commonMain.earth.worldwind.geom.Vec2.kt Maven / Gradle / Ivy
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The WorldWind Kotlin SDK (WWK) includes the library, examples and tutorials for building multiplatform 3D virtual globe applications for Android, Web and Java.
package earth.worldwind.geom
import earth.worldwind.util.Logger.ERROR
import earth.worldwind.util.Logger.logMessage
import kotlin.math.sqrt
/**
* Two-component vector with X and Y coordinates.
*/
open class Vec2(
/**
* The vector's X component.
*/
var x: Double,
/**
* The vector's Y component.
*/
var y: Double
) {
/**
* Computes the squared magnitude of this vector. This is equivalent to squaring the result of
* `magnitude` but is potentially much more efficient.
*
* @return the squared magnitude of this vector
*/
open val magnitudeSquared get() = x * x + y * y
/**
* Computes the magnitude of this vector.
*
* @return the magnitude of this vector
*/
val magnitude get() = sqrt(magnitudeSquared)
/**
* Constructs a two-component vector with X and Y both 0.
*/
constructor(): this(x = 0.0, y = 0.0)
/**
* Constructs a two-component vector with the X and Y of a specified vector.
*
* @param vector the vector specifying the components
*/
constructor(vector: Vec2): this(vector.x, vector.y)
/**
* Copies this vector's components to the specified single precision array. The result is compatible with GLSL
* uniform vectors, and can be passed to the function glUniform2fv.
*
* @param result a pre-allocated array of length 2 in which to return the components
*
* @return the result argument set to this vector's components
*/
open fun toArray(result: FloatArray, offset: Int): FloatArray {
var o = offset
require(result.size - o >= 2) {
logMessage(ERROR, "Vec2", "toArray", "missingArray")
}
result[o++] = x.toFloat()
result[o] = y.toFloat()
return result
}
/**
* Computes the distance from this vector to another vector.
*
* @param vector the vector to compute the distance to
*
* @return the distance between the vectors
*/
fun distanceTo(vector: Vec2) = sqrt(distanceToSquared(vector))
/**
* Computes the squared distance from this vector to a specified vector. This is equivalent to squaring the result
* of `distanceTo` but is potentially much more efficient.
*
* @param vector the vector to compute the distance to
*
* @return the squared distance between the vectors
*/
fun distanceToSquared(vector: Vec2): Double {
val dx = x - vector.x
val dy = y - vector.y
return dx * dx + dy * dy
}
/**
* Sets this vector to the specified X and Y.
*
* @param x the new X component
* @param y the new Y component
*
* @return this vector set to the specified values
*/
fun set(x: Double, y: Double) = apply {
this.x = x
this.y = y
}
/**
* Sets this vector to the X and Y of a specified vector.
*
* @param vector the vector specifying the new components
*
* @return this vector with its X and Y set to that of the specified vector
*/
fun copy(vector: Vec2) = set(vector.x, vector.y)
/**
* Swaps this vector with the specified vector. This vector's components are set to the values of the specified
* vector's components, and the specified vector's components are set to the values of this vector's components.
*
* @param vector the vector to swap with this vector
*
* @return this vector set to the values of the specified vector
*/
fun swap(vector: Vec2) = apply {
var tmp = x
x = vector.x
vector.x = tmp
tmp = y
y = vector.y
vector.y = tmp
}
/**
* Adds a specified vector to this vector.
*
* @param vector the vector to add
*
* @return this vector after adding the specified vector to it
*/
fun add(vector: Vec2) = apply { plusAssign(vector) }
/**
* Creates new vector containing sum of this and specified vectors.
*
* @param vector the vector to add
*
* @return new vector containing sum of this and specified vectors.
*/
operator fun plus(vector: Vec2) = Vec2(this).apply { plusAssign(vector) }
/**
* Adds a specified vector to this vector.
*
* @param vector the vector to add
*/
operator fun plusAssign(vector: Vec2) {
x += vector.x
y += vector.y
}
/**
* Subtracts a specified vector from this vector.
*
* @param vector the vector to subtract
*
* @return this vector after subtracting the specified vector from it
*/
fun subtract(vector: Vec2) = apply { minusAssign(vector) }
/**
* Creates new vector containing difference of this and specified vectors.
*
* @param vector the vector to subtract
*
* @return new vector containing difference of this and specified vectors.
*/
operator fun minus(vector: Vec2) = Vec2(this).apply { minusAssign(vector) }
/**
* Subtracts a specified vector from this vector.
*
* @param vector the vector to subtract
*/
operator fun minusAssign(vector: Vec2) {
x -= vector.x
y -= vector.y
}
/**
* Multiplies this vector by a scalar.
*
* @param scalar the scalar to multiply this vector by
*
* @return this vector multiplied by the specified scalar
*/
open fun multiply(scalar: Double) = apply { timesAssign(scalar) }
/**
* Creates new vector containing this vector multiplied by a scalar.
*
* @param scalar the scalar to multiply this vector by
*
* @return new vector containing this vector multiplied by a scalar.
*/
open operator fun times(scalar: Double) = Vec2(this).apply { timesAssign(scalar) }
/**
* Multiplies this vector by a scalar.
*
* @param scalar the scalar to multiply this vector by
*/
open operator fun timesAssign(scalar: Double) {
x *= scalar
y *= scalar
}
/**
* Multiplies this vector by a 3x3 matrix. The multiplication is performed with an implicit Z component of 1. The
* resultant Z component of the product is then divided through the X and Y components.
*
* @param matrix the matrix to multiply this vector by
*
* @return this vector multiplied by the specified matrix
*/
fun multiplyByMatrix(matrix: Matrix3) = apply {
val m = matrix.m
val x = m[0] * x + m[1] * y + m[2]
val y = m[3] * this.x + m[4] * y + m[5]
val z = m[6] * this.x + m[7] * this.y + m[8]
this.x = x / z
this.y = y / z
}
/**
* Divides this vector by a scalar.
*
* @param divisor the scalar to divide this vector by
*
* @return this vector divided by the specified scalar
*/
open fun divide(divisor: Double) = apply { divAssign(divisor) }
/**
* Creates new vector containing this vector divided by a scalar.
*
* @param divisor the scalar to divide this vector by
*
* @return new vector containing this vector divided by a scalar
*/
open operator fun div(divisor: Double) = Vec2(this).apply { divAssign(divisor) }
/**
* Divides this vector by a scalar.
*
* @param divisor the scalar to divide this vector by
*/
open operator fun divAssign(divisor: Double) {
x /= divisor
y /= divisor
}
/**
* Creates new vector which has components with opposite sign to the vector.
*
* @return new vector, which has components with opposite sign to the vector
*/
open operator fun unaryMinus() = Vec2(this).negate()
/**
* Negates the components of this vector.
*
* @return this vector, negated
*/
open fun negate() = apply {
x = -x
y = -y
}
/**
* Normalizes this vector to a unit vector.
*
* @return this vector, normalized
*/
open fun normalize() = apply {
val magnitude = magnitude
if (magnitude != 0.0) {
x /= magnitude
y /= magnitude
}
}
/**
* Computes the scalar dot product of this vector and a specified vector.
*
* @param vector the vector to multiply
*
* @return the dot product of the two vectors
*/
fun dot(vector: Vec2) = x * vector.x + y * vector.y
/**
* Mixes (interpolates) a specified vector with this vector, modifying this vector.
*
* @param vector The vector to mix with this one
* @param weight The relative weight of this vector, typically in the range [0,1]
*
* @return this vector modified to the mix of itself and the specified vector
*/
fun mix(vector: Vec2, weight: Double) = apply {
val w0 = 1 - weight
x = x * w0 + vector.x * weight
y = y * w0 + vector.y * weight
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is Vec2) return false
return x == other.x && y == other.y
}
override fun hashCode(): Int {
var result = x.hashCode()
result = 31 * result + y.hashCode()
return result
}
override fun toString() = "Vec2(x=$x, y=$y)"
}