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what you set to setPosition is not exactly what you get from getPosition — Gideros Forum
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    what you set to setPosition is not exactly what you get from getPosition

    XmanXman Member
    edited October 2015 in General questions
    local s1 = Sprite.new()

    stage:addChild(s1)

    ---331.81048583984
    s1:setPosition(331.81047773361, 331.81047773361)

    print(s1:getPosition())

    output
    331.81048583984 331.81048583984 0

    that's make it impossible to do collision check by x, y position
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    Comments

    • hgy29hgy29 Maintainer
      Thats because coordinates in gideros are stored as 32bit floats (single precision), wheras the number you try to set would have required double precision (64 bits). Check with this online tool: http://www.h-schmidt.net/FloatConverter/IEEE754.html

      However this shouldn't prevent you from doing collision tests by checking if the position is inside some range.

      Likes: Holonist

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    • XmanXman Member
      That really make it impossible to determine whether the bottom of an object is just on the surface of the top of another. That puzzled me all day to figure it out. Finally,I solved it by keeping the position value in the object itself.

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    • HolonistHolonist Member
      edited October 2015
      In your example, the difference starts at the fifth decimal.
      If you have to check your objects in ranges of a 10000th PIXEL (a pixel is actually the smallest amount that you can move an object on the screen), I don't believe your game design is appropriate.

      Maybe you're missing the usage of >=, <= operators instead of ==?
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