Re: [xmoto-dev] SDL_gfx help

[nadenislamarre@xxxxxxx]

Quoting Kees Jongenburger <kees.jongenburger@xxxxxxxxx>:

> On 1/24/07, Rasmus Neckelmann <neckelmann@xxxxxxxxx> wrote:
> > On 1/21/07, Kees Jongenburger <kees.jongenburger@xxxxxxxxx> wrote:
> > > So given the input texture , the texture coordinates and the vertex
> > > coordinates I want to define a transformation on the base image. we
> > > are in 2d space and do not perform squeaking. The transformations that
> > > are possible are scaling,rotating and flipping .
> >
> > I'm not sure I understand your problem correctly... Ideally it should
> > be possible to draw any textured polygon, not knowing about
> > transformations or anything. I don't know about SDL_gfx, but making
> > such a drawing function should be quite basic - interpolate the x
> > (screen) coordinate and the u,v (texture) coordinates over the edges
> > of the polygon, and then render the horizontal lines of the polygon
> > (with interpolated u,v coordinates). Nice thing about x-moto is that
> > no perspective correction or shading is required - i.e. it can be
> > implemented quite efficiently in plain c/c++ (even with no asm).
> > Sub-pixel accuracy (or texture filtering) is probably not required
> > either, if it just has to be fast.
> >
> > Actually I thought SDL_gfx provided such functions?
> Yes, the funtion it there but there are some rendering bug.
>
> You make it sounds so easy that I would really
> appreciate if you could take some time to look into it.
> 95% of the code is there it only really requires a few magic lines of math
> to determine the rotation x and y zoom of the texture.
>
> I can not do anything else until I get this fixed. I would like to
> start helping whit the network play and implementing more performance
> improvements.
>
>

just note that
xmoto -drawlib SDLGFX -level 1 crashes in my vmware (without -level 1, it's ok)
crashing in endDraw of VDrawSDLGFX.cpp
I've not analysed why

Nicolas