gbdev/rgbds
1
0
Fork 0
mirror of https://github.com/gbdev/rgbds.git synced 2025-11-20 10:12:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

Document character maps

Browse Source 
Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>
This commit is contained in:
Antonio Niño Díaz
2018-03-13 21:10:36 +00:00
parent 5a4bbe4985
commit 483a63156b
4 changed files with 91 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
docs/rgbasm.5.html
View File

@@ -1309,6 +1309,32 @@ Whenever the macro-language expects a string you can actually use a string
returns the new string.</td>
</tr>
</table>
<h2 class="Ss" title="Ss" id="Character_maps"><a class="selflink" href="#Character_maps">Character
maps</a></h2>
When writing text that is meant to be displayed in the Game Boy, the ASCII
characters used in the source code may not be the same ones used in the
tileset used in the ROM. For example, the tiles used for uppercase letters may
be placed starting at tile index 128, which makes it difficult to add text
strings to the ROM.
<div class="Pp"></div>
Character maps allow the code to map strings up to 16 characters long to an
abitrary 8-bit value:
<div class="Pp"></div>
<div class="Bd" style="margin-left: 5.00ex;">
<pre class="Li">
CHARMAP &quot;&lt;LF&gt;&quot;, 10
CHARMAP &quot;&amp;iacute&quot;, 20
CHARMAP &quot;A&quot;, 128
</pre>
</div>
<div class="Pp"></div>
<b class="Sy" title="Sy">Note:</b> Character maps affect all strings in the file
from the point in which they are defined. This means that any string that the
code may want to print as debug information will also be affected by it.
<div class="Pp"></div>
<b class="Sy" title="Sy">Note:</b> The output value of a mapping can be 0. If
this happens, the assembler will treat this as the end of the string and the
rest of it will be trimmed.
<h2 class="Ss" title="Ss" id="Other_functions"><a class="selflink" href="#Other_functions">Other
functions</a></h2>
There are a few other functions that do various useful things:
@@ -1429,6 +1455,8 @@ The options that OPT can modify are currently: <b class="Sy" title="Sy">b</b>,
<dd class="It-inset"></dd>
<dt class="It-inset"><a class="Sx" title="Sx" href="#BANK">BANK</a></dt>
<dd class="It-inset"></dd>
<dt class="It-inset"><a class="Sx" title="Sx" href="#CHARMAP">CHARMAP</a></dt>
<dd class="It-inset"></dd>
<dt class="It-inset"><a class="Sx" title="Sx" href="#COS">COS</a></dt>
<dd class="It-inset"></dd>
<dt class="It-inset"><a class="Sx" title="Sx" href="#DB">DB</a></dt>
@@ -1563,7 +1591,7 @@ The options that OPT can modify are currently: <b class="Sy" title="Sy">b</b>,
<a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</div>
<table class="foot">
<tr>
<td class="foot-date">February 26, 2018</td>
<td class="foot-date">March 13, 2018</td>
<td class="foot-os">RGBDS Manual</td>
</tr>
</table>