Hey all,

I'm trying to make my custom crafting table with specific recipes, and I've come into this crash that I cannot understand..

 

The crash report:

net.minecraft.util.ReportedException: Rendering screen
at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1175) ~[EntityRenderer.class:?]
at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1140) ~[Minecraft.class:?]
at net.minecraft.client.Minecraft.run(Minecraft.java:404) [Minecraft.class:?]
at net.minecraft.client.main.Main.main(Main.java:118) [Main.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_45]
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_45]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_45]
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_45]
at net.minecraftforge.gradle.GradleStartCommon.launch(GradleStartCommon.java:97) [start/:?]
at GradleStart.main(GradleStart.java:26) [start/:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_45]
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_45]
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:?]
Caused by: java.lang.NullPointerException: Rendering screen
at net.minecraft.client.renderer.RenderItem.renderItemOverlayIntoGUI(RenderItem.java:429)
at net.minecraft.client.gui.inventory.GuiContainer.drawSlot(GuiContainer.java:299)
at net.minecraft.client.gui.inventory.GuiContainer.drawScreen(GuiContainer.java:114)
at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:355)
at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1148)
at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1140)
at net.minecraft.client.Minecraft.run(Minecraft.java:404)
at net.minecraft.client.main.Main.main(Main.java:118)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraftforge.gradle.GradleStartCommon.launch(GradleStartCommon.java:97)
at GradleStart.main(GradleStart.java:26)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

 

I can see that the exception is reported in Minecraft's code, and that it is a NullPointerException, but I can't understand how to fix it...

 

My code (I hope it'll have a use in finding the solution)

 

TileEntityConstructionTable (The "checkRecipes" method is called whenever an Item is placed or removed in the gui)

private ItemStack[] slots = new ItemStack[18];

public void checkRecipes() {
	ItemStack[] gridInputs = getGridInputs();
	ItemStack[] secInputs = getSecInputs();

	CraftingHandlerConstructionTable.RecipeType recipeType = CraftingHandlerConstructionTable.getCurrentRecipeType(gridInputs, secInputs, worldObj);
	ItemStack output = null;
	if (recipeType != CraftingHandlerConstructionTable.RecipeType.None) {
		if (recipeType == CraftingHandlerConstructionTable.RecipeType.Vanilla && CraftingHandlerConstructionTable.getVanillaRecipeOutput(gridInputs, worldObj) != null) {
			output = CraftingHandlerConstructionTable.getVanillaRecipeOutput(gridInputs, worldObj);
		} else if (recipeType == CraftingHandlerConstructionTable.RecipeType.CTShaped && CraftingHandlerConstructionTable.getConstructionTableShapedRecipeOutput(gridInputs, secInputs) != null) {
			output = CraftingHandlerConstructionTable.getConstructionTableShapedRecipeOutput(gridInputs, secInputs);
		}
	}

	this.slots[0] = output;
}

 

CraftingHandlerConstructionTable

public static ItemStack getVanillaRecipeOutput(ItemStack[] gridInputs, World world) {
	InventoryCrafting ic = new InventoryCrafting(new ContainerDummy(), 3, 3);
	for (int i = 0; i < 9; i++) {
		ic.setInventorySlotContents(i, gridInputs[i]);
	}
	return CraftingManager.getInstance().findMatchingRecipe(ic, world);
}

public static ItemStack getConstructionTableShapedRecipeOutput(ItemStack[] gridInputs, ItemStack[] secInputs) {
	ItemStack output = null;
	int numOfItemStacks = 0;
	for (ItemStack secInput : secInputs) {
		if (secInput != null) {
			numOfItemStacks++;
		}
	}
	ItemStack[] secNoNulls = new ItemStack[numOfItemStacks];
	int index = 0;
	for (ItemStack secInput : secInputs) {
		if (secInput != null) {
			secNoNulls[index] = secInput;
			index++;
		}
	}
	for (RecipeBaseConstructionTable recipe : IJCAPI.constructionTableRecipes) {
		if (recipe instanceof RecipeShapedConstructionTable) {
			if (recipe.matches(gridInputs, secNoNulls)) {
				output = recipe.getOutput();
			}
		}
	}
	return output;
}

public static RecipeType getCurrentRecipeType(ItemStack[] gridInputs, ItemStack[] secInputs, World world) {
	RecipeType currentType = RecipeType.None;

	if (getVanillaRecipeOutput(gridInputs, world) != null) currentType = RecipeType.Vanilla;
	if (getConstructionTableShapedRecipeOutput(gridInputs, secInputs) != null) currentType = RecipeType.CTShaped;

	return currentType;
}

public enum RecipeType {
	None,
	Vanilla,
	CTShaped,
	CTShapeless,
	CTPrecise
}

 

I hope this is enough. I can also post the actual methods of matching the recipes (those work, and I don't think they are the problem..)

 

Caused by: java.lang.NullPointerException: Rendering screen

at net.minecraft.client.renderer.RenderItem.renderItemOverlayIntoGUI(RenderItem.java:429)

 

This exception is thrown when Minecraft attempts to render an

ItemStack

with a

null

Item

. Ensure all of your

Item

s have been properly initialised.

You were correct,  thank you!

I was registering my blocks and crafting recipes both in preInit. Once I moved the recipes to init, that problem was fixed... I still have a few other minor fixes to do to this constructionTable, but this problem was solved. Thanks again!