Jump to content

GUI Overlay - drawString - NullPointerException


Recommended Posts

Hello everyone,


I'm trying to create an overlay mod. I'm pretty much at the beginning of it and I'm trying to understand how rendering and gui-classes works.


My goal is a pretty simple overlay that shows a current state of an item i already created. (goal -> somewhat like the energy level of the ultimate lappack from the GraviChestPlate MOD)


I'm trying to render a string onto the screen with the FontRenderer - drawString method. I pretty much copied it together from the GuiIngame class.


GUI class

public class GuiMasterWrench extends Gui {
private final Minecraft mc;

public GuiMasterWrench(Minecraft minecraft) {
this.mc = minecraft;

public void renderWrenchState() {
FontRenderer fontRender = this.mc.fontRenderer;
ScaledResolution sclRes = new ScaledResolution(this.mc.gameSettings, this.mc.displayWidth, this.mc.displayHeight);
//GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
fontRender.drawStringWithShadow("This is the test string!", 1, 1, 0xffffffff);


In the item class I'm trying to call the overlay with the onItemUseFirst method.


public boolean onItemUseFirst(ItemStack stack, EntityPlayer player, World world, int X, int Y, int Z, int side) {
if (world.isRemote)
return false;
if (Keyboard.isKeyDown(Keyboard.KEY_M)) {
if (wrenchState > 3) wrenchState = 0;
GuiMasterWrench mwGui = new GuiMasterWrench(Minecraft.getMinecraft());
player.addChatMessage("You've set the Master Wrench to state "+ wrenchState);
} else {
player.addChatMessage("You've used the Master Wrench!");
return false;



When i try to right-click my item ingame, i get the following error.


Error - Stack Trace


2012-08-31 11:24:54 [sEVERE] [ForgeModLoader] A critical server error occured handling a packet, kicking net.minecraft.src.NetServerHandler@109099d
at org.lwjgl.opengl.GL11.glColor4f(GL11.java:881)
at net.minecraft.src.FontRenderer.renderString(FontRenderer.java:606)
at net.minecraft.src.FontRenderer.drawStringWithShadow(FontRenderer.java:327)
at tay.mods.masterwrench.common.GuiMasterWrench.renderWrenchState(GuiMasterWrench.java:34)
at tay.mods.masterwrench.common.ItemMasterWrench.onItemUseFirst(ItemMasterWrench.java:35)
at net.minecraft.src.Item.onItemUseFirst(Item.java:692)
at net.minecraft.src.ItemInWorldManager.activateBlockOrUseItem(ItemInWorldManager.java:340)
at net.minecraft.src.NetServerHandler.handlePlace(NetServerHandler.java:500)
at net.minecraft.src.Packet15Place.processPacket(Packet15Place.java:78)
at net.minecraft.src.MemoryConnection.processReadPackets(MemoryConnection.java:75)
at net.minecraft.src.NetServerHandler.networkTick(NetServerHandler.java:72)
at net.minecraft.src.NetworkListenThread.networkTick(NetworkListenThread.java:55)
at net.minecraft.src.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:132)
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:630)
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:547)
at net.minecraft.src.IntegratedServer.tick(IntegratedServer.java:105)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:453)
at net.minecraft.src.ThreadServerApplication.run(ThreadServerApplication.java:17)



I would appreciate any kind of help.

Link to comment
Share on other sites

Is it attached to a container?

Is it a screen GUI?

If it is a container, have it extend GuiContainer, go from there.

If it's a screen GUI without a container, extend GuiScreen.

So, what would happen if I did push that shiny red button over there? ... Really? ... Can I try it? ... Damn.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.