Fix LCE/ECE obstruction check (GregTechCEu#2346)

src/main/java/gregtech/api/util/RelativeDirection.java

@@ -163,4 +163,33 @@ public static EnumFacing simulateAxisRotation(EnumFacing newFrontFacing, EnumFac
             return upwardsFacing.getOpposite();
         }
     }
+
+    /**
+     * Offset a BlockPos relatively in any direction by any amount. Pass negative values to offset down, right or
+     * backwards.
+     */
+    public static BlockPos offsetPos(BlockPos pos, EnumFacing frontFacing, EnumFacing upwardsFacing, boolean isFlipped,
+                                     int upOffset, int leftOffset, int forwardOffset) {
+        if (upOffset == 0 && leftOffset == 0 && forwardOffset == 0) {
+            return pos;
+        }
+
+        int oX = 0, oY = 0, oZ = 0;
+        final EnumFacing relUp = UP.getRelativeFacing(frontFacing, upwardsFacing, isFlipped);
+        oX += relUp.getXOffset() * upOffset;
+        oY += relUp.getYOffset() * upOffset;
+        oZ += relUp.getZOffset() * upOffset;
+
+        final EnumFacing relLeft = LEFT.getRelativeFacing(frontFacing, upwardsFacing, isFlipped);
+        oX += relLeft.getXOffset() * leftOffset;
+        oY += relLeft.getYOffset() * leftOffset;
+        oZ += relLeft.getZOffset() * leftOffset;
+
+        final EnumFacing relForward = FRONT.getRelativeFacing(frontFacing, upwardsFacing, isFlipped);
+        oX += relForward.getXOffset() * forwardOffset;
+        oY += relForward.getYOffset() * forwardOffset;
+        oZ += relForward.getZOffset() * forwardOffset;
+
+        return pos.add(oX, oY, oZ);
+    }
 }

src/main/java/gregtech/common/metatileentities/multi/electric/generator/MetaTileEntityLargeCombustionEngine.java

@@ -16,6 +16,7 @@
 import gregtech.api.pattern.PatternMatchContext;
 import gregtech.api.recipes.RecipeMaps;
 import gregtech.api.unification.material.Materials;
+import gregtech.api.util.RelativeDirection;
 import gregtech.api.util.TextComponentUtil;
 import gregtech.api.util.TextFormattingUtil;
 import gregtech.client.renderer.ICubeRenderer;
@@ -28,7 +29,6 @@
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.client.resources.I18n;
 import net.minecraft.item.ItemStack;
-import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.text.ITextComponent;
@@ -192,18 +192,19 @@ protected void formStructure(PatternMatchContext context) {
     }
 
     private boolean checkIntakesObstructed() {
-        EnumFacing facing = this.getFrontFacing();
-        boolean permuteXZ = facing.getAxis() == EnumFacing.Axis.Z;
-        BlockPos centerPos = this.getPos().offset(facing);
-        for (int x = -1; x < 2; x++) {
-            for (int y = -1; y < 2; y++) {
-                // Skip the controller block itself
-                if (x == 0 && y == 0)
+        for (int left = -1; left <= 1; left++) {
+            for (int up = -1; up <= 1; up++) {
+                if (left == 0 && up == 0) {
+                    // Skip the controller block itself
                     continue;
-                BlockPos blockPos = centerPos.add(permuteXZ ? x : 0, y, permuteXZ ? 0 : x);
-                IBlockState blockState = this.getWorld().getBlockState(blockPos);
-                if (!blockState.getBlock().isAir(blockState, this.getWorld(), blockPos))
+                }
+
+                final BlockPos checkPos = RelativeDirection.offsetPos(
+                        getPos(), getFrontFacing(), getUpwardsFacing(), isFlipped(), up, left, 1);
+                final IBlockState state = getWorld().getBlockState(checkPos);
+                if (!state.getBlock().isAir(state, getWorld(), checkPos)) {
                     return true;
+                }
             }
         }
         return false;

src/main/java/gregtech/common/metatileentities/multi/multiblockpart/MetaTileEntityRotorHolder.java

@@ -12,6 +12,7 @@
 import gregtech.api.metatileentity.interfaces.IGregTechTileEntity;
 import gregtech.api.metatileentity.multiblock.IMultiblockAbilityPart;
 import gregtech.api.metatileentity.multiblock.MultiblockAbility;
+import gregtech.api.util.RelativeDirection;
 import gregtech.client.renderer.texture.Textures;
 import gregtech.common.items.behaviors.AbstractMaterialPartBehavior;
 import gregtech.common.items.behaviors.TurbineRotorBehavior;
@@ -163,14 +164,17 @@ public boolean isFrontFaceFree() {
     }
 
     private boolean checkTurbineFaceFree() {
-        EnumFacing facing = getFrontFacing();
-        boolean permuteXZ = facing.getAxis() == EnumFacing.Axis.Z;
-        BlockPos centerPos = getPos().offset(facing);
-        for (int x = -1; x < 2; x++) {
-            for (int y = -1; y < 2; y++) {
-                BlockPos blockPos = centerPos.add(permuteXZ ? x : 0, y, permuteXZ ? 0 : x);
-                IBlockState blockState = getWorld().getBlockState(blockPos);
-                if (!blockState.getBlock().isAir(blockState, getWorld(), blockPos)) {
+        final EnumFacing front = getFrontFacing();
+        // this can be anything really, as long as it is not up/down when on Y axis
+        final EnumFacing upwards = front.getAxis() == EnumFacing.Axis.Y ? EnumFacing.NORTH : EnumFacing.UP;
+
+        for (int left = -1; left <= 1; left++) {
+            for (int up = -1; up <= 1; up++) {
+                // flip doesn't affect anything here since we are checking a square anyway
+                final BlockPos checkPos = RelativeDirection.offsetPos(
+                        getPos(), front, upwards, false, up, left, 1);
+                final IBlockState state = getWorld().getBlockState(checkPos);
+                if (!state.getBlock().isAir(state, getWorld(), checkPos)) {
                     return false;
                 }
             }