feat: Highlight century cake slice players

src/main/kotlin/util/render/TintedOverlayTexture.kt

@@ -0,0 +1,44 @@
+package moe.nea.firmament.util.render
+
+import com.mojang.blaze3d.platform.GlConst
+import com.mojang.blaze3d.systems.RenderSystem
+import me.shedaniel.math.Color
+import net.minecraft.client.render.OverlayTexture
+import net.minecraft.util.math.ColorHelper
+import moe.nea.firmament.util.ErrorUtil
+
+class TintedOverlayTexture : OverlayTexture() {
+	companion object {
+		val size = 16
+	}
+
+	private var lastColor: Color? = null
+	fun setColor(color: Color): TintedOverlayTexture {
+		val image = ErrorUtil.notNullOr(texture.image, "Disposed TintedOverlayTexture written to") { return this }
+		if (color == lastColor) return this
+		lastColor = color
+
+		for (i in 0..<size) {
+			for (j in 0..<size) {
+				if (i < 8) {
+					image.setColorArgb(j, i, 0xB2FF0000.toInt())
+				} else {
+					val k = ((1F - j / 15F * 0.75F) * 255F).toInt()
+					image.setColorArgb(j, i, ColorHelper.withAlpha(k, color.color))
+				}
+			}
+		}
+
+		RenderSystem.activeTexture(GlConst.GL_TEXTURE1)
+		texture.bindTexture()
+		texture.setFilter(false, false)
+		texture.setClamp(true)
+		image.upload(0,
+		             0, 0,
+		             0, 0,
+		             image.width, image.height,
+		             false)
+		RenderSystem.activeTexture(GlConst.GL_TEXTURE0)
+		return this
+	}
+}