xil_get_tilesize(3)

NAME

xil_get_tilesize, xil_set_tilesize − get and set the tile size of an image

SYNOPSIS

#include <xil/xil.h>

void xil_get_tilesize (XilImage image,

unsigned int ∗tile_xsize,
unsigned int ∗tile_ysize);

void xil_set_tilesize (XilImage image,

unsigned int tile_xsize,
unsigned int tile_ysize);

DESCRIPTION

xil_get_tilesize() returns the current tile size of the image’s data. The image must first be exported via the xil_export() call, as the tile size is subject to change while under XIL’s control. The tile size can be used to access the image’s storage on a tile basis to avoid the costly overhead of cobbling the image into one contiguous memory buffer. If the tiling mode is the default XIL_WHOLE_IMAGE, then the tile_xsize and tile_ysize returned are the image’s width and height respectively.

xil_set_tilesize() allows the user to set a new tile size on the image. The image must be exported via xil_export(3) before the user can change the tile size. If the image already has data associated with it, changing the tile size will cause a potentially expensive internal reformatting of the existing data. In cases where the existing data is not needed, the user should use a different image or destroy and recreate the image using xil_destroy(3) and xil_create(3). If the tiling mode is the default XIL_WHOLE_IMAGE, then tile_xsize and tile_ysize can only be set to greater than or equal to the image’s width and height respectively.

NOTES

While an image is imported the tile size may change. Therefore it is necessary that the user re-obtain the tile size after every xil_import(3) and subsequent xil_export(3).

Care should be taken in changing the tile size for an image. Operations between images with different tile sizes are slower than operations between images with the same tile size. XIL chooses a default tile size for all images according to the configuration. Imprudent tile sizes can cause significant performance penalties.

ERRORS

For a complete list of XIL error messages by number, consult Appendix B of the XIL Programmer’s Guide.

Museum