Allow proper representation of recipes with multiple results

src/main/java/codechicken/nei/FavoriteRecipes.java

@@ -8,7 +8,6 @@
 import java.io.OutputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -129,8 +128,8 @@ public void execute() {
         }
 
         protected List<PositionedStack> getOutputs(IRecipeHandler handler, int recipeIndex) {
-            final PositionedStack pStackResult = handler.getResultStack(recipeIndex);
-            return pStackResult != null ? Collections.singletonList(pStackResult) : handler.getOtherStacks(recipeIndex);
+            final List<PositionedStack> pStackResults = handler.getResultStacks(recipeIndex);
+            return !pStackResults.isEmpty() ? pStackResults : handler.getOtherStacks(recipeIndex);
         }
 
     };

src/main/java/codechicken/nei/PresetsList.java

@@ -89,9 +89,9 @@ public boolean matches(IRecipeHandler handler, int recipeIndex) {
                 return false;
             }
 
-            final PositionedStack result = handler.getResultStack(recipeIndex);
+            final List<PositionedStack> results = handler.getResultStacks(recipeIndex);
 
-            if (result != null && matchPositionedStack(result)) {
+            if (!results.isEmpty() && matchPositionedStack(results, true)) {
                 return true;
             }
 
@@ -101,7 +101,13 @@ public boolean matches(IRecipeHandler handler, int recipeIndex) {
                 return true;
             }
 
-            return result == null && others.isEmpty();
+            final List<PositionedStack> extraInputs = handler.getCatalystStacks(recipeIndex);
+
+            if (!extraInputs.isEmpty() && matchPositionedStack(extraInputs, true)) {
+                return true;
+            }
+
+            return results.isEmpty() && others.isEmpty();
         }
 
         private boolean matchPositionedStack(List<PositionedStack> items, boolean dir) {

src/main/java/codechicken/nei/filter/AllOthersRecipeFilter.java

@@ -24,6 +24,12 @@ public boolean matches(IRecipeHandler handler, int recipeIndex) {
             }
         }
 
+        for (PositionedStack pStack : handler.getCatalystStacks(recipeIndex)) {
+            if (!match(pStack)) {
+                return false;
+            }
+        }
+
         return true;
     }
 

src/main/java/codechicken/nei/filter/AnyOthersRecipeFilter.java

@@ -24,6 +24,12 @@ public boolean matches(IRecipeHandler handler, int recipeIndex) {
             }
         }
 
+        for (PositionedStack pStack : handler.getCatalystStacks(recipeIndex)) {
+            if (match(pStack)) {
+                return true;
+            }
+        }
+
         return false;
     }
 

src/main/java/codechicken/nei/filter/RecipeFilter.java

@@ -48,16 +48,18 @@ && matchPositionedStack(handler.getIngredientStacks(recipeIndex), this.anyMatch)
         }
 
         if (this.context == FilterContext.ANY || this.context == FilterContext.OUTPUT) {
-            final PositionedStack result = handler.getResultStack(recipeIndex);
-
-            if (result != null && matchPositionedStack(result) == this.anyMatch) {
+            if (matchPositionedStack(handler.getResultStacks(recipeIndex), this.anyMatch)) {
                 return this.anyMatch;
             }
 
             if (matchPositionedStack(handler.getOtherStacks(recipeIndex), this.anyMatch)) {
                 return this.anyMatch;
             }
 
+            if (matchPositionedStack(handler.getCatalystStacks(recipeIndex), this.anyMatch)) {
+                return this.anyMatch;
+            }
+
         }
 
         return !this.anyMatch;

src/main/java/codechicken/nei/recipe/FuelRecipeHandler.java

@@ -38,6 +38,11 @@ public PositionedStack getResult() {
         public PositionedStack getOtherStack() {
             return fuel.stack;
         }
+
+        @Override
+        public PositionedStack getCatalyst() {
+            return fuel.stack;
+        }
     }
 
     private final ArrayList<SmeltingPair> mfurnace = new ArrayList<>();

src/main/java/codechicken/nei/recipe/IRecipeHandler.java

@@ -1,5 +1,6 @@
 package codechicken.nei.recipe;
 
+import java.util.Collections;
 import java.util.List;
 
 import net.minecraft.client.gui.inventory.GuiContainer;
@@ -82,15 +83,38 @@ default int getRecipeHeight(int recipe) {
      * @return A list of the other {@link PositionedStack}s in this recipe relative to the top left corner of your
      *         recipe drawing space. For example fuel in furnaces.
      */
+    default List<PositionedStack> getCatalystStacks(int recipe) {
+        return Collections.emptyList();
+    }
+
+    /**
+     * Legacy API, define either {@link #getCatalystStacks(int)} or {@link #getResultStacks(int)}
+     *
+     * @param recipe The recipe index to get items for.
+     * @return A list of the other {@link PositionedStack}s in this recipe relative to the top left corner of your
+     *         recipe drawing space. For example fuel in furnaces.
+     */
     List<PositionedStack> getOtherStacks(int recipe);
 
     /**
+     * Legacy API, use {@link #getResultStacks(int) getResultStacks.get(0)} if you want the primary result
      *
      * @param recipe The recipe index to get the result for.
      * @return The recipe result {@link PositionedStack} relative to the top left corner of your recipe drawing space.
      */
     PositionedStack getResultStack(int recipe);
 
+    /**
+     *
+     * @param recipe The recipe index to get the result for.
+     * @return A list of the result {@link PositionedStack}s relative to the top left corner of your recipe drawing
+     *         space.
+     */
+    default List<PositionedStack> getResultStacks(int recipe) {
+        final PositionedStack result = getResultStack(recipe);
+        return result != null ? Collections.singletonList(result) : Collections.emptyList();
+    }
+
     /**
      * A tick function called for updating progress bars and cycling damage items.
      */

src/main/java/codechicken/nei/recipe/NEIRecipeWidget.java

@@ -6,6 +6,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.WeakHashMap;
 import java.util.function.Function;
 import java.util.stream.Stream;
@@ -36,6 +37,7 @@
 import codechicken.nei.recipe.Recipe.RecipeId;
 import codechicken.nei.recipe.debug.DebugHandlerWidget;
 import codechicken.nei.util.NEIMouseUtils;
+import it.unimi.dsi.fastutil.longs.LongArraySet;
 
 public class NEIRecipeWidget extends Widget {
 
@@ -54,6 +56,9 @@ public class NEIRecipeWidget extends Widget {
     protected boolean showAsWidget = false;
     protected List<GuiRecipeButton> recipeButtons = null;
 
+    // Handles re-draws for catalysts-outputs duplication to preserve full backward compatibility for otherStacks
+    private final Set<Long> drawnSlots = new LongArraySet();
+
     public NEIRecipeWidget(RecipeHandlerRef handlerRef) {
         this.handlerRef = handlerRef;
         this.handlerInfo = GuiRecipeTab.getHandlerInfo(this.handlerRef.handler);
@@ -193,7 +198,20 @@ public void draw(int mouseX, int mouseY) {
 
         GuiContainerManager.enableMatrixStackLogging();
 
-        for (PositionedStack pStack : getInputs()) {
+        final List<PositionedStack> inputs = getInputs();
+        final List<PositionedStack> catalysts = getCatalysts();
+        final List<PositionedStack> outputs = getOutputs();
+
+        drawnSlots.clear();
+        for (PositionedStack pStack : inputs) {
+            drawnSlots.add(slotKey(pStack));
+            drawItem(pStack, mouseX, mouseY, yShift, false);
+        }
+
+        for (PositionedStack pStack : catalysts) {
+            if (!drawnSlots.add(slotKey(pStack))) {
+                continue;
+            }
 
             if (!this.permutations.containsKey(pStack)) {
                 updatePermutationsFor(pStack);
@@ -202,7 +220,10 @@ public void draw(int mouseX, int mouseY) {
             drawItem(pStack, mouseX, mouseY, yShift, true);
         }
 
-        for (PositionedStack pStack : getCatalysts()) {
+        for (PositionedStack pStack : outputs) {
+            if (!drawnSlots.add(slotKey(pStack))) {
+                continue;
+            }
 
             if (!this.permutations.containsKey(pStack)) {
                 updatePermutationsFor(pStack);
@@ -211,10 +232,6 @@ public void draw(int mouseX, int mouseY) {
             drawItem(pStack, mouseX, mouseY, yShift, true);
         }
 
-        for (PositionedStack pStack : getOutputs()) {
-            drawItem(pStack, mouseX, mouseY, yShift, false);
-        }
-
         GuiContainerManager.disableMatrixStackLogging();
 
         this.handlerRef.handler.drawForeground(this.handlerRef.recipeIndex);
@@ -246,6 +263,10 @@ public void draw(int mouseX, int mouseY) {
         DebugHandlerWidget.instance.drawGuiPlaceholder(this);
     }
 
+    private static long slotKey(PositionedStack pStack) {
+        return ((long) pStack.relx << 32) ^ (pStack.rely & 0xFFFFFFFFL);
+    }
+
     protected void drawItem(PositionedStack pStack, int mouseX, int mouseY, int yShift, boolean input) {
         GuiContainerManager.drawItem(pStack.relx, pStack.rely, pStack.item);
 
@@ -656,13 +677,19 @@ protected List<PositionedStack> getInputs() {
     }
 
     protected List<PositionedStack> getOutputs() {
-        final PositionedStack pStackResult = this.handlerRef.handler.getResultStack(this.handlerRef.recipeIndex);
-        return pStackResult != null ? Arrays.asList(pStackResult)
+        final List<PositionedStack> pStackResults = this.handlerRef.handler
+                .getResultStacks(this.handlerRef.recipeIndex);
+        return !pStackResults.isEmpty() ? pStackResults
                 : this.handlerRef.handler.getOtherStacks(this.handlerRef.recipeIndex);
     }
 
     protected List<PositionedStack> getCatalysts() {
-        if (this.handlerRef.handler.getResultStack(this.handlerRef.recipeIndex) == null) {
+        List<PositionedStack> catalysts = this.handlerRef.handler.getCatalystStacks(this.handlerRef.recipeIndex);
+        if (!catalysts.isEmpty()) {
+            return catalysts;
+        }
+
+        if (this.handlerRef.handler.getResultStacks(this.handlerRef.recipeIndex).isEmpty()) {
             return Collections.emptyList();
         }
         return this.handlerRef.handler.getOtherStacks(this.handlerRef.recipeIndex);

src/main/java/codechicken/nei/recipe/Recipe.java

@@ -54,19 +54,26 @@ public static RecipeId of(Object result, String handlerName, Iterable<?> ingredi
         public static RecipeId of(IRecipeHandler handler, int recipeIndex) {
             final List<PositionedStack> ingredients = handler.getIngredientStacks(recipeIndex);
             final String handlerName = GuiRecipeTab.getHandlerInfo(handler).getHandlerName();
-            PositionedStack pStackResult = handler.getResultStack(recipeIndex);
+            // Use getResultStacks even though getResult could work because if a handler, like GT for example, doesn't
+            // return anything from getResult, but will define all the outputs in getResultStacks we can still pick up
+            // the results here. If a handler still doesn't define getResultStacks, then it will naturally fall back to
+            // getResult anyway
+            List<PositionedStack> pStackResults = handler.getResultStacks(recipeIndex);
 
-            if (pStackResult == null) {
+            if (pStackResults.isEmpty()) {
                 for (PositionedStack otherStack : handler.getOtherStacks(recipeIndex)) {
                     if (!FluidContainerRegistry.isContainer(otherStack.items[0])
                             || StackInfo.getFluid(otherStack.items[0]) != null) {
-                        pStackResult = otherStack;
+                        pStackResults.add(otherStack);
                         break;
                     }
                 }
             }
 
-            return new RecipeId(extractItem(pStackResult), handlerName, extractIngredients(ingredients));
+            return new RecipeId(
+                    extractItem(!pStackResults.isEmpty() ? pStackResults.get(0) : null),
+                    handlerName,
+                    extractIngredients(ingredients));
         }
 
         public static RecipeId of(JsonObject json) {
@@ -389,8 +396,12 @@ public static Recipe of(IRecipeHandler handler, int recipeIndex) {
             ingredients.add(RecipeIngredient.of(positionedStack));
         }
 
-        if (handler.getResultStack(recipeIndex) != null) {
-            results.add(RecipeIngredient.of(handler.getResultStack(recipeIndex)));
+        final List<PositionedStack> resultStacks = handler.getResultStacks(recipeIndex);
+
+        if (!resultStacks.isEmpty()) {
+            for (PositionedStack positionedStack : resultStacks) {
+                results.add(RecipeIngredient.of(positionedStack));
+            }
         } else {
             for (PositionedStack positionedStack : handler.getOtherStacks(recipeIndex)) {
                 results.add(RecipeIngredient.of(positionedStack));

src/main/java/codechicken/nei/recipe/TemplateRecipeHandler.java

@@ -4,6 +4,7 @@
 import java.awt.Rectangle;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -132,7 +133,48 @@ public abstract class CachedRecipe {
         public abstract PositionedStack getResult();
 
         /**
-         * The ingredients required to produce the result Use this if you have more than one ingredient
+         * The multiple items produced by this recipe, with position
+         *
+         * @return A list of positioned ingredient items.
+         */
+        public List<PositionedStack> getResults() {
+            ArrayList<PositionedStack> stacks = new ArrayList<>();
+            try {
+                PositionedStack stack = getResult();
+                if (stack != null) stacks.add(stack);
+            } catch (ArithmeticException e) {
+                NEIClientConfig.logger.error("Error in getOtherStacks: " + e);
+            }
+            return stacks;
+        }
+
+        /**
+         * Return extra items that are not directly involved in the ingredient->result relationship. Eg fuels.
+         *
+         * @return A list of positioned ingredient items.
+         */
+        public List<PositionedStack> getCatalysts() {
+            ArrayList<PositionedStack> stacks = new ArrayList<>();
+            try {
+                PositionedStack stack = getCatalyst();
+                if (stack != null) stacks.add(stack);
+            } catch (ArithmeticException e) {
+                NEIClientConfig.logger.error("Error in getCatalysts: " + e);
+            }
+            return stacks;
+        }
+
+        /**
+         * Simple utility
+         *
+         * @return The another positioned stack
+         */
+        public PositionedStack getCatalyst() {
+            return null;
+        }
+
+        /**
+         * The ingredients required to produce the result. Use this if you have more than one ingredient
          *
          * @return A list of positioned ingredient items.
          */
@@ -151,6 +193,8 @@ public PositionedStack getIngredient() {
         }
 
         /**
+         * Legacy API
+         *
          * Return extra items that are not directly involved in the ingredient->result relationship. Eg fuels. Use this
          * if you have more than one other stack
          *
@@ -625,13 +669,23 @@ public List<PositionedStack> getIngredientStacks(int recipe) {
     }
 
     public PositionedStack getResultStack(int recipe) {
+        List<PositionedStack> results = getResultStacks(recipe);
+        if (results == null || results.isEmpty()) return null;
+        return results.get(0);
+    }
+
+    public List<PositionedStack> getResultStacks(int recipe) {
         try {
-            return arecipes.get(recipe).getResult();
+            return arecipes.get(recipe).getResults();
         } catch (ArrayIndexOutOfBoundsException ignored) {
-            return null;
+            return Collections.emptyList();
         }
     }
 
+    public List<PositionedStack> getCatalystStacks(int recipe) {
+        return arecipes.get(recipe).getCatalysts();
+    }
+
     public List<PositionedStack> getOtherStacks(int recipe) {
         return arecipes.get(recipe).getOtherStacks();
     }