Change package.

src/main/java/dev/lambdaurora/lambdacontrols/client/LambdaReacharound.java

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+/*
+ * Copyright © 2020 LambdAurora <aurora42lambda@gmail.com>
+ *
+ * This file is part of LambdaControls.
+ *
+ * Licensed under the MIT license. For more information,
+ * see the LICENSE file.
+ */
+
+package dev.lambdaurora.lambdacontrols.client;
+
+import dev.lambdaurora.lambdacontrols.LambdaControlsFeature;
+import net.minecraft.block.Block;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.FluidBlock;
+import net.minecraft.block.SlabBlock;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.item.BlockItem;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.HitResult;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.RaycastContext;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Represents the reach-around API of LambdaControls.
+ *
+ * @version 1.5.0
+ * @since 1.3.2
+ */
+public class LambdaReacharound
+{
+    private BlockHitResult lastReacharoundResult   = null;
+    private boolean        lastReacharoundVertical = false;
+    private boolean        onSlab                  = false;
+
+    public void tick(@NotNull MinecraftClient client)
+    {
+        this.lastReacharoundResult = this.tryVerticalReachAround(client);
+        if (this.lastReacharoundResult == null) {
+            this.lastReacharoundResult = this.tryHorizontalReachAround(client);
+            this.lastReacharoundVertical = false;
+        } else this.lastReacharoundVertical = true;
+    }
+
+    /**
+     * Returns the last reach around result.
+     *
+     * @return The last reach around result.
+     */
+    public @Nullable BlockHitResult getLastReacharoundResult()
+    {
+        return this.lastReacharoundResult;
+    }
+
+    /**
+     * Returns whether the last reach around is vertical.
+     *
+     * @return True if the reach around is vertical.
+     */
+    public boolean isLastReacharoundVertical()
+    {
+        return this.lastReacharoundVertical;
+    }
+
+    /**
+     * Returns whether reacharound is available or not.
+     *
+     * @return True if reacharound is available, else false.
+     */
+    public boolean isReacharoundAvailable()
+    {
+        return LambdaControlsFeature.HORIZONTAL_REACHAROUND.isAvailable() || LambdaControlsFeature.VERTICAL_REACHAROUND.isAvailable();
+    }
+
+    private float getPlayerRange(@NotNull MinecraftClient client)
+    {
+        return client.interactionManager != null ? client.interactionManager.getReachDistance() : 0.f;
+    }
+
+    /**
+     * Returns a nullable block hit result if vertical reach-around is possible.
+     *
+     * @param client The client instance.
+     * @return A block hit result if vertical reach-around is possible, else null.
+     */
+    public @Nullable BlockHitResult tryVerticalReachAround(@NotNull MinecraftClient client)
+    {
+        if (!LambdaControlsFeature.VERTICAL_REACHAROUND.isAvailable())
+            return null;
+        if (client.player == null || client.world == null || client.crosshairTarget == null || client.crosshairTarget.getType() != HitResult.Type.MISS
+                || !client.player.isOnGround() || client.player.pitch < 80.0F
+                || client.player.isRiding())
+            return null;
+
+        Vec3d pos = client.player.getCameraPosVec(1.0F);
+        Vec3d rotationVec = client.player.getRotationVec(1.0F);
+        float range = getPlayerRange(client);
+        Vec3d rayVec = pos.add(rotationVec.x * range, rotationVec.y * range, rotationVec.z * range).add(0, 0.75, 0);
+        BlockHitResult result = client.world.raycast(new RaycastContext(pos, rayVec, RaycastContext.ShapeType.OUTLINE, RaycastContext.FluidHandling.NONE, client.player));
+
+        if (result.getType() == HitResult.Type.BLOCK) {
+            BlockPos blockPos = result.getBlockPos().down();
+            BlockState state = client.world.getBlockState(blockPos);
+
+            if (client.player.getBlockPos().getY() - blockPos.getY() > 1 && (client.world.isAir(blockPos) || state.getMaterial().isReplaceable())) {
+                return new BlockHitResult(result.getPos(), Direction.DOWN, blockPos, false);
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Returns a nullable block hit result if horizontal reach-around is possible.
+     *
+     * @param client The client instance.
+     * @return A block hit result if horizontal reach-around is possible.
+     */
+    public @Nullable BlockHitResult tryHorizontalReachAround(@NotNull MinecraftClient client)
+    {
+        if (!LambdaControlsFeature.HORIZONTAL_REACHAROUND.isAvailable())
+            return null;
+
+        if (client.player != null && client.crosshairTarget != null && client.crosshairTarget.getType() == HitResult.Type.MISS && client.player.isOnGround() && client.player.pitch > 35.0F) {
+            if (client.player.isRiding())
+                return null;
+            BlockPos playerPos = client.player.getBlockPos().down();
+            if (client.player.getY() - playerPos.getY() - 1.0 >= 0.25) {
+                playerPos = playerPos.up();
+                this.onSlab = true;
+            } else {
+                this.onSlab = false;
+            }
+            BlockPos targetPos = new BlockPos(client.crosshairTarget.getPos()).subtract(playerPos);
+            BlockPos vector = new BlockPos(MathHelper.clamp(targetPos.getX(), -1, 1), 0, MathHelper.clamp(targetPos.getZ(), -1, 1));
+            BlockPos blockPos = playerPos.add(vector);
+
+            Direction direction = client.player.getHorizontalFacing();
+
+            BlockState state = client.world.getBlockState(blockPos);
+            if (!state.isAir())
+                return null;
+            BlockState adjacentBlockState = client.world.getBlockState(blockPos.offset(direction.getOpposite()));
+            if (adjacentBlockState.isAir() || adjacentBlockState.getBlock() instanceof FluidBlock || (vector.getX() == 0 && vector.getZ() == 0)) {
+                return null;
+            }
+
+            return new BlockHitResult(client.crosshairTarget.getPos(), direction, blockPos, false);
+        }
+        return null;
+    }
+
+    public @NotNull BlockHitResult withSideForReacharound(@NotNull BlockHitResult result, @Nullable ItemStack stack)
+    {
+        if (stack == null || stack.isEmpty() || !(stack.getItem() instanceof BlockItem))
+            return result;
+        return withSideForReacharound(result, Block.getBlockFromItem(stack.getItem()));
+    }
+
+    public @NotNull BlockHitResult withSideForReacharound(@NotNull BlockHitResult result, @NotNull Block block)
+    {
+        if (block instanceof SlabBlock) {
+            if (this.onSlab) result = result.withSide(Direction.UP);
+            else result = result.withSide(Direction.DOWN);
+        }
+        return result;
+    }
+}