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There's nothing quite like a library where you can write graphics drawing code once and run it on any display be it monochrome, e-paper, color, etc.
In order to enable this I dither monochrome to give me grayscales. As far as the rest, I do automatic color conversion where necessary.
I'm finding myself greatly amused by running an alpha blending and JPG loading demo on a 128x64 monochrome OLED display.
The funny thing is, it's actually at least viewable - even the alpha blending - you can at least see what it's trying to do, and that's pretty good when you are overlapping and blending random shapes of random colors and opacities.
I may have taken device independence a little far.
To err is human. Fortune favors the monsters.
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Device independence: Hummm. Long time goal in computer graphics. CORE, PHIGS, GKS, maybe more but I haven't kept up.
Does the display device declare what it is, what it can display? etc.
If so then display independence ends at the end of that list?
If not does software have tuning to adapt with user intervention or without?
What you have done is impressive especially for e-paper displays (tricky hardware) but, device independence is a carrot.
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Well, it's not resolution independent. You still specify everything in pixels, but you can size things relative to the dimensions() of your draw target.
The key here though is automatic conversion of pixel formats. You can draw any type of pixel to any draw destination. That means, for example, if you get 24-bit Y'CbCr pixels, like from a JPG, you can write them out to a 16-bit RGB display transparently. Same with going from color to monochrome or grayscale. If you add an alpha channel to the pixel, it will do alpha blending on the draw target with whatever color was at the current location on the draw target. If you draw to a device with a palette it will do color matching to that palette.
Basically, you don't have to worry about pixel formats. You can just draw. You can just load jpgs. You can just choose any of the colors from the X11 color palette, or make your own.
The upshot here is you can write your drawing code once, and run it on any display.
To err is human. Fortune favors the monsters.
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Understood. The pixel pipeline is sort of the lowest common denominator for displays. A first key measure of independence. Good job.
Some graphics history. In late 70's, my first computer graphics device for which I had to write a library was the Tektronix 4010. It was just an electronic etch-a-sketch. No real pixels just draw lines with a beam of light. It was a very inexpensive way to do graphics because no refresh cycle was required to keep the screen lit up.
Then on to Silicon graphics, etc.
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I've heard of those. They're like plotters, basically, no? Cool tech, even if it's a bit dated.
The code in this article:
Using GFX in PlatformIO[^]
Yields this on different displays (e-paper among them but I didn't record that one and it doesn't animate)
Same demo code running on 3 different displays - GFX : esp32[^]
like between 80% and 90% of the actual lines of code for drawing are the same. The most major change I did was using a different JPG for color displays than ones that aren't.
To err is human. Fortune favors the monsters.
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yes, they were. For physical line plotters, it was optimal to keep the pen down as long as possible from line to line, so one sorted the lines to connect them as long as possible. Although line plotters are not common these days; it's quite a sight to see a high speed line plotter in action; a real pen on a giant piece of paper, both moving all over the place, like there was no tomorrow.
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I haven't seen a monochrome monitor in years. Where do you get them?
blind squirrel
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Dithering to produce grayscale when the total resolution is 128*64 sounds somewhat limited in my ears 
This kind of display is fair enough for embedded devices (which, I understand, is exactly what you are making) for simple text messages, and very simple graphic indications. To me, a 'binary' (no grayscale) (max) 16*8 chars text display the size of your thumbnail is not a 'monitor'. My microwave, or my baking oven, doesn't have a 'monitor', but a display. (I do notice, however, that the term 'monitor' was introduced by Slow Eddie, not by you!)
Another side is that if you buy something sold as an 'Oled LCD LED' display, several spelling and grammatical errors, 'ar duino' referred to several times, as well as du-pont, inconsistent dimension data, quite meaningless disclaimer about US power plugs, and why is a 40-pin flat cable included with a device that provides 4 control lines? ... then you know approximately what you will get. It is not quite at the same level as buying components from an internationally renowned manufacturer with a strong support department.
It still might be a good buy, considering the price, but I would always check price and functionality against what is offered on Mouser.com. You'll find a quite large selection of displays in this class, and the web interface provides a filtering mechanism that is at least tolerable. Usually, a product sheet link is provided. Mouser is primarily aimed at professional customers buying lots of hundreds or thousands, so if you order one component at a time, P&H may be excessive. But usually, you can buy one at a time (with the obvious exception of e.g. products delivered on a reel - you can buy one reel at a time, but not having a single component cut from a reel).
I'd recommend checking Mouser if you are in search of components. Taking a look at the web site costs nothing (except your time).
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I wasn't endorsing that purchase - it was merely the first link I found that displayed the device prominently and had an option to buy.
The dithering is primarily so you can do things like load JPEGs onto the display, which may even be good for an IoT gadget because it means you can put the logo on the screen, but yes it is limited.
I should add, I'm familiar with mouser, but i tend to use digi-key more just because i have a client who prefers them.
To err is human. Fortune favors the monsters.
modified 13-Mar-22 18:02pm.
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Found 4 words that use 20 different letters. Seems to make much easier.
I’m not posting them as to not ruin your fun.
"Time flies like an arrow. Fruit flies like a banana."
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If you switch hard mode on, this trick may not work.
"It is easy to decipher extraterrestrial signals after deciphering Javascript and VB6 themselves.", ISanti[ ^]
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Thank you !!!!
"Time flies like an arrow. Fruit flies like a banana."
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Just for the fun of it, I always start with "quack".
Money makes the world go round ... but documentation moves the money.
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SWF - it's not just for the web anymore!
Quite some time ago I wrote a little SWF displayer in VB6, but that was I don't know how long ago - dinosaurs.
However, more recently digging through Fallout 4 (released in 2015 or so) I noticed that it has SWF files in its game files for doing small animations.
It's actually a pretty great little format for that, as long as you don't use the gold-plated features adobe put in it.
Has anyone else seen SWF files in the wild in the last decade or so?
I'm kind of wondering if it might be worth it to make a viewer for IoT to run simple animations.
To err is human. Fortune favors the monsters.
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I never studied the file format, and can't tell how well (or bad) designed it was.
Independent of its technical merits, it did spur a great wave of animation art in a style of its own, one which I enjoyed a lot. Too late did I realize that the format was dying, so I managed to save only a small handful of them.
There were some instruction/pedagogical ones, too, and I was lucky to save a couple of the best ones. Like this interactive historical map of the Middle East, showing how various powers have washed back and forth over that region, effectively nulling any claim of 'Historically, this is our land!' (any such claim serves only to show that you do not know history).
Another interactive one shows takes you through the full range of dimensions, starting with the entire observable universe at one end of the scale, strings at the other end. I never realized how immensely small strings are until 'universe.swf' showed me the vast void ranging from quarks to strings!
Having seen so much funny, grotesque, and great instructional .swf movies, I think it is a pity that it has disappeared more or less completely. I have seen a few of the products ported to other technologies - but usually as a pure playback, without the interactive functionality. Often the port is done in very low quality.
Maybe we have equally good replacement technologies today. Apparently, they are far less accessible to the creative minds that made all those great swfs. We certainly do not have a flow of new productions comparable to what we had when swf was at its peak. I sort of miss it.
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I wasn't thinking anything so ambitious as an interactive implementation. I was thinking just enough to do some basic animation. This is IoT after all that I'm targeting. But that *would* be cool. It's just probably not feasible on these devices. Then again, they can sort of run python so who knows?
To err is human. Fortune favors the monsters.
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SVG animations seem to be very popular nowadays ...
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SVG is super complicated though. I was going to make a code generator to convert SVG paths into something my GFX library could use, but the spec is ridiculous.
To err is human. Fortune favors the monsters.
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When I looked at SVG, it reminded me of the old exercise of copying a map over the telephone.
True story: One of my firefighting comms colleagues got everybody's tits in a tangle doing that exercise.
We eventually figured out that he was East-West dyslexic.
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
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I once made a huge East-West mixup because my frame of reference was heading South.
Heading South… right turn will take you … east! East is always right!
I realized the mistake way too late!
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Decades ago, on my first couple of trips to the US, I used to regularly get lost driving back to my motel, but only in the daytime.
Finally twigged it was because I unconsciously navigated by the sun, and it went round the sky the wrong way.
Go somewhere, following a map or street signs ... 3 hours later go to drive back. The sun is now 90deg clockwise from where it should be.
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
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To go even more off topic…
Do Australian maps typical orient with North as up, or does it make more sense with South as up?
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On serious maps, North is always up. There are some exceptions for small areas (e.g. building/lot plans) and joke maps.
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
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