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.
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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)"
}