Fix bad centering with libngdevkit's display functions

Closes #121

Author: dciabrin

runtime/libngdevkit/ng-text.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2026 Damien Ciabrini
+ * This file is part of ngdevkit
+ *
+ * ngdevkit is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * ngdevkit is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with ngdevkit.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __NG_TEXT_H__
+#define __NG_TEXT_H__
+
+#define FIXED_LAYOUT_WIDTH 40
+
+#endif /* __NG_TEXT_H__ */

runtime/libngdevkit/ng_center_text_args.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Damien Ciabrini
+ * Copyright (c) 2020-2026 Damien Ciabrini
  * This file is part of ngdevkit
  *
  * ngdevkit is free software: you can redistribute it and/or modify
@@ -19,10 +19,11 @@
 #include <ngdevkit/neogeo.h>
 #include <ngdevkit/ng-fix.h>
 #include <string.h>
+#include "ng-text.h"
 
 
 /// Handy function to display a centered string on the fix map
 void ng_center_text_args(u8 y, u8 palette, u16 start_tile, const char *text) {
     u8 len = strlen(text);
-    ng_text_args((42 - len)>>1, y, palette, start_tile, text);
+    ng_text_args((FIXED_LAYOUT_WIDTH - len)>>1, y, palette, start_tile, text);
 }

runtime/libngdevkit/ng_center_text_tall_args.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Damien Ciabrini
+ * Copyright (c) 2020-2026 Damien Ciabrini
  * This file is part of ngdevkit
  *
  * ngdevkit is free software: you can redistribute it and/or modify
@@ -19,11 +19,12 @@
 #include <ngdevkit/neogeo.h>
 #include <ngdevkit/ng-fix.h>
 #include <string.h>
+#include "ng-text.h"
 
 
 /// Handy function to display a tall string on the fix map
 void ng_center_text_tall_args(u8 y, u8 palette, u16 start_tile, const char *text) {
     u8 len = strlen(text);
-    ng_text_args((42 - len)>>1, y, palette, start_tile, text);
-    ng_text_args((42 - len)>>1, y+1, palette, start_tile+256, text);
+    ng_text_args((FIXED_LAYOUT_WIDTH - len)>>1, y, palette, start_tile, text);
+    ng_text_args((FIXED_LAYOUT_WIDTH - len)>>1, y+1, palette, start_tile+256, text);
 }