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calc84maniac
Elite
Joined: 22 Jan 2007
Posts: 770
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 Posted: 25 Apr 2009 03:17:53 pm Post subject: |
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TKD_01 wrote: EDIT:
The push method works a bit faster, but the only problem is that the last 7 pixel pixels of the bottom row constantly flash on and off when one of my sprites goes on top of that section.
Okay, try this instead (which is the correct version):
Code:
di
ld b,(768/2)/6
ld hl,0
ld d,h \ ld e,l ;little optimization here
add hl,sp
ld sp,plotSScreen+768 ;PUSH decreases SP before writing the MSB
loop:
push de
push de
push de
push de
push de
push de
djnz loop
ld sp,hl
ei
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Taricorp
Member
Joined: 09 Mar 2006
Posts: 188
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| Posted: 25 Apr 2009 05:27:24 pm Post subject: |
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| Oh yes, I forgot about that. (I wasn't sure exactly what the behavior of PUSH is, and forgot to put in a disclaimer.) |
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Mapar007
Advanced Member
Joined: 04 Oct 2008
Posts: 365
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| Posted: 26 Apr 2009 04:17:47 am Post subject: |
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darkstone knight wrote: also, the "fast" code is waaaay overkill
When was the last time I heard you say "overkill" in an optimization discussion? XD |
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darkstone knight
Advanced Member
Joined: 07 Sep 2008
Posts: 438
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| Posted: 26 Apr 2009 10:45:32 am Post subject: |
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this time  |
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TKD_01
Advanced Newbie
Joined: 20 Feb 2009
Posts: 51
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| Posted: 26 Apr 2009 07:19:25 pm Post subject: |
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FloppusMaximus wrote: In any case I think this is a rather silly thing to be arguing about. For most purposes, LDIR is quite fast enough to clear the screen. If you really need the extra speed, use the PUSH loop or the funky copy-and-clear routine Galandros mentioned.
First of all, I dont believe we were arguing about that matter. We were simply recommending multiple methods to acheive a common end.
Second, thank you for clearing that up, FloppusMaximus, about the randseed. So, for further clarification, if randseed1 is located at plotsscreen+768, then randseed2 would be located at plotsscreen+777? I didnt think the plotsscreen was that large...
@calc84maniac:
So the pushing was essientially going beyond the plotsscreen in the faulty code?
Last edited by Guest on 26 Apr 2009 07:36:25 pm; edited 1 time in total |
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calc84maniac
Elite
Joined: 22 Jan 2007
Posts: 770
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| Posted: 26 Apr 2009 07:53:10 pm Post subject: |
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TKD_01 wrote: @calc84maniac:
So the pushing was essientially going beyond the plotsscreen in the faulty code?
It wasn't overwriting the last byte in the buffer, and it was overwriting the byte before the buffer. A simple change of the value of SP fixed that. |
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