Pixel-perfect drawing, reference bitmaps for visible pixels

Hello,

I'm trying to create an astrology-related widget that would draw a comparatively complex bitmap based on reasonably complex calculations (which only have to be done once every few hours or so, or could even be done on the mobile phone, hence not a battery issue).

When trying to plan the display I noticed that my Forerunner 645 Music (the only device I'm currently developing for) has a 240x240 display of which not all pixels are visible - which should be common knowledge. Sadly, the simulator antialiases everything, so I can't really map the visible pixels.

So, the following questions come up:

- is there a reference what pixels are actually visible on a given device/group of devices? (should be a 1-bit bitmap picture, I guess). If not, this would be a request.

- is there a way to disable antialiasing in the Simulator? if not, this would be a feature request.

- is there a way to zoom in on the Simulator? if not, this would be a feature request. I can also do without the watch picture around the display in the simulator ;)

- is there a way to test on the watch directly? how do I do so?

being able to plan how I render stuff to the screen and what pixels I can actually use would be key to preparation for me, and being able to determine available pixels precisely would be key to supporting more/other devices than one I own.

any help or advice is very welcome!

Thanks in advance!

Top Replies

markdotai over 4 years ago +1

My notes after reading your notes

I've never noticed any antialiasing being performed by the simulator - how are you seeing this?

For zooming in I tend to just use the Magnifier app on PC at 500%…
FlowState over 4 years ago +1

berlincount said:
- is there a way to zoom in on the Simulator? if not, this would be a feature request. I can also do without the watch picture around the display in the simulator ;)

It's not exactly the…

All Replies

0 markdotai over 4 years ago

My notes after reading your notes

I've never noticed any antialiasing being performed by the simulator - how are you seeing this?

For zooming in I tend to just use the Magnifier app on PC at 500% (after turning off "smooth edges of images and text" in its settings)

One difference I've noticed with pixel rendering on the simulator is that it is shifted slightly compared to a real device (only checked with a Fenix 5X+) - I can't remember precisely without testing again, but I think it could be half a pixel in both x & y - although that was using a font to draw the image.

I suspect that to work out exactly which pixels of a 240x240 display are visible you would have to try drawing a texture to the display with different colors and then visually seeing which pixels you can see … In the past I tried drawing a 240x240 texture which had a circle of radius 120 and line width 1 pixel (antialiased line) and it appeared to look like a perfect 1 pixel wide circle on my watch. But obviously some of the pixels could have been slightly cut off or extra outside pixels visible. Maybe you could try drawing a red background with a black 120 or 119 radius circle on it and see where red pixels are visible ...

0 FlowState over 4 years ago

berlincount said:
- is there a way to zoom in on the Simulator? if not, this would be a feature request. I can also do without the watch picture around the display in the simulator ;)

It's not exactly the same thing, but if you select File > Save Screen Capture, you get a pixel-perfect rectangular PNG (with no watch picture), which you can open in an editor like Paint.NET, GIMP or Photoshop and use the app to zoom-in and look at the individual pixels.

Of course that doesn't really help you determine which pixels are available.