don't render hidden faces on connected grass

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

@@ -6,6 +6,8 @@ import mods.octarinecore.client.render.AbstractBlockRenderingHandler
 import mods.octarinecore.client.render.BlockContext
 import mods.octarinecore.client.render.withOffset
 import mods.octarinecore.common.Int3
+import mods.octarinecore.common.forgeDirsHorizontal
+import mods.octarinecore.common.offset
 import net.minecraft.client.renderer.BlockRendererDispatcher
 import net.minecraft.client.renderer.VertexBuffer
 import net.minecraft.util.BlockRenderLayer
@@ -21,6 +23,10 @@ class RenderConnectedGrass : AbstractBlockRenderingHandler(BetterFoliageMod.MOD_
         (Config.connectedGrass.snowEnabled || !ctx.blockState(up2).isSnow)
 
     override fun render(ctx: BlockContext, dispatcher: BlockRendererDispatcher, renderer: VertexBuffer, layer: BlockRenderLayer): Boolean {
+        // if the block sides are not visible anyway, render normally
+        if (forgeDirsHorizontal.all { ctx.blockState(it.offset).isOpaqueCube }) return renderWorldBlockBase(ctx, dispatcher, renderer, null)
+
+        if (ctx.isSurroundedBy { it.isOpaqueCube } ) return false
         return ctx.withOffset(Int3.zero, up1) {
             ctx.withOffset(up1, up2) {
                 renderWorldBlockBase(ctx, dispatcher, renderer, null)

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

@@ -6,9 +6,7 @@ import mods.betterfoliage.client.config.Config
 import mods.betterfoliage.client.integration.ShadersModIntegration
 import mods.betterfoliage.client.texture.GrassRegistry
 import mods.octarinecore.client.render.*
-import mods.octarinecore.common.Double3
-import mods.octarinecore.common.Int3
-import mods.octarinecore.common.Rotation
+import mods.octarinecore.common.*
 import mods.octarinecore.random
 import net.minecraft.client.renderer.BlockRendererDispatcher
 import net.minecraft.client.renderer.VertexBuffer
@@ -66,13 +64,15 @@ class RenderGrass : AbstractBlockRenderingHandler(BetterFoliageMod.MOD_ID) {
             // get full AO data
             modelRenderer.updateShading(Int3.zero, allFaces)
 
+            // check occlusion
+            val isHidden = forgeDirs.map { ctx.blockState(it.offset).isOpaqueCube }
+
             // render full grass block
             ShadersModIntegration.renderAs(ctx.blockState(Int3.zero), renderer) {
                 modelRenderer.render(
                     renderer,
                     fullCube,
-                    Rotation.identity,
-                    ctx.blockCenter,
+                    quadFilter = { qi, _ -> !isHidden[qi] },
                     icon = { _, _, _ -> grassInfo.grassTopTexture },
                     postProcess = { ctx, _, _, _, _ ->
                         rotateUV(2)

src/main/kotlin/mods/octarinecore/client/render/AbstractBlockRenderingHandler.kt

@@ -49,7 +49,7 @@ abstract class AbstractBlockRenderingHandler(modId: String) : ResourceHandler(mo
      */
     fun renderWorldBlockBase(ctx: BlockContext, dispatcher: BlockRendererDispatcher, renderer: VertexBuffer, layer: BlockRenderLayer?): Boolean {
         ctx.blockState(Int3.zero).let {
-            if (layer == null || it.block.canRenderInLayer(layer))
+            if (layer == null || it.block.canRenderInLayer(it, layer))
                 return dispatcher.renderBlock(it, ctx.pos, ctx.world, renderer)
         }
         return false

src/main/kotlin/mods/octarinecore/client/render/ModelRenderer.kt

@@ -34,6 +34,7 @@ class ModelRenderer : ShadingContext() {
         rot: Rotation = Rotation.identity,
         trans: Double3 = blockContext.blockCenter,
         forceFlat: Boolean = false,
+        quadFilter: (Int, Quad) -> Boolean = { _, _ -> true },
         icon: QuadIconResolver,
         postProcess: PostProcessLambda
     ) {
@@ -44,6 +45,7 @@ class ModelRenderer : ShadingContext() {
         worldRenderer.ensureSpaceForQuads(model.quads.size + 1)
 
         model.quads.forEachIndexed { quadIdx, quad ->
+            if (quadFilter(quadIdx, quad)) {
                 val drawIcon = icon(this, quadIdx, quad)
                 if (drawIcon != null) {
                     quad.verts.forEachIndexed { vertIdx, vert ->
@@ -63,6 +65,7 @@ class ModelRenderer : ShadingContext() {
                 }
             }
         }
+    }
 }
 
 /**

src/main/kotlin/mods/octarinecore/common/Geometry.kt

@@ -16,6 +16,7 @@ val axisDirs = listOf(POSITIVE, NEGATIVE)
 val EnumFacing.dir: AxisDirection get() = axisDirection
 val AxisDirection.sign: String get() = when(this) { POSITIVE -> "+"; NEGATIVE -> "-" }
 val forgeDirs = EnumFacing.values()
+val forgeDirsHorizontal = listOf(NORTH, SOUTH, EAST, WEST)
 val forgeDirOffsets = forgeDirs.map { Int3(it) }
 val Pair<Axis, AxisDirection>.face: EnumFacing get() = when(this) {
     X to POSITIVE -> EAST; X to NEGATIVE -> WEST;