From ddd1be04ef7f786c9376cd5187d7c148267c65bd Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sat, 4 Sep 2021 09:59:40 +0900
Subject: [PATCH] Map gaiji to Unicode Private Use Area U+E000-U+E0BB

---
 src/sys/ags_text.cpp | 14 ++++++++------
 src/utfsjis.cpp      | 12 ++++++++++--
 src/utfsjis.h        |  4 ++++
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/sys/ags_text.cpp b/src/sys/ags_text.cpp
index 3a895ab..43c23b4 100644
--- a/src/sys/ags_text.cpp
+++ b/src/sys/ags_text.cpp
@@ -57,26 +57,28 @@ void AGS::draw_text(const char* string, bool text_wait)
 		if(is_2byte_message(c)) {
 			code = (code << 8) | (uint8)string[p++];
 		}
+
 		if(draw_hankaku) {
 			code = convert_hankaku(code);
 		} else {
 			code = convert_zenkaku(code);
 		}
 
+		code = sjis_to_unicode(code);
+
 		// 文字出力
-		if((0xeb9f <= code && code <= 0xebfc) || (0xec40 <= code && code <= 0xec9e)) {
+		if (GAIJI_FIRST <= code && code <= GAIJI_LAST) {
 			// Use unadjusted dest_y here.
 			draw_gaiji(screen, dest_x, draw_menu ? menu_dest_y : text_dest_y, code, font_size, font_color);
 			dest_x += font_size;
 		} else {
-			int unicode = sjis_to_unicode(code);
 			if (!draw_menu)
-				texthook_character(nact->get_scenario_page(), unicode);
+				texthook_character(nact->get_scenario_page(), code);
 
 			if (antialias)
-				draw_char_antialias(screen, dest_x, dest_y, unicode, font, font_color, antialias_cache);
+				draw_char_antialias(screen, dest_x, dest_y, code, font, font_color, antialias_cache);
 			else
-				draw_char(screen, dest_x, dest_y, unicode, font, font_color);
+				draw_char(screen, dest_x, dest_y, code, font, font_color);
 
 			int miny, maxy, advance;
 			TTF_GlyphMetrics(font, code, NULL, NULL, &miny, &maxy, &advance);
@@ -175,7 +177,7 @@ void AGS::draw_char_antialias(int dest, int dest_x, int dest_y, uint16 code, TTF
 
 void AGS::draw_gaiji(int dest, int dest_x, int dest_y, uint16 code, int size, uint8 color)
 {
-	int index = (0xeb9f <= code && code <= 0xebfc) ? code - 0xeb9f : (0xec40 <= code && code <= 0xec9e) ? code - 0xec40 + 94 : 0;
+	int index = code - GAIJI_FIRST;
 	bool pattern[16][16];
 
 	// パターン取得
diff --git a/src/utfsjis.cpp b/src/utfsjis.cpp
index d0bce1d..8da335b 100644
--- a/src/utfsjis.cpp
+++ b/src/utfsjis.cpp
@@ -21,10 +21,18 @@ int unicode_to_sjis(int u) {
 
 uint16 sjis_to_unicode(uint16 code)
 {
+	// ASCII characters.
+	if (code < 0x80)
+		return code;
+	// 1-byte kana characters.
 	if (code >= 0xa0 && code <= 0xdf)
 		return 0xff60 + code - 0xa0;
-	if (code < 0x100)
-		return code;
+	// Gaiji characters.
+	if (0xeb9f <= code && code <= 0xebfc)
+		return code - 0xeb9f + GAIJI_FIRST;
+	if (0xec40 <= code && code <= 0xec9e)
+		return code - 0xec40 + 94 + GAIJI_FIRST;
+
 	return s2u[(code >> 8) - 0x80][(code & 0xff) - 0x40];
 }
 
diff --git a/src/utfsjis.h b/src/utfsjis.h
index e5c84ec..d640217 100644
--- a/src/utfsjis.h
+++ b/src/utfsjis.h
@@ -3,6 +3,10 @@
 
 #include "common.h"
 
+// Gaiji characters are mapped to Unicode Private Use Area U+E000-U+E0BB.
+const int GAIJI_FIRST = 0xE000;
+const int GAIJI_LAST = 0xE0BB;
+
 uint16 sjis_to_unicode(uint16 code);
 char* sjis2utf(char* src);
 char* utf2sjis(char* src);