gen_checker_region
— Create a checkered region.
gen_checker_region( : RegionChecker : WidthRegion, HeightRegion, WidthPattern, HeightPattern : )
The operator gen_checker_region
returns a checkered region.
Every black field of the checkerboard belongs to the region.
The horizontal and vertical expansion of the region is limited by
WidthRegion
, HeightRegion
respectively,
the size of the fields of the checkerboard by
WidthPattern
* HeightPattern
.
If a very small pattern is chosen
(WidthPattern
< 4) the created region requires much storage.
RegionChecker
(output_object) region →
object
Created checkerboard region.
WidthRegion
(input_control) extent.x →
(integer)
Largest occurring x value of the region.
Default value: 511
Suggested values: 10, 20, 31, 63, 127, 255, 300, 400, 511
Typical range of values: 1
≤
WidthRegion
≤
1024
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction: WidthRegion >= 1
HeightRegion
(input_control) extent.y →
(integer)
Largest occurring y value of the region.
Default value: 511
Suggested values: 10, 20, 31, 63, 127, 255, 300, 400, 511
Typical range of values: 1
≤
HeightRegion
≤
1024
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction: HeightRegion >= 1
WidthPattern
(input_control) extent.x →
(integer)
Width of a field of the checkerboard.
Default value: 64
Suggested values: 1, 2, 4, 8, 16, 20, 32, 64, 100, 128, 200, 300, 500
Typical range of values: 1
≤
WidthPattern
≤
1024
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction: WidthPattern > 0 && WidthPattern < WidthRegion
HeightPattern
(input_control) extent.y →
(integer)
Height of a field of the checkerboard.
Default value: 64
Suggested values: 1, 2, 4, 8, 16, 20, 32, 64, 100, 128, 200, 300, 500
Typical range of values: 1
≤
HeightPattern
≤
1024
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction: HeightPattern > 0 && HeightPattern < HeightRegion
gen_checker_region(Checker,512,512,32,64) dev_set_draw('fill') dev_display (Checker)
The required storage (in bytes) for the region is:
O((WidthRegion
* HeightRegion
) /
WidthPattern
)
The operator gen_checker_region
returns the value 2 (H_MSG_TRUE)
if the parameter values are correct.
Otherwise an exception is raised.
The clipping according to the current image format is set via the operator
set_system('clip_region',<'true'/'false'>)
.
gen_grid_region
,
gen_region_polygon_filled
,
gen_region_points
,
gen_region_runs
,
gen_rectangle1
,
concat_obj
,
gen_random_region
,
gen_random_regions
Foundation