/*$
mlk in apdtool
Copyright (c) 2020 Azel

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
$*/

/*****************************************
 * BMP 保存
 *****************************************/

#include <stdio.h>

#include "mlk.h"
#include "mlk_saveimage.h"
#include "mlk_stdio.h"
#include "mlk_util.h"
#include "mlk_imageconv.h"


//---------------

typedef struct
{
	FILE *fp;
	uint8_t *rowbuf;	//Y1行分のバッファ

	int bits,
		pitch,				//4byte 境界の余白あり
		pitch_nopad,		//余白なし
		infoheader_size;	//INFOHEADER サイズ
}bmpdata;

//---------------


//===========================
// 書き込み
//===========================


/** ファイルヘッダ書き込み */

static int _write_fileheader(bmpdata *p,mSaveImage *si)
{
	uint8_t d[14];
	uint32_t headsize;

	headsize = 14 + p->infoheader_size;

	if(p->bits <= 8)
		headsize += si->palette_num << 2;

	//

	mSetBuf_format(d, "<siii",
		"BM",
		headsize + p->pitch * si->height, //イメージサイズ
		0,
		headsize);	//イメージまでのオフセット

	if(fwrite(d, 1, 14, p->fp) == 14)
		return MLKERR_OK;
	else
		return MLKERR_IO;
}

/** 情報ヘッダ書き込み */

static int _write_infoheader(bmpdata *p,mSaveImage *si)
{
	uint8_t d[40],
		bitfields[16] = {0,0,0xff,0, 0,0xff,0,0, 0xff,0,0,0, 0,0,0,0xff};
	int resoh,resov;

	//解像度 (DPM)

	mSaveImage_getDPM(si, &resoh, &resov);

	//基本情報

	mSetBuf_format(d, "<iiihhiiiiii",
		p->infoheader_size,
		si->width,
		si->height,
		1,			//plane
		p->bits,	//ビット数
		(p->bits == 32)? 3: 0,	//compression (アルファ値ありなら BI_BITFIELDS)
		p->pitch * si->height,	//イメージサイズ
		resoh,
		resov,
		(p->bits <= 8)? si->palette_num: 0,	//パレット数
		0);		//重要な色数

	if(fwrite(d, 1, 40, p->fp) != 40)
		return MLKERR_IO;

	//アルファチャンネルありなら ver4 追加

	if(p->bits == 32)
	{
		//ビットフィールド & 他は0

		if(fwrite(bitfields, 1, 16, p->fp) != 16
			|| mFILEwrite0(p->fp, 108 - 40 - 16))
			return MLKERR_IO;
	}

	return MLKERR_OK;
}

/** パレット書き込み */

static int _write_palette(bmpdata *p,mSaveImage *si)
{
	int i,num,size,ret = 0;
	uint8_t *buf,*ps,*pd;

	num = si->palette_num;
	size = num << 2;

	buf = (uint8_t *)mMalloc(size);
	if(!buf) return MLKERR_ALLOC;

	//RGBX => BGRX に変換

	ps = si->palette_buf;
	pd = buf;

	for(i = num; i > 0; i--, ps += 4, pd += 4)
	{
		pd[0] = ps[2];
		pd[1] = ps[1];
		pd[2] = ps[0];
		pd[3] = 0;
	}

	if(fwrite(buf, 1, size, p->fp) != size)
		ret = MLKERR_IO;

	mFree(buf);

	return ret;
}


//===========================


/** 初期化 */

static int _init(bmpdata *p,mSaveImage *si)
{
	//ピクセルビット数

	if(si->coltype == MSAVEIMAGE_COLTYPE_PALETTE)
		p->bits = si->bits_per_sample;
	else
		p->bits = si->samples_per_pixel * 8;

	//INFOHEADER サイズ (アルファ値ありなら ver 4)

	p->infoheader_size = (p->bits == 32)? 108: 40;

	//Y1行バイト数

	p->pitch_nopad = (si->width * p->bits + 7) >> 3;
	p->pitch = (p->pitch_nopad + 3) & (~3);

	//Y1行バッファ
	/* 4byte 境界の余白を 0 にするため、ゼロクリアしておく */
	
	p->rowbuf = (uint8_t *)mMalloc0(p->pitch);
	if(!p->rowbuf) return MLKERR_ALLOC;

	return MLKERR_OK;
}

/** メイン処理 */

static int _main_proc(bmpdata *p,mSaveImage *si)
{
	int ret,i,height,last_prog,new_prog;
	uint8_t *rowbuf;
	mFuncSaveImageProgress progress;

	//開く

	p->fp = (FILE *)mSaveImage_openFile(si);
	if(!p->fp) return MLKERR_OPEN;

	//初期化

	ret = _init(p, si);
	if(ret) return ret;

	//ファイルヘッダ

	ret = _write_fileheader(p, si);
	if(ret) return ret;

	//情報ヘッダ

	ret = _write_infoheader(p, si);
	if(ret) return ret;

	//パレット

	if(p->bits <= 8)
	{
		ret = _write_palette(p, si);
		if(ret) return ret;
	}

	//イメージ

	rowbuf = p->rowbuf;
	progress = si->progress;
	height = si->height;
	last_prog = 0;

	for(i = 0; i < height; i++)
	{
		ret = (si->setrow)(si, height - 1 - i, rowbuf, p->pitch_nopad);
		if(ret) return ret;

		//RGB 変換

		if(p->bits >= 24)
			mImageConv_swap_rb_8(rowbuf, si->width, si->samples_per_pixel);

		//書き込み

		if(fwrite(rowbuf, 1, p->pitch, p->fp) != p->pitch)
			return MLKERR_IO;

		//経過

		if(progress)
		{
			new_prog = (i + 1) * 100 / height;

			if(new_prog != last_prog)
			{
				(progress)(si, new_prog);
				last_prog = new_prog;
			}
		}
	}

	return MLKERR_OK;
}


//========================


/**@ BMP 保存 */

mlkerr mSaveImageBMP(mSaveImage *si,void *opt)
{
	bmpdata dat;
	int ret;

	mMemset0(&dat, sizeof(bmpdata));

	ret = _main_proc(&dat, si);

	//

	mSaveImage_closeFile(si, dat.fp);

	mFree(dat.rowbuf);

	return ret;
}
