Add helpers for converting points/rects between view coordinate systems

This commit is contained in:
Shadowfacts 2019-06-22 23:03:23 -04:00
parent 51528c4cbe
commit a55cd950d0
Signed by: shadowfacts
GPG Key ID: 94A5AB95422746E5
3 changed files with 157 additions and 4 deletions

View File

@ -7,6 +7,8 @@ package net.shadowfacts.cacao.geometry
*/
data class Rect(val left: Double, val top: Double, val width: Double, val height: Double) {
constructor(origin: Point, size: Size): this(origin.x, origin.y, size.width, size.height)
val right: Double by lazy {
left + width
}

View File

@ -3,11 +3,9 @@ package net.shadowfacts.cacao.view
import com.mojang.blaze3d.platform.GlStateManager
import net.shadowfacts.kiwidsl.dsl
import net.shadowfacts.cacao.LayoutVariable
import net.shadowfacts.cacao.geometry.Axis
import net.shadowfacts.cacao.geometry.AxisPosition
import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.geometry.Size
import net.shadowfacts.cacao.geometry.*
import net.shadowfacts.cacao.util.Color
import net.shadowfacts.cacao.util.LowestCommonAncestor
import net.shadowfacts.cacao.util.RenderHelper
import no.birkett.kiwi.Constraint
import no.birkett.kiwi.Solver
@ -214,4 +212,47 @@ open class View {
*/
open fun drawContent() {}
/**
* Converts the given point in this view's coordinate system to the coordinate system of another view or the window.
*
* @param point The point to convert, in the coordinate system of this view.
* @param to The view to convert to. If `null`, it will be converted to the window's coordinate system.
* @return The point in the coordinate system of the [to] view.
*/
fun convert(point: Point, to: View?): Point {
if (to != null) {
val ancestor = LowestCommonAncestor.find(this, to, View::superview)
@Suppress("NAME_SHADOWING") var point = point
// Convert up to the LCA
var view: View? = this
while (view != null && view != ancestor) {
point = Point(point.x + view.frame.left, point.y + view.frame.top)
view = view.superview
}
// Convert back down to the other view
view = to
while (view != null && view != ancestor) {
point = Point(point.x - view.frame.left, point.y - view.frame.top)
view = view.superview
}
return point
} else {
return Point(leftAnchor.value + point.x, topAnchor.value + point.y)
}
}
/**
* Converts the given rectangle in this view's coordinate system to the coordinate system of another view or the window.
*
* @param rect The rectangle to convert, in the coordinate system of this view.
* @param to The view to convert to. If `null`, it will be converted to the window's coordinate system.
* @return The rectangle in the coordinate system of the [to] view.
*/
fun convert(rect: Rect, to: View?): Rect {
return Rect(convert(rect.origin, to), rect.size)
}
}

View File

@ -0,0 +1,110 @@
package net.shadowfacts.cacao
import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.view.View
import org.junit.jupiter.api.Assertions.assertEquals
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
/**
* @author shadowfacts
*/
class CoordinateConversionTests {
lateinit var window: Window
@BeforeEach
fun setup() {
window = Window()
}
@Test
fun testConvertToParent() {
val a = window.addView(View().apply {
frame = Rect(0.0, 0.0, 100.0, 100.0)
})
val b = a.addSubview(View().apply {
frame = Rect(25.0, 25.0, 50.0, 50.0)
})
assertEquals(Point(25.0, 25.0), b.convert(Point(0.0, 0.0), to = a))
assertEquals(Point(75.0, 75.0), b.convert(Point(50.0, 50.0), to = a))
assertEquals(Rect(25.0, 25.0, 50.0, 50.0), b.convert(Rect(0.0, 0.0, 50.0, 50.0), to = a))
}
@Test
fun testConvertToSibling() {
val root = window.addView(View().apply {
frame = Rect(0.0, 0.0, 200.0, 200.0)
})
val a = root.addSubview(View().apply {
frame = Rect(25.0, 25.0, 50.0, 50.0)
})
val b = root.addSubview(View().apply {
frame = Rect(75.0, 75.0, 50.0, 50.0)
})
assertEquals(Point(-50.0, -50.0), a.convert(Point(0.0, 0.0), to = b))
assertEquals(Point(100.0, 100.0), b.convert(Point(50.0, 50.0), to = a))
assertEquals(Rect(50.0, 50.0, 50.0, 50.0), b.convert(Rect(0.0, 0.0, 50.0, 50.0), to = a))
}
@Test
fun testConvertBetweenSubtrees() {
val root = window.addView(View().apply {
frame = Rect(0.0, 0.0, 200.0, 100.0)
})
val a = root.addSubview(View().apply {
frame = Rect(0.0, 0.0, 100.0, 100.0)
})
val b = root.addSubview(View().apply {
frame = Rect(100.0, 0.0, 100.0, 100.0)
})
val c = a.addSubview(View().apply {
frame = Rect(0.0, 0.0, 50.0, 50.0)
})
val d = b.addSubview(View().apply {
frame = Rect(0.0, 0.0, 50.0, 50.0)
})
assertEquals(Point(-100.0, 0.0), c.convert(Point(0.0, 0.0), to = b))
assertEquals(Point(-50.0, 50.0), c.convert(Point(50.0, 50.0), to = d))
assertEquals(Rect(100.0, 0.0, 50.0, 50.0), d.convert(Rect(0.0, 0.0, 50.0, 50.0), to = c))
}
@Test
fun testConvertBetweenTopLevelViews() {
val a = window.addView(View().apply {
frame = Rect(0.0, 0.0, 100.0, 100.0)
})
val b = window.addView(View().apply {
frame = Rect(100.0, 100.0, 100.0, 100.0)
})
assertEquals(Point(0.0, 0.0), a.convert(Point(100.0, 100.0), to = b))
assertEquals(Point(200.0, 200.0), b.convert(Point(100.0, 100.0), to = a))
assertEquals(Rect(100.0, 100.0, 100.0, 100.0), b.convert(Rect(0.0, 0.0, 100.0, 100.0), to = a))
}
@Test
fun testConvertBetweenTopLevelSubtrees() {
val a = window.addView(View().apply {
frame = Rect(0.0, 0.0, 100.0, 100.0)
})
val b = window.addView(View().apply {
frame = Rect(100.0, 100.0, 100.0, 100.0)
})
val c = a.addSubview(View().apply {
frame = Rect(25.0, 25.0, 50.0, 50.0)
})
val d = b.addSubview(View().apply {
frame = Rect(25.0, 25.0, 50.0, 50.0)
})
assertEquals(Point(-50.0, -50.0), c.convert(Point(50.0, 50.0), to = d))
assertEquals(Point(100.0, 100.0), d.convert(Point(0.0, 0.0), to = c))
assertEquals(Rect(100.0, 100.0, 50.0, 50.0), d.convert(Rect(0.0, 0.0, 50.0, 50.0), to = c))
}
}