🚀 go-pugleaf

In article <TAC.93Jan26103859@rena.inesc.pt> tac@rena.inesc.pt writes:

>
>
>Hello
>
>I would like some advice on the following problem.
>
>I need to draw may graphical objects, which use different 
>pens, brushes, fonts and bitmaps(used for custom brush patterns).
>
>The objects can be created dynamically, so I don't now at start how many
>pen/brushes/*,  I will need.
>
>Should I, Each time I need to draw, use the Paint DC or the dc from GetDC(hWnd)
>and create the pen/brush/* selected it to the dc, draw, and then deselect it?
>
>What are the penalties of using allways GetDC() (instead of the Paint DC)
>even when processing PAINT events?
>

It's not a question of *penalties* - it's a question of what works!
BeginPaint/EndPaint doesn't only give you the DC; more importantly it
validates the invalid region and clips to it.  If you respond to WM_PAINT
using GetDC your invalid region will *never* get validated, and you'll
get an endless stream of WM_PAINT messages!

>Would it be faster (since I need to draw many graphical objects) to draw
>first on a bitmap and then BitBlt it to the window?
>

If you have a static complex scene then yes - draw it once to a bitmap or
metafile, then blit/play it back on receipt of WM_PAINT.

If you're only going to be drawing it once, then it'll be faster if you 
paint directly to the screen.

>Should I have lists of pre-created pens/brushes/* and each time I need to
>perform a graphic operation try to find on those lists the best matching
>pen/brush/* instead of creating it?
>

That depends how many you're talking about.  Creating a few hundred pens
when you draw is insignificant; creating half a million takes a long time.
If you really have a *lot* a creating/deleting to do (>100,000), create
the pens once and store them in an array or something.  If you have less,
create and destroy them dynamically.

>        Thanks for any info.
>
>Telmo Carmo - tac@inesc.pt
>

Best wishes,

Chris
>--
>=============================================================================
>Telmo Carmo -- tac@inesc.pt           | 'Old programmers never die,
>Tel: +351-1-3100085 FAX: 351-1-525843 |  they just branch to another address'
>==============================================================================
>

-- 
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| Chris Marriott                           | chris@chrism.demon.co.uk    |
| Warrington, UK                           | BIX: cmarriott              |
|                                          | CIX: cmarriott              |
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