Map Editor Questions

Few more general questions:

a) Rather than use arrays to store tiles and maps, I was thinking of using Types for botht he tiles and the map data, allowing me to combine information. Is this more efficent/faster than using arrays? Or am I better off with separate collison maps/tiles?

b) I wish to implement a Zoom function, allowing the user to Zoom out from their map (probably -2x, -4x, and -8x) - is there a graceful way of doing this?

What kind of map? Tile based? 2D? 3D?

a) also consider banks .. (but then again, I'm the banktype :)

b) .. in Blitzplus it would be somewhat easier by having scalable canvasses .. but I assume you want blitz2d/3d :) So, dunno!

It's a 2D map editor written in Blitz+ - at the moment I'm using arrays to store the maps, with tiles imported as a strip of images in a BMP...

Well then just create an array of types...

I guess for your average 2d tilemapped game an array is safe enough, and by far the easiest format to parse at run time when you are moving around/rendering the map.

If the maps were *huge* with only a limited amount of the 'grid' populated with tiles then I guess you could look for a more optimal solution but I serious doubt that it would be a problem. Tn real terms the memory taken up storing a 2d map in an array is tiny compared to other resources such as graphics and samples.

Ello Rik :)

I guess I'm just trying to refine the way I code, make things a little more efficient. I've seen a few editors which use Types for each tile and so forth - I just assumed it was a more efficient way of doing things.

I guess the format isn't that crucial - I can always put in export options to suit any requirement - but I get paranoid that my code is sloppy... :/

You don't even need to make a 2D tile editor. Just use one of the many available ones. Here's a good one: www.blitzbase.de/_mapeditor/

>> You don't even need to make a 2D tile editor.

You're kind of missing the point - why should anyone make a platform game when there are dozens out there already?

There are a number of reasons I chose to write my editor:

a) good for learning new techniques

b) useful to be able to change the way an editor exports data or add new features

c) I need an editor that will integrate with my game so I can make changes in real time.

So... back on topic... ;)

As for me, I tend to favor the method that makes it easiest for the programmer. I really like types, so I make liberal use of them. Sometimes I use arrays of types, so that they can be indexed directly, but I don't often need to with the stuff I do; it's just as well to do an O(n/2) search through the list of types.

I suggest trying both (or all three, if you want to take CS_TBL's advice). Most likely, you'll probably end up with a nice mix. And you certainly will learn the differences, pros/cons, etc, which is a goal of yours, unless I'm mistaken.

As for the zoom thing, there is a graceful way. Basically, just resize the canvas. Check out this small example:

Global w=CreateWindow("Canvas Resize / Zoom", 200, 200, 400, 400, 0, 3)
Global c=CreateCanvas(0,0,ClientWidth(w),ClientHeight(w),w)

CreateTimer(60)
SetBuffer(CanvasBuffer(c))

Notify "Press mouse buttons to zoom in/out"

Repeat
	Select WaitEvent()
		Case $803 : End
		Case $201
			If EventData() = 1 Then
				zoom = zoom + 50
			Else
				zoom = zoom - 50
				If zoom < -150 Then zoom = -150 ; don't get too small
			EndIf
			SetGadgetShape(c,0-zoom,0-zoom,400+zoom*2,400+zoom*2)
		Case $4001
			Render()
	End Select
Forever

Function Render()
	;Cls ;if you want
	Color Rand(256), Rand(256), Rand(256)
	Rect(Rand(ClientWidth(c)), Rand(ClientHeight(c)), Rand(10), Rand(10), True)
	FlipCanvas(c)
End Function

Cheers Soja :)

Back on the subject of Arrays and Types: in my editor, I wish to include a library of commonly-used brushes.

Each brush is an array, and I want to use an index to access the relevant brush.

Is it possible to have an array of arrays, or is this where Types come to the fore?

An array of arrays is a multi-dimensional array.

Dim a(100)
Dim a(100, 100)
Dim a(100, 100, 100)
Dim a(100, 100, 100, 100)

Whatever you want.

I started a programming tutorial a while back (but didn't get very far). However, it just so happened that I started writing about arrays and types:
http://home.cmit.net/rwolbeck/programmingtutorial/


Here is some text on multi-dimensional arrays from the tutorial:

Think of your array as a chess board.
dim chess$(7,7)

will give you 0-7 across and 0-7 down (64 square in total). So you can reference a point and see what's there or set what's there.
chess$(5,5) = "Black Knight"
chess$(1,2) = "White Queen"
print chess$(3,3)

Then you can take it even further and stack several chess boards on top of one another.
dim chess$(7,7,2)

This has stacked 3 chess boards on top on each other. You can now reference any squre on any board.
This sets position 5,2 on chess board 1
chess$(5,2,1) = "White Bishop"
print chess$(5,2,1)

Sets position 2,1 on chess board 0...
chess$(2,1,0) = "Black Pawn"

You ready to take it even further...

Well, lets have our stacked chess boards spanning across different rooms...
dim chess$(7,7,2,9)

You getting the idea?

We now have 10 (0-9) rooms we are playing our 3 stacked chess games in. We can reference any square on any chess board in any room...
chess$(5,1,2,7) = "Black Rook"

So, in room 7, on board 2, at position 5,1 on that board there is now a black rook...

Expand it further... Lets add any building...
dim chess$(7,7,2,9,4)

we now have x,y on the board, board number, room number, and building number which we can instantly reference...
chess$(1,2,2,8,3) = "White Pawn"

So the piece at 1,2 on board 2 in room 8 in building 3 is a white pawn.

Cheers WolRon, that's a very nice explanation :)

However, the problem still remains - what if I want to change the size of a particular element?

The chessboard example assumes that all of the boards are the same size, whereas I need to have ones that can change size.

I've been struggling with this for a couple of hours but can't find a way around it without using Types...

Dim your array again to the size you want.. (note: the original contents will be lost)


What you could consider: make a bank of banks!

Each bankhandle costs you 4 bytes (1 int) .. if you create a bank of 40 bytes, then you can store 10 bankhandles in it.. each bankhandle is ofcourse a seperate bank of ANY size.
You can easily resize a bank using ResizeBank and the contents wont get lost then ..
But again, as I'm the banktype, I'm not exactly neutral in this advice :)

Blimey - I never even knew Banks existed (someone somewhere take note and provide some comprehensive Blitz docs...!).

So how do Banks work? Presumably I just access them like arrays?

Ah, just found a tutorial by Krylar... :)

Once you start working with banks, you'll want to use this for sure!

http://www.blitzbasic.co.nz/Community/posts.php?topic=29266

(don't forget to include that minor SetCanvas function)

Arrays are wastefull for a tile map where you may have very little data in most tiles, so types can help a good bit there.

Also I find type much easier to use in a tile map, because it makes it alot easier to add new data to existing data without the need to x to the power of n the entire array.

Types are plenty fast enough and the for loops on types make itterating through them a snap. I created a editor game map engine that supported unlimitted layers, in the game I was working on I used 10. I could do this because unlike DIM I did not need to allocate all that memory for unused tile positions.

Im fairly sure I posted it to Blitz Coder at some time. It was over a year ago.


So IMHO you should go types over arrays, unless the map is very simple and will not change much.

Wolron, I wrote that... It's nice to see you're taking credit for something you didn't write.
http://www.blitzbasic.com/Community/posts.php?topic=35512#388017

Umm, I didn't take credit for it.

Nowhere here does it say that I wrote it.

"I started writing about arrays and types"

That sounds like you wrote it to me.

which I did...
but I didn't say that I wrote that particular text that I copied to the screen.

If you would like me to remove it from my tutorial then I will. I just thought that you did a well enough job explaining it that it wasn't necessary for me to rewrite it. Nor did I feel that it was necessary to include a page of names of people that I might have borrowed text from - people who to most readers would probably just be nobodys anyways.

However, if you would like me to still use it in my tutorial but give you credit somewhere, then I can do that too.

I love arrays - they're cuter than types.

So back on topic... how do i create a library of "brush" arrays? Use a type for each brush, then within the type itself include an array?