[PATCH 1/4] wined3d: only activate blit_shader in arbfp_blit_surface for source fixups

[Roderick Colenbrander]

On Tue, May 18, 2010 at 10:58 AM, Henri Verbeet <hverbeet at gmail.com> wrote:
> On 18 May 2010 10:45, Roderick Colenbrander <thunderbird2k at gmail.com> wrote:
>> isn't right since set_shader does useful things as well like
>> glEnable(tex_type).
> Yeah. In the bigger picture it's also slightly insane that we have a
> shader based blit backend that doesn't actually use a shader for
> blitting most of the time, but instead invalidates lots of fixed
> function state.
>

I think we might be able to get rid of a lot of that code. At this
point two out of the three cases which use the blit_shader are routed
through draw_textured_quad which for instance already does the
glEnable(tex_type) for us. In this case I guess if draw_textured_quad
also handles glDisable (it knows the target) this could already be
more efficient and get rid of unneeded state changes. The other case
is swapchain_blit but as I mentioned before the non-fbo path in this
call doesn't fit well into the design, so that's something I should
perhaps fix first perhaps by letting it use draw_textured_quad if
possible.

In general to what degree should we disable blindly disable
texture_2d, cubemaps, texture_rectangle? I thought the policy (though
not sure how the other code behaves) is that other code should be
smart enough to enable/disable states it needs to avoid unneeded state
switches or should functions clean up their own mess?

Roderick