Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
Solved

# Splitting a bmp into small pieces

Posted on 2001-07-31
Medium Priority
215 Views
Hi there,
I need a code example of how to split a bmp into small pieces. My problem:

I have a large bmp with tiles on it (for use in a tiled based game) only, it's like 14tiles x 30tiles in size. A tile is 48x48 and there is a 3 pixel sperater around the tiles, ie....

------------------
|    ||    ||    |
|    ||    ||    |
------------------

Kinda like that. I need to know how i can load a bmp up and have eg:

Tile height: ??
Tile width: ??
Skip width: ??
Skip height: ??

The values would be (for my purpose):
48,48,3,3

If anyone can help me, please do so.

Thanks
Stephen
0
Question by:St3v13
[X]
###### Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

• Help others & share knowledge
• Earn cash & points
• 2

Author Comment

ID: 6338174
Btw, the program will then spit out seperate bmps of the sperate tiles.

Thanks
Stephen
0

LVL 27

Expert Comment

ID: 6338200
sorry had no time to code, but its not so heavy to solve

the heart, beside the calculation is the bitmap.canvas.copyrect-method
or as alternative the bitblt-api funtion
to copy a part from the source bitmap into the new one

meikl ;-)
0

LVL 2

Accepted Solution

bugroger earned 780 total points
ID: 6338832
Hi,
Try this code:

Type
TXYWH     = Record
x, y, w, h : integer;
End;
TTileXY   = array of TXYWH;

//Calc the XYPos in the Source-Bitmap and
//the width, height
//SkipL/R/T/B are Left, Right, Top, Bottom
Procedure CalcTileXY(VAR _TileXY : TTileXY;
horzCount, vertCount, TileHeight, TileWidth,
SkipL, SkipR, SkipT, SkipB : Integer);
VAR
x, y, i : integer;

Begin
SetLength(_TileXY, horzCount * vertCount);
i := 0;
For y := 0 to (vertCount -1) do
For x := 0 to (horzCount -1) do
Begin
_TileXY[i].x := (x * TileWidth) + SkipL;
_TileXY[i].y := (y * TileHeight) + SkipT;
_TileXY[i].w := TileWidth - (SkipL + SkipR);
_TileXY[i].h := TileHeight - (SkipT + SkipB);
Inc(i);
End;
End;

// TileNo from 1 to ...
Procedure GetTileBitmap(SourceBitmap : TBitmap; VAR DestBitmap : TBitmap;
_TileXY : TTileXY; TileNo : Cardinal);
Begin
Dec(TileNo);
DestBitmap.Canvas.CopyRect(
Rect(0,0, _TileXY[TileNo].w , _TileXY[TileNo].h ),
SourceBitmap.Canvas,
Rect(_TileXY[TileNo].x, _TileXY[TileNo].y,
_TileXY[TileNo].x + _TileXY[TileNo].w,
_TileXY[TileNo].y + _TileXY[TileNo].h));
End;

Procedure DestroyTileXY(VAR _TileXY : TTileXY);
Begin
SetLength(_TileXY, 0);
End;

-----------------------------------
example how to use these functions:
-----------------------------------

VAR
TileXY : TTileXY;
TileBitmap : TBitmap;

begin
CalcTileXY(TileXY, 5, 5, 50, 50, 1, 1, 1, 1);
TileBitmap := TBitmap.Create;
TileBitmap.Width := TileXY[0].w;
TileBitmap.height := TileXY[0].h;
GetTileBitmap(Image1.Picture.Bitmap, TileBitmap, TileXY, StrToInt(Edit1.Text));
Image2.Canvas.Draw(0,0, TileBitmap);
DestroyTileXY(TileXY);
TileBitmap.Free;
end;

GL
Bug
0

Author Comment

ID: 6338865
Excellent answer! Thanks so much for your time and effort. I hope these 195 points are enough :-)

Regards
Stephen
0

## Featured Post

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
In this episode Don builds upon the troubleshooting techniques by demonstrating how to properly monitor a vSphere deployment to detect problems before they occur. He begins the show using tools found within the vSphere suite as ends the show demonst…
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…
###### Suggested Courses
Course of the Month8 days, 13 hours left to enroll