Sort sprites by Y axis
BlitzMax Forums/BlitzMax Beginners Area/Sort sprites by Y axis
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| Hi all, I have tried numerous times since I got blitz a few years ago to figure this out and still haven't been able to make sense of it. I have read all the guides on using bubblesort or quicksort, but still not sure how to apply it to blitz. Lets say I have a class Type dudes Field x:Float Field y:Float Method New() EntityList.AddLast(Self) totaldudes = totaldudes + 1 End Method End Type Somewhere here, I need to insert a coding algorithm to sort them by the y, so that they are more organized. I can't figure out how to do that with a tlist. For guys:dudes = EachIn Entitylist DrawImage guys.img, guys.x + mapx ,guys.y + mapy,guys.frame next thanks!!!! |
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Basically this.SortList( EntityList,True,YSort ) Function YSort:Int( o1:Object,o2:Object ) Return dudes(o1).y-dudes(o2).y End Function But you might want to clean it up a bit with some type checking first. |
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| hi dave, could you explain that a little bit more? thanks a lot for your response. I am trying to understand it. |
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| The function SortList() sorts a list using a function provided. I have provided a function YSort() that sorts using the y field. For more info on SortList() type it into the IDE and press f1 twice. |
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| The function SortList() sorts a list using a function provided. This means you can program a sorting function to sort objects in whatever way you want - based on a name, on a certain field's value etc. In this case, Oddball programmed a sorting function that sorts objects based on their 'y' field value. You can program a sorting function to sort in the specific way you want and then supply it to SortList() or Sort() (the latter is a method of every TList). Take note it must be specially formatted: it must return an Int value being '-1', '0' or '1', and take two 'Object' values. Refer to YSort(), above. - You can call it as a function: SortList(list, ascend, YSort). - You can call it as a Method directly from the TList to be sorted: EntityList.Sort(ascend, YSort) In either case it works the same, it's just the way you're calling it. More info on SortList\Sort: http://en.wikibooks.org/wiki/BlitzMax/Modules/Data_structures/Linked_lists#SortList http://blitzbasic.com/bmdocs/command.php?name=SortList |
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| Thanks guys! |
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