[WIP] start 1.15 port

reorganize packages to match Fabric version
use util classes from Fabric version

src/main/kotlin/mods/betterfoliage/render/column/RenderData.kt

@@ -0,0 +1,32 @@
+package mods.betterfoliage.render.column
+
+import mods.betterfoliage.render.lighting.QuadIconResolver
+import mods.betterfoliage.util.rotate
+import net.minecraft.client.renderer.texture.TextureAtlasSprite
+import net.minecraft.util.Direction.*
+
+interface ColumnTextureInfo {
+    val axis: Axis?
+    val top: QuadIconResolver
+    val bottom: QuadIconResolver
+    val side: QuadIconResolver
+}
+
+open class SimpleColumnInfo(
+    override val axis: Axis?,
+    val topTexture: TextureAtlasSprite,
+    val bottomTexture: TextureAtlasSprite,
+    val sideTextures: List<TextureAtlasSprite>
+) : ColumnTextureInfo {
+
+    // index offsets for EnumFacings, to make it less likely for neighboring faces to get the same bark texture
+    val dirToIdx = arrayOf(0, 1, 2, 4, 3, 5)
+
+    override val top: QuadIconResolver = { _, _, _ -> topTexture }
+    override val bottom: QuadIconResolver = { _, _, _ -> bottomTexture }
+    override val side: QuadIconResolver = { ctx, idx, _ ->
+        val worldFace = (if ((idx and 1) == 0) SOUTH else EAST).rotate(ctx.modelRotation)
+        val sideIdx = if (sideTextures.size > 1) (ctx.semiRandom(1) + dirToIdx[worldFace.ordinal]) % sideTextures.size else 0
+        sideTextures[sideIdx]
+    }
+}