/**************************************************************************/
/* script_iterator.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* 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. */
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/**************************************************************************/
#include "script_iterator.h"
// This implementation is derived from ICU: icu4c/source/extra/scrptrun/scrptrun.cpp
inline constexpr UChar32 ZERO_WIDTH_JOINER = 0x200d;
inline constexpr UChar32 VARIATION_SELECTOR_15 = 0xfe0e;
inline constexpr UChar32 VARIATION_SELECTOR_16 = 0xfe0f;
inline constexpr UChar32 COMBINING_ENCLOSING_KEYCAP = 0x20e3;
inline bool ScriptIterator::same_script(int32_t p_script_one, int32_t p_script_two) {
return p_script_one <= USCRIPT_INHERITED || p_script_two <= USCRIPT_INHERITED || p_script_one == p_script_two;
}
inline bool ScriptIterator::is_emoji(UChar32 p_c, UChar32 p_next) {
if (p_next == VARIATION_SELECTOR_15 && (u_hasBinaryProperty(p_c, UCHAR_EMOJI) || u_hasBinaryProperty(p_c, UCHAR_EXTENDED_PICTOGRAPHIC))) {
return false;
} else if (p_next == VARIATION_SELECTOR_16 && (u_hasBinaryProperty(p_c, UCHAR_EMOJI) || u_hasBinaryProperty(p_c, UCHAR_EXTENDED_PICTOGRAPHIC))) {
return true;
} else {
return u_hasBinaryProperty(p_c, UCHAR_EMOJI_PRESENTATION) || u_hasBinaryProperty(p_c, UCHAR_EMOJI_MODIFIER) || u_hasBinaryProperty(p_c, UCHAR_REGIONAL_INDICATOR);
}
}
ScriptIterator::ScriptIterator(const String &p_string, int p_start, int p_length) {
struct ParenStackEntry {
int pair_index;
UScriptCode script_code;
};
struct EmojiSubrunEntry {
int start;
int end;
};
if (p_start >= p_length) {
p_start = p_length - 1;
}
if (p_start < 0) {
p_start = 0;
}
int paren_size = PAREN_STACK_DEPTH;
ParenStackEntry starter_paren_stack[PAREN_STACK_DEPTH];
ParenStackEntry *paren_stack = starter_paren_stack;
int emoji_size = EMOJI_STACK_DEPTH;
EmojiSubrunEntry starter_emoji_stack[EMOJI_STACK_DEPTH];
EmojiSubrunEntry *emoji_stack = starter_emoji_stack;
int script_start;
int script_end = p_start;
UScriptCode script_code;
int paren_sp = -1;
int start_sp = paren_sp;
UErrorCode err = U_ZERO_ERROR;
const char32_t *str = p_string.ptr();
do {
script_code = USCRIPT_COMMON;
int emoji_sp = -1;
bool emoji_run = false;
for (script_start = script_end; script_end < p_length; script_end++) {
UChar32 ch = str[script_end];
UChar32 n = (script_end + 1 < p_length) ? str[script_end + 1] : 0;
if (is_emoji(ch, n)) {
if (!emoji_run) {
emoji_run = true;
emoji_sp++;
if (unlikely(emoji_sp >= emoji_size)) {
emoji_size += EMOJI_STACK_DEPTH;
if (emoji_stack == starter_emoji_stack) {
emoji_stack = static_cast<EmojiSubrunEntry *>(memalloc(emoji_size * sizeof(EmojiSubrunEntry)));
} else {
emoji_stack = static_cast<EmojiSubrunEntry *>(memrealloc(emoji_stack, emoji_size * sizeof(EmojiSubrunEntry)));
}
}
emoji_stack[emoji_sp].start = script_end;
emoji_stack[emoji_sp].end = script_end;
}
} else if (emoji_run && ch != ZERO_WIDTH_JOINER && ch != VARIATION_SELECTOR_16 && ch != COMBINING_ENCLOSING_KEYCAP && !(u_hasBinaryProperty(ch, UCHAR_EXTENDED_PICTOGRAPHIC) && n != VARIATION_SELECTOR_15)) {
emoji_run = false;
emoji_stack[emoji_sp].end = script_end;
}
UScriptCode sc = uscript_getScript(ch, &err);
if (U_FAILURE(err)) {
if (paren_stack != starter_paren_stack) {
memfree(paren_stack);
}
ERR_FAIL_MSG(u_errorName(err));
}
if (u_getIntPropertyValue(ch, UCHAR_BIDI_PAIRED_BRACKET_TYPE) != U_BPT_NONE) {
if (u_getIntPropertyValue(ch, UCHAR_BIDI_PAIRED_BRACKET_TYPE) == U_BPT_OPEN) {
// If it's an open character, push it onto the stack.
paren_sp++;
if (unlikely(paren_sp >= paren_size)) {
// If the stack is full, allocate more space to handle deeply nested parentheses. This is unlikely to happen with any real text.
paren_size += PAREN_STACK_DEPTH;
if (paren_stack == starter_paren_stack) {
paren_stack = static_cast<ParenStackEntry *>(memalloc(paren_size * sizeof(ParenStackEntry)));
} else {
paren_stack = static_cast<ParenStackEntry *>(memrealloc(paren_stack, paren_size * sizeof(ParenStackEntry)));
}
}
paren_stack[paren_sp].pair_index = ch;
paren_stack[paren_sp].script_code = script_code;
} else if (paren_sp >= 0) {
// If it's a close character, find the matching open on the stack, and use that script code. Any non-matching open characters above it on the stack will be popped.
UChar32 paired_ch = u_getBidiPairedBracket(ch);
while (paren_sp >= 0 && paren_stack[paren_sp].pair_index != paired_ch) {
paren_sp -= 1;
}
if (paren_sp < start_sp) {
start_sp = paren_sp;
}
if (paren_sp >= 0) {
sc = paren_stack[paren_sp].script_code;
}
}
}
if (same_script(script_code, sc)) {
if (script_code <= USCRIPT_INHERITED && sc > USCRIPT_INHERITED) {
script_code = sc;
// Now that we have a final script code, fix any open characters we pushed before we knew the script code.
while (start_sp < paren_sp) {
paren_stack[++start_sp].script_code = script_code;
}
}
if ((u_getIntPropertyValue(ch, UCHAR_BIDI_PAIRED_BRACKET_TYPE) == U_BPT_CLOSE) && paren_sp >= 0) {
// If this character is a close paired character pop the matching open character from the stack.
paren_sp -= 1;
if (start_sp >= 0) {
start_sp -= 1;
}
}
} else {
break;
}
}
if (emoji_run) {
emoji_stack[emoji_sp].end = script_end;
}
for (int sub = 0; sub <= emoji_sp; sub++) {
if (emoji_stack[sub].start > script_start) {
ScriptRange rng;
rng.script = hb_icu_script_to_script(script_code);
rng.start = script_start;
rng.end = emoji_stack[sub].start;
script_ranges.push_back(rng);
}
ScriptRange rng;
rng.script = (hb_script_t)HB_TAG('Z', 's', 'y', 'e');
rng.start = emoji_stack[sub].start;
rng.end = emoji_stack[sub].end;
script_ranges.push_back(rng);
script_start = emoji_stack[sub].end;
}
if (script_start != script_end) {
ScriptRange rng;
rng.script = hb_icu_script_to_script(script_code);
rng.start = script_start;
rng.end = script_end;
script_ranges.push_back(rng);
}
if (emoji_stack != starter_emoji_stack) {
memfree(emoji_stack);
}
} while (script_end < p_length);
if (paren_stack != starter_paren_stack) {
memfree(paren_stack);
}
}