Thread: I need help making a grid!

Originally posted by Unregistered
Greetings!

I am making a level editor for a game of mine, and I wish to use a grid to define an overhead view of the level. My questions are:
A. How do I make a grid using the win32 API (I'm using win 98)
B How can I make certain parts of the grid a differnt color (like to highlight the boundries of a room)
C. How can I place small pictures in a square formed in the grid (as to indicate the placement of an item or NPC)

I'm actually well into the game engine, but I really am stuck on those three things for my editor. The rest of the game and editor are easy, but that is not. I am not using a graphics API for it because I favor this method, and I don't belive many games use this editor. Any ideas or code for those things would be appreciated. I am not asking anyone to do it for me, just give me a bit of help. Thanks for your time everyone.

A) A trivial way to make a grid is to make the grid a bitmap and just blt it on the screen. If you want you can use MoveToEx and LineTo functions to draw lines. For different colors look up CreatePen.

B) Store the status of the squares in a 2-dimensional array and then update them in WM_PAINT or wherever. Multiply the dimenions by constants for the size of each square. Then use something like FillRect( ) to uh fill with color.

C) Look up BitBlt. It will let you specify where you want the image to be drawn.

Hope that helps a little! These may certainly not be the best way but I was trying to think of simple ways to do this. Good Luck sir.

Remember when using GDI objects (pens, brushes, DC ect) that they are special memory. If you do not free the memory it will crash your PC.

If you 'Get' an object 'Release' it.

If you 'Create' an object 'Delete' it.

Always catch the returned GDI object from SelectObject() to replace them later.

roughly

Code:

#define    BLACK     RGB(0,0,0)
#define    WHITE     RGB(255,255,255)

hdc=GetDC(hWnd);// get the DC to draw on and create the objects to draw with
hdPen=CreatePen(PS_SOLID,iLineThickness,BLACK);
hBrush=CreateSolidBrush(WHITE);
GetClientRect(hWnd,&ClientRect);
hOriginalPen=(HPEN)SelectObject(hdc,hPen);//catch the pen already in the DC
//do the drawing
FrameRect(hdc,&ClientRect,hBrush);
//clean up by putting the DC back the way we got it
SelectObject(hdc,hOriginalPen);
//then delete the pen
DeleteObject(hPen);
//the brush was not in a DC so can just delete
DeleteObject(hBrush);
//the DC was 'Get'ed so 'Release' it
ReleaseDC(hWnd,hdc);