Search found 122 matches

by metalages
Thu Oct 11, 2018 7:55 pm
Forum: 680x0
Topic: efficient polygon drawing
Replies: 8
Views: 823

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: 19118

Re: Blitter sound routine

Thanks :)
by metalages
Fri Aug 03, 2018 7:39 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

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: 19118

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: 19118

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: 19118

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: 16725

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: 1942

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: 1942

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: 16725

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: 19118

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: 19118

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: 19118

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: 173714

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: 19118

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: 19118

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: 19118

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 :(
by metalages
Sat Jun 02, 2018 9:34 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

Re: Using blitter for sound mixing

... and sources + binary released here

https://github.com/gibs75/demOS
by metalages
Sat Jun 02, 2018 9:15 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

Re: Using blitter for sound mixing

I have tested on STe. Here is the result : https://youtu.be/ehSvjL8RLo4 It works the same way than in Hatari => nearly no click, but I have the feeling that even with DMA in loop mode, I have some clicks when running at display time instead of start of VBL (not really a problem as I do not see the p...
by metalages
Sat May 26, 2018 9:31 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

Re: Using blitter for sound mixing

Ok it now works in C and ASM perfectly on Hatari :)
Need to check on real hardware now...
by metalages
Sat May 26, 2018 8:17 pm
Forum: Games - General
Topic: Escape 2042 - A new game for Atari STe / Falcon
Replies: 52
Views: 7874

Re: Escape 2042 - A new game for Atari STe

It looks really cool. Nice work.
by metalages
Tue May 22, 2018 9:26 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

Re: Using blitter for sound mixing

Ok. In order to avoid these problems I went for something like you have proposed in a first time Nicolas : - DMA in loop mode - 3 buffers - chain assignments of dma start / end adresses on buffers (1, 2, 3, 1, 2, 3...) at a point later where I am sure new adresses have been acquired by dma - monitor...
by metalages
Mon May 21, 2018 6:13 pm
Forum: Coding
Topic: Blitter sound routine
Replies: 79
Views: 19118

Re: Using blitter for sound mixing

Ok I have something working with de-sync looping-dma and replay routine using 4 buffers. So no more click indeed. Drawbacks with this approach are : - there is a small desync in replay / rythm when I catch up. Can be accpetable as it does not happen so often. - it would be difficult with this approa...
by metalages
Mon May 21, 2018 9:03 am
Forum: Ym rockin'
Topic: Turbochip - 7-channel YM+DMA replay
Replies: 29
Views: 6493

Re: Turbochip - 7-channel YM+DMA replay

Before going on this prototype http://cyber.savina.net/sound/sound.htm I have tried to figure out how to work in a cheap way with wave table. I had the feeling would be possible to have something rather cheap on 2 channels : 1 for wavetable, 1 for drum - use looping DMA buffer set with the length of...

Go to advanced search