ClassesClasses | | Operators

gen_circlegen_circleGenCircleGenCircle (Operator)

Name

gen_circlegen_circleGenCircleGenCircle — Create a circle.

Signature

gen_circle( : Circle : Row, Column, Radius : )

Herror gen_circle(Hobject* Circle, double Row, double Column, double Radius)

Herror T_gen_circle(Hobject* Circle, const Htuple Row, const Htuple Column, const Htuple Radius)

void GenCircle(HObject* Circle, const HTuple& Row, const HTuple& Column, const HTuple& Radius)

void HRegion::HRegion(const HTuple& Row, const HTuple& Column, const HTuple& Radius)

void HRegion::HRegion(double Row, double Column, double Radius)

void HRegion::GenCircle(const HTuple& Row, const HTuple& Column, const HTuple& Radius)

void HRegion::GenCircle(double Row, double Column, double Radius)

static void HOperatorSet.GenCircle(out HObject circle, HTuple row, HTuple column, HTuple radius)

public HRegion(HTuple row, HTuple column, HTuple radius)

public HRegion(double row, double column, double radius)

void HRegion.GenCircle(HTuple row, HTuple column, HTuple radius)

void HRegion.GenCircle(double row, double column, double radius)

Description

The operator gen_circlegen_circleGenCircleGenCircleGenCircle generates one or more circles described by the center and RadiusRadiusRadiusRadiusradius. If several circles shall be generated the coordinates must be passed in the form of tuples.

gen_circlegen_circleGenCircleGenCircleGenCircle only creates symmetric circles. To achieve this, the radius is internally rounded down to a multiple of 0.5. If an integer number is specified for the radius (i.e., 1, 2, 3, ...) an even diameter is obtained, and hence the circle can only be symmetric with respect to a center with coordinates that have a fractional part of 0.5. Consequently, internally the coordinates of the center are adapted to the closest coordinates that have a fractional part of 0.5. Here, integer coordinates are rounded down to the next smaller values with a fractional part of 0.5. For odd diameters (i.e., radius = 1.5, 2.5, 3.5, ...), the circle can only be symmetric with respect to a center with integer coordinates. Hence, internally the coordinates of the center are rounded to the nearest integer coordinates. It should be noted that the above algorithm may lead to the fact that circles with an even diameter are not contained in circles with the next larger odd diameter, even if the coordinates specified in RowRowRowRowrow and ColumnColumnColumnColumncolumn are identical.

If the circle extends beyond the image edge it is clipped to the current image format if the value of the system flag 'clip_region' is set to 'true' (set_systemset_systemSetSystemSetSystemSetSystem).

Attention

For speed reasons, the resulting region may contain additional pixels at the border and some individual pixels at the border may be missing. This may lead to an inconsistency between the operators smallest_circlesmallest_circleSmallestCircleSmallestCircleSmallestCircle and gen_circlegen_circleGenCircleGenCircleGenCircle.

Execution Information

Parameters

CircleCircleCircleCirclecircle (output_object)  region(-array) objectHRegionHRegionHobject *

Generated circle.

RowRowRowRowrow (input_control)  circle.center.y(-array) HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Line index of center.

Default value: 200.0

Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0

Typical range of values: 1.0 ≤ Row Row Row Row row ≤ 1024.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

ColumnColumnColumnColumncolumn (input_control)  circle.center.x(-array) HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Column index of center.

Default value: 200.0

Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0

Typical range of values: 1.0 ≤ Column Column Column Column column ≤ 1024.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

RadiusRadiusRadiusRadiusradius (input_control)  circle.radius(-array) HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Radius of circle.

Default value: 100.5

Suggested values: 1.0, 1.5, 2.0, 2.5, 3, 3.5, 4, 4.5, 5.5, 6.5, 7.5, 9.5, 11.5, 15.5, 20.5, 25.5, 31.5, 50.5

Typical range of values: 1.0 ≤ Radius Radius Radius Radius radius ≤ 1024.0 (lin)

Restriction: Radius > 0.0

Example (HDevelop)

read_image(Image,'fabrik')
gen_circle(Circle,300.0,200.0,150.5)
reduce_domain(Image,Circle,Mask)
dev_clear_window ()
dev_display (Mask)

Example (C)

open_window(0,0,-1,-1,"root","visible","",&WindowHandle);
read_image(&Image,"montery");
gen_circle(&Circle,300.0,200.0,150.5);
reduce_domain(Image,Circle,Mask);
disp_color(Mask,WindowHandle);

Example (HDevelop)

read_image(Image,'fabrik')
gen_circle(Circle,300.0,200.0,150.5)
reduce_domain(Image,Circle,Mask)
dev_clear_window ()
dev_display (Mask)

Example (HDevelop)

read_image(Image,'fabrik')
gen_circle(Circle,300.0,200.0,150.5)
reduce_domain(Image,Circle,Mask)
dev_clear_window ()
dev_display (Mask)

Example (HDevelop)

read_image(Image,'fabrik')
gen_circle(Circle,300.0,200.0,150.5)
reduce_domain(Image,Circle,Mask)
dev_clear_window ()
dev_display (Mask)

Complexity

Runtime complexity: O(RadiusRadiusRadiusRadiusradius * 2)

Storage complexity (byte): O(RadiusRadiusRadiusRadiusradius * 8)

Result

If the parameter values are correct, the operator gen_circlegen_circleGenCircleGenCircleGenCircle returns the value 2 (H_MSG_TRUE). Otherwise an exception is raised. The clipping according to the current image format is set via the operator set_system('clip_region',<'true'/'false'>)set_system("clip_region",<"true"/"false">)SetSystem("clip_region",<"true"/"false">)SetSystem("clip_region",<"true"/"false">)SetSystem("clip_region",<"true"/"false">). If an empty region is created by clipping (the circle is completely outside of the image format) the operator set_system('store_empty_region',<'true'/'false'>)set_system("store_empty_region",<"true"/"false">)SetSystem("store_empty_region",<"true"/"false">)SetSystem("store_empty_region",<"true"/"false">)SetSystem("store_empty_region",<"true"/"false">) determines whether the empty region is put out.

Possible Successors

paint_regionpaint_regionPaintRegionPaintRegionPaintRegion, reduce_domainreduce_domainReduceDomainReduceDomainReduceDomain

Alternatives

gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse, gen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilledGenRegionPolygonFilled, gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints, gen_region_runsgen_region_runsGenRegionRunsGenRegionRunsGenRegionRuns, draw_circledraw_circleDrawCircleDrawCircleDrawCircle

See also

disp_circledisp_circleDispCircleDispCircleDispCircle, set_shapeset_shapeSetShapeSetShapeSetShape, smallest_circlesmallest_circleSmallestCircleSmallestCircleSmallestCircle, reduce_domainreduce_domainReduceDomainReduceDomainReduceDomain

Module

Foundation


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