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by RichardRussell
Sat Aug 12, 2017 9:49 am
Forum: Raspberry Pi OS
Topic: Raspbian repository: SDL 2.0
Replies: 5
Views: 1275

Re: Raspbian repository: SDL 2.0

FYI Pixel Desktop has been obsoleted, to be replaced by ""Raspberry Pi Desktop powered by Raspbian"" Whatever. It makes no difference to my question: BBC BASIC needs to run in windowed mode on whatever desktop comes with Raspbian Stretch, and that relies on SDL 2.0 being built to support that capab...
by RichardRussell
Sat Aug 12, 2017 9:11 am
Forum: Raspberry Pi OS
Topic: Raspbian repository: SDL 2.0
Replies: 5
Views: 1275

Raspbian repository: SDL 2.0

How can I find out who maintains the SDL 2.0 distribution at the repository (or at least send them a message)? I want to ensure that the version of SDL that will be available for Raspbian Stretch (presumably 2.0.5) will be built to support windowed operation on the Pixel desktop, as the current 2.0....
by RichardRussell
Mon Aug 07, 2017 10:19 am
Forum: Other programming languages
Topic: BBC BASIC for Raspbian updated to v0.18a
Replies: 0
Views: 1642

BBC BASIC for Raspbian updated to v0.18a

I have updated the Raspbian edition of BBCSDL, the free cross-platform version of BBC BASIC, to v0.18a. A major new feature of this release is full support for 3D graphics on the RPi (so long as the OpenGL driver is enabled) bringing it into line with the Windows, Linux (86), Mac OS-X and Android ed...
by RichardRussell
Wed Jul 12, 2017 8:50 am
Forum: Raspberry Pi OS
Topic: VC4 driver interferes with HDMI audio
Replies: 7
Views: 1814

Re: VC4 driver interferes with HDMI audio

jamesh wrote:As I said, known issue, already fixed. Fix will be in Stretch.
So is it a policy decision or a technical issue which prevents the fix being incorporated in Jessie?
by RichardRussell
Tue Jul 11, 2017 5:21 pm
Forum: Raspberry Pi OS
Topic: VC4 driver interferes with HDMI audio
Replies: 7
Views: 1814

Re: VC4 driver interferes with HDMI audio

The OpenGL driver is very much bleeding edge (in fact, right on the edge of bleeding edge), use at your own risk. I know, but I'm almost certain the HDMI audio issue is recent. I don't have any choice in using the VC4 driver, and from the point of view of OpenGL rendering it works extremely well, s...
by RichardRussell
Mon Jul 10, 2017 3:32 pm
Forum: Raspberry Pi OS
Topic: VC4 driver interferes with HDMI audio
Replies: 7
Views: 1814

VC4 driver interferes with HDMI audio

This is the setup: RPi3, Raspbian Jessie desktop, fully updated (today). The symptom I am experiencing is as follows: * VC4 driver disabled (legacy): 3.5 mm audio OK, HDMI audio OK * VC4 driver enabled (full KMS): 3.5 mm audio OK, HDMI audio highly distorted What I assume to be the same issue has be...
by RichardRussell
Thu Jul 06, 2017 7:01 pm
Forum: OpenGLES
Topic: VC4 driver and display lists
Replies: 2
Views: 2656

Re: VC4 driver and display lists

As you were; it wasn't a problem with the VC4 driver. Turned out to be an obscure bug in the ARM edition of my BBC BASIC interpreter, causing the MOD function (modulus of an array) to misbehave, and this was mucking up the 3D computations.

Richard.
by RichardRussell
Thu Jul 06, 2017 11:42 am
Forum: Raspberry Pi OS
Topic: Why the hard-float ABI?
Replies: 8
Views: 2918

Re: Why the hard-float ABI?

Take the statement: SYS "function", x If you do not know whether "function" wants an int32 or a float32, then how do you decide what to do with a 40bit real variant "x"? BBC BASIC assumes that all SYS parameters are integers, so 'x' is truncated. If you want to pass a 32-bit float (which is not a n...
by RichardRussell
Thu Jul 06, 2017 11:30 am
Forum: OpenGLES
Topic: VC4 driver and display lists
Replies: 2
Views: 2656

VC4 driver and display lists

I've got 'simple' OpenGL programs running successfully with the VC4 GL driver, but programs that use display lists are not rendering anything except the background colour (although glGetError returns zero). Before attempting more detailed debugging, are there any known issues regarding the use of di...
by RichardRussell
Tue Jul 04, 2017 8:13 pm
Forum: Raspberry Pi OS
Topic: Why the hard-float ABI?
Replies: 8
Views: 2918

Re: Why the hard-float ABI?

But what is the situation where passing float values in integer registers is better? There is none. Ah, but there is! It's a niche application, I grant you, but my version of BBC BASIC for the RPi is partially broken by this characteristic of Raspbian. If you know the language, it all has to do wit...
by RichardRussell
Tue Jul 04, 2017 10:51 am
Forum: Raspberry Pi OS
Topic: Why the hard-float ABI?
Replies: 8
Views: 2918

Why the hard-float ABI?

Sorry if this is a FAQ, but why does Raspbian use the hard-float ABI when (for example) Google/Android has gone in the opposite direction and removed this option altogether? This page explains the reasoning behind that decision and superficially I cannot see why the same arguments would not apply to...
by RichardRussell
Tue Jun 06, 2017 10:05 am
Forum: Troubleshooting
Topic: GL Driver breaks HDMI audio
Replies: 0
Views: 239

GL Driver breaks HDMI audio

If I enable the 'experimental' GL Driver any attempt to output HDMI audio crashes the system (even a reboot hangs, and a power-cycle is required). Either disabling the GL Driver or force-selecting the 3.5mm audio output fixes the problem. I'm guessing that the GL Driver reconfigures the HDMI connect...
by RichardRussell
Mon May 01, 2017 12:00 pm
Forum: Other programming languages
Topic: BBC BASIC for Raspbian updated
Replies: 0
Views: 1089

BBC BASIC for Raspbian updated

I've updated BBCSDL, the free cross-platform version of BBC BASIC, to version 0.17a. The Raspberry Pi edition may be downloaded as follows, it requires a RPi 2 or RPi 3 running Raspbian Jessie: http://www.rtr.myzen.co.uk/bbc-rpi.zip Installation instructions are included in the ZIP file. Details of ...
by RichardRussell
Tue Mar 21, 2017 6:04 pm
Forum: OpenGLES
Topic: OpenGL/SDL2 issue
Replies: 3
Views: 4128

OpenGL/SDL2 issue

I'm using SDL 2.0.2 (from the repository) in windowed mode on an RPi 3, using the 'experimental' OpenGL driver, and all the normal 2D SDL functions work as I would expect (and appear to be accelerated). However even the simplest attempt to access the OpenGL context directly isn't working: glcontext ...
by RichardRussell
Fri Mar 17, 2017 4:37 pm
Forum: Other programming languages
Topic: GPIO library for BBC BASIC
Replies: 12
Views: 4069

Re: GPIO library for BBC BASIC

For some reason I was thinking yours was a port of Sophie's. It was more than a year ago that I proposed creating an SDL2-based version of BBC BASIC for ARM CPUs by linking Sophie's interpreter to my BBCSDL framework. After a substantial amount of investigation and preliminary work, much of it by D...
by RichardRussell
Fri Mar 17, 2017 10:11 am
Forum: Other programming languages
Topic: GPIO library for BBC BASIC
Replies: 12
Views: 4069

Re: GPIO library for BBC BASIC

BBC BASIC written in very tight assembly language, and is very fast. I think you're talking about Sophie's BASIC, not mine! I can't claim mine is particularly fast, especially when running under Raspbian - at least until the 'experimental' GL Driver actually works properly. But there are compensati...
by RichardRussell
Wed Mar 15, 2017 11:37 pm
Forum: Other programming languages
Topic: GPIO library for BBC BASIC
Replies: 12
Views: 4069

Re: GPIO library for BBC BASIC

gordon@drogon.net wrote:I know how to do it - I do it in my BASIC interpreter that is written in C and runs under Linux.
Same here, but I'd still choose BBC BASIC over C every time, so long as the performance is acceptable.

Richard.
by RichardRussell
Sat Mar 04, 2017 4:12 pm
Forum: Other programming languages
Topic: BBC BASIC running Dropperz game
Replies: 0
Views: 455

BBC BASIC running Dropperz game

Here's a short video of BBC BASIC on a Raspberry Pi 3 running the 'Dropperz' video game. There are no sound effects because they need SDL 2.0.4 and currently only 2.0.2 is available from the repository:

https://youtu.be/da6QjMAuHw4

Richard.
by RichardRussell
Mon Feb 27, 2017 6:58 pm
Forum: Other programming languages
Topic: GPIO library for BBC BASIC
Replies: 12
Views: 4069

Re: GPIO library for BBC BASIC

DavidS wrote:For GPIO from BBC BASIC why not just call the GPIO module SWI's?
GPIO SWIs in Raspbian? Do they exist? I thought that was a RISC OS thing. My GPIO library is based on the C code listed here.

Richard.
by RichardRussell
Mon Feb 27, 2017 6:57 pm
Forum: Other programming languages
Topic: BBC Basic
Replies: 70
Views: 23289

Re: BBC Basic

Ok you can add your own libraries, though they are not required to implement the core language at all. Of course libraries aren't required to implement the "core language" (by definition!) but BBC BASIC is missing many valuable features (some that are common in other BASICs) and the obvious way of ...
by RichardRussell
Mon Feb 27, 2017 2:50 pm
Forum: Other programming languages
Topic: GPIO library for BBC BASIC
Replies: 12
Views: 4069

GPIO library for BBC BASIC

I've written a simple BBC BASIC library which provides access to the Raspberry Pi's GPIO (compatible with RPi 2 and RPi 3). This is included with the latest release of BBC BASIC . To illustrate its use here is a simple demo/test program: REM Simple GPIO test program for the Raspberry Pi 2, RPi 3 or ...
by RichardRussell
Mon Feb 27, 2017 9:49 am
Forum: Other programming languages
Topic: BBC Basic
Replies: 70
Views: 23289

Re: BBC Basic

I mean creating callbacks for as many arbitrary sources, of anything that can call a callback, with out needing a specific lib, and then assigning them with an ON <event> statement. You say "without needing a specific lib" but BB4W is highly dependent on libraries. Just as Sophie was, I am determin...
by RichardRussell
Sun Feb 26, 2017 10:35 pm
Forum: Other programming languages
Topic: BBC Basic
Replies: 70
Views: 23289

Re: BBC Basic

Yes like that, though no need for the ON CLOSE, ON MOUSE, ON MOVE, events, as these are part of the standard polling loop. It's true that you could probably make do with just ON TIME, because that could poll everything else (there would be no requirement for a 'polling loop' as such). But once the ...
by RichardRussell
Sun Feb 26, 2017 5:10 pm
Forum: Other programming languages
Topic: BBC Basic
Replies: 70
Views: 23289

Re: BBC Basic

DavidS wrote:Though the reasonable way to implement something like that would be to extend the ON keyword
Like BB4W's ON CLOSE, ON MOUSE, ON MOVE, ON SYS and ON TIME statements you mean?! :roll:

Richard.
by RichardRussell
Sun Feb 26, 2017 10:48 am
Forum: Other programming languages
Topic: BBC Basic
Replies: 70
Views: 23289

Re: BBC Basic

Those "interrupts" are called from an old-fashioned polling loop. Are you talking specifically about RISC OS here? Windows supports genuine asynchronous interrupts (callbacks), for example from the Multimedia Timers . If a BASIC program is going to respond to such timer interrupts without needing a...

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