Misc/abrash-black-book
Watch
1
0
Fork
You've already forked abrash-black-book
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Strip comments and inline ids onto h*

Browse source
This commit is contained in:
James Gregory 2013-12-30 15:11:04 +11:00
commit 0f5f617adb
362 changed files with 2519 additions and 6694 deletions
Download patch file Download diff file Expand all files Collapse all files

21
49-02.html
View file

@ -10,16 +10,9 @@
<meta name="vspubdate" content="07/01/97" />
<meta name="vscategory" content="Web and Software Development: Game Development,Web and Software Development: Graphics and Multimedia Development" />
<title>Michael Abrash's Graphics Programming Black Book Special Edition: Mode X 256-Color Animation</title><!-- HEADER -->
<!-- Empty Reference Subhead -->
<!--ISBN=1576101746//-->
<!--TITLE=Michael Abrash's Graphics Programming Black Book Special Edition//-->
<!--AUTHOR=Michael Abrash//-->
<!--PUBLISHER=The Coriolis Group, Inc.//-->
<title>Michael Abrash's Graphics Programming Black Book Special Edition: Mode X 256-Color Animation</title>
<meta name="chapter" content="49" />
<meta name="pages" content="918-922" />
<!--UNASSIGNED1//-->
<!--UNASSIGNED2//-->
</head>
<body>
@ -37,7 +30,7 @@
<p><br /></p>
<h4 align="left"><a id="Heading4"></a>Faster Masked Copying</h4>
<h4 align="left" id="Heading4">Faster Masked Copying</h4>
<p>In the previous chapter we saw how the VGA&rsquo;s latches can be used to copy four pixels at a time from one area of display memory to another in Mode X. We&rsquo;ve further seen that in Mode X the Map Mask register can be used to select which planes are copied. That&rsquo;s all we need to know to be able to perform fast masked copies; we can store an image in off-screen display memory, and set the Map Mask to the appropriate mask value as up to four pixels at a time are copied.</p>
@ -45,7 +38,7 @@
<p>Listing 49.2 performs fast masked copying. This code expects to receive a pointer to a <b>MaskedImage</b> structure, which in turn points to four <b>AlignedMaskedImage</b> structures that describe the four possible image and mask alignments. The aligned images are already stored in display memory, and the aligned masks are already stored in system memory; further, the masks are predigested into Map Mask register-compatible form. Given all that ready-to-use data, Listing 49.2 selects and works with the appropriate image-mask pair for the destination&rsquo;s left edge alignment.</p>
<p><b>LISTING 49.2 L49-2.ASM</b></p><!-- CODE //-->
<p><b>LISTING 49.2 L49-2.ASM</b></p>
<pre>
; Mode X (320x240, 256 colors) display memory to display memory masked copy
; routine. Works on all VGAs. Uses approach of reading 4 pixels at a time from
@ -208,7 +201,7 @@ CopyDone:
_CopyScreenToScreenMaskedX endp
end
</pre><!-- END CODE //-->
</pre>
<p><br /></p>
@ -227,10 +220,6 @@ _CopyScreenToScreenMaskedX endp
<div align="center">
Graphics Programming Black Book &copy; 2001 Michael Abrash
</div><!-- all of the reference materials (books) have the footer and subfoot reveresed -->
<!-- reference_subfoot = footer -->
<!-- reference_footer = subfoot -->
<!-- BEGIN SUB FOOTER -->
<!-- END FOOTER -->
</div>
</body>
</html>