Expect retrieved value to be the same as assigned value

[khiav223577]

Example:

sprite = Sprite.new
sprite.zoom_x = 0.9
p sprite.zoom_x

In original RPG Maker XP engine, it prints 0.9
But it prints 0.8999999761581421 in mkxp (OSX binary)

[cremno]

mkxp uses the single-precision floating-point format for this and similar attributes while RGSS uses double-precision.

However even if it would be changed to double-precision you would still be able to find differences in very few cases. 1.8.1 is ancient and the code to convert between floating-point numbers and strings contained some bugs.

[khiav223577]

Maybe a wrapper class is one possible solution?

1. Rename the Sprite class implemented by mkxp as MkxpSprite
2. Define new Sprite class that inherits from MkxpSprite
3. Override zoom_x and zoom_x= method.

class Sprite < MkxpSprite
  attr_reader :zoom_x

  def zoom_x=(val)
    @zoom_x = val
    super
  end
end

It will be nice if mkxp can implement it. Make mkxp behave more consistent with original engine.

---

The following is a surprising behavior I found in current implementation:

# let (xxxxx / yyyyy.to_f) to be 0.9
sprite.zoom_x = xxxxx / yyyyy.to_f 

# ...
# ...

# sprite.zoom_x is 0.8999 here and fail to enter the if-condition since 0.8999 is not larger than or equals to 0.9
if sprite.zoom_x >= 0.9 
  #  ...
  #  ...
end

[Ancurio]

I am curious what exact in-game issues this inaccuracy is causing.