Get all stacked sprites? - GameCreators Forum

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Ron2019

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Posted: 12th Feb 2020 17:27

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I am developing a game that uses stacked sprites. GetSpriteHit only returns the top-most sprite ID per Depth, but I need to know the IDs for ALL of the sprites in the Stack, not just the top-most one. Is there some easy way to get a collection of the IDs for all of the stacked sprites? I am unable to identify a command to do so, but may not be looking for the right term? Functionality like that provided by GetSpriteFirstContact & GetSpriteNextContact would be my second choice, but neither GetSpriteHitNext nor GetSpriteNextHit appear to exist?

I am currently either moving each of the stacked sprites off-screen or to the bottom of the stack before issuing additional GetSpriteHit calls to obtain the list of sprites. Both of these work-arounds then require resetting either position or depth, which is a PITA for the number of sprites concerned. And I'd really like to avoid GetSpriteHitTest, because I don't want to have to iterate through every sprite in the game just to figure out which ones were hit.

Has anybody developed a better way to do this?

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Ron2019

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Posted: 13th Feb 2020 15:57

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Evidently not.

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JosephB

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Posted: 13th Feb 2020 17:14

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I have not yet had a need to develop code to determine the sprite IDs within a stack of sprites, but I have tried to imagine how to do this, but really need more information about the sprites and what is happening on the screen to try to help, if possible. Are the sprites moving or static? Is there a maximum number of sprites that are stacked? Do the sprites have a uniform shape and size? Do you have a picture and/or partial code you could provide? Not sure I am able to help, but willing to give it a try.

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hendron

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Posted: 13th Feb 2020 18:36

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You would think AppGameKit would provide this kind of functionality built in and I'm surprised it doesn't. I believe moving them off the screen or changing their depth like you said you're doing now is pretty much the simplest way to do it. I would just put it in a function.

+ Code Snippet

function GetSpriteHitStack(x#, y#)
	
	local hit_ids as integer[]
	local old_x as float[]
	local old_y as float[]
	
	repeat
		hit = GetSpriteHit(x#, y#)
		if hit > 0
			hit_ids.insert(hit)
			old_x.insert(GetSpriteX(hit))
			old_y.insert(GetSpriteY(hit))
			SetSpritePosition(hit, -1000000, -1000000)
		endif
	until hit = 0
	
	for i = 0 to hit_ids.length
		SetSpritePosition(hit_ids[i], old_x[i], old_y[i])
	next i
	
endfunction hit_ids

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Ron2019

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Posted: 14th Feb 2020 17:47 Edited at: 14th Feb 2020 17:50

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Stacks may currently be as deep as 10 sprites, but I can easily envision a need for more. All use transparent backgrounds to construct composite graphics on the fly, consisting of:
* 1 to 3 sprites used to construct a basic playing piece;
* Overlaid sprites indicating valid and invalid moves, which are added to the top of a stack during play validation;
* Underlying sprites to apply a background color for an entire stack, also added during validation;
* Sprites inserted between layers of the stack to highlight specific sprites in the stack when played;
* And there are also board sprites at the deepest level, which I need to identify as the sprite stack is moved around, in order to validate play.
IOW, I need the ID for every sprite in the stack as well as those in adjacent board positions to validate movement.

Only one stack of sprites is in motion at any time, controlled by the pointer. Pieces may be rotated before play. When successfully played, an entire stack remains on the board and the player picks up another stack. Moving a stack from one board position to another invokes move validation, which requires:
* Identifying adjacent board positions;
* Identifying all of the sprites in previously played stacks in those adjacent positions;
* Determining whether the move is valid based on the contents of all of the sprite stacks involved;
* Applying many of the same sprite modifications listed above to effected sprite stacks played previously in adjacent board positions;
* And then removing all those modifications every time the stack is moved.
IOW, I need the ID for every sprite in adjacent board positions, including the board itself, to validate movement.

Successfully playing a stack tallies the score for a move, which requires:
* Checking the stacks and board positions of many other previously played stacks in non-adjacent board positions because of a cascading effect (of sorts) highlighting all of the stacks used to calculate the score;
* Changing the depths of the three sprites used to create the playing piece, to move the most relevant sprite to the top of its stack;
* Making many of the same sprite stack changes listed above to any effected sprite stacks;
* And then removing all of these changes when the player selects a new sprite stack to play.

So although only one stack is in motion at any time, changes occur all over the board whenever the player moves or places a stack. Moving or changing the depths of sprites in order to get the IDs of underlying sprites is a major effort when the stacks are constantly changing. And building an array to avoid moving sprites seems almost as cumbersome. As you can see, the process is complex and highly repetitive.

I doubt there's an elegant solution.

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JosephB

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Posted: 14th Feb 2020 22:38

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Thanks for the detailed information. I am not aware of any AppGameKit commands that would provide the IDs of stacked sprites. As you mentioned and hendron suggested, arrays should help track what is happening each move. If you are not already doing so, I believe it could be helpful to use a type for your game pieces and then make that type an array, possibly an array for the piece number, sprite ID and the sprite depth. You might be able to eliminate the sprite board position from the stack if you are able to develop a grid array for your board positions, something akin to a breakout game grid design based on columns and rows and the pixel size of the grid segment. This would hopefully prevent having to move or change the depth of sprites in stacks to identify all sprites in the stack.

Example code for type and array:

// Project: Arraytest 
// Created: 2020-02-14

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Arraytest" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts

type myType
    num as integer
    ID as integer[9]  //IDs for 10 sprites in the stack
    depth as integer[9] //10 depths, one for each sprite in the stack
endtype
myArray as myType[19] //20 pieces
myArray[0].num = 1
myArray[0].ID[0] = 20
myArray[0].depth[0] = 10
myArray[0].ID[1] = 21
myArray[0].depth[1] = 11

do

Print("Piece Num: " + Str(myArray[0].num)) 
    Print("Sprite One: " + Str(myArray[0].ID[0]) + " Depth: " + Str(myArray[0].depth[0]))
	Print("Sprite Two: " + Str(myArray[0].ID[1]) + " Depth: " + Str(myArray[0].depth[1]))
    Sync()
loop

+ Code Snippet

// Project: Arraytest 
// Created: 2020-02-14

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Arraytest" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts

type myType
    num as integer
    ID as integer[9]  //IDs for 10 sprites in the stack
    depth as integer[9] //10 depths, one for each sprite in the stack
endtype
myArray as myType[19] //20 pieces
myArray[0].num = 1
myArray[0].ID[0] = 20
myArray[0].depth[0] = 10
myArray[0].ID[1] = 21
myArray[0].depth[1] = 11


do
    

    Print("Piece Num: " + Str(myArray[0].num)) 
    Print("Sprite One: " + Str(myArray[0].ID[0]) + " Depth: " + Str(myArray[0].depth[0]))
	Print("Sprite Two: " + Str(myArray[0].ID[1]) + " Depth: " + Str(myArray[0].depth[1]))
    Sync()
loop

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Ron2019

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Posted: 15th Feb 2020 17:04 Edited at: 15th Feb 2020 17:19

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Thanks for your suggestion! I'm already using a typed array to store the board to piece relationships and the challenge is identifying the array position using the pointer's screen location because I need to search the array for either piece or board ID, which I can only determine with GetSpriteHit. Adding sprite bounds in the array would simplify things considerably if the pieces weren't hexagonal.

I'd explore Tier 2 but don't want to rewrite the whole thing in C. It sounds like the best approach for now is shuffling sprites around.

Thanks again for listening!

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hendron

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Posted: 15th Feb 2020 17:24

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This post has been marked by the post author as the answer.

Quote: "If nobody has already created something akin to GetAllSpritesHit, perhaps I can?"

If you're wanting a function that is the same as GetSpriteHit(), but returns all of the sprites that are hit at the given coordinate instead of only the top-most, that's exactly what the function I provided in my previous post does. It takes a coordinate and returns an array of all of the sprites hit at that coordinate. Apologies if I'm misunderstanding and this isn't what you're after.

Here's a quick demo snippet using the function.

SetWindowSize(1024,768,0)
SetVirtualResolution(1024,768)
SetSyncRate(0,0)

for spr = 1 to 500
	CreateSprite(spr,CreateImageColor(random(0,100),random(0,100),random(0,100),255))
	SetSpriteSize(spr,Random(32,64),Random(32,64))
	SetSpritePosition(spr,Random(0,1024),Random(0,768))
next spr

while not GetRawKeyPressed(27)
	
	
	sprite_ids as integer[]

if GetPointerPressed()
		sprite_ids = GetSpriteHitStack(GetPointerX(),GetPointerY())
	endif
	
	Print(ScreenFPS())
	Print("Click to hit test")
	Print("")
	Print("Sprites Hit: ")
	
	for i = 0 to sprite_ids.length
		print(sprite_ids[i])
	next i
	
	sync()
	
endwhile

function GetSpriteHitStack(x#, y#)
     
    local hit_ids as integer[]
    local old_x as float[]
    local old_y as float[]
     
    repeat
        hit = GetSpriteHit(x#, y#)
        if hit > 0
            hit_ids.insert(hit)
            old_x.insert(GetSpriteX(hit))
            old_y.insert(GetSpriteY(hit))
            SetSpritePosition(hit, -1000000, -1000000)
        endif
    until hit = 0
     
    for i = 0 to hit_ids.length
        SetSpritePosition(hit_ids[i], old_x[i], old_y[i])
    next i
     
endfunction hit_ids

+ Code Snippet

SetWindowSize(1024,768,0)
SetVirtualResolution(1024,768)
SetSyncRate(0,0)

for spr = 1 to 500
	CreateSprite(spr,CreateImageColor(random(0,100),random(0,100),random(0,100),255))
	SetSpriteSize(spr,Random(32,64),Random(32,64))
	SetSpritePosition(spr,Random(0,1024),Random(0,768))
next spr

while not GetRawKeyPressed(27)
	
	
	sprite_ids as integer[]

	if GetPointerPressed()
		sprite_ids = GetSpriteHitStack(GetPointerX(),GetPointerY())
	endif
	
	Print(ScreenFPS())
	Print("Click to hit test")
	Print("")
	Print("Sprites Hit: ")
	
	for i = 0 to sprite_ids.length
		print(sprite_ids[i])
	next i
	
	sync()
	
endwhile


function GetSpriteHitStack(x#, y#)
     
    local hit_ids as integer[]
    local old_x as float[]
    local old_y as float[]
     
    repeat
        hit = GetSpriteHit(x#, y#)
        if hit > 0
            hit_ids.insert(hit)
            old_x.insert(GetSpriteX(hit))
            old_y.insert(GetSpriteY(hit))
            SetSpritePosition(hit, -1000000, -1000000)
        endif
    until hit = 0
     
    for i = 0 to hit_ids.length
        SetSpritePosition(hit_ids[i], old_x[i], old_y[i])
    next i
     
endfunction hit_ids

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janbo

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Posted: 16th Feb 2020 16:15

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If you have many sprites, a collision system using QuadTrees should be predestined for those kind of tasks as it wouldn't need to iterate through all sprites but only down a few knots of the Tree.
Not sure how AppGameKit did the hit test or if it is overpowered and maybe even have a bigger overhead for your task than actally run through all your sprites, just one option.

QuadTree Code I had lying around.

type vec2
	X#
	Y#
endtype

type QuadTree_NodeData
	Depth as integer
	MinX# as float
	MinY# as float
	MaxX# as float
	MaxY# as float
	ChildID as integer[3]
	Point as vec2[]
endtype

global MaxPoints
MaxPoints=4
global MaxDepth
MaxDepth=6

Node as QuadTree_NodeData
MyQuadTree as QuadTree_NodeData[]
RootNode as QuadTree_NodeData
RootNodeID=QuadTree_CreateNode(MyQuadTree, 0,0,100,100, Node)

function AddPoint(Node ref as QuadTree_NodeData,X#,Y#)
	TempPoint as vec2
	TempPoint.X#=X#
	TempPoint.Y#=Y#
	Node.Point.insert(TempPoint)
endfunction

function RemovePoint(Node ref as QuadTree_NodeData, PointID as integer)
	Node.Point.remove(PointID)
endfunction

function QuadTree_Clear(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData)
	for ChildID=3 to 0 step -1
		if Node.ChildID[ChildID]<>-1
			QuadTree_Clear(QuadTree, QuadTree[Node.ChildID[ChildID]])
			Node.ChildID.remove(ChildID)
		endif
	next ChildID
endfunction

function QuadTree_CreateNode(QuadTree ref as QuadTree_NodeData[], MinX#,MinY#,MaxX#,MaxY#,ParentNode ref as QuadTree_NodeData)
	TempNode as QuadTree_NodeData

TempNode.Depth=ParentNode.Depth+1
	TempNode.MinX#=MinX#
	TempNode.MinY#=MinY#
	TempNode.MaxX#=MaxX#
	TempNode.MaxY#=MaxY#

for ChildID=0 to 3
		TempNode.ChildID[ChildID]=-1
	next ChildID

QuadTree.insert(TempNode)
endfunction QuadTree.length

function QuadTree_SplitNode(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData)
	X#=(Node.MinX#+Node.MaxX#)*0.5
	Y#=(Node.MinY#+Node.MaxY#)*0.5
	Node.ChildID[0]=QuadTree_CreateNode(QuadTree, Node.MinX#,Node.MinY#,X#,Y#,Node)
	Node.ChildID[1]=QuadTree_CreateNode(QuadTree, X#,Node.MinY#,Node.MaxX#,Y#,Node)
	Node.ChildID[2]=QuadTree_CreateNode(QuadTree, Node.MinX#,Y#,X#,Node.MaxY#,Node)
	Node.ChildID[3]=QuadTree_CreateNode(QuadTree, X#,Y#,Node.MaxX#,Node.MaxY#,Node)
endfunction

function QuadTree_InsertPoint(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData,X#,Y#)
	if Node.Point.length<MaxPoints
		AddPoint(Node,X#,Y#)
	else
		QuadTree_SplitNode(QuadTree, Node)
		for ChildID=0 to 3
			if QuadTree_InsideNode(QuadTree[Node.ChildID[ChildID]],X#,Y#)=1
				QuadTree_InsertPoint(QuadTree, QuadTree[Node.ChildID[ChildID]],X#,Y#)
				exit
			endif
		next ChildID
	endif
endfunction

function QuadTree_Exist(QuadTree ref as QuadTree_NodeData[], NodeID,X#,Y#)
	for ChildID=0 to 3
		if QuadTree[NodeID].ChildID[ChildID]<>-1
			if QuadTree_InsideNode(QuadTree[QuadTree[NodeID].ChildID[ChildID]],X#,Y#)=1
				ID=QuadTree_Exist(QuadTree,QuadTree[NodeID].ChildID[ChildID],X#,Y#)
				if ID<>-1 then exitfunction ID
			endif
		endif
	next ChildID
	if QuadTree_InsideNode(QuadTree[NodeID],X#,Y#)=1 then exitfunction NodeID
endfunction -1

function QuadTree_InsideNode(Node ref as QuadTree_NodeData,X#,Y#)
	if X#>=Node.MinX# and X#<Node.MaxX#
		if Y#>=Node.MinY# and Y#<Node.MaxY#
			exitfunction 1
		endif
	endif
endfunction 0

function QuadTree_IntersectBounds(Node ref as QuadTree_NodeData,MinX#,MinY#,MaxX#,MaxY#)
endfunction Not (MinX#>Node.MaxX# or MaxX#<Node.MinX# or MinY#>=Node.MaxY# or MaxY#<Node.MinY#)

function QuadTree_InsideBounds(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData,MinX#,MinY#,MaxX#,MaxY#, Points ref as vec2[])
	if QuadTree_IntersectBounds(Node,MinX#,MinY#,MaxX#,MaxY#)
		for p=0 to Node.Point.length
			if Node.Point[p].X#>=MinX# and Node.Point[p].X#<MaxX#
				if Node.Point[p].Y#>=MinY# and Node.Point[p].Y#<MaxY#
					Points.insert(Node.Point[p])
				endif
			endif
		next p
		if Node.Point.length=MaxPoints
			for ChildID=0 to 3
				if Node.ChildID[ChildID]>-1
					QuadTree_InsideBounds(QuadTree,QuadTree[Node.ChildID[ChildID]],MinX#,MinY#,MaxX#,MaxY#, Points)
				endif
			next ChildID
		endif
	endif
endfunction Points

+ Code Snippet

type vec2
	X#
	Y#
endtype

type QuadTree_NodeData
	Depth as integer
	MinX# as float
	MinY# as float
	MaxX# as float
	MaxY# as float
	ChildID as integer[3]
	Point as vec2[]
endtype

global MaxPoints
MaxPoints=4
global MaxDepth
MaxDepth=6

Node as QuadTree_NodeData
MyQuadTree as QuadTree_NodeData[]
RootNode as QuadTree_NodeData
RootNodeID=QuadTree_CreateNode(MyQuadTree, 0,0,100,100, Node)

function AddPoint(Node ref as QuadTree_NodeData,X#,Y#)
	TempPoint as vec2
	TempPoint.X#=X#
	TempPoint.Y#=Y#
	Node.Point.insert(TempPoint)
endfunction

function RemovePoint(Node ref as QuadTree_NodeData, PointID as integer)
	Node.Point.remove(PointID)
endfunction

function QuadTree_Clear(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData)
	for ChildID=3 to 0 step -1
		if Node.ChildID[ChildID]<>-1
			QuadTree_Clear(QuadTree, QuadTree[Node.ChildID[ChildID]])
			Node.ChildID.remove(ChildID)
		endif
	next ChildID
endfunction

function QuadTree_CreateNode(QuadTree ref as QuadTree_NodeData[], MinX#,MinY#,MaxX#,MaxY#,ParentNode ref as QuadTree_NodeData)
	TempNode as QuadTree_NodeData

	TempNode.Depth=ParentNode.Depth+1
	TempNode.MinX#=MinX#
	TempNode.MinY#=MinY#
	TempNode.MaxX#=MaxX#
	TempNode.MaxY#=MaxY#

	for ChildID=0 to 3
		TempNode.ChildID[ChildID]=-1
	next ChildID

	QuadTree.insert(TempNode)
endfunction QuadTree.length

function QuadTree_SplitNode(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData)
	X#=(Node.MinX#+Node.MaxX#)*0.5
	Y#=(Node.MinY#+Node.MaxY#)*0.5
	Node.ChildID[0]=QuadTree_CreateNode(QuadTree, Node.MinX#,Node.MinY#,X#,Y#,Node)
	Node.ChildID[1]=QuadTree_CreateNode(QuadTree, X#,Node.MinY#,Node.MaxX#,Y#,Node)
	Node.ChildID[2]=QuadTree_CreateNode(QuadTree, Node.MinX#,Y#,X#,Node.MaxY#,Node)
	Node.ChildID[3]=QuadTree_CreateNode(QuadTree, X#,Y#,Node.MaxX#,Node.MaxY#,Node)
endfunction

function QuadTree_InsertPoint(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData,X#,Y#)
	if Node.Point.length<MaxPoints
		AddPoint(Node,X#,Y#)
	else
		QuadTree_SplitNode(QuadTree, Node)
		for ChildID=0 to 3
			if QuadTree_InsideNode(QuadTree[Node.ChildID[ChildID]],X#,Y#)=1
				QuadTree_InsertPoint(QuadTree, QuadTree[Node.ChildID[ChildID]],X#,Y#)
				exit
			endif
		next ChildID
	endif
endfunction

function QuadTree_Exist(QuadTree ref as QuadTree_NodeData[], NodeID,X#,Y#)
	for ChildID=0 to 3
		if QuadTree[NodeID].ChildID[ChildID]<>-1
			if QuadTree_InsideNode(QuadTree[QuadTree[NodeID].ChildID[ChildID]],X#,Y#)=1
				ID=QuadTree_Exist(QuadTree,QuadTree[NodeID].ChildID[ChildID],X#,Y#)
				if ID<>-1 then exitfunction ID
			endif
		endif
	next ChildID
	if QuadTree_InsideNode(QuadTree[NodeID],X#,Y#)=1 then exitfunction NodeID
endfunction -1

function QuadTree_InsideNode(Node ref as QuadTree_NodeData,X#,Y#)
	if X#>=Node.MinX# and X#<Node.MaxX#
		if Y#>=Node.MinY# and Y#<Node.MaxY#
			exitfunction 1
		endif
	endif
endfunction 0

function QuadTree_IntersectBounds(Node ref as QuadTree_NodeData,MinX#,MinY#,MaxX#,MaxY#)
endfunction Not (MinX#>Node.MaxX# or MaxX#<Node.MinX# or MinY#>=Node.MaxY# or MaxY#<Node.MinY#)

function QuadTree_InsideBounds(QuadTree ref as QuadTree_NodeData[], Node ref as QuadTree_NodeData,MinX#,MinY#,MaxX#,MaxY#, Points ref as vec2[])
	if QuadTree_IntersectBounds(Node,MinX#,MinY#,MaxX#,MaxY#)
		for p=0 to Node.Point.length
			if Node.Point[p].X#>=MinX# and Node.Point[p].X#<MaxX#
				if Node.Point[p].Y#>=MinY# and Node.Point[p].Y#<MaxY#
					Points.insert(Node.Point[p])
				endif
			endif
		next p
		if Node.Point.length=MaxPoints
			for ChildID=0 to 3
				if Node.ChildID[ChildID]>-1
					QuadTree_InsideBounds(QuadTree,QuadTree[Node.ChildID[ChildID]],MinX#,MinY#,MaxX#,MaxY#, Points)
				endif
			next ChildID
		endif
	endif
endfunction Points

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blink0k

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Posted: 16th Feb 2020 18:46

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Would 2dPhysics help?
It has functions like GetFirstContact()/GetNextContact()

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Ron2019

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Posted: 16th Feb 2020 18:53

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Thanks, Hendron! Temporarily re-positioning sprites as they are hit certainly avoids the issue with changing sprite depths and iterating through an array is ideal for my processing.

Thanks for responding, Janbo, but Hendron's solution uses the physics engine to determine hits against non-rectangular sprites, which is closer to what I need and I think somewhat easier to implement with my existing code. But thank you very much for your suggestion!

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Ron2019

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Posted: 16th Feb 2020 19:32 Edited at: 16th Feb 2020 19:40

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blinkOk: I've been unable to find a working example using GetFirstContact or GetNextContact in the Help pages. I do note, though, that the Description for GetNextContact says "Returns 1 if a contact exists, you can get the sprites involved in this contact using GetContactSpriteID1 and GetContactSpriteID2..." which suggests these commands only capture collisions between sprites, not an overlap between sprites and the pointer?

To be sure, I've tried creating a test but GetFirstContact returns 0 when the mouse is hovered over or clicked on any sprite in the scene. Can you provide or point me to a working example that captures a list of hexes under the pointer?

Thanks for your response!

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Virtual Nomad

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Posted: 16th Feb 2020 20:19

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is collision necessary?

IE, put the sprites into a stack (typed array?), then place the stack into the grid (another typed array?), record it all & retrieve the sprite IDs when you need them?

IE, determine which hex you're in:
https://www.redblobgames.com/grids/hexagons/#pixel-to-hex

pull the stack(s?) that lay in the space from the grid array, and do what you need to with the sprites in the stack.

if you need to be able to determine which sprite in the stack was clicked specifically, at least you'd have much fewer hits to detect (that's assuming there is no uniform alignment of the sprites that you could otherwise use math to determine which sprite in the stack is selected).

if you wanted to use collision to determine which hex you're hovering over, you could do similar. give each hex a background sprite that you could use as a reference to look up stacks, then sprites, etc.

hope that makes sense.

but, it sounds like you need some "real" sprite/data handling so i would take a "divide and conquer" approach and make sure everything is well organized so you can reference what you need (vs any notion of mass collision checks).

My Itch.io Home.

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Bengismo

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Posted: 17th Feb 2020 13:22 Edited at: 17th Feb 2020 13:24

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You could use the sprites group functionality that is built in...

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Collision Checking" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts

// Create some sprites in random positions
for i = 0 to 80
	spr = CreateSprite(0)
	SetSpritesize(spr,100,100)
	SetSpritePosition(spr,random2(1,800),random2(1,600))
	SetSpriteColor(spr,Random2(30,255),Random2(30,255),Random2(30,255),255)
next i

global hitlist as integer[] // this holds the sprites under the cursor

do
    hitlist = GetSpritesHit(GetPointerx(),getpointery())

Print( ScreenFPS() )
    
    for i=0 to hitlist.length
		Print(hitlist[i])
	next i
    
    
    Sync()
loop

// A function to get a list of sprite under a position
function GetSpritesHit(x as float,y as float)
	
	list as integer[]
	
	// Get a list of the sprites under the position
	sp1 = GetSpriteHitGroup( 0, x, y )
	while sp1<>0
		list.insert(sp1)
		SetSpriteGroup(sp1,1)
		sp1 = GetSpriteHitGroup( 0, x, y )
	endwhile
	
	// reset the group to standard group of 0
	for i = 0 to List.length
		SetSpriteGroup(list[i],0)
	next i 
	
endfunction list

+ Code Snippet

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Collision Checking" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts

// Create some sprites in random positions
for i = 0 to 80
	spr = CreateSprite(0)
	SetSpritesize(spr,100,100)
	SetSpritePosition(spr,random2(1,800),random2(1,600))
	SetSpriteColor(spr,Random2(30,255),Random2(30,255),Random2(30,255),255)
next i

global hitlist as integer[] // this holds the sprites under the cursor

do
    hitlist = GetSpritesHit(GetPointerx(),getpointery())

    Print( ScreenFPS() )
    
    for i=0 to hitlist.length
		Print(hitlist[i])
	next i
    
    
    Sync()
loop

// A function to get a list of sprite under a position
function GetSpritesHit(x as float,y as float)
	
	list as integer[]
	
	// Get a list of the sprites under the position
	sp1 = GetSpriteHitGroup( 0, x, y )
	while sp1<>0
		list.insert(sp1)
		SetSpriteGroup(sp1,1)
		sp1 = GetSpriteHitGroup( 0, x, y )
	endwhile
	
	// reset the group to standard group of 0
	for i = 0 to List.length
		SetSpriteGroup(list[i],0)
	next i 
	
endfunction list

In the example above it gets a list of sprites under the cursor and they are ordered by depth.

The GetSpriteHitGroup() command can be used to get only certain sprites under the mouse position depending on what group you want.

You can also use the category bits too and GetSpriteHitCategory().

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Ron2019

4

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Joined: 27th Jul 2019

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Posted: 17th Feb 2020 16:53

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Thanks for all of the responses! I have marked Hendron's response as the one I am adopting, as it seems to simplest to implement. I have also entered a request for such a function in GitHub.

Thanks, again, everybody!

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smerf

19

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Joined: 24th Feb 2005

Location: nm usa

Posted: 18th Feb 2020 00:49

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hmm i woulda just done a for loop
spr as integer[100]
startrange= whatever num to starton
x=getrawmousex():y=getrawmousey()

for i=1 to max
spritehit=getspritehit(x,y)
if spritehit=>startrange
spr[i]=spritehit
hidesprite spritehit
inc max,1
endif
next
if background image returned or hiy=0 end is reached then show all the sprites peviously hidden.
can sort a thousand sprites deep no problem

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hendron

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Joined: 20th Dec 2015

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Posted: 18th Feb 2020 01:56 Edited at: 18th Feb 2020 01:56

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GetSpriteHit() still detects sprites when they're hidden (and even when they're deactivated, which is odd)

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smerf

19

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Joined: 24th Feb 2005

Location: nm usa

Posted: 18th Feb 2020 04:59

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yes very odd id imagine something hidden would be excluded from all checks except existence and property requests. could always move the sprite left or right a few pixes then move back when done it would all happen before a refresh so not visible to a user.

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AppGameKit Studio Chat / [SOLVED] Get all stacked sprites?