Multi-layer rendering support

src/main/kotlin/mods/betterfoliage/render/pipeline/Layers.kt

@@ -0,0 +1,42 @@
+package mods.betterfoliage.render.pipeline
+
+import mods.betterfoliage.model.SpecialRenderData
+import mods.octarinecore.RenderTypeLookup
+import net.minecraft.block.Block
+import net.minecraft.client.renderer.RenderType
+import java.util.function.Predicate
+
+object Layers {
+    val tufts = RenderType.cutout()
+    val connectedGrass = RenderType.solid()
+    val connectedDirt = RenderType.cutoutMipped()
+    val coral = RenderType.cutoutMipped()
+}
+
+val defaultLayerBehaviour = Predicate<RenderType> { layer -> layer == RenderType.solid() }
+
+class WrappedLayerPredicate(val original: Predicate<RenderType>, val func: (RenderType, Predicate<RenderType>) -> Boolean) : Predicate<RenderType> {
+    override fun test(layer: RenderType) = func(layer, original)
+}
+
+/**
+ * Extension method to access the canRenderInLayer() predicate in [RenderTypeLookup]
+ */
+var Block.layerPredicate : Predicate<RenderType>?
+    get() = RenderTypeLookup.blockRenderChecks.getStatic()[delegate]
+    set(value) {
+        RenderTypeLookup.blockRenderChecks.getStatic()[delegate] = value!!
+    }
+
+/**
+ * Add a wrapper to the block's canRenderInLayer() predicate to enable dynamic multi-layer rendering.
+ * If the render data for the block implements [SpecialRenderData], the layers it enables will be
+ * rendered _in addition to_ the block's normal layers.
+ */
+fun Block.extendLayers() {
+    val original = layerPredicate ?: defaultLayerBehaviour
+    if (original !is WrappedLayerPredicate) layerPredicate = WrappedLayerPredicate(original) { layer, original ->
+        original.test(layer) ||
+        (RenderCtxBase.specialRenderData.get() as? SpecialRenderData)?.canRenderInLayer(layer) ?: false
+    }
+}

src/main/kotlin/mods/betterfoliage/render/pipeline/RenderCtxBase.kt

@@ -12,9 +12,10 @@ import mods.betterfoliage.util.Int3
 import mods.betterfoliage.util.plus
 import net.minecraft.block.Block
 import net.minecraft.client.Minecraft
+import net.minecraft.client.renderer.BlockRendererDispatcher
+import net.minecraft.client.renderer.chunk.ChunkRenderCache
 import net.minecraft.util.Direction
 import net.minecraft.util.math.BlockPos
-import net.minecraft.world.IBlockDisplayReader
 import net.minecraftforge.client.model.data.IModelData
 import java.util.Random
 
@@ -25,17 +26,19 @@ import java.util.Random
  * push-based partial rendering pipeline for [SpecialRenderModel] instances.
  */
 abstract class RenderCtxBase(
-    world: IBlockDisplayReader,
-    pos: BlockPos,
+    blockCtx: BlockCtx,
     val matrixStack: MatrixStack,
     var checkSides: Boolean,
     val random: Random,
-    val modelData: IModelData
-) : BlockCtx by BasicBlockCtx(world, pos) {
-
-    abstract fun renderQuad(quad: HalfBakedQuad)
+    val modelData: IModelData,
+) : BlockCtx by blockCtx {
 
     var hasRendered = false
+    var modelRenderData: Any? = null
+    inline fun <reified T> withRenderData(renderFunc: (T)->Boolean) = (modelRenderData as? T?).let {
+        if (it == null) false else renderFunc(it)
+    }
+
     val blockModelShapes = Minecraft.getInstance().blockRenderer.blockModelShaper
     var vertexLighter: VanillaVertexLighter = VanillaFullBlockLighting
     protected val lightingData = RenderCtxBase.lightingData.get().apply {
@@ -43,6 +46,8 @@ abstract class RenderCtxBase(
         blockColors = Minecraft.getInstance().blockColors
     }
 
+    abstract fun renderQuad(quad: HalfBakedQuad)
+
     inline fun Direction?.shouldRender() = this == null || !checkSides || Block.shouldRenderFace(state, world, pos, this)
 
     fun renderQuads(quads: Iterable<HalfBakedQuad>) {
@@ -61,6 +66,17 @@ abstract class RenderCtxBase(
     }
 
     companion object {
+        @JvmStatic
+        fun reset(chunkRenderCache: ChunkRenderCache, blockRendererDispatcher: BlockRendererDispatcher, pos: BlockPos, random: Random) {
+            // prepare render data
+            val blockCtx = BasicBlockCtx(chunkRenderCache, pos)
+            val model = blockRendererDispatcher.getBlockModel(blockCtx.state)
+            random.setSeed(blockCtx.seed)
+            val data = if (model is SpecialRenderModel) model.prepare(blockCtx, random) else Unit
+            specialRenderData.set(data)
+        }
+
         val lightingData = ThreadLocal.withInitial { VanillaQuadLighting() }
+        val specialRenderData = ThreadLocal<Any?>()
     }
 }

src/main/kotlin/mods/betterfoliage/render/pipeline/RenderCtxForge.kt

@@ -1,27 +1,31 @@
 package mods.betterfoliage.render.pipeline
 
 import com.mojang.blaze3d.matrix.MatrixStack
+import mods.betterfoliage.chunk.BasicBlockCtx
+import mods.betterfoliage.chunk.BlockCtx
 import mods.betterfoliage.model.HalfBakedQuad
 import mods.betterfoliage.model.SpecialRenderModel
 import mods.betterfoliage.render.lighting.ForgeVertexLighter
 import mods.betterfoliage.render.lighting.ForgeVertexLighterAccess
+import mods.betterfoliage.util.getWithDefault
 import net.minecraft.block.BlockState
 import net.minecraft.client.renderer.LightTexture
 import net.minecraft.util.math.BlockPos
 import net.minecraft.world.IBlockDisplayReader
+import net.minecraftforge.client.ForgeHooksClient
+import net.minecraftforge.client.MinecraftForgeClient
 import net.minecraftforge.client.model.data.IModelData
 import net.minecraftforge.client.model.pipeline.VertexLighterFlat
 import java.util.Random
 
 class RenderCtxForge(
-    world: IBlockDisplayReader,
-    pos: BlockPos,
+    blockCtx: BlockCtx,
     val lighter: VertexLighterFlat,
     matrixStack: MatrixStack,
     checkSides: Boolean,
     random: Random,
-    modelData: IModelData
-): RenderCtxBase(world, pos, matrixStack, checkSides, random, modelData), ForgeVertexLighter {
+    modelData: IModelData,
+) : RenderCtxBase(blockCtx, matrixStack, checkSides, random, modelData), ForgeVertexLighter {
 
     override fun renderQuad(quad: HalfBakedQuad) {
         // set Forge lighter AO calculator to us
@@ -38,7 +42,15 @@ class RenderCtxForge(
         }
     }
 
-    override fun updateVertexColor(normal: FloatArray, color: FloatArray, x: Float, y: Float, z: Float, tint: Float, multiplier: Int) {
+    override fun updateVertexColor(
+        normal: FloatArray,
+        color: FloatArray,
+        x: Float,
+        y: Float,
+        z: Float,
+        tint: Float,
+        multiplier: Int
+    ) {
         color[0] = lightingData.tint[0] * lightingData.colorMultiplier[vIdx]
         color[1] = lightingData.tint[1] * lightingData.colorMultiplier[vIdx]
         color[2] = lightingData.tint[2] * lightingData.colorMultiplier[vIdx]
@@ -55,17 +67,21 @@ class RenderCtxForge(
             pos: BlockPos,
             matrixStack: MatrixStack,
             checkSides: Boolean,
-            rand: Random, seed: Long,
+            random: Random, seed: Long,
             modelData: IModelData
         ): Boolean {
-            lighter.setWorld(world)
-            lighter.setState(state)
-            lighter.setBlockPos(pos)
-            rand.setSeed(seed)
-            lighter.updateBlockInfo()
-            return RenderCtxForge(world, pos, lighter, matrixStack, checkSides, rand, modelData).let {
+            val blockCtx = BasicBlockCtx(world, pos)
+            val ctx = RenderCtxForge(blockCtx, lighter, matrixStack, checkSides, random, modelData).apply {
+                lighter.setWorld(world)
+                lighter.setState(state)
+                lighter.setBlockPos(pos)
+                lighter.updateBlockInfo()
+            }
+
+            // render layer
+            return ctx.let {
                 (lighter as ForgeVertexLighterAccess).vertexLighter = it
-                model.render(it, false)
+                model.renderLayer(it, specialRenderData.get()!!, MinecraftForgeClient.getRenderLayer())
                 lighter.resetBlockInfo()
                 it.hasRendered
             }

src/main/kotlin/mods/betterfoliage/render/pipeline/RenderCtxVanilla.kt

@@ -2,28 +2,31 @@ package mods.betterfoliage.render.pipeline
 
 import com.mojang.blaze3d.matrix.MatrixStack
 import com.mojang.blaze3d.vertex.IVertexBuilder
+import mods.betterfoliage.chunk.BasicBlockCtx
+import mods.betterfoliage.chunk.BlockCtx
 import mods.betterfoliage.model.HalfBakedQuad
 import mods.betterfoliage.model.SpecialRenderModel
+import mods.betterfoliage.util.getWithDefault
 import net.minecraft.block.BlockState
 import net.minecraft.client.renderer.BlockModelRenderer
 import net.minecraft.util.math.BlockPos
 import net.minecraft.world.IBlockDisplayReader
+import net.minecraftforge.client.MinecraftForgeClient
 import net.minecraftforge.client.model.data.IModelData
 import java.util.Random
 
 class RenderCtxVanilla(
     val renderer: BlockModelRenderer,
-    world: IBlockDisplayReader,
-    pos: BlockPos,
+    blockCtx: BlockCtx,
     val buffer: IVertexBuilder,
     val combinedOverlay: Int,
     matrixStack: MatrixStack,
     checkSides: Boolean,
     random: Random,
-    val seed: Long,
+    val randomSeed: Long,
     modelData: IModelData,
     val useAO: Boolean
-): RenderCtxBase(world, pos, matrixStack, checkSides, random, modelData) {
+): RenderCtxBase(blockCtx, matrixStack, checkSides, random, modelData) {
 
     override fun renderQuad(quad: HalfBakedQuad) {
         vertexLighter.updateLightmapAndColor(quad, lightingData)
@@ -47,20 +50,16 @@ class RenderCtxVanilla(
             buffer: IVertexBuilder,
             checkSides: Boolean,
             random: Random,
-            rand: Long,
+            seed: Long,
             combinedOverlay: Int,
             modelData: IModelData,
             smooth: Boolean
         ): Boolean {
-            random.setSeed(rand)
-            val ctx = RenderCtxVanilla(renderer, world, pos, buffer, combinedOverlay, matrixStack, checkSides, random, rand, modelData, smooth)
-            lightingData.apply {
-
-            }
-            model.render(ctx, false)
+            val blockCtx = BasicBlockCtx(world, pos)
+            // init context if missing (this is the first render layer)
+            val ctx = RenderCtxVanilla(renderer, blockCtx, buffer, combinedOverlay, matrixStack, checkSides, random, seed, modelData, smooth)
+            model.renderLayer(ctx, specialRenderData.get()!!, MinecraftForgeClient.getRenderLayer())
             return ctx.hasRendered
         }
-
-
     }
 }