Implemented the bedrock snow leaves feature (Really buggy)

src/main/java/net/qzimyion/cellulose/mixin/snowing/LeafBlocksMixin.java

@@ -0,0 +1,91 @@
+package net.qzimyion.cellulose.mixin.snowing;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.LightLayer;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.LeavesBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.block.state.properties.BooleanProperty;
+import net.minecraft.world.level.levelgen.Heightmap;
+import net.qzimyion.cellulose.util.ISnow;
+import net.qzimyion.cellulose.util.TintManager;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(LeavesBlock.class)
+public class LeafBlocksMixin extends Block implements ISnow {
+
+    @Shadow
+    @Final
+    public static BooleanProperty PERSISTENT;
+
+    @Unique
+    private boolean isSnowing = false;
+    @Unique
+    private long lastUpdateTime = 0;
+
+    public LeafBlocksMixin(Properties properties) {
+        super(properties);
+    }
+
+    @Override
+    public boolean isSnowy(Level level, BlockPos pos) {
+        return updateSnow(level, pos);
+    }
+
+    @Unique
+    private boolean updateSnow(Level level, BlockPos pos) {
+        if (level.getBiome(pos).value().warmEnoughToRain(pos)) return false;
+
+        int topY = level.getHeightmapPos(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, pos).getY();
+        if (topY > pos.getY()) {
+            BlockPos checkPos = pos.above();
+            for (int i = 0; i < topY - pos.getY(); i++) {
+                if (level.getBrightness(LightLayer.SKY, checkPos) == 15) return true;
+
+                Block block = level.getBlockState(checkPos).getBlock();
+                if (!(block instanceof LeavesBlock) && !block.equals(Blocks.AIR) && !block.equals(Blocks.SNOW) && !block.equals(Blocks.SNOW_BLOCK)) {
+                    return false;
+                }
+                checkPos = checkPos.above();
+            }
+        }
+        return true;
+    }
+
+    @Inject(method = "animateTick", at = @At("HEAD"))
+    public void animateTick(
+            BlockState state,
+            Level level,
+            BlockPos pos,
+            RandomSource random,
+            CallbackInfo ci
+    ) {
+        if (level.getBiome(pos).value().warmEnoughToRain(pos)) return;
+
+        boolean isCurrentlySnowing = level.isRaining();
+        if (isCurrentlySnowing != isSnowing) {
+            isSnowing = isCurrentlySnowing;
+            lastUpdateTime = level.getGameTime();
+            TintManager.updateTint();
+        }
+
+        if (level.getGameTime() - lastUpdateTime > 400) return;
+
+        boolean persistent = state.getValue(PERSISTENT);
+//        if (persistent != isSnowing) {
+//            level.setBlock(pos, state.setValue(PERSISTENT, isSnowing), 2);
+//        }
+        level.setBlockAndUpdate(pos, state.setValue(PERSISTENT, !persistent));
+        level.setBlockAndUpdate(pos, state.setValue(PERSISTENT, persistent));
+    }
+
+}

src/main/java/net/qzimyion/cellulose/mixin/snowing/LeafRender.java

@@ -0,0 +1,51 @@
+package net.qzimyion.cellulose.mixin.snowing;
+
+
+import net.minecraft.client.color.block.BlockColors;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.BlockAndTintGetter;
+import net.minecraft.world.level.block.LeavesBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import net.qzimyion.cellulose.util.TintManager;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(BlockColors.class)
+public class LeafRender {
+
+    @Unique
+    private int adjustColor(int baseColor, float gradient) {
+        int red = (baseColor >> 16) & 0xFF;
+        int green = (baseColor >> 8) & 0xFF;
+        int blue = baseColor & 0xFF;
+
+        red += (int) (gradient * (255 - red));
+        green += (int) (gradient * (255 - green));
+        blue += (int) (gradient * (255 - blue));
+
+        return (red << 16) | (green << 8) | blue;
+    }
+
+    @Inject(
+            method = "getColor(Lnet/minecraft/world/level/block/state/BlockState;Lnet/minecraft/world/level/BlockAndTintGetter;Lnet/minecraft/core/BlockPos;I)I",
+            at = @At("RETURN"),
+            cancellable = true
+    )
+    public void getColor(
+            BlockState state,
+            net.minecraft.world.level.BlockAndTintGetter tintGetter,
+            BlockPos pos,
+            int tintIndex,
+            CallbackInfoReturnable<Integer> cir
+    ) {
+        if (pos == null || !(state.getBlock() instanceof LeavesBlock)) return;
+
+        int baseColor = cir.getReturnValue();
+        float gradient = TintManager.getGradient();
+        cir.setReturnValue(adjustColor(baseColor, gradient));
+    }
+}

src/main/java/net/qzimyion/cellulose/util/ISnow.java

@@ -0,0 +1,8 @@
+package net.qzimyion.cellulose.util;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.Level;
+
+public interface ISnow {
+    boolean isSnowy(Level level, BlockPos pos);
+}

src/main/java/net/qzimyion/cellulose/util/TintManager.java

@@ -0,0 +1,44 @@
+package net.qzimyion.cellulose.util;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.multiplayer.ClientLevel;
+import net.minecraft.util.Mth;
+
+import java.util.Objects;
+
+public class TintManager {
+    private static float gradient = 0;
+    private static long lastUpdateTime = 0;
+
+    public static void updateTint() {
+        Minecraft client = Minecraft.getInstance();
+        ClientLevel clientLevel = client.level;
+        if (clientLevel == null) return;
+
+        long currentTime = clientLevel.getGameTime();
+        boolean isSnowing = clientLevel.isRaining() &&
+                !clientLevel.getBiome(Objects.requireNonNull(client.player).blockPosition())
+                        .value()
+                        .warmEnoughToRain(client.player.blockPosition());
+
+        if (isSnowing) {
+            gradient += (currentTime - lastUpdateTime) / 300.0f;
+        } else {
+            gradient -= (currentTime - lastUpdateTime) / 300.0f;
+        }
+
+        gradient = Mth.clamp(gradient, 0, 1);
+        lastUpdateTime = currentTime;
+        updateChunks(clientLevel);
+    }
+
+    public static void updateChunks(ClientLevel level) {
+        if (level != null) {
+            Minecraft.getInstance().levelRenderer.allChanged();
+        }
+    }
+
+    public static float getGradient() {
+        return gradient;
+    }
+}