I don’t suppose anyone has already written (or knows where one is hidden in the image) a bitmap exporter that can write rgb565 ? Pretty daft for me to faff around doing it if there is already one around. I’ve spotted assorted kinda-sorta related code but not (yet) what I need.
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim No program done by an undergrad will work after she graduates.
On 27.07.2015, at 04:31, tim Rowledge tim@rowledge.org wrote:
I don’t suppose anyone has already written (or knows where one is hidden in the image) a bitmap exporter that can write rgb565 ? Pretty daft for me to faff around doing it if there is already one around. I’ve spotted assorted kinda-sorta related code but not (yet) what I need.
So what *do* you need? Which file format? Why 565? (Windows BMP supports both 555 and 565)
- Bert -
On 27-07-2015, at 8:10 AM, Bert Freudenberg bert@freudenbergs.de wrote:
On 27.07.2015, at 04:31, tim Rowledge tim@rowledge.org wrote:
I don’t suppose anyone has already written (or knows where one is hidden in the image) a bitmap exporter that can write rgb565 ? Pretty daft for me to faff around doing it if there is already one around. I’ve spotted assorted kinda-sorta related code but not (yet) what I need.
So what *do* you need? Which file format? Why 565? (Windows BMP supports both 555 and 565)
I need to write rgb565 to /dev/fb1 on my AstroPi :-) How else will astronauts be able to play with Scratch in orbit?
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim Computer possessed? Try DEVICE=C:\EXOR.SYS
On 27.07.2015, at 21:06, tim Rowledge tim@rowledge.org wrote:
On 27-07-2015, at 8:10 AM, Bert Freudenberg bert@freudenbergs.de wrote:
On 27.07.2015, at 04:31, tim Rowledge tim@rowledge.org wrote:
I don’t suppose anyone has already written (or knows where one is hidden in the image) a bitmap exporter that can write rgb565 ? Pretty daft for me to faff around doing it if there is already one around. I’ve spotted assorted kinda-sorta related code but not (yet) what I need.
So what *do* you need? Which file format? Why 565? (Windows BMP supports both 555 and 565)
I need to write rgb565 to /dev/fb1 on my AstroPi :-) How else will astronauts be able to play with Scratch in orbit?
sqUnixX11.c: copyImage16To16() should do it. If you replace the stRNMask/stRShift variables with constants it might even be reasonably efficient. ARM SIMD code would be better, obviously.
Or are you talking about Smalltalk code? A single bitblt copy with a suitable color map should do it.
- Bert -
On 28-07-2015, at 5:24 AM, Bert Freudenberg bert@freudenbergs.de wrote:
sqUnixX11.c: copyImage16To16() should do it. If you replace the stRNMask/stRShift variables with constants it might even be reasonably efficient. ARM SIMD code would be better, obviously.
Oh, it certainly would - indeed it does since some devious ARM simd code is hooked up on ARM platforms.
Or are you talking about Smalltalk code? A single bitblt copy with a suitable color map should do it.
Since it’s only an 8x8 array of ws28-something LEDs that has to be written by opening /dev/fb*, then writing to the ‘file’, then closing the file to make it actually display, performance of the conversion is not a huge problem. Right now I can display scrolling paragraphs, arbitrary screen-grabs, whatever, and it’s now a case of deciding what people want to display rather than how to display. I did discover to my surprise that some font glyphs are 16bpp with antialiasing that makes for really surprising displays on a physically large 8x8 display. It took a while to work out what was going on there...
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim "How many Carlos Wus does it take to change a lightbulb?” "With an unlimited breeding licence, who needs lightbulbs?"
Quoting tim Rowledge tim@rowledge.org:
... I did discover to my surprise that some font glyphs are 16bpp with antialiasing that makes for really surprising displays on a physically large 8x8 display. It took a while to work out what was going on there...
Can you post a photograph? I would like to see that!
tim
tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim "How many Carlos Wus does it take to change a lightbulb?” "With an unlimited breeding licence, who needs lightbulbs?"
Cheers, Juan Vuletich
On 29.07.2015, at 04:04, J. Vuletich (mail lists) juanlists@jvuletich.org wrote:
Quoting tim Rowledge tim@rowledge.org:
... I did discover to my surprise that some font glyphs are 16bpp with antialiasing that makes for really surprising displays on a physically large 8x8 display. It took a while to work out what was going on there...
Can you post a photograph? I would like to see that!
- Bert -
On 28-07-2015, at 7:04 PM, J. Vuletich (mail lists) juanlists@jvuletich.org wrote:
Quoting tim Rowledge tim@rowledge.org:
... I did discover to my surprise that some font glyphs are 16bpp with antialiasing that makes for really surprising displays on a physically large 8x8 display. It took a while to work out what was going on there...
Can you post a photograph? I would like to see that!
This is part of the glyph form for Deja Vu Sans 7 -
You can probably imagine how strange that looked scrolling by at 45mm high 8 pixels when I was expecting a black and white image.
It looks like - out of the fonts in my image by default - only the Deja Vu fonts are 16bpp. Of course they are the default that I got when doing experiments on the astropi board, just to add some confusion to the day.
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim Oxymorons: Taped live
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Bert Freudenberg -
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tim Rowledge