Search found 130 matches

by metalages
Fri Nov 16, 2018 7:33 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

in my routine I draw in order A -> B -> C -> D -> ... -> A have you tried drawing from x1 to < x2 ? instead of <= x2 ? I think I do something like that because of this part : if dx = 0 => do nothing and if dy = 0 => hline trace: lea -pitch.w,a2 * sub.w d2,d0 * d0: width beq.s return * if dx = 0 => d...
by metalages
Fri Nov 16, 2018 7:16 am
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

Does your testgetpixel gives 0 when y == -1 ?
by metalages
Thu Nov 15, 2018 11:04 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

I have not made special checks / cases except : - for the clipping routine : when the polygon exits the screen at top, I draw an horizontal line y=0 for the corresponding abscisses - as said before, for lines where dy > dx, I have a different line routine that draw only one pixel for each x But exce...
by metalages
Tue Nov 13, 2018 5:39 pm
Forum: Chat forum [ENG]
Topic: .sndh playback on Android devices?
Replies: 20
Views: 9861

Re: .sndh playback on Android devices?

Do you know if there is a reason why Droidsound-E is no more available on Google play ?
by metalages
Fri Nov 09, 2018 8:34 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

Another trick to have this working is to draw the lines using "xor" instead of "or" to avoid having 1 pixel edges
In your case it means you would have an outline looking like this :

001100
010010
000000
010010
001100
by metalages
Thu Nov 08, 2018 11:14 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

Here i only draw the outline of the letter and do a xor pass to fillb the rotating logo. https://youtu.be/iNbVcFThTxY?t=18 You just have to be careful when drawing lines when dy is greater than dx. In this case you need a line draw than put only one pixel for each x. This is not a regular line draw ...
by metalages
Wed Nov 07, 2018 10:31 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

you copy a full bitplane on itself in xor mode with blitter with destadr = sourceadr + line size (160 bytes for instance). what it does is to make the horizontal borders of the outline working as a toggle fill / do not fill
by metalages
Mon Oct 22, 2018 9:52 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

Thanks mlynn.
Feel free to ask if you need more info.
by metalages
Thu Oct 11, 2018 7:55 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 24
Views: 6412

Re: efficient polygon drawing

If you can use the blitter, there is a way to just draw the outline of the polygon, then make a xor pass vertically from one screen plane on itself one line lower => it will fill the polygon. I do this here : https://youtu.be/iNbVcFThTxY?t=18 Sources are here : https://github.com/gibs75/demOS/blob/m...
by metalages
Mon Aug 20, 2018 9:45 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

Thanks :)
by metalages
Fri Aug 03, 2018 7:39 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

The score is interpreted at each frame (50hz). The $F (15 in decimal) effect allow to specify how many frames a line into the score will last. For lowest tempos there is another calculation method as described in the mod format http://www.textfiles.com/programming/FORMATS/mod-form.txt (look at 15 Se...
by metalages
Thu Aug 02, 2018 9:28 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

It uses a format that is close to Amiga .MOD format (reason why I currently use regular soundtrackers to edit songs). In this file format you have both a samples table and then score data. Score data is composed of a list of patterns that tells which sample to play on which key, which effect to appl...
by metalages
Thu Aug 02, 2018 8:53 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

Thanx :) My first goal with this routine was to have a sound routine : - using STe DMA sound - that do not take too much CPU time in order to be used in a demo or a game. Currently it fits into the upper border (50hz) which is really convenient... - that can fits some minutes of musik on a floppy, w...
by metalages
Wed Aug 01, 2018 9:43 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

Hi Mark, Thanks for the great feedback :) It will take time for me to analyze all this ;) Some elements to begin : About the DMA timing I have received great advices from Nicolas Pomarede. Currently the routine expects the DMA to play between 2000 and 2004 samples per 20 ms frame and adapt dynamical...
by metalages
Wed Aug 01, 2018 6:39 am
Forum: Games - General
Topic: Audio vs Amiga
Replies: 105
Views: 17525

Re: Audio vs Amiga

Note this is a chapter named "possible future improvements" :)
But yeah having ym in parallel with this routine would be really complementary.
by metalages
Tue Jul 10, 2018 8:35 am
Forum: Coding
Topic: YM + digidrum won't work
Replies: 21
Views: 2170

Re: YM + digidrum won't work

I am curious : how do PC players emulate timer stuffs ?
Do they have a complete 68k + MFP emulation ?
by metalages
Mon Jul 09, 2018 6:00 am
Forum: Coding
Topic: YM + digidrum won't work
Replies: 21
Views: 2170

Re: YM + digidrum won't work

I do not know anything about ym but guessing what can be done in terms of code, would it be possible the interupt stops as soon as it finds a zero value into the sample ?
by metalages
Wed Jun 27, 2018 2:17 pm
Forum: Games - General
Topic: Audio vs Amiga
Replies: 105
Views: 17525

Re: Audio vs Amiga

Looking for info / facts about Microwire, I have found this old thread about sound routines. Let's wake it up with stats coming from another stuff... :) Here is my approach : https://github.com/gibs75/demOS/blob/master/DOCS/BLITSnd/README.md Keeping things fast, let's say below 16 cycles per sample ...
by metalages
Mon Jun 25, 2018 9:43 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

Yep, using it brings me to some necessary adjustements ;)
Too short unfortunately for Sommarhack.
But some design for a musik disk is currently growing in my mind ;)
by metalages
Mon Jun 25, 2018 9:19 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Blitter sound routine

new commit : https://github.com/gibs75/demOS

BLSconvert 1.1.1
- fix convertion when different samples have same transposed size

BLSplay 1.5.0
- display v=* when voices are off (optimized)
- little optimization in ASM version
by metalages
Tue Jun 19, 2018 8:01 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Using blitter for sound mixing

new commit : https://github.com/gibs75/demOS BLSplay 1.4.0 - add support for delay sample effect (0xEDx) - on PC : closing the window closes the player - little optimizations in ASM - split ASM source (inits / play) - update unit tests - update doc BLSconvert 1.1.0 - add support for delay sample eff...
by metalages
Thu Jun 14, 2018 6:12 am
Forum: CosmosEx
Topic: CosmosEx - new device for your Atari ST
Replies: 543
Views: 177913

Re: CosmosEx - new device for your Atari ST

... I'd be very, very, very, very interested in such an extension! I pondered the possibility in this thread: http://atari-forum.com/viewtopic.php?f=15&t=33207&p=339572#p339572 The way I imagined it would be to tap into the VDI calls, and send the drawing instructions (not bitmap data) over...
by metalages
Thu Jun 07, 2018 7:39 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Using blitter for sound mixing

BLSplay v1.2.0 submitted => speed up init samples process (was really slow)
by metalages
Tue Jun 05, 2018 8:32 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Using blitter for sound mixing

New release of BLSplay and BLSconvert with support of STe balance (microwire) like described into doc

https://github.com/gibs75/demOS
by metalages
Sun Jun 03, 2018 7:06 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 20392

Re: Using blitter for sound mixing

Code and binaries are on github :)

So it is available for musicians and coders (ask me if you need help)

I think at some point I will find time to make a musik disk if some musicians are interested to collaborate but I am currently quite busy :(

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