[WIP] start 1.15 port

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

src/main/kotlin/mods/betterfoliage/texture/GrassRegistry.kt

@@ -0,0 +1,68 @@
+package mods.betterfoliage.texture
+
+import mods.betterfoliage.BetterFoliage
+import mods.betterfoliage.config.BlockConfig
+import mods.betterfoliage.config.Config
+import mods.betterfoliage.resource.Identifier
+import mods.betterfoliage.render.lighting.HSB
+import mods.betterfoliage.resource.discovery.ConfigurableModelDiscovery
+import mods.betterfoliage.resource.discovery.ModelRenderRegistryRoot
+import mods.octarinecore.client.resource.*
+import mods.betterfoliage.config.ConfigurableBlockMatcher
+import mods.betterfoliage.config.ModelTextureList
+import mods.betterfoliage.util.averageColor
+import net.minecraft.block.BlockState
+import net.minecraft.client.renderer.texture.TextureAtlasSprite
+import org.apache.logging.log4j.Level
+import java.lang.Math.min
+import java.util.concurrent.CompletableFuture
+
+const val defaultGrassColor = 0
+
+/** Rendering-related information for a grass block. */
+class GrassInfo(
+    /** Top texture of the grass block. */
+    val grassTopTexture: TextureAtlasSprite,
+
+    /**
+     * Color to use for Short Grass rendering instead of the biome color.
+     *
+     * Value is null if the texture is mostly grey (the saturation of its average color is under a configurable limit),
+     * the average color of the texture otherwise.
+     */
+    val overrideColor: Int?
+)
+
+object GrassRegistry : ModelRenderRegistryRoot<GrassInfo>()
+
+object AsyncGrassDiscovery : ConfigurableModelDiscovery<GrassInfo>() {
+    override val logger = BetterFoliage.logDetail
+    override val matchClasses: ConfigurableBlockMatcher get() = BlockConfig.grassBlocks
+    override val modelTextures: List<ModelTextureList> get() = BlockConfig.grassModels.modelList
+
+    override fun processModel(state: BlockState, textures: List<Identifier>, atlas: AtlasFuture): CompletableFuture<GrassInfo> {
+        val textureName = textures[0]
+        val spriteF = atlas.sprite(textureName)
+        logger.log(Level.DEBUG, "$logName:       texture $textureName")
+        return atlas.mapAfter {
+            val sprite = spriteF.get()
+            logger.log(Level.DEBUG, "$logName: block state $state")
+            logger.log(Level.DEBUG, "$logName:       texture $textureName")
+            val hsb = HSB.fromColor(sprite.averageColor)
+            val overrideColor = if (hsb.saturation >= Config.shortGrass.saturationThreshold) {
+                logger.log(Level.DEBUG, "$logName:         brightness ${hsb.brightness}")
+                logger.log(Level.DEBUG, "$logName:         saturation ${hsb.saturation} >= ${Config.shortGrass.saturationThreshold}, using texture color")
+                hsb.copy(brightness = min(0.9f, hsb.brightness * 2.0f)).asColor
+            } else {
+                logger.log(Level.DEBUG, "$logName:         saturation ${hsb.saturation} < ${Config.shortGrass.saturationThreshold}, using block color")
+                null
+            }
+            GrassInfo(sprite, overrideColor)
+        }
+    }
+
+    fun init() {
+        GrassRegistry.registries.add(this)
+        BetterFoliage.blockSprites.providers.add(this)
+    }
+}