mirror of
https://github.com/lihop/godot-xterm.git
synced 2024-11-10 04:40:25 +01:00
266 lines
7.1 KiB
GDScript
266 lines
7.1 KiB
GDScript
# Copyright (c) 2020 The GodotXterm authors.
|
|
# Copyright (c) 2019 The xterm.js authors. All rights reserved.
|
|
# License MIT
|
|
extends Reference
|
|
|
|
# Convert a given to a utf8 PoolByteArray.
|
|
# The code for this function is based on the stackoverflow
|
|
# answer by user Schwern https://stackoverflow.com/a/42013984.
|
|
static func utf32_to_utf8(codepoint: int):
|
|
var utf8 = PoolByteArray([])
|
|
|
|
if codepoint <= 0x007F:
|
|
utf8.append(codepoint)
|
|
elif codepoint <= 0x07FF:
|
|
utf8.append(0b11000000 | codepoint >> 6 & 0b00011111)
|
|
utf8.append(0b10000000 | codepoint & 0b00111111)
|
|
elif codepoint <= 0xFFFF:
|
|
utf8.append(0b11100000 | codepoint >> 12 & 0b00001111)
|
|
utf8.append(0b10000000 | codepoint >> 6 & 0b00111111)
|
|
utf8.append(0b10000000 | codepoint & 0b00111111)
|
|
elif codepoint <= 0x10FFFF:
|
|
utf8.append(0b11110000 | codepoint >> 18 & 0b00000111)
|
|
utf8.append(0b10000000 | codepoint >> 12 & 0b00111111)
|
|
utf8.append(0b10000000 | codepoint >> 6 & 0b00111111)
|
|
utf8.append(0b10000000 | codepoint & 0b00111111)
|
|
else:
|
|
push_warning("Codepoint " + String(codepoint) + " is out of UTF-8 range")
|
|
|
|
return utf8
|
|
|
|
|
|
# Covert UTF32 char codes into a String.
|
|
# Basically the same as `char` but for multiple codepoints
|
|
# in a loop (which is a lot faster).
|
|
static func utf32_to_string(data: Array, start: int = 0, end: int = -1):
|
|
if end == -1:
|
|
end = data.size()
|
|
var result = ''
|
|
for i in range(start, end):
|
|
result += char(data[i])
|
|
return result
|
|
|
|
|
|
# Utf8Decoder - decodes UTF8 byte sequences into UTF32 codepoints.
|
|
class Utf8ToUtf32:
|
|
var interim = PoolByteArray()
|
|
|
|
func _init():
|
|
interim.resize(3)
|
|
|
|
# Clears interim bytes and resets decoder to clean state.
|
|
func clear():
|
|
for i in interim.size():
|
|
interim[i] = 0
|
|
|
|
# Decodes UTF8 byte sequences in `input` to UTF32 codepoints in `target`.
|
|
# The methods assumes stream input and will store partly transmitted bytes
|
|
# and decode them with the next data chunk.
|
|
# Note: The method does no bound checks for target, therefore make sure
|
|
# the provided data chunk does not exceed the size of `target`.
|
|
# Returns the number of written codepoints in `target`.
|
|
func decode(input: PoolByteArray, target: Array):
|
|
var length = input.size()
|
|
|
|
if !length:
|
|
return 0
|
|
|
|
if length > target.size():
|
|
target.resize(length)
|
|
|
|
var size = 0
|
|
var byte1: int
|
|
var byte2: int
|
|
var byte3: int
|
|
var byte4: int
|
|
var codepoint = 0
|
|
var start_pos = 0
|
|
|
|
# handle leftover bytes
|
|
if interim[0]:
|
|
var discard_interim = false
|
|
var cp = interim[0]
|
|
cp &= 0x1F if (cp & 0xE0) == 0xC0 else 0x0F if (cp & 0xF0) == 0xE0 else 0x07
|
|
var pos = 1
|
|
var tmp = interim[pos] & 0x3F
|
|
while tmp && pos < 4:
|
|
cp <<= 6
|
|
cp |= tmp
|
|
pos += 1
|
|
tmp = interim[pos] & 0x3F if interim.size() < pos else 0
|
|
# missing bytes - read from input
|
|
var type = 2 if (interim[0] & 0xE0) == 0xC0 else 3 if (interim[0] & 0xF0) == 0xE0 else 4
|
|
var missing = type - pos
|
|
while start_pos < missing:
|
|
if start_pos >= length:
|
|
return 0
|
|
tmp = input[start_pos]
|
|
start_pos += 1
|
|
if (tmp & 0xC0) != 0x80:
|
|
# wrong continuation, discard interim bytes completely
|
|
start_pos -= 1
|
|
discard_interim = true
|
|
break
|
|
else:
|
|
# need to save so we can continue short inputs in next call
|
|
interim[pos + 1] = tmp
|
|
pos += 1
|
|
cp <<= 6
|
|
cp |= tmp & 0x3F
|
|
if not discard_interim:
|
|
# final test is type dependent
|
|
match type:
|
|
2:
|
|
if cp < 0x80:
|
|
# wrong starter byte
|
|
start_pos -= 1
|
|
else:
|
|
target[size] = cp
|
|
size += 1
|
|
3:
|
|
if cp < 0x0800 or (cp >= 0xD800 and cp <= 0xDFFF):
|
|
# illegal codepoint
|
|
pass
|
|
else:
|
|
target[size] = cp
|
|
size += 1
|
|
_:
|
|
if cp < 0x10000 or cp > 0x10FFFF:
|
|
# illegal codepoint
|
|
pass
|
|
else:
|
|
target[size] = cp
|
|
size += 1
|
|
clear()
|
|
|
|
# loop through input
|
|
var four_stop = length - 4
|
|
var i = start_pos
|
|
while i < length:
|
|
# ASCII shortcut with loop unrolled to 4 consecutive ASCII chars.
|
|
# This is a compromise between speed gain for ASCII
|
|
# and penalty for non ASCII:
|
|
# For best ASCII performance the char should be stored directly into target,
|
|
# but even a single attempt to write to target and compare afterwards
|
|
# penalizes non ASCII really bad (-50%), thus we load the char into byteX first,
|
|
# which reduces ASCII performance by ~15%.
|
|
# This trial for ASCII reduces non ASCII performance by ~10% which seems acceptible
|
|
# compared to the gains.
|
|
# Note that this optimization only takes place for 4 consecutive ASCII chars,
|
|
# for any shorter it bails out. Worst case - all 4 bytes being read but
|
|
# thrown away due to the last being a non ASCII char (-10% performance).
|
|
while i < four_stop:
|
|
byte1 = input[i]
|
|
byte2 = input[i + 1]
|
|
byte3 = input[i + 2]
|
|
byte4 = input[i + 3]
|
|
if not (byte1 & 0x80) | (byte2 & 0x80) | (byte3 & 0x80) | (byte4 & 0x80):
|
|
target[size] = byte1
|
|
target[size+1] = byte2
|
|
target[size+2] = byte3
|
|
target[size+3] = byte4
|
|
size += 4
|
|
i += 4
|
|
else:
|
|
break
|
|
|
|
# reread byte1
|
|
byte1 = input[i]
|
|
i += 1
|
|
|
|
# 1 byte
|
|
if byte1 < 0x80:
|
|
target[size] = byte1
|
|
size += 1
|
|
|
|
# 2 bytes
|
|
elif (byte1 & 0xE0) == 0xC0:
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
return size
|
|
byte2 = input[i]
|
|
i+=1
|
|
if (byte2 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i-=1
|
|
continue
|
|
codepoint = (byte1 & 0x1F) << 6 | (byte2 & 0x3F)
|
|
if (codepoint < 0x80):
|
|
# wrong starter byte
|
|
i-=1
|
|
continue
|
|
target[size] = codepoint
|
|
size+=1
|
|
|
|
# 3 bytes
|
|
elif (byte1 & 0xF0) == 0xE0:
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
return size
|
|
byte2 = input[i]
|
|
i+=1
|
|
if (byte2 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i-=1
|
|
continue
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
interim[1] = byte2
|
|
return size
|
|
byte3 = input[i]
|
|
i+=1
|
|
if (byte3 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i-=1
|
|
continue
|
|
codepoint = (byte1 & 0x0F) << 12 | (byte2 & 0x3F) << 6 | (byte3 & 0x3F)
|
|
if codepoint < 0x0800 or (codepoint >=0xD800 and codepoint <= 0xDFFF):
|
|
# illegal codepoint, no i-- here
|
|
continue
|
|
target[size] = codepoint
|
|
size+=1
|
|
|
|
# 4 bytes
|
|
elif (byte1 & 0xF8) == 0xF0:
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
return size
|
|
byte2 = input[i]
|
|
i += 1
|
|
if (byte2 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i -= 1
|
|
continue
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
interim[1] = byte2
|
|
return size
|
|
byte3 = input[i]
|
|
i += 1
|
|
if (byte3 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i -= 1
|
|
continue
|
|
if i >= length:
|
|
interim[0] = byte1
|
|
interim[1] = byte2
|
|
interim[2] = byte3
|
|
return size
|
|
byte4 = input[i]
|
|
i += 1
|
|
if (byte4 & 0xC0) != 0x80:
|
|
# wrong continuation
|
|
i -= 1
|
|
continue
|
|
codepoint = (byte1 & 0x07) << 18 | (byte2 & 0x3F) << 12 | (byte3 & 0x3F) << 6 | (byte4 & 0x3F)
|
|
if codepoint < 0x010000 or codepoint > 0x10FFFF:
|
|
# illegal codepoint, no i-- here
|
|
continue
|
|
target[size] = codepoint
|
|
size += 1
|
|
else:
|
|
# illegal byte, just skip
|
|
pass
|
|
|
|
target.resize(size)
|
|
return size
|