src/main/java/fr/adrien1106/reframed/block/ReFramedHalfStairBlock.java

@@ -73,6 +73,13 @@ public class ReFramedHalfStairBlock extends WaterloggableReFramedBlock {
                 ReFramed.SMALL_CUBE.getDefaultState().with(CORNER, corner.getOpposite(dir))
             );
 
+        if (block == ReFramed.SLAB)
+            return ReFramed.SLAB.matchesShape(
+                context.getHitPos(),
+                context.getBlockPos(),
+                ReFramed.SLAB.getDefaultState().with(FACING, dir.getOpposite())
+            );
+
         return false;
     }
 
@@ -135,6 +142,7 @@ public class ReFramedHalfStairBlock extends WaterloggableReFramedBlock {
             || new_state.isOf(ReFramed.HALF_STAIRS_CUBE_STAIR)
             || new_state.isOf(ReFramed.HALF_STAIRS_STEP_STAIR)
         ) return Map.of(1, 1);
+        if (new_state.isOf(ReFramed.SLABS_INNER_STAIR)) return Map.of(1, 2);
         if (new_state.isOf(ReFramed.HALF_STAIRS_STAIR))
             return Map.of(
                 1,

src/main/java/fr/adrien1106/reframed/block/ReFramedSlabBlock.java

@@ -1,6 +1,8 @@
 package fr.adrien1106.reframed.block;
 
 import fr.adrien1106.reframed.ReFramed;
+import fr.adrien1106.reframed.util.blocks.BlockHelper;
+import fr.adrien1106.reframed.util.blocks.Corner;
 import fr.adrien1106.reframed.util.blocks.Edge;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
@@ -19,8 +21,7 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
 
-import static fr.adrien1106.reframed.util.blocks.BlockProperties.EDGE;
+import static fr.adrien1106.reframed.util.blocks.BlockProperties.*;
-import static fr.adrien1106.reframed.util.blocks.BlockProperties.EDGE_FACE;
 import static net.minecraft.state.property.Properties.*;
 
 public class ReFramedSlabBlock extends WaterloggableReFramedBlock {
@@ -89,6 +90,72 @@ public class ReFramedSlabBlock extends WaterloggableReFramedBlock {
                 .with(WATERLOGGED, current_state.get(WATERLOGGED));
         }
 
+        if (current_state.isOf(ReFramed.HALF_STAIR)) {
+            Corner corner = current_state.get(CORNER);
+            Direction face = corner.getDirection(current_state.get(CORNER_FACE));
+            corner = corner.change(face);
+            return ReFramed.SLABS_INNER_STAIR.getDefaultState()
+                .with(CORNER, corner)
+                .with(CORNER_FACE, corner.getDirectionIndex(face.getOpposite()))
+                .with(WATERLOGGED, current_state.get(WATERLOGGED));
+        }
+
+        if (current_state.isOf(ReFramed.STEP)) {
+            Edge edge = current_state.get(EDGE),
+                placed = BlockHelper.getPlacementEdge(ctx),
+                new_edge;
+            Direction face = edge.getFirstDirection(),
+                other = edge.getSecondDirection().getOpposite();
+
+            if (!ReFramed.STEP.matchesShape(
+                    ctx.getHitPos(),
+                    ctx.getBlockPos(),
+                    current_state.with(EDGE, new_edge = edge.getOpposite(face))
+                )
+                && ctx.getSide() != other.getOpposite()
+                && (placed.getAxis() == edge.getAxis()
+                || ctx.getSide() == other
+                || !placed.hasDirection(other))
+            ) {
+                new_edge = edge.getOpposite(edge.getSecondDirection());
+                other = edge.getFirstDirection().getOpposite();
+            }
+
+            return ReFramed.SLABS_STAIR.getDefaultState()
+                .with(EDGE, new_edge)
+                .with(EDGE_FACE, new_edge.getDirectionIndex(other))
+                .with(WATERLOGGED, current_state.get(WATERLOGGED));
+        }
+
+        if (current_state.isOf(ReFramed.SMALL_CUBE)) {
+            Corner corner = current_state.get(CORNER);
+            Edge placed = BlockHelper.getPlacementEdge(ctx);
+            Direction face;
+            Corner new_corner;
+
+            if (!corner.hasDirection(face = ctx.getSide())) {
+                int i = 0;
+                do {
+                    face = corner.getDirection(i);
+                    new_corner = corner.change(face);
+                } while (!ReFramed.SMALL_CUBE.matchesShape(
+                    ctx.getHitPos(),
+                    ctx.getBlockPos(),
+                    current_state.with(CORNER, new_corner)
+                ) && ++i < 3);
+
+                if (i == 3) {
+                    face = placed.getOtherDirection(corner.getMatchingDirection(placed)).getOpposite();
+                    new_corner = corner.change(face);
+                }
+            } else new_corner = corner.change(face);
+
+            return ReFramed.SLABS_OUTER_STAIR.getDefaultState()
+                .with(CORNER, new_corner)
+                .with(CORNER_FACE, new_corner.getDirectionIndex(face.getOpposite()))
+                .with(WATERLOGGED, current_state.get(WATERLOGGED));
+        }
+
 		return super.getPlacementState(ctx).with(FACING, ctx.getSide().getOpposite());
 	}
 

src/main/java/fr/adrien1106/reframed/block/ReFramedSmallCubeBlock.java

@@ -4,6 +4,8 @@ import fr.adrien1106.reframed.ReFramed;
 import fr.adrien1106.reframed.util.VoxelHelper;
 import fr.adrien1106.reframed.util.blocks.BlockHelper;
 import fr.adrien1106.reframed.util.blocks.Corner;
+import fr.adrien1106.reframed.util.blocks.Edge;
+import fr.adrien1106.reframed.util.blocks.StairShape;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
 import net.minecraft.block.ShapeContext;
@@ -45,51 +47,51 @@ public class ReFramedSmallCubeBlock extends WaterloggableReFramedBlock {
     @Override
     @SuppressWarnings("deprecation")
     public boolean canReplace(BlockState state, ItemPlacementContext context) {
-        if (context.getPlayer() == null) return false;
+        if (context.getPlayer() == null
+            || context.getPlayer().isSneaking()
+            || !(context.getStack().getItem() instanceof BlockItem block_item)
+        ) return false;
+
+        Block block = block_item.getBlock();
         Corner corner = state.get(CORNER);
-        return !(
+        if (block == this)
-            context.getPlayer().isSneaking()
+            return matchesShape(
-                || !(context.getStack().getItem() instanceof BlockItem block_item)
+                context.getHitPos(),
-                || (
+                context.getBlockPos(),
-                    !(
+                getDefaultState().with(CORNER, corner.change(corner.getFirstDirection()))
-                        block_item.getBlock() == ReFramed.HALF_STAIR
+            ) || matchesShape(
-                        && !(corner.hasDirection(context.getSide())
+                context.getHitPos(),
-                            || (corner.hasDirection(context.getSide().getOpposite())
+                context.getBlockPos(),
-                                && BlockHelper.cursorMatchesFace(
+                getDefaultState().with(CORNER, corner.change(corner.getSecondDirection()))
-                                    getOutlineShape(state, context.getWorld(), context.getBlockPos(), null),
+            ) || matchesShape(
-                                    BlockHelper.getRelativePos(context.getHitPos(), context.getBlockPos())
+                context.getHitPos(),
-                                )
+                context.getBlockPos(),
-                            )
+                getDefaultState().with(CORNER, corner.change(corner.getThirdDirection()))
-                        )
+            );
+
+        if (block == ReFramed.HALF_STAIR || block == ReFramed.SLAB) {
+            corner = corner.getOpposite();
+            Direction face = corner.getFirstDirection();
+            Edge edge = corner.getEdge(face);
+            if (ReFramed.STAIR.matchesShape(
+                context.getHitPos(),
+                context.getBlockPos(),
+                ReFramed.STAIR.getDefaultState()
+                    .with(EDGE, edge)
+                    .with(
+                        STAIR_SHAPE,
+                        face.getDirection() == Direction.AxisDirection.POSITIVE
+                            ? StairShape.INNER_LEFT
+                            : StairShape.INNER_RIGHT
                     )
-                    && !(
+            )) return block == ReFramed.SLAB || !matchesShape(
-                        block_item.getBlock() == this
+                context.getHitPos(),
-                        && (
+                context.getBlockPos(),
-                            ReFramed.SMALL_CUBES_STEP
+                getDefaultState().with(CORNER, corner)
-                                .matchesShape(
+            );
-                                    context.getHitPos(),
+        }
-                                    context.getBlockPos(),
+
-                                    ReFramed.SMALL_CUBES_STEP.getDefaultState().with(EDGE, corner.getEdge(corner.getFirstDirection())),
+        return false;
-                                    corner.getFirstDirection().getDirection() == Direction.AxisDirection.POSITIVE ? 1 : 2
-                                )
-                            || ReFramed.SMALL_CUBES_STEP
-                                .matchesShape(
-                                    context.getHitPos(),
-                                    context.getBlockPos(),
-                                    ReFramed.SMALL_CUBES_STEP.getDefaultState().with(EDGE, corner.getEdge(corner.getSecondDirection())),
-                                    corner.getSecondDirection().getDirection() == Direction.AxisDirection.POSITIVE ? 1 : 2
-                                )
-                            || ReFramed.SMALL_CUBES_STEP
-                                .matchesShape(
-                                    context.getHitPos(),
-                                    context.getBlockPos(),
-                                    ReFramed.SMALL_CUBES_STEP.getDefaultState().with(EDGE, corner.getEdge(corner.getThirdDirection())),
-                                    corner.getThirdDirection().getDirection() == Direction.AxisDirection.POSITIVE ? 1 : 2
-                                )
-                        )
-                )
-            )
-        );
     }
 
     @Override
@@ -163,7 +165,9 @@ public class ReFramedSmallCubeBlock extends WaterloggableReFramedBlock {
 
     @Override
     public Map<Integer, Integer> getThemeMap(BlockState state, BlockState new_state) {
-        if (new_state.isOf(ReFramed.HALF_STAIRS_SLAB)) return Map.of(1, 2);
+        if (new_state.isOf(ReFramed.HALF_STAIRS_SLAB)
+            || new_state.isOf(ReFramed.SLABS_OUTER_STAIR)
+        ) return Map.of(1, 2);
         if (new_state.isOf(ReFramed.SMALL_CUBES_STEP))
             return Map.of(
                 1,

src/main/java/fr/adrien1106/reframed/block/ReFramedStepBlock.java

@@ -63,7 +63,10 @@ public class ReFramedStepBlock extends WaterloggableReFramedBlock {
             );
 
         // allow replacing with stair
-        if (block != this && block != ReFramed.STAIR) return false;
+        if (block != this
+            && block != ReFramed.STAIR
+            && block != ReFramed.SLAB
+        ) return false;
 
         return ReFramed.STAIR
             .matchesShape(
@@ -186,7 +189,8 @@ public class ReFramedStepBlock extends WaterloggableReFramedBlock {
         if (new_state.isOf(ReFramed.STEPS_CROSS)
             || new_state.isOf(ReFramed.STEPS_HALF_LAYER)
         ) return Map.of(1, 1);
-        if (new_state.isOf(ReFramed.STAIRS_CUBE)) return Map.of(1, 2);
+        if (new_state.isOf(ReFramed.STAIRS_CUBE)
+            || new_state.isOf(ReFramed.SLABS_STAIR)) return Map.of(1, 2);
         if (new_state.isOf(ReFramed.STEPS_SLAB))
             return Map.of(
                 1,

src/main/java/fr/adrien1106/reframed/util/blocks/Corner.java

@@ -154,4 +154,8 @@ public enum Corner implements StringIdentifiable {
             third_direction == face ? opposite : third_direction
         );
     }
+
+    public Direction getMatchingDirection(Edge edge) {
+        return hasDirection(edge.getSecondDirection()) ? edge.getSecondDirection() : edge.getFirstDirection();
+    }
 }