Drawing polygon between sprites

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1

Hello! I'm trying to draw a polygon between a background (sprite) and another sprite.
playdate-20220422-151456
If I draw the polygon after sprite.update() then the sprites appear under the polygon, and if I call draw polygon before update() then the whole polygon disappears.

I also tried putting the drawing inside setBackgroundDrawingCallback() but it won't clean the background
playdate-20220422-154929

(also ideally I do wanna put the boat sprite behind the wave and fish in front of the wave)

I'm on Windows using SDK 1.10.0. Thanks in advance.

2

While there are several ways of solving this, my favorite is to simply make everything a sprite. Do it with the polygon too!

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3

Thank you! That works great for the z index! But now I'm not sure how to optimize the drawing rect now. It seems like it's updating the entire screen now. This is currently how I'm doing the image drawing

-- draw wave to a image
waterImage = gfx.image.new(400, 240)
waterSprite = gfx.sprite.new(waterImage)
waterSprite:setZIndex(4)
waterSprite:setCenter(0, 0)
waterSprite:add()

function playdate.update()
    -- draw dynamic waves
    gfx.lockFocus(waterImage)
    gfx.setScreenClipRect(0, waterHeight - waterStrength, 400, 240 - waterHeight + waterStrength)
    waterImage:clear(gfx.kColorClear)
    drawWave(calcWave(100, waterHeight), gfx.kColorXOR)
    gfx.clearClipRect()
    gfx.unlockFocus()
    
    -- update sprites
    gfx.sprite.update()
end

It's my first project in Playdate as I'm also trying to learn about the drawing so I'm not sure what I'm missing😅

4

You could manually set the sprite dirty rect:

  • playdate.graphics.sprite.addDirtyRect(x, y, width, height)

Using the bounds of your polygon:

  • playdate.geometry.polygon:getBounds()
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