fbsubtexload(3G)					      fbsubtexload(3G)

NAME    [Toc]    [Back]

     fbsubtexload - load part or all of	a texture defined with TX_FASTDEFINE

C SPECIFICATION    [Toc]    [Back]

     void fbsubtexload(long x, long y, long target, long id, float s0, float s1, float t0, float t1, unsigned long flags)

PARAMETERS    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     fbsubtexload is supported only on RealityEngine systems with release
     5.0.1 or greater.


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