first Kotlin version

src/main/kotlin/mods/betterfoliage/client/render/Utils.kt

@@ -0,0 +1,54 @@
+@file:JvmName("Utils")
+package mods.betterfoliage.client.render
+
+import mods.octarinecore.PI2
+import mods.octarinecore.client.render.*
+import net.minecraft.block.Block
+import net.minecraft.block.material.Material
+import net.minecraft.tileentity.TileEntity
+import net.minecraft.world.IBlockAccess
+import net.minecraft.world.biome.BiomeGenBase
+import net.minecraftforge.common.util.ForgeDirection
+import net.minecraftforge.common.util.ForgeDirection.*
+
+val up1 = Int3(1 to UP)
+val up2 = Int3(2 to UP)
+val down1 = Int3(1 to DOWN)
+val snowOffset = UP * 0.0625
+
+val normalLeavesRot = arrayOf(Rotation.identity)
+val denseLeavesRot = arrayOf(Rotation.identity, Rotation.rot90[EAST.ordinal], Rotation.rot90[SOUTH.ordinal])
+
+val whitewash: RenderVertex.(ShadingContext, Int, Quad, Int, Vertex)->Unit = { ctx, qi, q, vi, v -> setGrey(1.4f) }
+val greywash: RenderVertex.(ShadingContext, Int, Quad, Int, Vertex)->Unit = { ctx, qi, q, vi, v -> setGrey(1.0f) }
+
+val Block.isSnow: Boolean get() = material.let { it == Material.snow || it == Material.craftedSnow }
+
+fun Quad.toCross(rotAxis: ForgeDirection, trans: (Quad)->Quad) =
+    (0..3).map { rotIdx ->
+        trans(rotate(Rotation.rot90[rotAxis.ordinal] * rotIdx).mirrorUV(rotIdx > 1, false))
+    }
+fun Quad.toCross(rotAxis: ForgeDirection) = toCross(rotAxis) { it }
+
+fun xzDisk(modelIdx: Int) = (PI2 * modelIdx / 64.0).let { Double3(Math.cos(it), 0.0, Math.sin(it)) }
+
+val rotationFromUp = arrayOf(
+    Rotation.rot90[EAST.ordinal] * 2,
+    Rotation.identity,
+    Rotation.rot90[WEST.ordinal],
+    Rotation.rot90[EAST.ordinal],
+    Rotation.rot90[SOUTH.ordinal],
+    Rotation.rot90[NORTH.ordinal]
+)
+
+fun Model.mix(first: Model, second: Model, predicate: (Int)->Boolean) {
+    first.quads.forEachIndexed { qi, quad ->
+        val otherQuad = second.quads[qi]
+        Quad(
+            if (predicate(0)) otherQuad.v1.copy() else quad.v1.copy(),
+            if (predicate(1)) otherQuad.v2.copy() else quad.v2.copy(),
+            if (predicate(2)) otherQuad.v3.copy() else quad.v3.copy(),
+            if (predicate(3)) otherQuad.v4.copy() else quad.v4.copy()
+        ).add()
+    }
+}