Adds stalactite ore placing override API

src/main/java/twilightforest/world/DefaultOrePlacer.java

@@ -0,0 +1,14 @@
+package twilightforest.world;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+
+class DefaultOrePlacer implements OrePlacer {
+
+    @Override
+    public void placeOre(World world, int x, int y, int z, Block block) {
+        // Set the block without block updates.
+        // Taken from WorldGenerator::func_150515_a
+        world.setBlock(x, y, z, block, 0, 2);
+    }
+}

src/main/java/twilightforest/world/OrePlacer.java

@@ -0,0 +1,13 @@
+package twilightforest.world;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+
+public interface OrePlacer {
+
+    /**
+     * Method which is expected to place a block in the given world at the given coordinates. The block can be
+     * overridden as the implementer chooses.
+     */
+    void placeOre(World world, int x, int y, int z, Block block);
+}

src/main/java/twilightforest/world/StalactiteOreGen.java

@@ -0,0 +1,31 @@
+package twilightforest.world;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+import net.minecraft.block.Block;
+
+public class StalactiteOreGen {
+
+    private static final OrePlacer DEFAULT_ORE_PLACER = new DefaultOrePlacer();
+    private static final List<Function<Block, Optional<OrePlacer>>> orePlacerSources = new ArrayList<>();
+
+    /**
+     * Add an OrePlacer source that can determine which OrePlacer, if any, it wants to provide to a stalactite wanting
+     * to generate with a given Block.
+     */
+    public static void addOrePlacerSource(Function<Block, Optional<OrePlacer>> orePlacerSource) {
+        orePlacerSources.add(orePlacerSource);
+    }
+
+    static OrePlacer getOrePlacer(Block block) {
+        // Given this only runs once per stalactite generated, I think we can afford the assumption there could
+        // eventually be several alternate sources of ore placers.
+        return orePlacerSources.stream().map(f -> f.apply(block))
+                .flatMap(o -> o.isPresent() ? Stream.of(o.get()) : Stream.empty()).findFirst()
+                .orElse(DEFAULT_ORE_PLACER);
+    }
+}

src/main/java/twilightforest/world/TFGenCaveStalactite.java

@@ -152,7 +152,7 @@ public boolean generate(World world, Random random, int x, int y, int z) {
     }
 
     public boolean makeSpike(World world, Random random, int x, int y, int z, int maxLength) {
-
+        OrePlacer orePlacer = StalactiteOreGen.getOrePlacer(blockID);
         int diameter = (int) (maxLength / 4.5); // diameter of the base
 
         // let's see...
@@ -180,7 +180,7 @@ public boolean makeSpike(World world, Random random, int x, int y, int z, int ma
                 }
 
                 for (int dy = 0; dy != (spikeLength * dir); dy += dir) {
-                    setBlock(world, x + dx, y + dy, z + dz, blockID);
+                    orePlacer.placeOre(world, x + dx, y + dy, z + dz, blockID);
                 }
             }
         }