DrawRotatedBitmap rendering error when rendering out of bounds at specific angles

SDK Bug Reports
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1

I found a rendering error that happens only in a very specific case.

When you render a bitmap rotated 90 degrees exactly partially out of the right side of the screen (or a bitmap rotated 270 degrees partially out of the left side of the screen), a rendering artefact occurs. The gif below demonstrate this error:
RenderingError

(This error has only been tested on simulator, and I don't know if it occurs on console as well)

2

I am experiencing a similar issue with playdate.graphics.image:drawRotated

error

In the gif, I have images that are from an image table being drawn within an image-less-sprite's drawFunction. The images are being rotated. When they leave the screen, the image becomes invisible (even though the sprite's isVisible property remains true). In the gif, you can see an invisible image return to the screen (after being forced out of bounds) as just an unfilled circle (I am drawing these primitive circle shapes for debugging purposes).

There appears to be no way to solve this issue using the existing SDK

4

Literal edge cases. :stuck_out_tongue: My hunch is the two aren't related (not that that matters at all) but they're equally annoying. It's in the tracker now, will fix as soon as I can.

3 Likes
5

Popping in here to bump this this as I'm still seeing this issue on device and simulator with SDK 2.1.1.

rotate-bug

Code used to demo the repro in the GIF:

import("CoreLibs/graphics")

local image = playdate.graphics.image.new("asteroid")
local x = 400
local angle = 90
function playdate.update()
  playdate.graphics.clear()

  playdate.graphics.fillCircleAtPoint(x, 50, 16)
  image:drawRotated(x, 120, angle)

  if playdate.buttonIsPressed("left") then
    x = x - 2
  elseif playdate.buttonIsPressed("right") then
    x = x + 2
  end

  if playdate.buttonJustPressed("up") then
    angle = angle + 2
  elseif playdate.buttonJustPressed("down") then
    angle = angle - 2
  end

  playdate.graphics.drawText("angle="..angle, 0, 0)
end
1 Like
6

I've got a fix in for this, at last, scheduled for the next update. Thank you so much for the demo! :pray:

8

Fix is out today. Please let us know if it doesn't do the trick!

1 Like
9

Thanks for the update, looks like that did the trick :tada:

10

@dave This issue seems to have regressed - I'm seeing the same problem in Simulator and on device SDK 2.6.2.
drawscreen-offset

11

Not having any luck reproducing it here. I changed my demo for the previous bugfix to draw all four 90-degree rotations, no difference. Added transparency to my test image, still nothing. Is that just a single image being drawn with drawRotatedBitmap()? Anything else unusual that you can think of going on there? Also, could you post the image you're using and I'll try that? Maybe that's where the difference is.

12

Apologies, I should have included all this my my last post!

I've attached the image below:

pipe_junction

I used the above image in the code from my old post, and I'm able to repro.

I'm also still able to repro with the old asteroid image, although its a bit weirder:

playdate-20250108-063950

Here's that image too:

asteroid

Some other thoughts on what may be required to repro:

  • I'm using the Lua SDK - just realized this thread was originally started for a C SDK issue.
  • I'm on Windows - I've haven't tried on my Linux or Mac machines...but probably doesn't matter since this happens on device.
  • I can only repro the issue when the sprite is rotated at 90 degrees at the right side of the screen, or 270 degrees at the left side of the screen.
  • Sprite size doesn't seem to matter - the pipe is 32x32 and asteroid is 64x64.
  • Both images have transparency.
13

agh! Sorry, I pushed a fix for this and started writing a message here but as usual got distracted by something else. Yes, it was a dumb bug--when I fixed the previous problem by offsetting for the clipped columns at the top of the source I forgot to do the same thing with the mask data. :man_facepalming:

I'm not sure when the next update will be out, but this will be fixed then!

1 Like