Tile Based Surface Issue.

[DBridle]

Hi guys, all of my code is in c++, but my guess is the same should apply for VB. I am using the Direct Draw 7 interface to create a small tile editor for my tile based game. The problem is (i think) quite simple, I just cant seem to get it to work. Right now all I am concentrating on, is attaching a tile to my cursor and plonking it down somewhere on the screen. Here is some code fragments..

First off inside an initialize function, create the surfaces then load a bitmap onto my surface (I think this is where things might be going wrong). I have 3 surfaces, backdrop, tileset and my mousedrag surface that the tile will move around the screen based on mouse coordinates.

if( FAILED (lpdd7->CreateSurface(&ddsd, &lpddsTileset, NULL)))
		return(FALSE);

	if( FAILED (lpdd7->CreateSurface(&ddsd, &lpddsBackdrop, NULL)))
		return(FALSE);

	if( FAILED (lpdd7->CreateSurface(&ddsd, &lpddsMouseDrag, NULL)))
		return(FALSE);

	if(!Load_Bitmap(MAKEINTRESOURCE(IDB_BACKGROUND), 0, 0, lpddsBackdrop))
		return(FALSE);

	if(!Load_Bitmap(MAKEINTRESOURCE(IDB_BITMAP1), 0, 0, lpddsTileset))
		return(FALSE);


	if(!Load_Bitmap(MAKEINTRESOURCE(IDB_BITMAP1), 0, 0, lpddsMouseDrag))
		return(FALSE);

When I blit the background and tileset they work just fine. However, in the main render loop, I have this problem. I get the coordinates of the mouse and set my rectangle for blitting to a 32x32 square, with the top right being the mouse coordinates, then I blit the tile I want into that rectange, like so..

	rcDest3.top = mMouse.GetXAxis();
	rcDest3.bottom = mMouse.GetYAxis() + 32;
	rcDest3.right = mMouse.GetXAxis() + 32;
	rcDest3.left = mMouse.GetXAxis();
	
	byTile = byMap[0][1][0];
	lpddsBack->Blt(&rcDest3, lpddsMouseDrag, &lptile[byTile]->rcLocation , DDBLT_WAIT, NULL);

What happens is it attaches to my mouse pointer just fine, but each time it keeps itself in a square in the top right hand corner of the screen, when ever I move the mouse it just goes right back to the top right (0,0 is my guess). I also get like a trail effect of the tile. Its very hard to explain

If you need additional code, or want the program and resource files, let me know and I will attach them. I look forward to anyones help!

- Darren

[Gaming_World]

I don't know much C, but this looks kinda odd:

rcDest3.top = mMouse.GetXAxis();

Notice that you are getting the X corretiant for the top value. Other then this I can see nothing wrong (but like I said I know VB not C).

[DBridle]

Well the RECT struct looks something like this..

Top, Right ------------------ Top, Left
| |
| |
| |
| |
| |
Bottom, Right -------------- Bottom Left.

So top is X, right is y, left is y + 32, bottom is x + 32

I think thats ok, I just think my blitting is wrong or something, its starting to bug me

- Darren

[Machaira]

I'm not sure why your RECT structure is reversed but it still doesn't match your code:

rcDest3.top = mMouse.GetXAxis();

Either this line is wrong or all of them are wrong.It looks like it should be:

rcDest3.top = mMouse.GetYAxis();

[DBridle]

Yes, your right, I changed it, however, the tile still goes right back to 0,0 lol *cry*