Basic bezier curve rendering

This commit is contained in:
Shadowfacts 2019-10-21 11:32:18 -04:00
parent db66a89399
commit da8c5f73cf
Signed by: shadowfacts
GPG Key ID: 94A5AB95422746E5
4 changed files with 101 additions and 0 deletions

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@ -0,0 +1,49 @@
package net.shadowfacts.cacao.geometry
import java.lang.RuntimeException
import kotlin.math.pow
/**
* Helper class that represents a cubic bezier curve.
*
* @author shadowfacts
*/
data class BezierCurve(private val points: Array<Point>) {
init {
if (points.size != 4) {
throw RuntimeException("Cubic bezier curve must have exactly four points")
}
}
fun point(time: Double): Point {
val x = coordinate(time, Axis.HORIZONTAL)
val y = coordinate(time, Axis.VERTICAL)
return Point(x, y)
}
private fun coordinate(t: Double, axis: Axis): Double {
// B(t)=(1-t)^3*p0+3(1-t)^2*t*p1+3(1-t)*t^2*p2+t^3*p3
val p0 = points[0][axis]
val p1 = points[1][axis]
val p2 = points[2][axis]
val p3 = points[3][axis]
return ((1 - t).pow(3) * p0) + (3 * (1 - t).pow(2) * t * p1) + (3 * (1 - t) * t.pow(2) * p2) + (t.pow(3) * p3)
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (javaClass != other?.javaClass) return false
other as BezierCurve
if (!points.contentEquals(other.points)) return false
return true
}
override fun hashCode(): Int {
return points.contentHashCode()
}
}

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@ -21,4 +21,11 @@ data class Point(val x: Double, val y: Double) {
return Point(x - other.x, y - other.y) return Point(x - other.x, y - other.y)
} }
operator fun get(axis: Axis): Double {
return when (axis) {
Axis.HORIZONTAL -> x
Axis.VERTICAL -> y
}
}
} }

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@ -9,6 +9,7 @@ import net.minecraft.client.render.VertexFormat
import net.minecraft.client.render.VertexFormats import net.minecraft.client.render.VertexFormats
import net.minecraft.client.sound.PositionedSoundInstance import net.minecraft.client.sound.PositionedSoundInstance
import net.minecraft.sound.SoundEvent import net.minecraft.sound.SoundEvent
import net.shadowfacts.cacao.geometry.BezierCurve
import net.shadowfacts.cacao.geometry.Point import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.geometry.Rect import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.util.texture.Texture import net.shadowfacts.cacao.util.texture.Texture
@ -108,6 +109,14 @@ object RenderHelper {
GlStateManager.translated(x, y, z) GlStateManager.translated(x, y, z)
} }
/**
* @see org.lwjgl.opengl.GL11.glScaled
*/
fun scale(x: Double, y: Double, z: Double = 1.0) {
if (disabled) return
GlStateManager.scaled(x, y, z)
}
/** /**
* @see org.lwjgl.opengl.GL11.glColor4f * @see org.lwjgl.opengl.GL11.glColor4f
*/ */

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@ -0,0 +1,36 @@
package net.shadowfacts.cacao.view
import com.mojang.blaze3d.platform.GlStateManager
import net.shadowfacts.cacao.geometry.BezierCurve
import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.util.Color
import net.shadowfacts.cacao.util.RenderHelper
/**
* @author shadowfacts
*/
class BezierCurveView(val curve: BezierCurve): View() {
private val points by lazy {
val step = 0.05
var t = 0.0
val points = mutableListOf<Point>()
while (t <= 1) {
points.add(curve.point(t))
t += step
}
points
}
var lineWidth = 3f
var lineColor = Color.BLACK
override fun drawContent(mouse: Point, delta: Float) {
RenderHelper.scale(bounds.width, bounds.height)
for ((index, point) in points.withIndex()) {
val next = points.getOrNull(index + 1) ?: break
RenderHelper.drawLine(point, next, zIndex, lineWidth, lineColor)
}
}
}