;============================================================
;   iron_ply.hsp — Stanford PLY ローダ (pure HSP)
;
;   .ply (Stanford Polygon Library) の ASCII 版を読み込み、
;   頂点位置 / (オプションで) 法線・色・UV、および面リストを配列に展開する。
;   点群 (face 数 0) でも問題なく読める。
;
;   対応: format ascii 1.0 / binary_little_endian 1.0
;   element vertex N + element face M の典型構造を期待する。
;   vertex プロパティは x y z (+ nx ny nz + red green blue など) を
;   自動検出して可能な限り拾う。
;
;   API:
;     ply_load "file.ply", var_verts, var_cols, var_norms, var_tris,
;              var n_verts, var n_tris, var has_color, var has_norm
;        verts:   double[3 * n_verts]
;        cols:    int[3 * n_verts]  (0-255 RGB、色なし時は未使用)
;        norms:   double[3 * n_verts]
;        tris:    int[3 * n_tris]   (三角形化済、頂点インデックス)
;        戻り値: 0=OK / <0=エラー
;
;   制限: ASCII only / 255 > の頂点要素種別 / 三角以外の面は扇分割
;============================================================
#ifndef __iron_ply_hsp__
#define __iron_ply_hsp__

#ifndef PLY_MAX_VERTS
#define PLY_MAX_VERTS 1048576
#endif
#ifndef PLY_MAX_TRIS
#define PLY_MAX_TRIS 1048576
#endif

#module iron_ply

#deffunc ply_load str path, var v_verts, var v_cols, var v_norms, var v_tris, \
	var v_nv, var v_nt, var v_has_color, var v_has_norm, \
	local _size, local _buf, local _p, local _eol, local _line, \
	local _in_header, local _vert_count, local _face_count, \
	local _props, local _prop_sz, local _np, local _i, local _toks, local _ntok, \
	local _pi, local _n_verts, local _n_tris, local _is_binary, \
	local _ix, local _iy, local _iz, local _inx, local _iny, local _inz, \
	local _ir, local _ig, local _ib, local _stride, local _offsets, \
	local _val_x, local _val_y, local _val_z, \
	local _face_k, local _first_v, local _prev_v, local _cur_v, \
	local _list_cnt_sz, local _list_idx_sz, local _in_face_section
	exist path
	_size = strsize
	if _size <= 0 : return -1
	sdim _buf, _size + 16
	bload path, _buf, _size

	ddim v_verts, PLY_MAX_VERTS * 3
	ddim v_norms, PLY_MAX_VERTS * 3
	dim  v_cols,  PLY_MAX_VERTS * 3
	dim  v_tris,  PLY_MAX_TRIS * 3
	v_nv = 0 : v_nt = 0 : v_has_color = 0 : v_has_norm = 0
	_n_verts = 0 : _n_tris = 0
	_vert_count = 0 : _face_count = 0
	_ix = -1 : _iy = -1 : _iz = -1
	_inx = -1 : _iny = -1 : _inz = -1
	_ir = -1 : _ig = -1 : _ib = -1
	_list_cnt_sz = 1 : _list_idx_sz = 4
	_is_binary = 0
	sdim _props, 32, 32
	dim _prop_sz, 32
	dim _offsets, 32
	_np = 0 : _stride = 0
	_in_header = 1
	_in_face_section = 0
	_p = 0

	; ---- header ----
	repeat
		if _p >= _size : break
		_eol = instr(_buf, _p, "\n")
		if _eol < 0 {
			_line = strmid(_buf, _p, _size - _p)
			_p = _size
		} else {
			_line = strmid(_buf, _p, _eol - _p)
			_p = _eol + 1
		}
		if strlen(_line) > 0 {
			if peek(_line, strlen(_line) - 1) = 13 : _line = strmid(_line, 0, strlen(_line) - 1)
		}
		if strlen(_line) = 0 : continue
		if _line = "end_header" : _in_header = 0 : break
		sdim _toks, 64, 8
		_ntok = 0
		_ply_split_ws _line, _toks, _ntok
		if _ntok = 0 : continue
		if _toks(0) = "format" {
			if _toks(1) = "ascii" : _is_binary = 0
			if _toks(1) = "binary_little_endian" : _is_binary = 1
			if _toks(1) = "binary_big_endian" : return -2   ; BE 未対応
			continue
		}
		if _toks(0) = "element" {
			if _toks(1) = "vertex" : _vert_count = int(_toks(2)) : _in_face_section = 0
			if _toks(1) = "face"   : _face_count = int(_toks(2)) : _in_face_section = 1
			continue
		}
		if _toks(0) = "property" {
			if _toks(1) = "list" {
				; property list <count_type> <index_type> vertex_indices
				if _in_face_section {
					_list_cnt_sz = _ply_type_size(_toks(2))
					_list_idx_sz = _ply_type_size(_toks(3))
				}
				continue
			}
			; property <type> <name> — element vertex 側のみ index を記録
			if _in_face_section = 0 {
				if _np < 32 {
					_props(_np)   = _toks(2)
					_prop_sz(_np) = _ply_type_size(_toks(1))
					_offsets(_np) = _stride
					_stride = _stride + _prop_sz(_np)
					if _toks(2) = "x"  : _ix  = _np
					if _toks(2) = "y"  : _iy  = _np
					if _toks(2) = "z"  : _iz  = _np
					if _toks(2) = "nx" : _inx = _np
					if _toks(2) = "ny" : _iny = _np
					if _toks(2) = "nz" : _inz = _np
					if _toks(2) = "red"   : _ir = _np
					if _toks(2) = "green" : _ig = _np
					if _toks(2) = "blue"  : _ib = _np
					_np++
				}
			}
			continue
		}
	loop
	if _in_header = 1 : return -3
	if _ix < 0 | _iy < 0 | _iz < 0 : return -4
	if _inx >= 0 : v_has_norm = 1
	if _ir  >= 0 : v_has_color = 1

	; ---- Binary 分岐 (inline) ----
	if _is_binary {
		; 頂点
		repeat _vert_count
			if _p + _stride > _size : break
			if _n_verts >= PLY_MAX_VERTS : break
			if _prop_sz(_ix) = 4 {
				v_verts(_n_verts * 3 + 0) = _ply_float(_buf, _p + _offsets(_ix))
				v_verts(_n_verts * 3 + 1) = _ply_float(_buf, _p + _offsets(_iy))
				v_verts(_n_verts * 3 + 2) = _ply_float(_buf, _p + _offsets(_iz))
			}
			if v_has_norm : if _inx >= 0 {
				v_norms(_n_verts * 3 + 0) = _ply_float(_buf, _p + _offsets(_inx))
				v_norms(_n_verts * 3 + 1) = _ply_float(_buf, _p + _offsets(_iny))
				v_norms(_n_verts * 3 + 2) = _ply_float(_buf, _p + _offsets(_inz))
			}
			if v_has_color : if _ir >= 0 {
				v_cols(_n_verts * 3 + 0) = peek(_buf, _p + _offsets(_ir))
				v_cols(_n_verts * 3 + 1) = peek(_buf, _p + _offsets(_ig))
				v_cols(_n_verts * 3 + 2) = peek(_buf, _p + _offsets(_ib))
			}
			_n_verts++
			_p = _p + _stride
		loop
		; 面: property list <cnt_size> <idx_size>
		repeat _face_count
			if _p + _list_cnt_sz > _size : break
			_face_k = _ply_uint(_buf, _p, _list_cnt_sz)
			_p = _p + _list_cnt_sz
			if _face_k < 3 {
				_p = _p + _face_k * _list_idx_sz
				continue
			}
			_first_v = _ply_uint(_buf, _p, _list_idx_sz)
			_prev_v  = _ply_uint(_buf, _p + _list_idx_sz, _list_idx_sz)
			_i = 2
			repeat _face_k - 2
				if _n_tris >= PLY_MAX_TRIS : break
				_cur_v = _ply_uint(_buf, _p + _i * _list_idx_sz, _list_idx_sz)
				v_tris(_n_tris * 3 + 0) = _first_v
				v_tris(_n_tris * 3 + 1) = _prev_v
				v_tris(_n_tris * 3 + 2) = _cur_v
				_prev_v = _cur_v
				_i++
				_n_tris++
			loop
			_p = _p + _face_k * _list_idx_sz
		loop
		v_nv = _n_verts : v_nt = _n_tris
		return 0
	}

	; ---- vertex body ----
	_i = 0
	repeat _vert_count
		if _p >= _size : break
		_eol = instr(_buf, _p, "\n")
		if _eol < 0 {
			_line = strmid(_buf, _p, _size - _p)
			_p = _size
		} else {
			_line = strmid(_buf, _p, _eol - _p)
			_p = _eol + 1
		}
		if strlen(_line) > 0 {
			if peek(_line, strlen(_line) - 1) = 13 : _line = strmid(_line, 0, strlen(_line) - 1)
		}
		if strlen(_line) = 0 : continue
		sdim _toks, 64, 32
		_ntok = 0
		_ply_split_ws _line, _toks, _ntok
		if _n_verts >= PLY_MAX_VERTS : break
		v_verts(_n_verts * 3 + 0) = double(_toks(_ix))
		v_verts(_n_verts * 3 + 1) = double(_toks(_iy))
		v_verts(_n_verts * 3 + 2) = double(_toks(_iz))
		if v_has_norm {
			if (_inx < _ntok) & (_iny < _ntok) & (_inz < _ntok) {
				v_norms(_n_verts * 3 + 0) = double(_toks(_inx))
				v_norms(_n_verts * 3 + 1) = double(_toks(_iny))
				v_norms(_n_verts * 3 + 2) = double(_toks(_inz))
			}
		}
		if v_has_color {
			if (_ir < _ntok) & (_ig < _ntok) & (_ib < _ntok) {
				v_cols(_n_verts * 3 + 0) = int(_toks(_ir))
				v_cols(_n_verts * 3 + 1) = int(_toks(_ig))
				v_cols(_n_verts * 3 + 2) = int(_toks(_ib))
			}
		}
		_n_verts++
	loop

	; ---- face body ----
	_i = 0
	repeat _face_count
		if _p >= _size : break
		_eol = instr(_buf, _p, "\n")
		if _eol < 0 {
			_line = strmid(_buf, _p, _size - _p)
			_p = _size
		} else {
			_line = strmid(_buf, _p, _eol - _p)
			_p = _eol + 1
		}
		if strlen(_line) > 0 {
			if peek(_line, strlen(_line) - 1) = 13 : _line = strmid(_line, 0, strlen(_line) - 1)
		}
		if strlen(_line) = 0 : continue
		sdim _toks, 64, 32
		_ntok = 0
		_ply_split_ws _line, _toks, _ntok
		if _ntok < 4 : continue        ; "3 a b c" 最小
		_face_k = int(_toks(0))
		if _face_k < 3 : continue
		_first_v = int(_toks(1))
		_prev_v  = int(_toks(2))
		repeat _face_k - 2
			if _n_tris >= PLY_MAX_TRIS : break
			_cur_v = int(_toks(3 + cnt))
			v_tris(_n_tris * 3 + 0) = _first_v
			v_tris(_n_tris * 3 + 1) = _prev_v
			v_tris(_n_tris * 3 + 2) = _cur_v
			_prev_v = _cur_v
			_n_tris++
		loop
	loop

	v_nv = _n_verts : v_nt = _n_tris
	return 0

#deffunc _ply_split_ws str s, array v_out, var v_n, \
	local _start, local _in_tok, local _c
	_start = 0 : _in_tok = 0 : v_n = 0
	repeat strlen(s) + 1
		if cnt = strlen(s) {
			if _in_tok = 1 : v_out(v_n) = strmid(s, _start, cnt - _start) : v_n++
			break
		}
		_c = peek(s, cnt)
		if (_c = ' ') | (_c = 9) {
			if _in_tok = 1 {
				v_out(v_n) = strmid(s, _start, cnt - _start) : v_n++
				_in_tok = 0
			}
		} else {
			if _in_tok = 0 : _start = cnt : _in_tok = 1
		}
	loop
	return

;---------------------------------------------------------
; internal: PLY 型名 → バイトサイズ
;---------------------------------------------------------
#defcfunc _ply_type_size str t
	if t = "char"  : return 1
	if t = "uchar" : return 1
	if t = "int8"  : return 1
	if t = "uint8" : return 1
	if t = "short" : return 2
	if t = "ushort": return 2
	if t = "int16" : return 2
	if t = "uint16": return 2
	if t = "int"   : return 4
	if t = "uint"  : return 4
	if t = "int32" : return 4
	if t = "uint32": return 4
	if t = "float" : return 4
	if t = "float32": return 4
	if t = "double": return 8
	if t = "float64": return 8
	return 4

;---------------------------------------------------------
; internal: little-endian float 32bit 読み (pure HSP)
;---------------------------------------------------------
#defcfunc _ply_float 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

;---------------------------------------------------------
; internal: unsigned int read at given byte size (1/2/4)
;---------------------------------------------------------
#defcfunc _ply_uint var buf, int ofs, int sz
	if sz = 1 : return peek(buf, ofs)
	if sz = 2 : return wpeek(buf, ofs)
	return lpeek(buf, ofs)

#global
#endif