ZX Time #04 17 ноября 2001

Программирование

Coder - "The Saga of the curb is going on!" (Programming effects on the curb).

Coders, "The Saga of the curb is going on!"


                         Nicholas Vitenko


  Today I want to tell you about
these two parasites (DWT and Golden Max),
made me do podvuhpikselny
horizontal volume indicator AY (which will be considered in this
article) on BORDER'e.


  Resorting once to me DWT and so
among other things, said that Golden Max
made on the curb indicator that
"Grows" with the displacement of one pixel.


  Since I do dovolnotaki curb a long time and that there 
chtolibo shift by less than two pixels can not, I know as well 
as the fact that Max on the curb draws only team

BORDER 0 ... 7. And me, of course, is
very surprised and I certainly do not believe
this Labuda.


  But Dennis insisted and argued that
saw it with my own eyes. Then had
I go to Max'u, and what do you think? Really "runs", but as it 
turned out this is a service opportunity emulator (Unreal 
Speccy). BUT !!!!! Me this jammed. And the result is the fact 
that You've probably seen the "intro" to this number.



  In short, Dennis and Max decide to me
laugh, but in the end I laughed over
them when they saw that I made
similar emulator indikatorik. :)


  Proceed. I hope you read the article about
how to draw "ZX" on the curb.
The indicator is created in a similar way.
It creates a certain buffer in which
there are delays, "offset". That is,
reads the value from the channel AY'ka appeal to this buffer, 
which "gives" the number of ticks by which to 'shift' 
indicator. Then calculate how much the we need to produce yet 
another delay to move to the next line, and then the next 
channel. Reduce everything to the next algorithmics: 



   Reads the value from the channel AY'ka



     Calculation of the delay in accordance

   with the value read from channel



                Delay



        Draw a line of color X



Delay complementing 'line', ie

    up to 224 cycles, the background color



      And so on for each channel ...


  But for this indicator, you must have a fast and smooth 
"music player. In the example source code, which is located in 
the annex to the newspaper, has been used for decomposed Music

a very fast player.


  The second source - this is what you saw at the bottom of the 
curb in the intro. This is me Five years ago wrote, but still

he did not understand how it works. The idea is
he must "draw" on the curb at all
But what is more, that is. Maybe some one of you will be able 
to explain all this action? 


  And finally, request and offer.


  Request: Help me find a fee (s)
General sound and DMA. Only with the ability to obtain here in 
Ukraine. 


  Proposal: coders involved in the effects on the curb, can 
exchange experience?


 That's all. Sources - Annex!


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