;============================================================
;   iron_mmd.hsp — MikuMiku Dance PMD / PMX ローダ (最小実装)
;
;   MMD の PMD (旧) / PMX (新) バイナリモデルから頂点位置 / 法線 /
;   UV / 三角形インデックスのみを抜き出す最小実装。
;
;   対応:
;     PMD 1.0 (ヘッダ "Pmd\0")    — vertex / face のみ
;     PMX 2.0 / 2.1 (ヘッダ "PMX ") — vertex / face のみ (bone/morph/material 無視)
;
;   対応外:
;     マテリアル / ボーン / モーフ / IK / 剛体 / ジョイント / 物理 /
;     テクスチャ / 英名表示 / toon / SDEF ...
;
;   API:
;     mmd_load "file.pmx", var_verts, var_norms, var_uvs, var_tris,
;              var n_verts, var n_tris, var kind
;        verts: double[3 * n_verts]
;        norms: double[3 * n_verts]
;        uvs:   double[2 * n_verts]
;        tris:  int[3 * n_tris]
;        kind:  1=PMD / 2=PMX
;        戻り値: 0=OK / <0=エラー
;
;     mmd_meta "file.pmx", var_name_jp, var_name_en, var_comment_jp, var_comment_en
;        PMX モデル名 / コメントを取得 (PMX のみ、PMD は空文字返却)
;
;   文字エンコーディング:
;     PMX 2.0 ヘッダ[0]=0 なら UTF-16LE、=1 なら UTF-8。
;     mmd_meta は hsp3net の cnvwtos でシステム依存 SJIS に、
;     cnvstow 経由で wstr に変換してから返す。
;============================================================
#ifndef __iron_mmd_hsp__
#define __iron_mmd_hsp__

#module iron_mmd

;---------------------------------------------------------
; internal: PMX TextBuf (u32 len + bytes) から文字列取り出し
;   encoding: 0=UTF-16LE / 1=UTF-8
;   v_out に SJIS 相当を格納、new_off に次の offset を返す
;---------------------------------------------------------
#deffunc _mmd_read_text var buf, int ofs, int encoding, var v_out, var v_new_off, \
	local _len, local _tmp, local _i, local _cp, local _hi, local _lo
	_len = lpeek(buf, ofs)
	sdim v_out, 1024
	if _len <= 0 {
		v_out = ""
		v_new_off = ofs + 4
		return
	}
	if encoding = 1 {
		; UTF-8: そのまま SJIS としては扱えないが、hsp3net ならそのまま入れる
		sdim v_out, _len + 16
		memcpy v_out, buf, _len, 0, ofs + 4
		poke v_out, _len, 0
	} else {
		; UTF-16LE → BMP 範囲なら UTF-8 化して返す (簡易版)
		sdim v_out, _len * 3 + 16
		sdim _tmp, _len * 3 + 16
		_i = 0
		repeat _len / 2
			_cp = wpeek(buf, ofs + 4 + _i)
			_i = _i + 2
			if _cp < 0x80 {
				poke _tmp, strlen(_tmp), _cp
			} else {
				if _cp < 0x800 {
					poke _tmp, strlen(_tmp), 0xC0 | (_cp >> 6)
					poke _tmp, strlen(_tmp), 0x80 | (_cp & 0x3F)
				} else {
					poke _tmp, strlen(_tmp), 0xE0 | (_cp >> 12)
					poke _tmp, strlen(_tmp), 0x80 | ((_cp >> 6) & 0x3F)
					poke _tmp, strlen(_tmp), 0x80 | (_cp & 0x3F)
				}
			}
		loop
		v_out = _tmp
	}
	v_new_off = ofs + 4 + _len
	return

#defcfunc _mmd_flt var buf, int ofs, \
	local _b, local _s, local _e, local _m, local _md, local _ex, local _v
	_b = lpeek(buf, ofs)
	_s = (_b >> 31) & 1
	_e = (_b >> 23) & 0xFF
	_m = _b & 0x7FFFFF
	if _e = 0 : return 0.0
	if _e = 0xFF : return 0.0
	_md = 1.0 + (1.0 * _m) / 8388608.0
	_ex = _e - 127
	_v = _md
	if _ex >= 0 : repeat _ex : _v *= 2.0 : loop
	if _ex < 0  : repeat 0 - _ex : _v *= 0.5 : loop
	if _s = 1 : _v = 0.0 - _v
	return _v

#defcfunc _mmd_idx_signed var buf, int ofs, int nbytes
	if nbytes = 1 {
		if peek(buf, ofs) & 0x80 : return peek(buf, ofs) - 256
		return peek(buf, ofs)
	}
	if nbytes = 2 {
		if wpeek(buf, ofs) & 0x8000 : return wpeek(buf, ofs) - 65536
		return wpeek(buf, ofs)
	}
	return lpeek(buf, ofs)

#defcfunc _mmd_idx_unsigned var buf, int ofs, int nbytes
	if nbytes = 1 : return peek(buf, ofs)
	if nbytes = 2 : return wpeek(buf, ofs)
	return lpeek(buf, ofs)

;---------------------------------------------------------
; mmd_load メイン
;---------------------------------------------------------
#deffunc mmd_load str path, var v_verts, var v_norms, var v_uvs, var v_tris, \
	var v_nv, var v_nt, var v_kind, \
	local _size, local _buf, local _off, local _kind, \
	local _vcount, local _fcount, local _i, local _globals_count, \
	local _text_enc, local _add_uv, local _vidx_size, local _texidx_size, \
	local _matidx_size, local _boneidx_size, local _morphidx_size, local _rbidx_size, \
	local _tmp_count, local _skip_len, local _wdef
	exist path
	_size = strsize
	if _size <= 0 : return -1
	sdim _buf, _size + 16
	bload path, _buf, _size

	; ヘッダ判別
	_kind = 0
	if (peek(_buf, 0) = 'P') & (peek(_buf, 1) = 'm') & (peek(_buf, 2) = 'd') : _kind = 1
	if (peek(_buf, 0) = 'P') & (peek(_buf, 1) = 'M') & (peek(_buf, 2) = 'X') : _kind = 2
	if _kind = 0 : return -2

	if _kind = 1 {
		; ========== PMD ==========
		; 0-2  "Pmd"
		; 3-6  version float
		; 7-26 model name (20 bytes SJIS)
		; 27-282 comment (256 bytes)
		; 283- vertex count (u32)
		_off = 283
		_vcount = lpeek(_buf, _off)
		_off = _off + 4
		; vertex: 38 bytes × N
		;  position float[3] (12), normal float[3] (12), uv float[2] (8),
		;  bone_num u16[2] (4), bone_weight u8 (1), edge_flag u8 (1)
		ddim v_verts, _vcount * 3
		ddim v_norms, _vcount * 3
		ddim v_uvs,   _vcount * 2
		repeat _vcount
			v_verts(cnt * 3 + 0) = _mmd_flt(_buf, _off + cnt * 38 + 0)
			v_verts(cnt * 3 + 1) = _mmd_flt(_buf, _off + cnt * 38 + 4)
			v_verts(cnt * 3 + 2) = _mmd_flt(_buf, _off + cnt * 38 + 8)
			v_norms(cnt * 3 + 0) = _mmd_flt(_buf, _off + cnt * 38 + 12)
			v_norms(cnt * 3 + 1) = _mmd_flt(_buf, _off + cnt * 38 + 16)
			v_norms(cnt * 3 + 2) = _mmd_flt(_buf, _off + cnt * 38 + 20)
			v_uvs(cnt * 2 + 0)   = _mmd_flt(_buf, _off + cnt * 38 + 24)
			v_uvs(cnt * 2 + 1)   = _mmd_flt(_buf, _off + cnt * 38 + 28)
		loop
		_off = _off + _vcount * 38
		; face index count (u32) → triangle = count / 3
		_fcount = lpeek(_buf, _off) / 3
		_off = _off + 4
		dim v_tris, _fcount * 3
		repeat _fcount
			v_tris(cnt * 3 + 0) = wpeek(_buf, _off + cnt * 6 + 0)
			v_tris(cnt * 3 + 1) = wpeek(_buf, _off + cnt * 6 + 2)
			v_tris(cnt * 3 + 2) = wpeek(_buf, _off + cnt * 6 + 4)
		loop
		v_nv = _vcount : v_nt = _fcount : v_kind = 1
		return 0
	}

	; ========== PMX ==========
	; 0-3  "PMX "
	; 4-7  version float (2.0 / 2.1)
	; 8    globals count (expected 8)
	; 9..  globals[globals_count]:
	;   [0] text encoding (0=UTF-16LE / 1=UTF-8)
	;   [1] extra UV count (0-4)
	;   [2] vertex index size (1/2/4)
	;   [3] texture index size (1/2/4)
	;   [4] material index size
	;   [5] bone index size
	;   [6] morph index size
	;   [7] rigidbody index size
	_globals_count = peek(_buf, 8)
	_off = 9
	if _globals_count < 8 : return -3
	_text_enc     = peek(_buf, _off + 0)
	_add_uv       = peek(_buf, _off + 1)
	_vidx_size    = peek(_buf, _off + 2)
	_texidx_size  = peek(_buf, _off + 3)
	_matidx_size  = peek(_buf, _off + 4)
	_boneidx_size = peek(_buf, _off + 5)
	_morphidx_size= peek(_buf, _off + 6)
	_rbidx_size   = peek(_buf, _off + 7)
	_off = _off + _globals_count
	; model info: 4 TextBuf (Japanese name / English name / Japanese comment / English comment)
	; PMX スペックでは name_jp, name_en, comment_jp, comment_en の順
	; スキップのみ (名前を取るのは mmd_meta で別途)
	repeat 4
		_tmp_count = lpeek(_buf, _off)
		_off = _off + 4 + _tmp_count
	loop
	; vertex count
	_vcount = lpeek(_buf, _off)
	_off = _off + 4
	; vertex size (2.0): pos[3] (12) + normal[3] (12) + uv[2] (8)
	;                  + additional_uv[4]*addUV (16*addUV) + weight_kind (1)
	;                  + variable weight data + edge factor (4)
	ddim v_verts, _vcount * 3
	ddim v_norms, _vcount * 3
	ddim v_uvs,   _vcount * 2
	_i = 0
	repeat _vcount
		v_verts(cnt * 3 + 0) = _mmd_flt(_buf, _off + 0)
		v_verts(cnt * 3 + 1) = _mmd_flt(_buf, _off + 4)
		v_verts(cnt * 3 + 2) = _mmd_flt(_buf, _off + 8)
		v_norms(cnt * 3 + 0) = _mmd_flt(_buf, _off + 12)
		v_norms(cnt * 3 + 1) = _mmd_flt(_buf, _off + 16)
		v_norms(cnt * 3 + 2) = _mmd_flt(_buf, _off + 20)
		v_uvs(cnt * 2 + 0)   = _mmd_flt(_buf, _off + 24)
		v_uvs(cnt * 2 + 1)   = _mmd_flt(_buf, _off + 28)
		_off = _off + 32 + 16 * _add_uv
		; weight
		_wdef = peek(_buf, _off)
		_off++
		if _wdef = 0 : _skip_len = _boneidx_size                                   ; BDEF1
		if _wdef = 1 : _skip_len = _boneidx_size * 2 + 4                           ; BDEF2
		if _wdef = 2 : _skip_len = _boneidx_size * 4 + 16                          ; BDEF4
		if _wdef = 3 : _skip_len = _boneidx_size * 2 + 4 + 36                      ; SDEF
		if _wdef = 4 : _skip_len = _boneidx_size * 4 + 16                          ; QDEF (PMX 2.1)
		_off = _off + _skip_len
		; edge factor
		_off = _off + 4
	loop
	; face index count (u32)
	_tmp_count = lpeek(_buf, _off)
	_off = _off + 4
	_fcount = _tmp_count / 3
	dim v_tris, _fcount * 3
	repeat _fcount
		v_tris(cnt * 3 + 0) = _mmd_idx_unsigned(_buf, _off + 0 * _vidx_size, _vidx_size)
		v_tris(cnt * 3 + 1) = _mmd_idx_unsigned(_buf, _off + 1 * _vidx_size, _vidx_size)
		v_tris(cnt * 3 + 2) = _mmd_idx_unsigned(_buf, _off + 2 * _vidx_size, _vidx_size)
		_off = _off + 3 * _vidx_size
	loop
	v_nv = _vcount : v_nt = _fcount : v_kind = 2
	return 0

;---------------------------------------------------------
; mmd_meta  — PMX のモデル名 / コメントを UTF-8 で取得
;   PMD は未対応 (SJIS 固定文字列だが省略)
;---------------------------------------------------------
#deffunc mmd_meta str path, var v_name_jp, var v_name_en, var v_comment_jp, var v_comment_en, \
	local _size, local _buf, local _off, local _enc, local _globals_count
	sdim v_name_jp, 256 : sdim v_name_en, 256
	sdim v_comment_jp, 2048 : sdim v_comment_en, 2048
	v_name_jp = "" : v_name_en = "" : v_comment_jp = "" : v_comment_en = ""
	exist path
	_size = strsize
	if _size <= 0 : return -1
	sdim _buf, _size + 16
	bload path, _buf, _size
	if (peek(_buf, 0) != 'P') | (peek(_buf, 1) != 'M') | (peek(_buf, 2) != 'X') : return -2
	_globals_count = peek(_buf, 8)
	_enc = peek(_buf, 9)    ; globals[0] = text encoding
	_off = 9 + _globals_count
	_mmd_read_text _buf, _off, _enc, v_name_jp,    _off
	_mmd_read_text _buf, _off, _enc, v_name_en,    _off
	_mmd_read_text _buf, _off, _enc, v_comment_jp, _off
	_mmd_read_text _buf, _off, _enc, v_comment_en, _off
	return 0

#global
#endif