Bliting transparency

SDL Development
1

Hi.
I’m wrinting a app that scroll a lot of tiles on the screen
the question is thar the app uses 5~10% of the processor time bliting only
simple tiles, but when I blit another layer with colorkey transparency it
goes up to 60%.
transparency is so heavy even without alpha or is anything wrong with my
code?
I’m using windows xp sp3 in a C2D @2.2GHz with on board videocard.
thanks in advance.

2

Have you made sure to replace your surfaces with the result of SDL_DisplayFormat()? Are you using hardware or software surfaces?

Jonny D________________________________

Date: Thu, 16 Oct 2008 16:51:37 -0300
From: andrebotelhomail at gmail.com
To: sdl at lists.libsdl.org
Subject: [SDL] Bliting transparency

Hi.
I’m wrinting a app that scroll a lot of tiles on the screen
the question is thar the app uses 5~10% of the processor time bliting only simple tiles, but when I blit another layer with colorkey transparency it goes up to 60%.
transparency is so heavy even without alpha or is anything wrong with my code?
I’m using windows xp sp3 in a C2D @2.2GHz with on board videocard.
thanks in advance.

When your life is on the go?take your life with you.
http://clk.atdmt.com/MRT/go/115298558/direct/01/

3

2008/10/17 Andre Botelho <@Andre_Botelho>>

Message: 1
Date: Thu, 16 Oct 2008 22:24:12 -0400
From: Jonathan Dearborn
Subject: Re: [SDL] Bliting transparency
To: “A list for developers using the SDL library. (includes
SDL-announce)”
Message-ID:
Content-Type: text/plain; charset=“Windows-1252”

Have you made sure to replace your surfaces with the result of
SDL_DisplayFormat()? Are you using hardware or software surfaces?

Jonny D

Yes, they’re on displayformat and are software surfaces.
I thought that colorkey was to tell the blit to not blit that pixel, or
not?