added support for reduced font bitmaps with lower case characters

While support for font bitmaps with full ISO-8859-1 character maps
already exists, this change adds support for specially crafted font
bitmaps containing the usual reduced character map plus lower case
characters (including umlaut characters) by choosing ".frames: 112"
for the font definition. To use this, the last line in the font's
character map that looks like this

©ÄÖÜ°™_

is replaced with the following three lines (where the underscore
characters are usually replaced with filled, cursor style blocks):

`abcdefghijklmno
pqrstuvwxyz{|}~_
©ÄÖÜ°™_äöüß

The layout of the characters in the font bitmap may differ from the
above example (which reflects the default font bitmap layout), and can
be set using the ".frames_per_line" configuration option (which would
be "16" for the example above).

(In fact, this extended, reduced font character map currently has only
107 characters defined, so a few special characters may be added later
to the remaining five slots.)

diff --git a/src/libgame/text.c b/src/libgame/text.c
index 9b9ad87f36f0d7a0b9f4b672d41301268240b000..446a873b23dcfd9c137ed1792b1399f1525ed1d6 100644 (file)
--- a/src/libgame/text.c
+++ b/src/libgame/text.c
@@ -101,12 +101,13 @@ static int getFontCharPosition(int font_nr, char c)
 {
   int font_bitmap_id = gfx.select_font_function(font_nr);
   struct FontBitmapInfo *font = &gfx.font_bitmap_info[font_bitmap_id];
-  boolean default_font = (font->num_chars == DEFAULT_NUM_CHARS_PER_FONT);
   int font_pos = (unsigned char)c - 32;
 
   // map some special characters to their ascii values in default font
-  if (default_font)
+  if (font->num_chars == DEFAULT_NUM_CHARS_PER_FONT)
     font_pos = MAP_FONT_ASCII(c) - 32;
+  else if (font->num_chars == NUM_CHARS_PER_FONT_EXT)
+    font_pos = MAP_FONT_ASCII_EXT(c) - 32;
 
   // this allows dynamic special characters together with special font
   if (font_pos < 0 || font_pos >= font->num_chars)

diff --git a/src/libgame/text.h b/src/libgame/text.h
index 57a8d224e270f71ca2f0fd6040ace8b5214efffa..9295a037b7469ce6ebca8c1944898b81bfce6970 100644 (file)
--- a/src/libgame/text.h
+++ b/src/libgame/text.h
@@ -67,8 +67,25 @@
                                 (c) == FONT_ASCII_DOWN      ? 111 :    \
                                 (c))
 
+#define MAP_FONT_ASCII_EXT(c)  ((c) == CHAR_BYTE_COPYRIGHT  ? 128 :    \
+                                (c) == CHAR_BYTE_UMLAUT_A   ? 129 :    \
+                                (c) == CHAR_BYTE_UMLAUT_O   ? 130 :    \
+                                (c) == CHAR_BYTE_UMLAUT_U   ? 131 :    \
+                                (c) == CHAR_BYTE_DEGREE     ? 132 :    \
+                                (c) == CHAR_BYTE_REGISTERED ? 133 :    \
+                                (c) == FONT_ASCII_CURSOR    ? 134 :    \
+                                (c) == CHAR_BYTE_UMLAUT_a   ? 135 :    \
+                                (c) == CHAR_BYTE_UMLAUT_o   ? 136 :    \
+                                (c) == CHAR_BYTE_UMLAUT_u   ? 137 :    \
+                                (c) == CHAR_BYTE_SHARP_S    ? 138 :    \
+                                (c) == FONT_ASCII_BUTTON    ? 141 :    \
+                                (c) == FONT_ASCII_UP        ? 142 :    \
+                                (c) == FONT_ASCII_DOWN      ? 143 :    \
+                                (c))
+
 // 64 regular ordered ASCII characters, 6 special characters, 1 cursor char.
 #define MIN_NUM_CHARS_PER_FONT                 64
+#define NUM_CHARS_PER_FONT_EXT                 112
 #define DEFAULT_NUM_CHARS_PER_FONT             (MIN_NUM_CHARS_PER_FONT + 6 +1)
 #define DEFAULT_NUM_CHARS_PER_LINE             16