AngleSweep Class
An AngleSweep is a pair of angles at start and end of an interval.
- For stroking purposes, the "included interval" is all angles numerically reached by theta = start + f*(end-start), where f is between 0 and 1.
- This stroking formula is simple numbers -- 2PI shifts are not involved.
- 2PI shifts do become important in the reverse mapping of an angle to a fraction.
- If (start < end) the angle proceeds CCW around the unit circle.
- If (end < start) the angle proceeds CW around the unit circle.
- Angles beyond 360 are fine as endpoints.
- (350,370) covers the same unit angles as (-10,10).
- (370,350) covers the same unit angles as (10,-10).
Implements
Methods
| Name | Description | |
|---|---|---|
| angleToPositivePeriodicFraction(theta: Angle): number | map an angle to a fractional coordinate which is: the start angle is at fraction 0 the end angle is at fraction 1 interior angles are between 0 and 1 all exterior angles are at fractions greater than 1 * the periodic jump is at full wraparound to the start angle |
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| angleToSignedPeriodicFraction(theta: Angle): number | map an angle to a fractional coordinate which is: the start angle is at fraction 0 the end angle is at fraction 1 interior angles are between 0 and 1 small negative for angles just "before" the start angle more than one for angles just "after" the end angle the periodic jump is at the middle of the "outside" interval |
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| angleToUnboundedFraction(theta: Angle): number | return the fractionalized position of the angle, computed without consideration of 2PI period. |
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| capLatitudeInPlace(): void | Restrict start and end angles into the range (-90,+90) in degrees. | |
| clone(): AngleSweep | return a clone of this sweep. | |
| cloneComplement(reverseDirection: boolean = false, result?: AngleSweep): AngleSweep | return a sweep for the "other" part of the circe. | |
| cloneMinusRadians(radians: number): AngleSweep | Return the angle obtained by subtracting radians from this angle. | |
| fractionPeriod(): number | return 2PI divided by the sweep radians (i.e. | |
| fractionToAngle(fraction: number): Angle | Convert fractional position in the sweep to strongly typed Angle object. | |
| fractionToRadians(fraction: number): number | Convert fractional position in the sweep to radians. | |
| interpolate(fraction: number, other: AngleSweep): AngleSweep | Return a sweep with limits interpolated between this and other. | |
| isAlmostEqual(other: AngleSweep): boolean | test if start and end angles match with radians tolerance. | |
| isAlmostEqualAllowPeriodShift(other: AngleSweep): boolean | test if start and end angles match, with explicit name to clarify that there is no test for 360-degree shifts. | |
| isAlmostEqualNoPeriodShift(other: AngleSweep): boolean | test if start and end angles match, explicit name to clarify that 360-degree shifts are allowed. | |
| isAngleInSweep(angle: Angle): boolean | test if an angle is within the sweep | |
| isRadiansInSweep(radians: number, allowPeriodShift: boolean = true): boolean | test if radians are within sweep | |
| radiansArraytoPositivePeriodicFractions(data: GrowableFloat64Array): void | Convert each value in an array from radians to fraction. | |
| radiansToPositivePeriodicFraction(radians: number): number | Convert a radians value to a fraction that is always positive and can wrap. | |
| radiansToSignedPeriodicFraction(radians: number): number | Convert a radians value to a fraction, allowing wraparound. | |
| reverseInPlace(): void | Reverse the start and end angle in place. | |
| setFrom(other: AngleSweep): void | copy from other AngleSweep. | |
| setFromJSON(json?: any): void | set this AngleSweep from various sources: * if json is undefined, a full-circle sweep is returned. |
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| setStartEndDegrees(startDegrees: number = 0, endDegrees: number = 360): void | directly set the start and end angles in degrees | |
| setStartEndRadians(startRadians: number = 0, endRadians: number = 2.0 * Math.PI): void | directly set the start and end angles in radians | |
| toJSON(): any | Convert an AngleSweep to a JSON object. | |
| create360(startRadians?: number): AngleSweep Static | create a full circle sweep (CCW). | |
| createFullLatitude(): AngleSweep Static | create a sweep from the south pole to the north pole. | |
| createStartEnd(startAngle: Angle, endAngle: Angle, result?: AngleSweep): AngleSweep Static | create an angle sweep from strongly typed start and end angles | |
| createStartEndDegrees(startDegrees: number = 0, endDegrees: number = 360, result?: AngleSweep): AngleSweep Static | create an AngleSweep from start and end angles given in degrees. | |
| createStartEndRadians(startRadians: number = 0, endRadians: number = 2.0 * Math.PI, result?: AngleSweep): AngleSweep Static | create an AngleSweep from start and end angles given in radians. | |
| createStartSweep(startAngle: Angle, sweepAngle: Angle, result?: AngleSweep): AngleSweep Static | Create an angle sweep with limits given as (strongly typed) angles for start and sweep | |
| createStartSweepDegrees(startDegrees: number = 0, sweepDegrees: number = 360, result?: AngleSweep): AngleSweep Static | create an AngleSweep from start and sweep given in degrees. | |
| createStartSweepRadians(startRadians: number = 0, sweepRadians: number = Math.PI, result?: AngleSweep): AngleSweep Static | create an AngleSweep from start and end angles given in radians. | |
| fromJSON(json?: AngleSweepProps): AngleSweep Static | create an AngleSweep from a json object. | |
| isRadiansInStartEnd(radians: number, radians0: number, radians1: number, allowPeriodShift: boolean = true): boolean Static | test if radians are within sweep | |
| radiansToPositivePeriodicFractionStartEnd(radians: number, radians0: number, radians1: number): number Static | Convert a radians value to a fraction that is always positive and can wrap. |
Properties
| Name | Type | Description | |
|---|---|---|---|
| endAngle Accessor ReadOnly | Angle | Return the (strongly typed) end angle | |
| endDegrees Accessor ReadOnly | number | Read-property for degrees at the end of this AngleSweep. | |
| endRadians Accessor ReadOnly | number | Read-property for degrees at the end of this AngleSweep. | |
| isCCW Accessor ReadOnly | boolean | Ask if the sweep is counterclockwise, i.e. | |
| isFullCircle Accessor ReadOnly | boolean | Ask if the sweep is a full circle. | |
| isFullLatitudeSweep Accessor ReadOnly | boolean | Ask if the sweep is a full sweep from south pole to north pole. | |
| startAngle Accessor ReadOnly | Angle | Return the (strongly typed) start angle | |
| startDegrees Accessor ReadOnly | number | Read-property for degrees at the start of this AngleSweep. | |
| startRadians Accessor ReadOnly | number | Read-property for degrees at the start of this AngleSweep. | |
| sweepDegrees Accessor ReadOnly | number | Read-property for signed start-to-end sweep in degrees. | |
| sweepRadians Accessor ReadOnly | number | Read-property for signed start-to-end sweep in radians. |
Defined in
Last Updated: 08 January, 2020