fbsubt(3G)

NAME
     fbtxld - load part or all of a texture defined with TX_FASTDEFINE

FORTRAN 77 SPECIFICATION
     subroutine fbsubtexload()
     real

PARAMETERS
     x   is the window-relative starting x coordinate of the rectangle in the
         framebuffer that is being loaded into texture memory.

     y   is the window-relative starting y coordinate of the rectangle in the
         framebuffer that is being loaded into texture memory.

     target
         is the texture target to which the texture we are loading is bound.

     id  is the id of the texture we are loading.

     s0  is the starting S coordinate of the subtexture to load.

     s1  is the ending S coordinate of the subtexture to load.

     t0  is the starting T coordinate of the subtexture to load.

     t1  is the ending T coordinate of the subtexture to load.

     flags
         is a special modifier.

DESCRIPTION
     fbtxld loads some or all of a texture that is currently allocated space
     in texture memory by copying a rectangle from the framebuffer using the
     current readsource and readcomponent values.

     The transfer uses the scale and bias settings in effect at the time of
     the texdef2d if TX_EXTERNAL_FORMAT, TX_PIXMODE was specified in the
     properties.

     The values s0,s1,t0,t1 are mapped to texel values by
     start_s_texel = s0*texture_width;
     start_t_texel = t0*texture_height;
     end_s_texel   = s1*texture_width - 1;
     end_t_texel   = t1*texture_height - 1;

     s0,s1,t0,t1 should fall on texels that are a multiple of 32, i.e. for a
     texture that is 256x128, s0,s1 can be
     0,.125,.25..375,.5,.625,.750,.875,1.0, while t0,t1 can be
     0.,.25,.50.,75.,1.0. Results are undefined for any other values.
SEE ALSO
NOTES
     fbtxld is supported only on RealityEngine systems with release 5.0.1 or
     greater.