In a simple test, when setDrawOffset is used to pan the "camera" around a simple scene, and Image:draw(x, y, flip, sourcex, sourcey, w, h) is used to draw a small portion of a sprite sheet, the effect is to pan around within the source image, but always draw in the same location on screen. That doesn't seem useful. Adding the offset to both the location and sourceRect seems to make it do the thing you want, but defeats the purpose of drawOffset.
Here's a demonstration, including the (commented) workaround:
local gfx = playdate.graphics
local ox = 0
local oy = 0
local sheet = gfx.image.new("pokemonoverworldspriteslarger")
function playdate.update()
if playdate.buttonIsPressed(playdate.kButtonLeft) then
ox -= 1
elseif playdate.buttonIsPressed(playdate.kButtonRight) then
ox += 1
end
if playdate.buttonIsPressed(playdate.kButtonUp) then
oy -= 1
elseif playdate.buttonIsPressed(playdate.kButtonDown) then
oy += 1
end
gfx.setDrawOffset(ox, oy)
gfx.clear()
-- A simple rect moves around as expected:
gfx.drawRect(178, 98, 68, 67)
-- Image with sourceRect: drawOffset seems to affect `sourceRect`, not `x` and `y`;
-- a different portion of the image is drawn, but always at the same fixed location
sheet:draw(180, 100, gfx.kImageUnflipped, 124, 64, 64, 63)
-- Workaround: add the offset to both the location and sourceRect:
-- sheet:draw(180+ox, 100+oy, gfx.kImageUnflipped, 124+ox, 64+oy, 64, 63)
end
I grabbed that sprite sheet randomly here
Actual result:
Desired result:
Testing on macOS with pdc and simulator 1.9.0 (132294).
Note: in the context of my game, the behavior is less clear, with the rendered portion of the image clipping and jumping around in an unpredictable way. I'm hoping this simple demonstration is enough to identify the problem (or my misunderstanding) but I can try to reproduce the stranger behavior if necessary.
