Replace invalid characters with HTML entities
— with — ’ with ’ + with + × with x ç with ç “ with “ ” with ” ‘ with ‘ • with • – with - µ with µ † with † Fix C++ θ with θ Yen symbol instead of times Fix broken apos Bullet again E-circumflex
This commit is contained in:
James Gregory
parent
9e52de9586
commit
500e7f5654
353 changed files with 5091 additions and 5091 deletions
14
49-05.html
14
49-05.html
|
|
@ -36,9 +36,9 @@
|
|||
</TABLE>
|
||||
</CENTER>
|
||||
<P><BR></P>
|
||||
<P>Here’s something worth noting: The animation is extremely smooth on a 20 MHz 386. It is somewhat more jerky on an 8 MHz 286, because only 30 frames a second can be processed. If animation looks jerky on your PC, try reducing the number of kites.
|
||||
<P>Here’s something worth noting: The animation is extremely smooth on a 20 MHz 386. It is somewhat more jerky on an 8 MHz 286, because only 30 frames a second can be processed. If animation looks jerky on your PC, try reducing the number of kites.
|
||||
</P>
|
||||
<P>The kites draw perfectly into the background, with no interference or fringe, thanks to masked copying. In fact, the kites also cross with no interference (the last-drawn kite is always in front), although that’s not readily apparent because they all look the same anyway and are moving fast. Listing 49.5 isn’t inherently limited to kites; create your own images and initialize the object list to display a mix of those images and see the full power of Mode X animation.</P>
|
||||
<P>The kites draw perfectly into the background, with no interference or fringe, thanks to masked copying. In fact, the kites also cross with no interference (the last-drawn kite is always in front), although that’s not readily apparent because they all look the same anyway and are moving fast. Listing 49.5 isn’t inherently limited to kites; create your own images and initialize the object list to display a mix of those images and see the full power of Mode X animation.</P>
|
||||
<P>The external functions called by Listing 49.5 can be found in Listings 49.1, 49.2, 49.3, and 49.6, and in the listings for the previous two chapters.</P>
|
||||
<P><B>LISTING 49.6 L49-6.ASM</B></P>
|
||||
<!-- CODE //-->
|
||||
|
|
@ -59,14 +59,14 @@ ShowPageParms ends
|
|||
.code
|
||||
public _ShowPage
|
||||
_ShowPage proc near
|
||||
push bp ;preserve caller’s stack frame
|
||||
push bp ;preserve caller’s stack frame
|
||||
mov bp,sp ;point to local stack frame
|
||||
; Wait for display enable to be active (status is active low), to be
|
||||
; sure both halves of the start address will take in the same frame.
|
||||
mov bl,START_ADDRESS_LOW ;preload for fastest
|
||||
mov bh,byte ptr StartOffset[bp] ; flipping once display
|
||||
mov cl,START_ADDRESS_HIGH ; enable is detected
|
||||
mov ch,byte ptr StartOffset+1[bp]
|
||||
mov ch,byte ptr StartOffset+1[bp]
|
||||
mov dx,INPUT_STATUS_1
|
||||
WaitDE:
|
||||
in al,dx
|
||||
|
|
@ -85,15 +85,15 @@ WaitVS:
|
|||
in al,dx
|
||||
test al,08h
|
||||
jz WaitVS ;vertical sync is active high (1 = active)
|
||||
pop bp ;restore caller’s stack frame
|
||||
pop bp ;restore caller’s stack frame
|
||||
ret
|
||||
_ShowPage endp
|
||||
end
|
||||
</PRE>
|
||||
<!-- END CODE //-->
|
||||
<H3><A NAME="Heading8"></A><FONT COLOR="#000077">Works Fast, Looks Great</FONT></H3>
|
||||
<P>We now end our exploration of Mode X, although we’ll use it again shortly for 3-D animation. Mode X admittedly has its complexities; that’s why I’ve provided a broad and flexible primitive set. Still, so what if it <I>is</I> complex? Take a look at Listing 49.5 in action. That sort of colorful, high-performance animation is worth jumping through a few hoops for; drawing 20, or even 10, fair-sized objects at a rate of 60 Hz, with no flicker, interference, or fringe, is no mean accomplishment, even on a 386.</P>
|
||||
<P>There’s much more we could do with animation in general and with Mode X in particular, but it’s time to move on to new challenges. In closing, I’d like to point out that all of the VGA’s hardware features, including the built-in AND, OR, and XOR functions, are available in Mode X, just as they are in the standard VGA modes. If you understand the VGA’s hardware in mode 12H, try applying that knowledge to Mode X; you might be surprised at what you find you can do.</P><P><BR></P>
|
||||
<P>We now end our exploration of Mode X, although we’ll use it again shortly for 3-D animation. Mode X admittedly has its complexities; that’s why I’ve provided a broad and flexible primitive set. Still, so what if it <I>is</I> complex? Take a look at Listing 49.5 in action. That sort of colorful, high-performance animation is worth jumping through a few hoops for; drawing 20, or even 10, fair-sized objects at a rate of 60 Hz, with no flicker, interference, or fringe, is no mean accomplishment, even on a 386.</P>
|
||||
<P>There’s much more we could do with animation in general and with Mode X in particular, but it’s time to move on to new challenges. In closing, I’d like to point out that all of the VGA’s hardware features, including the built-in AND, OR, and XOR functions, are available in Mode X, just as they are in the standard VGA modes. If you understand the VGA’s hardware in mode 12H, try applying that knowledge to Mode X; you might be surprised at what you find you can do.</P><P><BR></P>
|
||||
<CENTER>
|
||||
<TABLE BORDER>
|
||||
<TR>
|
||||
|
|
|
|||
Loading…
Reference in a new issue