initial commit, 4.5 stable

modules/text_server_adv/script_iterator.cpp

@@ -0,0 +1,128 @@
+/**************************************************************************/
+/*  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. */
+/* 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.                 */
+/**************************************************************************/
+
+#include "script_iterator.h"
+
+// This implementation is derived from ICU: icu4c/source/extra/scrptrun/scrptrun.cpp
+
+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;
+}
+
+ScriptIterator::ScriptIterator(const String &p_string, int p_start, int p_length) {
+	struct ParenStackEntry {
+		int pair_index;
+		UScriptCode script_code;
+	};
+
+	if (p_start >= p_length) {
+		p_start = p_length - 1;
+	}
+
+	if (p_start < 0) {
+		p_start = 0;
+	}
+
+	int paren_size = PAREN_STACK_DEPTH;
+	ParenStackEntry *paren_stack = static_cast<ParenStackEntry *>(memalloc(paren_size * sizeof(ParenStackEntry)));
+
+	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;
+		for (script_start = script_end; script_end < p_length; script_end++) {
+			UChar32 ch = str[script_end];
+			UScriptCode sc = uscript_getScript(ch, &err);
+			if (U_FAILURE(err)) {
+				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;
+						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;
+			}
+		}
+
+		ScriptRange rng;
+		rng.script = hb_icu_script_to_script(script_code);
+		rng.start = script_start;
+		rng.end = script_end;
+
+		script_ranges.push_back(rng);
+	} while (script_end < p_length);
+
+	memfree(paren_stack);
+}