == 4){
 		      *(dst + 2) = (int)t;
			  *(dst + 1) = (int)p;
			  *dst = (int)hsv_v;
			  *(dst + 3) = *base_alpha;
		  }
	      else if (hi == 5){
 		      *(dst + 2) = (int)hsv_v;
			  *(dst + 1) = (int)p;
			  *dst = (int)q;
			  *(dst + 3) = *base_alpha;
		  }

		}

				dst += 4;
				col += col_step;
				base_col += col_step;
				alpha += alpha_step;
				base_alpha += base_alpha_step;
			}
		}
	}
}



}
BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
					 )
{
    return TRUE;
}

#ifdef _MANAGED
#pragma managed(pop)
#endif