/*$
 Copyright (C) 2016-2020 Azel.

 This file is part of AzPainterB.

 AzPainterB is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 AzPainterB is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
$*/

/*****************************************
 * ImageBuf24
 *
 * 24bit RGB イメージ
 *****************************************/
/*
 * - "R-G-B" のバイト順で並んでいる。
 * - レイヤ合成後のイメージなどで使われる。
 */

#include <string.h>

#include "mDef.h"
#include "mLoadImage.h"

#include "ImageBuf24.h"



/** 32bit カラー値から ImageBuf24Pix に変換 */

void ImageBuf24_coltopix(ImageBuf24Pix *dst,uint32_t col)
{
	dst->r = (uint8_t)(col >> 16);
	dst->g = (uint8_t)(col >> 8);
	dst->b = (uint8_t)col;
}

/** 解放 */

void ImageBuf24_free(ImageBuf24 *p)
{
	if(p)
	{
		mFree(p->buf);
		mFree(p);
	}
}

/** 作成 */

ImageBuf24 *ImageBuf24_new(int w,int h)
{
	ImageBuf24 *p;

	p = (ImageBuf24 *)mMalloc(sizeof(ImageBuf24), TRUE);
	if(!p) return NULL;

	p->w = w;
	p->h = h;
	p->pitch = w * 3;

	//バッファ確保

	p->buf = (uint8_t *)mMalloc(w * h * 3, FALSE);
	if(!p->buf)
	{
		mFree(p);
		return NULL;
	}

	return p;
}

/** 指定位置のポインタを取得
 *
 * @return NULL で範囲外 */

uint8_t *ImageBuf24_getPixelBuf(ImageBuf24 *p,int x,int y)
{
	if(x < 0 || y < 0 || x >= p->w || y >= p->h)
		return NULL;
	else
		return p->buf + y * p->pitch + x * 3;
}

/** 全体を指定色で埋める */

void ImageBuf24_fill(ImageBuf24 *p,uint32_t col)
{
	uint8_t *pd;
	ImageBuf24Pix pix;
	int i,pitch;

	ImageBuf24_coltopix(&pix, col);

	//Y1列分を埋める

	pd = p->buf;

	for(i = p->w; i > 0; i--, pd += 3)
	{
		pd[0] = pix.r;
		pd[1] = pix.g;
		pd[2] = pix.b;
	}

	//残りは、前の列をコピー

	pitch = p->pitch;
	pd = p->buf + pitch;

	for(i = p->h - 1; i > 0; i--, pd += pitch)
		memcpy(pd, pd - pitch, pitch);
}

/** 白色で全体を埋める */

void ImageBuf24_fillWhite(ImageBuf24 *p)
{
	memset(p->buf, 255, p->pitch * p->h);
}

/** 範囲を指定色で埋める */

void ImageBuf24_fillBox(ImageBuf24 *p,mBox *box,uint32_t col)
{
	uint8_t *pd;
	ImageBuf24Pix pix;
	int i,pitch,wsize;

	ImageBuf24_coltopix(&pix, col);

	pitch = p->pitch;
	wsize = box->w * 3;

	//Y1列分を埋める

	pd = p->buf + box->y * pitch + box->x * 3;

	for(i = box->w; i > 0; i--, pd += 3)
	{
		pd[0] = pix.r;
		pd[1] = pix.g;
		pd[2] = pix.b;
	}

	//前の列をコピー

	pd -= wsize;

	for(i = box->h - 1; i > 0; i--, pd += pitch)
		memcpy(pd + pitch, pd, wsize);
}

/** チェック柄で範囲を埋める */

void ImageBuf24_fillPlaid_box(ImageBuf24 *p,mBox *box,uint32_t col1,uint32_t col2)
{
	ImageBuf24Pix *pd,pix[2];
	uint8_t *bufd,*bufs;
	int ix,iy,pitch,xx,yy,fy;

	ImageBuf24_coltopix(pix, col1);
	ImageBuf24_coltopix(pix + 1, col2);

	//高さを 16px まで埋める

	pd = (ImageBuf24Pix *)(p->buf + box->y * p->pitch + box->x * 3);
	pitch = p->w - box->w;

	yy = box->y & 15;

	for(iy = (box->h > 16)? 16: box->h; iy > 0; iy--)
	{
		xx = box->x & 15;
		fy = yy >> 3;
		
		for(ix = box->w; ix > 0; ix--)
		{
			*(pd++) = pix[fy ^ (xx >> 3)];

			xx = (xx + 1) & 15;
		}

		pd += pitch;
		yy = (yy + 1) & 15;
	}

	//残りの高さをコピーして埋める

	if(box->h > 16)
	{
		pitch = p->pitch;
		bufd = (uint8_t *)pd;
		bufs = bufd - (pitch << 4);

		xx = box->w * 3;

		for(iy = box->h - 16; iy > 0; iy--)
		{
			memcpy(bufd, bufs, xx);

			bufd += pitch;
			bufs += pitch;
		}
	}
}

/** パレット取得 (最大256色)
 *
 * @param tpindex  透過色を入れておく。透過色のインデックス番号が入る。
 * @return 確保されたバッファ (R-G-B-A)。256色より多い場合は NULL */

uint8_t *ImageBuf24_getPalette(ImageBuf24 *p,int *pnum,int *tpcol)
{
	uint8_t *palbuf,*ps,*ppal,tr,tg,tb;
	uint32_t i;
	int j,cnt = 0,settp;

	//バッファ確保

	palbuf = (uint8_t *)mMalloc(256 * 4, FALSE);
	if(!palbuf) return NULL;

	//透過色 RGB

	if(*tpcol < 0)
		settp = FALSE;
	else
	{
		tr = M_GET_R(*tpcol);
		tg = M_GET_G(*tpcol);
		tb = M_GET_B(*tpcol);
		settp = TRUE;
	}

	//

	ps = p->buf;

	for(i = p->w * p->h; i; i--, ps += 3)
	{
		//すでに存在する色か

		for(j = 0, ppal = palbuf; j < cnt; j++, ppal += 4)
		{
			if(ps[0] == ppal[0] && ps[1] == ppal[1] && ps[2] == ppal[2])
				break;
		}

		//追加

		if(j == cnt)
		{
			//256色を超えた

			if(cnt == 256)
			{
				mFree(palbuf);
				return NULL;
			}

			//透過色のインデックスセット

			if(settp && ps[0] == tr && ps[1] == tg && ps[2] == tb)
			{
				*tpcol = cnt;
				settp = FALSE;
			}

			//
		
			ppal[0] = ps[0];
			ppal[1] = ps[1];
			ppal[2] = ps[2];
			ppal[3] = 0;
			
			cnt++;
		}
	}

	*pnum = cnt;

	return palbuf;
}

/** パレットイメージ保存用、Y1行セット */

void ImageBuf24_setRow_forPalette(ImageBuf24 *p,uint8_t *dst,uint8_t *src,uint8_t *palbuf,int palnum)
{
	uint8_t *ppal;
	int i,j;

	for(i = p->w; i; i--, src += 3)
	{
		//パレットから検索

		for(j = 0, ppal = palbuf; j < palnum; j++, ppal += 4)
		{
			if(src[0] == ppal[0] && src[1] == ppal[1] && src[2] == ppal[2])
				break;
		}

		if(j == palnum) j = 0;

		*(dst++) = j;
	}
}


//==============================
// 画像読み込み
//==============================


typedef struct
{
	mLoadImage base;
	ImageBuf24 *img;
	uint8_t *dstbuf;
	ImageBuf24Pix bgpix;
}_loadimageinfo;


/** 情報取得 */

static int _loadfile_getinfo(mLoadImage *param,mLoadImageInfo *info)
{
	_loadimageinfo *p = (_loadimageinfo *)param;

	//作成

	p->img = ImageBuf24_new(info->width, info->height);
	if(!p->img) return MLOADIMAGE_ERR_ALLOC;

	p->dstbuf = p->img->buf;
	if(info->bottomup) p->dstbuf += (info->height - 1) * p->img->pitch;

	return MLOADIMAGE_ERR_OK;
}

/** Y1行取得 */

static int _loadfile_getrow(mLoadImage *param,uint8_t *buf,int pitch)
{
	_loadimageinfo *p = (_loadimageinfo *)param;
	int i,a;
	uint8_t *pd;
	ImageBuf24Pix pix;

	pd = p->dstbuf;
	pix = p->bgpix;

	for(i = param->info.width; i > 0; i--, buf += 4, pd += 3)
	{
		a = buf[3];

		if(a == 255)
			pd[0] = buf[0], pd[1] = buf[1], pd[2] = buf[2];
		else if(a == 0)
			pd[0] = pix.r, pd[1] = pix.g, pd[2] = pix.b;
		else
		{
			pd[0] = (buf[0] - pix.r) * a / 255 + pix.r;
			pd[1] = (buf[1] - pix.g) * a / 255 + pix.g;
			pd[2] = (buf[2] - pix.b) * a / 255 + pix.b;
		}
	}

	p->dstbuf += (param->info.bottomup)? -(p->img->pitch): p->img->pitch;
	
	return MLOADIMAGE_ERR_OK;
}

/** 画像ファイルを読み込み (BMP/PNG/GIF/JPEG)
 *
 * @param bkgndcol アルファ値または透過色がある場合は、この背景色と合成される */

ImageBuf24 *ImageBuf24_loadFile(const char *filename,uint32_t bkgndcol)
{
	_loadimageinfo *p;
	mLoadImageFunc func;
	ImageBuf24 *img = NULL;

	p = (_loadimageinfo *)mLoadImage_create(sizeof(_loadimageinfo));
	if(!p) return NULL;

	ImageBuf24_coltopix(&p->bgpix, bkgndcol);

	p->base.format = MLOADIMAGE_FORMAT_RGBA;
	p->base.src.type = MLOADIMAGE_SOURCE_TYPE_PATH;
	p->base.src.filename = filename;
	p->base.getinfo = _loadfile_getinfo;
	p->base.getrow = _loadfile_getrow;

	//実行

	if(mLoadImage_checkFormat(&p->base.src, &func, MLOADIMAGE_CHECKFORMAT_F_ALL))
	{
		if((func)(M_LOADIMAGE(p)))
			img = p->img;
		else
			ImageBuf24_free(p->img);
	}

	mLoadImage_free(M_LOADIMAGE(p));

	return img;
}