fbsubtexload(3G) fbsubtexload(3G)
NAME
fbsubtexload - load part or all of a texture defined with TX_FASTDEFINE
C SPECIFICATION
void fbsubtexload(long x, long y, long target, long id, float s0, float s1, float t0, float t1, unsigned long flags)
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
fbsubtexload 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.
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fbsubtexload(3G) fbsubtexload(3G)
SEE ALSO
texdef2d,subtexload,readsource,readcomponent
NOTES
fbsubtexload is supported only on RealityEngine systems with release
5.0.1 or greater.
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