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Re: [SDL] Trying to grasp new rendering model

Subject: Re: [SDL] Trying to grasp new rendering model
From: Sam Lantinga
Date: Tue, 10 Feb 2009 06:58:19 -0800
> Yes, a texture is just a potentially hw accelerated surface.  In the new
> video model the front buffer isn't directly accessible.  All composition
> is done by drawing or blitting textures onto either a back buffer or 
> directly to the front buffer (using SDL_RENDERER_SINGLEBUFFER)

To expand on this a little, SDL_compat.c creates a single large texture
that it uses as the screen surface and then uses the current renderer to
copy it to the visible display.  Fortunately this is exactly a generalization
of how SDL 1.2 works under the hood, so the speed is roughly equivalent.

The advantage of the new model is that you aren't _required_ to make a
full screen texture.  You can instead create a number of smaller textures
and use them along with rect and line drawing to compose your scene, which
lends itself well to being hardware accelerated.

Anyone who uses the older style 1.2 API continues to get access to a
framebuffer interface at normal CPU blitting speed and anyone who uses
the newer API can get hardware accelerated rendering.

See ya!
        -Sam Lantinga, Founder and President, Galaxy Gameworks LLC
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