Base sprite can't setImage

SDK Get Help
, ,
1

I have a BaseSprite class:

import "CoreLibs/sprites"

local pd <const> = playdate
local gfx <const> = pd.graphics

class('BaseSprite').extends(gfx.sprite)

function BaseSprite:init(x, y, image)
    assert(image ~= nil, 'image is nil in BaseSprite')
    self:setImage(image)
    self:add()
    self:moveTo(x, y)
end

It's inherited by InheritedSprite:

import "CoreLibs/sprites"

import "BaseSprite"

local pd <const> = playdate
local gfx <const> = pd.graphics

class('InheritedSprite').extends(BaseSprite)

function InheritedSprite:init(x, y)
    local image = gfx.image.new(64, 64)
    gfx.pushContext(image)
    gfx.drawLine(0,0,64,64)
    gfx.popContext(image)
    assert(image ~= nil, 'image is nil in InheritedSprite')
    self.super:init(x, y, image)
end

I've added two assert statements, confirming that image is not nil but I get the following error thrown:

Load failed, error: BaseSprite.lua:10: bad argument #-2 to 'setImage' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'setImage'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk
Update error: BaseSprite.lua:10: bad argument #-2 to 'setImage' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'setImage'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk
2

Maybe the bad argument to setImage isn’t the image but the sprite because you never called its init function. Try adding self.super.init(self) before self:setImage(image).

3

According to the docs, you call super with the class name and without the colon:

InheritedSprite.super.init(self, x, y, image)
4

I've changed it to use InheritedSprite.super:init gives the same error.

import "CoreLibs/sprites"

import "BaseSprite"

local pd <const> = playdate
local gfx <const> = pd.graphics

class('InheritedSprite').extends(BaseSprite)

function InheritedSprite:init(x, y)
    local image = gfx.image.new(64, 64)
    gfx.pushContext(image)
    gfx.drawLine(0,0,64,64)
    gfx.popContext(image)
    assert(image ~= nil, 'image is nil in InheritedSprite')
    InheritedSprite.super:init(x, y, image)
end

Error:

Load failed, error: BaseSprite.lua:10: bad argument #-2 to 'setImage' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'setImage'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk
Update error: BaseSprite.lua:10: bad argument #-2 to 'setImage' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'setImage'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk
5

I've changed that:

import "CoreLibs/sprites"

local pd <const> = playdate
local gfx <const> = pd.graphics

class('BaseSprite').extends(gfx.sprite)

function BaseSprite:init(x, y, image)
    assert(image ~= nil, 'image is nil in BaseSprite')
    self.super.init(self)
    self:setImage(image)
    self:add()
    self:moveTo(x, y)
end

It does get past the self:setImage() now, but fails on the self:moveTo():

Load failed, error: CoreLibs/sprites.lua:38: bad argument #-2 to 'moveTo' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'moveTo'
	CoreLibs/sprites.lua:38: in field 'init'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk
Update error: CoreLibs/sprites.lua:38: bad argument #-2 to 'moveTo' (playdate.graphics.spriteud expected, got nil)
stack traceback:
	[C]: in method 'moveTo'
	CoreLibs/sprites.lua:38: in field 'init'
	BaseSprite.lua:10: in method 'init'
	InheritedSprite.lua:16: in field 'init'
	CoreLibs/object.lua:70: in global 'InheritedSprite'
	main.lua:7: in main chunk