[Fluxus] commits + warning

[Dave Griffiths]

Hi Scott,

Got it! I think it's the png texture loading code. The data from libpng
seems to come in flipped compared to how opengl expects. I've fixed this
in git and put the texture coords back to how they were for planes and
cubes.

This had resulted in problems in the past importing models with
textures, but I just flipped the texture in gimp and had completely
forgotten about it.

cheers,

dave

On Sun, 2009-03-22 at 09:33 -0700, Scott wrote:
> And I just checked -  build-plane makes things that look right, but
> they assume that textures are "upside down" too...
> 
>  (pdump p1)
> 0: P:  -0.500  -0.500   0.000 T:   0.000   1.000   0.000
> 1: P:   0.500  -0.500   0.000 T:   1.000   1.000   0.000
> 2: P:   0.500   0.500   0.000 T:   1.000   0.000   0.000
> 3: P:  -0.500   0.500   0.000 T:   0.000   0.000   0.000
> 4: P:  -0.500   0.500   0.000 T:   1.000   0.000   0.000
> 5: P:   0.500   0.500   0.000 T:   0.000   0.000   0.000
> 6: P:   0.500  -0.500   0.000 T:   0.000   1.000   0.000
> 7: P:  -0.500  -0.500   0.000 T:   1.000   1.000   0.000
> 
> Do I have the convention wrong?
> 
> On Sun, Mar 22, 2009 at 9:08 AM, Scott <alcoholiday at gmail.com> wrote:
> > Hmm... I picked up the commits and rebuilt, but I'm still seeing the
> > texture coords flipped.
> >
> > Here's how I'm testing. The quad on the right is built assuming that
> > S,T of [0,0] is in the lower left and [1,1] is in the upper right (aka
> > 1st quadrant), and I'm pretty sure the OpenGL convention. The quad on
> > the left assumes that [0,0] is in the upper left corner and [1,1] is
> > in the lower right.
> >
> > (define (build-quad uv-quadrant1)
> >  (let ([quad (build-polygons 4 'quad-list)])
> >    (with-primitive quad
> >                    (if uv-quadrant1
> >                        (begin
> >                          ;; assumes s,t coordinates are 1rst quadrant
> >                          (pdata-set! "p" 3 (vector 0 0 0))
> >                          (pdata-set! "t" 3 (vector 0 0 0))
> >                          (pdata-set! "p" 2 (vector 0 1 0))
> >                          (pdata-set! "t" 2 (vector 0 1 0))
> >                          (pdata-set! "p" 1 (vector 1 1 0))
> >                          (pdata-set! "t" 1 (vector 1 1 0))
> >                          (pdata-set! "p" 0 (vector 1 0 0))
> >                          (pdata-set! "t" 0 (vector 1 0 0))
> >                          )
> >                        (begin
> >                          ;; assume s,t coordinates are 4th quad
> >                          (pdata-set! "p" 0 #( 1 0 0))
> >                          (pdata-set! "t" 0 #( 1 1 0))
> >                          (pdata-set! "p" 1 #( 1 1 0))
> >                          (pdata-set! "t" 1 #( 1 0 0))
> >                          (pdata-set! "p" 2 #( 0 1 0))
> >                          (pdata-set! "t" 2 #( 0 0 0))
> >                          (pdata-set! "p" 3 #( 0 0 0))
> >                          (pdata-set! "t" 3 #( 0 1 0))
> >                          ))
> >                    (recalc-normals quad)
> >                    )
> >    quad))
> > ;; assumes 1st quad and looks wrong :(
> > (define quad-q1 (build-quad #t))
> > (grab quad-q1)
> > (translate (vector 1 0 0))
> > (scale 5)
> > (hint-wire)
> > (texture (load-texture "textures/flower.png"))
> >
> > ;; assumes 4th quad and looks right
> > (define quad-q4 (build-quad #f))
> > (grab quad-q4)
> > (translate (vector -5 0 0))
> > (scale 5)
> > (hint-wire)
> > (texture (load-texture "textures/flower.png"))
> >
> >
> >
> > On Sat, Mar 21, 2009 at 3:05 PM, Dave Griffiths <dave at pawfal.org> wrote:
> >> Hi all,
> >>
> >> I've fixed the planes, texture coords and flipped y rotation.
> >>
> >> If you update, existing scripts may change behaviour, so consider
> >> yourself warned :)
> >>
> >> Part of this was fixing the knots on the nurbs plane, so now the surface
> >> extends up to the control vertices rather than slightly inside. All the
> >> planes (build-plane, build-seg-plane and build-nurbs-plane) should all
> >> be coincident now.
> >>
> >> Scott, if you could check that things are ok, that would be good.
> >>
> >> I think I'll need to fix some of the example scripts too...
> >>
> >> cheers,
> >>
> >> dave
> >>
> >>
> >