3 PSPGL demos: bezier patches, spotlights and texture copies

jsgf · Post by **jsgf** » Thu Oct 13, 2005 10:45 am

I've packaged up three pre-compiled test programs I've been working on as demos of my recent PSPGL work:

bezier: draws a 3x3 array of bezier patches and shines lights on them. This looks like, but it demonstrates some interesting things. One is that lighting a tesselated bezier patch is much cheaper/faster than lighting a mesh of triangle strips. If you adjust the number of lights with triangle, there's about 2ms time difference between 0 and 4 lights; with strips its more like 12-15ms.
spots: basic demonstration of spotlights with specular+diffuse lighting. This is lighting a 64x64 mesh, and it shows a pretty severe slowdown with 4 lights vs 0 - it can barely manage 60fps.
copytex: this implements a magnifying-glass effect using glCopyTexImage2D to copy back from the framebuffer into a texture. On the PSP this can be fully pipelined, and is very efficient.

All three demos have a timing stats bar-graph; the scale is in milliseconds. This shows total per-frame render time (grey), time spent waiting for next frame swap (orange) and time spent waiting for GE to finish (green arrow). The green, yellow and red marker bars are 60fps, 30fps and 15fps.

Download from http://www.goop.org/psp/gl/pspgl-demos.zip. Source and information is at http://www.goop.org/psp/gl/.

dot_blank · Post by **dot_blank** » Thu Oct 13, 2005 3:16 pm

excellent analysis jsgf ;)
this brings pspgl much closer
to great efficiency on psp

since the beginning of the pspgl
ports it has seem to me that they
are much lagging in full support or
efficiency for general opengl 3d
programming for psp, and so i waited
or more acurately used the excellent
libgu and libgum libraries as these
have provided ample ability for 3d
opengl on psp. but sadly i have been
getting to comfortable with these
libraries ;) and so have not kept up
to speed as you say with the current
progress of pspgl and your patch
which i look very forward in seeing
at a efficient and extensive level

your test show many interesting
steps forward with psp 3d and im
quiet interested now into pspgl and
the progress of your patch :)

one question: and this relates to my
current situation, hows is fog handling
with pspgl or your patch, as fog atm
is not at its full ability with libgu etc...