fix +sa + update

Signed-off-by: Glease <4586901+Glease@users.noreply.github.com>

addon.gradle

@@ -1,7 +1,7 @@
 javadoc {
     javadocTool = javaToolchains.javadocToolFor {
         // Last version with frames, but it also has search
-        languageVersion = JavaLanguageVersion.of(11)
+        languageVersion = JavaLanguageVersion.of(21)
         vendor = JvmVendorSpec.ADOPTIUM
     }
 
@@ -20,7 +20,6 @@ javadoc {
         overview "src/main/javadoc/overview.html"
         links 'https://docs.oracle.com/javase/8/docs/api/'
         links 'https://skmedix.github.io/ForgeJavaDocs/javadoc/forge/1.7.10-10.13.4.1614/'
-        addBooleanOption("-frames", true)
     }
 }
 

dependencies.gradle

@@ -1,9 +1,13 @@
 // Add your dependencies here
 
 dependencies {
-    api("com.github.GTNewHorizons:GTNHLib:0.6.21:dev")
-    implementation("com.github.GTNewHorizons:NotEnoughItems:2.7.40-GTNH:dev")
+    api("com.github.GTNewHorizons:GTNHLib:0.6.19:dev")
+    implementation("com.github.GTNewHorizons:NotEnoughItems:2.7.38-GTNH:dev")
 
     testImplementation(platform('org.junit:junit-bom:5.9.2'))
     testImplementation('org.junit.jupiter:junit-jupiter')
+
+//    runtimeOnlyNonPublishable("com.github.GTNewHorizons:GT5-Unofficial:5.09.51.227:dev") {
+//        exclude group: "com.github.GTNewHorizons", module: "StructureLib"
+//    }
 }

src/main/java/com/gtnewhorizon/structurelib/ClientProxy.java

@@ -20,6 +20,7 @@ import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.culling.Frustrum;
 import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.client.resources.I18n;
+import net.minecraft.client.settings.KeyBinding;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
@@ -42,17 +43,23 @@ import org.lwjgl.opengl.GL11;
 import com.gtnewhorizon.structurelib.entity.fx.WeightlessParticleFX;
 import com.gtnewhorizon.structurelib.net.RegistryOrderSyncMessage;
 import com.gtnewhorizon.structurelib.net.SetChannelDataMessage;
+import com.gtnewhorizon.structurelib.net.StructureProjectorCycleModeMessage;
 
 import cpw.mods.fml.client.config.GuiConfig;
 import cpw.mods.fml.client.event.ConfigChangedEvent;
+import cpw.mods.fml.client.registry.ClientRegistry;
 import cpw.mods.fml.common.FMLCommonHandler;
+import cpw.mods.fml.common.event.FMLInitializationEvent;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
 import cpw.mods.fml.common.eventhandler.EventPriority;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
+import cpw.mods.fml.common.gameevent.InputEvent;
 import cpw.mods.fml.common.gameevent.TickEvent.ClientTickEvent;
 import cpw.mods.fml.common.gameevent.TickEvent.Phase;
 import cpw.mods.fml.common.network.FMLNetworkEvent;
+import cpw.mods.fml.relauncher.Side;
+import cpw.mods.fml.relauncher.SideOnly;
 
 public class ClientProxy extends CommonProxy {
 
@@ -259,6 +266,13 @@ public class ClientProxy extends CommonProxy {
         MinecraftForge.EVENT_BUS.register(new ForgeEventHandler());
     }
 
+    @Override
+    public void init(FMLInitializationEvent e) {
+        super.init(e);
+
+        MinecraftForge.EVENT_BUS.register(new KeybindHandler());
+    }
+
     static void markTextureUsed(IIcon icon) {
         if (StructureLib.COMPAT instanceof IStructureCompat)
             ((IStructureCompat) StructureLib.COMPAT).markTextureUsed(icon);
@@ -654,4 +668,30 @@ public class ClientProxy extends CommonProxy {
             p.endSection();
         }
     }
+
+    public static class KeybindHandler {
+
+        private static final KeyBinding CYCLE_PROJECTOR_MODE = new KeyBinding(
+                "item.structurelib.constructableTrigger.keys.cycleMode",
+                0,
+                "item.structurelib.constructableTrigger.keyCategory");
+
+        public KeybindHandler() {
+            FMLCommonHandler.instance().bus().register(this);
+            // If somebody wants to make a UI element for this, be my guest
+            ClientRegistry.registerKeyBinding(CYCLE_PROJECTOR_MODE);
+        }
+
+        @SideOnly(Side.CLIENT)
+        @SubscribeEvent
+        public void key(InputEvent.KeyInputEvent event) {
+            if (CYCLE_PROJECTOR_MODE.isPressed()) {
+                cycleProjectorMode();
+            }
+        }
+
+        private static void cycleProjectorMode() {
+            StructureLib.net.sendToServer(new StructureProjectorCycleModeMessage());
+        }
+    }
 }

src/main/java/com/gtnewhorizon/structurelib/CommonProxy.java

@@ -17,6 +17,7 @@ import net.minecraftforge.common.MinecraftForge;
 import com.gtnewhorizon.structurelib.net.ErrorHintParticleMessage;
 import com.gtnewhorizon.structurelib.net.UpdateHintParticleMessage;
 
+import cpw.mods.fml.common.event.FMLInitializationEvent;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
@@ -64,6 +65,8 @@ public class CommonProxy {
 
     public void preInit(FMLPreInitializationEvent e) {}
 
+    public void init(FMLInitializationEvent e) {}
+
     public long getOverworldTime() {
         return MinecraftServer.getServer().getEntityWorld().getTotalWorldTime();
     }

src/main/java/com/gtnewhorizon/structurelib/StructureLib.java

@@ -27,12 +27,14 @@ import com.gtnewhorizon.structurelib.net.AlignmentMessage;
 import com.gtnewhorizon.structurelib.net.ErrorHintParticleMessage;
 import com.gtnewhorizon.structurelib.net.RegistryOrderSyncMessage;
 import com.gtnewhorizon.structurelib.net.SetChannelDataMessage;
+import com.gtnewhorizon.structurelib.net.StructureProjectorCycleModeMessage;
 import com.gtnewhorizon.structurelib.net.UpdateHintParticleMessage;
 import com.gtnewhorizon.structurelib.util.InventoryUtility;
 import com.gtnewhorizon.structurelib.util.XSTR;
 
 import cpw.mods.fml.common.Mod;
 import cpw.mods.fml.common.SidedProxy;
+import cpw.mods.fml.common.event.FMLInitializationEvent;
 import cpw.mods.fml.common.event.FMLInterModComms;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
@@ -77,6 +79,11 @@ public class StructureLib {
         net.registerMessage(SetChannelDataMessage.Handler.class, SetChannelDataMessage.class, 3, Side.SERVER);
         net.registerMessage(ErrorHintParticleMessage.Handler.class, ErrorHintParticleMessage.class, 4, Side.CLIENT);
         net.registerMessage(RegistryOrderSyncMessage.Handler.class, RegistryOrderSyncMessage.class, 5, Side.SERVER);
+        net.registerMessage(
+                StructureProjectorCycleModeMessage.Handler.class,
+                StructureProjectorCycleModeMessage.class,
+                6,
+                Side.SERVER);
 
         try {
             DEBUG_MODE = Boolean.parseBoolean(System.getProperty("structurelib.debug"));
@@ -128,6 +135,11 @@ public class StructureLib {
         DevelopHelper.onPreInit();
     }
 
+    @Mod.EventHandler
+    public void init(FMLInitializationEvent e) {
+        proxy.init(e);
+    }
+
     @Mod.EventHandler
     public void loadComplete(FMLLoadCompleteEvent e) {
         proxy.loadComplete(e);

src/main/java/com/gtnewhorizon/structurelib/StructureLibAPI.java

@@ -9,6 +9,7 @@ import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.IChatComponent;
 import net.minecraft.util.IIcon;
+import net.minecraft.util.StatCollector;
 import net.minecraft.world.World;
 
 import com.gtnewhorizon.gtnhlib.util.AnimatedTooltipHandler;
@@ -380,9 +381,7 @@ public class StructureLibAPI {
         ChannelDescription.item(channel, channelValue, stack);
         AnimatedTooltipHandler.addItemTooltip(
                 stack,
-                AnimatedTooltipHandler.translatedText("structurelib.tooltip.channelvalue", channelValue, channel));
-        AnimatedTooltipHandler.addItemTooltip(
-                stack,
-                AnimatedTooltipHandler.translatedText("structurelib.tooltip.indicator_dnd", channelValue, channel));
+                () -> StatCollector
+                        .translateToLocalFormatted("structurelib.tooltip.channelvalue", channelValue, channel));
     }
 }

src/main/java/com/gtnewhorizon/structurelib/alignment/constructable/ConstructableUtility.java

@@ -57,12 +57,12 @@ public class ConstructableUtility {
         }
 
         IConstructable constructable = null;
-        if (tTileEntity instanceof IConstructableProvider)
-            constructable = ((IConstructableProvider) tTileEntity).getConstructable();
-        else if (tTileEntity instanceof IConstructable) {
-            constructable = (IConstructable) tTileEntity;
+        if (tTileEntity instanceof IConstructableProvider aConstructableProvider)
+            constructable = aConstructableProvider.getConstructable();
+        else if (tTileEntity instanceof IConstructable aConstructable) {
+            constructable = aConstructable;
         } else if (IMultiblockInfoContainer.contains(tTileEntity.getClass())) {
-            ExtendedFacing facing = tTileEntity instanceof IAlignment ? ((IAlignment) tTileEntity).getExtendedFacing()
+            ExtendedFacing facing = tTileEntity instanceof IAlignment alignment ? alignment.getExtendedFacing()
                     : ExtendedFacing.of(ForgeDirection.getOrientation(aSide));
             constructable = IMultiblockInfoContainer.<TileEntity>get(tTileEntity.getClass())
                     .toConstructable(tTileEntity, facing);
@@ -70,14 +70,13 @@ public class ConstructableUtility {
 
         if (constructable == null) return false;
 
-        if (aPlayer instanceof EntityPlayerMP) {
-            EntityPlayerMP playerMP = (EntityPlayerMP) aPlayer;
+        if (aPlayer instanceof EntityPlayerMP playerMP) {
             // server side and sneaking (already checked above)
             // do construct
             if (aPlayer.capabilities.isCreativeMode) {
                 constructable.construct(aStack, false);
-            } else if (constructable instanceof ISurvivalConstructable) {
-                int built = ((ISurvivalConstructable) constructable).survivalConstruct(
+            } else if (constructable instanceof ISurvivalConstructable aConstructable) {
+                int built = aConstructable.survivalConstruct(
                         aStack,
                         ConfigurationHandler.INSTANCE.getAutoPlaceBudget(),
                         ISurvivalBuildEnvironment.create(IItemSource.fromPlayer(playerMP), playerMP));

src/main/java/com/gtnewhorizon/structurelib/gui/GuiScreenConfigureChannels.java

@@ -1,5 +1,17 @@
 package com.gtnewhorizon.structurelib.gui;
 
+import static org.lwjgl.opengl.ARBImaging.*;
+import static org.lwjgl.opengl.ARBImaging.GL_SEPARABLE_2D;
+import static org.lwjgl.opengl.GL11.*;
+import static org.lwjgl.opengl.GL11.GL_ALPHA_TEST_FUNC;
+import static org.lwjgl.opengl.GL12.GL_RESCALE_NORMAL;
+import static org.lwjgl.opengl.GL12.GL_TEXTURE_3D;
+import static org.lwjgl.opengl.GL13.*;
+import static org.lwjgl.opengl.GL14.*;
+import static org.lwjgl.opengl.GL14.GL_BLEND_SRC_RGB;
+import static org.lwjgl.opengl.GL15.GL_FOG_COORD_ARRAY;
+import static org.lwjgl.opengl.GL20.*;
+
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -13,7 +25,6 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
 
 import net.minecraft.client.gui.GuiButton;
 import net.minecraft.client.gui.GuiTextField;
@@ -31,7 +42,7 @@ import org.lwjgl.input.Keyboard;
 import org.lwjgl.input.Mouse;
 import org.lwjgl.opengl.GL11;
 
-import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableMap;
 import com.gtnewhorizon.structurelib.ChannelDescription;
 import com.gtnewhorizon.structurelib.StructureLib;
 import com.gtnewhorizon.structurelib.alignment.constructable.ChannelDataAccessor;
@@ -55,7 +66,6 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
     private static final int WIPE_BTN = 2;
 
     private static final int KEY_MAX_WIDTH = 50;
-    private static final int INFO_BOX_SIZE = 11;
     private final ItemStack trigger;
     private final GuiChannelsList list;
     private final GuiAutoCompleteList autoCompleteList;
@@ -63,13 +73,12 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
     private final TIntObjectMap<Map<String, String>> trimCache = new TIntObjectHashMap<>();
     private GuiTextField key, value;
     protected int guiTop, guiLeft;
-    private List<String> info;
 
     public GuiScreenConfigureChannels(Container container, ItemStack trigger) {
         super(container);
 
         this.trigger = trigger;
-        list = new GuiChannelsList(152, 91, 12, 21, 14);
+        list = new GuiChannelsList(152, 100, 12, 12, 14);
         list.addSelectionListener((list, selectedIndex) -> {
             Entry<String, Integer> e = list.getElementAt(selectedIndex);
             key.setText(e.getKey());
@@ -191,14 +200,6 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
 
         updateButtons();
         tooltipSplitCache.clear();
-        info = StreamSupport
-                .stream(
-                        Splitter.on("\\n").split(
-                                StatCollector.translateToLocal("item.structurelib.constructableTrigger.gui.info"))
-                                .spliterator(),
-                        false)
-                .flatMap(line -> fontRendererObj.listFormattedStringToWidth(line, width * 3 / 5).stream())
-                .collect(Collectors.toList());
     }
 
     @Override
@@ -298,8 +299,6 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
                     key.setText(autoCompleteList.getSelectedElement());
                     key.setFocused(false);
                     value.setFocused(true);
-                    value.setText("1");
-                    value.setSelectionPos(0);
                     return;
                 }
                 GuiButton add = getButtonList().get(ADD_BTN);
@@ -397,11 +396,6 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
         int topLeftY = (this.height - this.getYSize()) / 2;
         drawTexturedModalRect(topLeftX, topLeftY, 0, 0, getXSize(), getYSize());
         list.drawScreen(mX, mY, partialTick);
-        fontRendererObj.drawString(
-                I18n.format("item.structurelib.constructableTrigger.gui.title"),
-                guiLeft + 12,
-                guiTop + 9,
-                0);
         fontRendererObj.drawString(
                 I18n.format("item.structurelib.constructableTrigger.gui.key"),
                 guiLeft + 12,
@@ -436,11 +430,6 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
         if (highlight != null) {
             drawChannelDescriptionTooltip(highlight);
         }
-        if (mouseX > xSize + guiLeft - INFO_BOX_SIZE - 12 && mouseX < xSize + guiLeft - 12
-                && mouseY > guiTop + 7
-                && mouseY < guiTop + INFO_BOX_SIZE + 7) {
-            drawHoveringText(info, mouseX, mouseY, fontRendererObj);
-        }
     }
 
     private void drawChannelDescriptionTooltip(String candidate) {
@@ -448,6 +437,105 @@ public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScre
         drawHoveringText(tooltip, guiLeft + 151 + 12, guiTop + 122, fontRendererObj);
     }
 
+    public static void debugPrintGLEnable() {
+        Map<Integer, String> functions = ImmutableMap.<Integer, String>builder().put(GL11.GL_NEVER, "GL_NEVER")
+                .put(GL11.GL_LESS, "GL_LESS").put(GL11.GL_EQUAL, "GL_EQUAL").put(GL11.GL_LEQUAL, "GL_LEQUAL")
+                .put(GL11.GL_GREATER, "GL_GREATER").put(GL11.GL_NOTEQUAL, "GL_NOTEQUAL")
+                .put(GL11.GL_GEQUAL, "GL_GEQUAL").put(GL11.GL_ALWAYS, "GL_ALWAYS").put(GL11.GL_ZERO, "GL_ZERO")
+                .put(GL11.GL_ONE, "GL_ONE").put(GL11.GL_SRC_COLOR, "GL_SRC_COLOR")
+                .put(GL11.GL_ONE_MINUS_SRC_COLOR, "GL_ONE_MINUS_SRC_COLOR").put(GL11.GL_DST_COLOR, "GL_DST_COLOR")
+                .put(GL11.GL_ONE_MINUS_DST_COLOR, "GL_ONE_MINUS_DST_COLOR").put(GL11.GL_SRC_ALPHA, "GL_SRC_ALPHA")
+                .put(GL11.GL_ONE_MINUS_SRC_ALPHA, "GL_ONE_MINUS_SRC_ALPHA").put(GL11.GL_DST_ALPHA, "GL_DST_ALPHA")
+                .put(GL11.GL_ONE_MINUS_DST_ALPHA, "GL_ONE_MINUS_DST_ALPHA")
+                .put(GL11.GL_CONSTANT_COLOR, "GL_CONSTANT_COLOR")
+                .put(GL11.GL_ONE_MINUS_CONSTANT_COLOR, "GL_ONE_MINUS_CONSTANT_COLOR")
+                .put(GL11.GL_CONSTANT_ALPHA, "GL_CONSTANT_ALPHA")
+                .put(GL11.GL_ONE_MINUS_CONSTANT_ALPHA, "GL_ONE_MINUS_CONSTANT_ALPHA")
+                .put(GL11.GL_SRC_ALPHA_SATURATE, "GL_SRC_ALPHA_SATURATE").build();
+        System.out.println("GL_ALPHA_TEST: " + GL11.glIsEnabled(GL_ALPHA_TEST));
+        System.out.println("GL_AUTO_NORMAL: " + GL11.glIsEnabled(GL_AUTO_NORMAL));
+        System.out.println("GL_BLEND: " + GL11.glIsEnabled(GL_BLEND));
+        System.out.println("GL_COLOR_ARRAY: " + GL11.glIsEnabled(GL_COLOR_ARRAY));
+        System.out.println("GL_COLOR_LOGIC_OP: " + GL11.glIsEnabled(GL_COLOR_LOGIC_OP));
+        System.out.println("GL_COLOR_MATERIAL: " + GL11.glIsEnabled(GL_COLOR_MATERIAL));
+        System.out.println("GL_COLOR_SUM: " + GL11.glIsEnabled(GL_COLOR_SUM));
+        System.out.println("GL_COLOR_TABLE: " + GL11.glIsEnabled(GL_COLOR_TABLE));
+        System.out.println("GL_CONVOLUTION_1D: " + GL11.glIsEnabled(GL_CONVOLUTION_1D));
+        System.out.println("GL_CONVOLUTION_2D: " + GL11.glIsEnabled(GL_CONVOLUTION_2D));
+        System.out.println("GL_CULL_FACE: " + GL11.glIsEnabled(GL_CULL_FACE));
+        System.out.println("GL_DEPTH_TEST: " + GL11.glIsEnabled(GL_DEPTH_TEST));
+        System.out.println("GL_DITHER: " + GL11.glIsEnabled(GL_DITHER));
+        System.out.println("GL_EDGE_FLAG_ARRAY: " + GL11.glIsEnabled(GL_EDGE_FLAG_ARRAY));
+        System.out.println("GL_FOG: " + GL11.glIsEnabled(GL_FOG));
+        System.out.println("GL_FOG_COORD_ARRAY: " + GL11.glIsEnabled(GL_FOG_COORD_ARRAY));
+        System.out.println("GL_HISTOGRAM: " + GL11.glIsEnabled(GL_HISTOGRAM));
+        System.out.println("GL_INDEX_ARRAY: " + GL11.glIsEnabled(GL_INDEX_ARRAY));
+        System.out.println("GL_INDEX_LOGIC_OP: " + GL11.glIsEnabled(GL_INDEX_LOGIC_OP));
+        System.out.println("GL_LIGHTING: " + GL11.glIsEnabled(GL_LIGHTING));
+        System.out.println("GL_LINE_SMOOTH: " + GL11.glIsEnabled(GL_LINE_SMOOTH));
+        System.out.println("GL_LINE_STIPPLE: " + GL11.glIsEnabled(GL_LINE_STIPPLE));
+        System.out.println("GL_MAP1_COLOR_4: " + GL11.glIsEnabled(GL_MAP1_COLOR_4));
+        System.out.println("GL_MAP1_INDEX: " + GL11.glIsEnabled(GL_MAP1_INDEX));
+        System.out.println("GL_MAP1_NORMAL: " + GL11.glIsEnabled(GL_MAP1_NORMAL));
+        System.out.println("GL_MAP1_TEXTURE_COORD_1: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_1));
+        System.out.println("GL_MAP1_TEXTURE_COORD_2: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_2));
+        System.out.println("GL_MAP1_TEXTURE_COORD_3: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_3));
+        System.out.println("GL_MAP1_TEXTURE_COORD_4: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_4));
+        System.out.println("GL_MAP2_COLOR_4: " + GL11.glIsEnabled(GL_MAP2_COLOR_4));
+        System.out.println("GL_MAP2_INDEX: " + GL11.glIsEnabled(GL_MAP2_INDEX));
+        System.out.println("GL_MAP2_NORMAL: " + GL11.glIsEnabled(GL_MAP2_NORMAL));
+        System.out.println("GL_MAP2_TEXTURE_COORD_1: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_1));
+        System.out.println("GL_MAP2_TEXTURE_COORD_2: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_2));
+        System.out.println("GL_MAP2_TEXTURE_COORD_3: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_3));
+        System.out.println("GL_MAP2_TEXTURE_COORD_4: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_4));
+        System.out.println("GL_MAP2_VERTEX_3: " + GL11.glIsEnabled(GL_MAP2_VERTEX_3));
+        System.out.println("GL_MAP2_VERTEX_4: " + GL11.glIsEnabled(GL_MAP2_VERTEX_4));
+        System.out.println("GL_MINMAX: " + GL11.glIsEnabled(GL_MINMAX));
+        System.out.println("GL_MULTISAMPLE: " + GL11.glIsEnabled(GL_MULTISAMPLE));
+        System.out.println("GL_NORMAL_ARRAY: " + GL11.glIsEnabled(GL_NORMAL_ARRAY));
+        System.out.println("GL_NORMALIZE: " + GL11.glIsEnabled(GL_NORMALIZE));
+        System.out.println("GL_POINT_SMOOTH: " + GL11.glIsEnabled(GL_POINT_SMOOTH));
+        System.out.println("GL_POINT_SPRITE: " + GL11.glIsEnabled(GL_POINT_SPRITE));
+        System.out.println("GL_POLYGON_SMOOTH: " + GL11.glIsEnabled(GL_POLYGON_SMOOTH));
+        System.out.println("GL_POLYGON_OFFSET_FILL: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_FILL));
+        System.out.println("GL_POLYGON_OFFSET_LINE: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_LINE));
+        System.out.println("GL_POLYGON_OFFSET_POINT: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_POINT));
+        System.out.println("GL_POLYGON_STIPPLE: " + GL11.glIsEnabled(GL_POLYGON_STIPPLE));
+        System.out.println("GL_POST_COLOR_MATRIX_COLOR_TABLE: " + GL11.glIsEnabled(GL_POST_COLOR_MATRIX_COLOR_TABLE));
+        System.out.println("GL_POST_CONVOLUTION_COLOR_TABLE: " + GL11.glIsEnabled(GL_POST_CONVOLUTION_COLOR_TABLE));
+        System.out.println("GL_RESCALE_NORMAL: " + GL11.glIsEnabled(GL_RESCALE_NORMAL));
+        System.out.println("GL_SAMPLE_ALPHA_TO_COVERAGE: " + GL11.glIsEnabled(GL_SAMPLE_ALPHA_TO_COVERAGE));
+        System.out.println("GL_SAMPLE_ALPHA_TO_ONE: " + GL11.glIsEnabled(GL_SAMPLE_ALPHA_TO_ONE));
+        System.out.println("GL_SAMPLE_COVERAGE: " + GL11.glIsEnabled(GL_SAMPLE_COVERAGE));
+        System.out.println("GL_SCISSOR_TEST: " + GL11.glIsEnabled(GL_SCISSOR_TEST));
+        System.out.println("GL_SECONDARY_COLOR_ARRAY: " + GL11.glIsEnabled(GL_SECONDARY_COLOR_ARRAY));
+        System.out.println("GL_SEPARABLE_2D: " + GL11.glIsEnabled(GL_SEPARABLE_2D));
+        System.out.println("GL_STENCIL_TEST: " + GL11.glIsEnabled(GL_STENCIL_TEST));
+        System.out.println("GL_TEXTURE_1D: " + GL11.glIsEnabled(GL_TEXTURE_1D));
+        System.out.println("GL_TEXTURE_2D: " + GL11.glIsEnabled(GL_TEXTURE_2D));
+        System.out.println("GL_TEXTURE_3D: " + GL11.glIsEnabled(GL_TEXTURE_3D));
+        System.out.println("GL_TEXTURE_COORD_ARRAY: " + GL11.glIsEnabled(GL_TEXTURE_COORD_ARRAY));
+        System.out.println("GL_TEXTURE_CUBE_MAP: " + GL11.glIsEnabled(GL_TEXTURE_CUBE_MAP));
+        System.out.println("GL_TEXTURE_GEN_Q: " + GL11.glIsEnabled(GL_TEXTURE_GEN_Q));
+        System.out.println("GL_TEXTURE_GEN_R: " + GL11.glIsEnabled(GL_TEXTURE_GEN_R));
+        System.out.println("GL_TEXTURE_GEN_S: " + GL11.glIsEnabled(GL_TEXTURE_GEN_S));
+        System.out.println("GL_TEXTURE_GEN_T: " + GL11.glIsEnabled(GL_TEXTURE_GEN_T));
+        System.out.println("GL_VERTEX_ARRAY: " + GL11.glIsEnabled(GL_VERTEX_ARRAY));
+        System.out.println("GL_VERTEX_PROGRAM_POINT_SIZE: " + GL11.glIsEnabled(GL_VERTEX_PROGRAM_POINT_SIZE));
+        System.out.println("GL_VERTEX_PROGRAM_TWO_SIDE: " + GL11.glIsEnabled(GL_VERTEX_PROGRAM_TWO_SIDE));
+        System.out.println("Depth Function: " + functions.get(GL11.glGetInteger(GL_DEPTH_FUNC)));
+        System.out.printf(
+                "Blend Function: DST: Alpha %s RGB %s, SRC: Alpha %s RGB %s\n",
+                functions.get(GL11.glGetInteger(GL_BLEND_DST_ALPHA)),
+                functions.get(GL11.glGetInteger(GL_BLEND_DST_RGB)),
+                functions.get(GL11.glGetInteger(GL_BLEND_SRC_ALPHA)),
+                functions.get(GL11.glGetInteger(GL_BLEND_SRC_RGB)));
+        System.out.println(
+                "Alpha Test Function: " + functions.get(GL11.glGetInteger(GL_ALPHA_TEST_FUNC))
+                        + ", Reference: "
+                        + GL11.glGetDouble(GL11.GL_ALPHA_TEST_REF));
+    }
+
     private List<String> getChannelDescriptionTooltip(String candidate) {
         List<String> tooltip = new ArrayList<>();
         int maxLine = width - (guiLeft + 151 + 12) - 12;

src/main/java/com/gtnewhorizon/structurelib/item/ItemConstructableTrigger.java

@@ -7,9 +7,14 @@ import static net.minecraft.util.StatCollector.translateToLocalFormatted;
 
 import java.util.List;
 
+import net.minecraft.client.renderer.texture.IIconRegister;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.nbt.NBTTagInt;
+import net.minecraft.util.IIcon;
+import net.minecraft.util.StatCollector;
 import net.minecraft.world.World;
 
 import org.lwjgl.input.Keyboard;
@@ -20,12 +25,73 @@ import com.gtnewhorizon.structurelib.alignment.constructable.ConstructableUtilit
 
 public class ItemConstructableTrigger extends Item {
 
+    private static final String TAG_MODE = "mode";
+
+    private static final IIcon[] textures = new IIcon[3];
+
     public ItemConstructableTrigger() {
         setUnlocalizedName("structurelib.constructableTrigger");
-        setTextureName(MOD_ID + ":itemConstructableTrigger");
         setCreativeTab(StructureLib.creativeTab);
     }
 
+    public static void cycleMode(ItemStack held) {
+        if (held.getTagCompound() == null) held.setTagCompound(new NBTTagCompound());
+        if (!held.getTagCompound().hasKey(TAG_MODE)) held.getTagCompound().setTag(TAG_MODE, new NBTTagInt(0));
+        held.getTagCompound().setInteger(TAG_MODE, (held.getTagCompound().getInteger(TAG_MODE) + 1) % 3);
+    }
+
+    @Override
+    public void registerIcons(IIconRegister register) {
+        textures[0] = register.registerIcon(MOD_ID + ":constructableTrigger/BUILDING");
+        textures[1] = register.registerIcon(MOD_ID + ":constructableTrigger/UPDATING");
+        textures[2] = register.registerIcon(MOD_ID + ":constructableTrigger/REMOVING");
+    }
+
+    @Override
+    public IIcon getIcon(ItemStack stack, int renderPass, EntityPlayer player, ItemStack usingItem, int useRemaining) {
+        return getIcon(stack, renderPass);
+    }
+
+    @Override
+    public IIcon getIcon(ItemStack stack, int pass) {
+        if (!stack.hasTagCompound() || !stack.getTagCompound().hasKey(TAG_MODE)) {
+            return textures[0];
+        }
+        return textures[stack.getTagCompound().getInteger(TAG_MODE)];
+    }
+
+    @Override
+    public String getItemStackDisplayName(ItemStack stack) {
+        if (!stack.hasTagCompound() || !stack.getTagCompound().hasKey(TAG_MODE)) {
+            return getDisplayName(0);
+        }
+        return getDisplayName(stack.getTagCompound().getInteger(TAG_MODE));
+    }
+
+    @Override
+    public IIcon getIconIndex(ItemStack stack) {
+        return getIcon(stack, 0);
+    }
+
+    @Override
+    public IIcon getIconFromDamage(int damage) {
+        return textures[damage];
+    }
+
+    private String getDisplayName(int mode) {
+        return StatCollector.translateToLocal("item.structurelib.constructableTrigger.name") + " - "
+                + StatCollector.translateToLocal("item.structurelib.constructableTrigger.modes." + mode);
+    }
+
+    public static int getMode(ItemStack held) {
+        if (held == null || !held.hasTagCompound() || !held.getTagCompound().hasKey(TAG_MODE)) {
+            // default behavior
+            return 0;
+        }
+        // get user-defined mode
+        return held.getTagCompound().getInteger(TAG_MODE);
+    }
+
     @Override
     public ItemStack onItemRightClick(ItemStack stack, World world, EntityPlayer player) {
         if (!world.isRemote && getMovingObjectPositionFromPlayer(world, player, true) == null) {

src/main/java/com/gtnewhorizon/structurelib/net/StructureProjectorCycleModeMessage.java

@@ -0,0 +1,37 @@
+package com.gtnewhorizon.structurelib.net;
+
+import net.minecraft.entity.player.EntityPlayerMP;
+import net.minecraft.item.ItemStack;
+
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
+
+import cpw.mods.fml.common.network.simpleimpl.IMessage;
+import cpw.mods.fml.common.network.simpleimpl.IMessageHandler;
+import cpw.mods.fml.common.network.simpleimpl.MessageContext;
+import io.netty.buffer.ByteBuf;
+
+public class StructureProjectorCycleModeMessage implements IMessage {
+
+    @Override
+    public void fromBytes(ByteBuf buf) {
+        // no op
+    }
+
+    @Override
+    public void toBytes(ByteBuf buf) {
+        // no op
+    }
+
+    public static class Handler implements IMessageHandler<StructureProjectorCycleModeMessage, IMessage> {
+
+        @Override
+        public IMessage onMessage(StructureProjectorCycleModeMessage message, MessageContext ctx) {
+            EntityPlayerMP player = ctx.getServerHandler().playerEntity;
+            final ItemStack held = player.getHeldItem();
+            if (held != null && held.getItem() instanceof ItemConstructableTrigger) {
+                ItemConstructableTrigger.cycleMode(held);
+            }
+            return null;
+        }
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/structure/IStructureDefinition.java

@@ -348,77 +348,47 @@ public interface IStructureDefinition<T> {
         }
 
         if (checkBlocksIfNotNullForceCheckAllIfTrue != null) {
-            boolean success;
-            if (checkBlocksIfNotNullForceCheckAllIfTrue) {
-                success = StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        (e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z),
-                        "check");
-            } else {
-                success = StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        skipBlockUnloaded((e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)),
-                        "check force");
-            }
+            boolean success = StructureUtility.iterateV2(
+                    elements,
+                    world,
+                    extendedFacing,
+                    basePositionX,
+                    basePositionY,
+                    basePositionZ,
+                    basePositionA,
+                    basePositionB,
+                    basePositionC,
+                    checkBlocksIfNotNullForceCheckAllIfTrue ? (e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)
+                            : skipBlockUnloaded((e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)),
+                    checkBlocksIfNotNullForceCheckAllIfTrue ? "check" : "check force");
             if (StructureLibAPI.isDebugEnabled() && success) {
                 StructureLib.LOGGER
                         .info("Multi [" + basePositionX + ", " + basePositionY + ", " + basePositionZ + "] pass");
             }
             return success;
         } else {
-            if (hintsOnly) {
-                StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
-                            e.spawnHint(object, world, x, y, z, trigger);
-                            if (ChannelDataAccessor.hasSubChannel(trigger, StructureLibAPI.CHANNEL_SHOW_ERROR)
-                                    && !e.couldBeValid(object, world, x, y, z, trigger)) {
-                                StructureLibAPI.markHintParticleError(StructureLib.getCurrentPlayer(), world, x, y, z);
-                            }
-                            return true;
-                        }),
-                        "spawnHint");
-            } else {
-                StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
-                            e.placeBlock(object, world, x, y, z, trigger);
-                            return true;
-                        }),
-                        "placeBlock");
-            }
+            StructureUtility.iterateV2(
+                    elements,
+                    world,
+                    extendedFacing,
+                    basePositionX,
+                    basePositionY,
+                    basePositionZ,
+                    basePositionA,
+                    basePositionB,
+                    basePositionC,
+                    hintsOnly ? ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
+                        e.spawnHint(object, world, x, y, z, trigger);
+                        if (ChannelDataAccessor.hasSubChannel(trigger, StructureLibAPI.CHANNEL_SHOW_ERROR)
+                                && !e.couldBeValid(object, world, x, y, z, trigger)) {
+                            StructureLibAPI.markHintParticleError(StructureLib.getCurrentPlayer(), world, x, y, z);
+                        }
+                        return true;
+                    }) : ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
+                        e.placeBlock(object, world, x, y, z, trigger);
+                        return true;
+                    }),
+                    hintsOnly ? "spawnHint" : "placeBlock");
         }
         return true;
     }

src/main/java/com/gtnewhorizon/structurelib/structure/IStructureElement.java

@@ -21,6 +21,7 @@ import net.minecraft.util.IChatComponent;
 import net.minecraft.world.World;
 
 import com.gtnewhorizon.structurelib.StructureLibAPI;
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
 import com.gtnewhorizon.structurelib.util.ItemStackPredicate;
 import com.gtnewhorizon.structurelib.util.ItemStackPredicate.NBTMode;
 
@@ -137,12 +138,13 @@ public interface IStructureElement<T> {
      */
     default PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
             AutoPlaceEnvironment env) {
+        int mode = ItemConstructableTrigger.getMode(trigger);
         BlocksToPlace e = getBlocksToPlace(t, world, x, y, z, trigger, env);
         IItemSource source = env.getSource();
         EntityPlayer actor = env.getActor();
         Consumer<IChatComponent> chatter = env.getChatter();
         if (e != null) {
-            if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+            if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
             if (e.getStacks() == null) {
                 ItemStack taken = source.takeOne(e.getPredicate(), true);
                 return StructureUtility.survivalPlaceBlock(
@@ -159,7 +161,7 @@ public interface IStructureElement<T> {
                         chatter);
             }
             for (ItemStack stack : e.getStacks()) {
-                if (!source.takeOne(stack, true)) continue;
+                if (mode < 2 && !source.takeOne(stack, true)) continue;
                 return StructureUtility.survivalPlaceBlock(
                         stack,
                         NBTMode.EXACT,

src/main/java/com/gtnewhorizon/structurelib/structure/StructureUtility.java

@@ -28,6 +28,7 @@ import java.util.function.Supplier;
 import javax.annotation.Nullable;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.init.Blocks;
@@ -51,6 +52,7 @@ import com.gtnewhorizon.structurelib.StructureLib;
 import com.gtnewhorizon.structurelib.StructureLibAPI;
 import com.gtnewhorizon.structurelib.alignment.constructable.ChannelDataAccessor;
 import com.gtnewhorizon.structurelib.alignment.enumerable.ExtendedFacing;
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
 import com.gtnewhorizon.structurelib.structure.IStructureElement.PlaceResult;
 import com.gtnewhorizon.structurelib.structure.adders.IBlockAdder;
 import com.gtnewhorizon.structurelib.structure.adders.ITileAdder;
@@ -206,7 +208,11 @@ public class StructureUtility {
 
         @Override
         public boolean placeBlock(Object o, World world, int x, int y, int z, ItemStack trigger) {
-            world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2);
+            placeRemoveOrUpdate(
+                    trigger,
+                    () -> world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2),
+                    () -> world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2),
+                    () -> world.setBlock(x, y, z, Blocks.air, 0, 2));
             return true;
         }
 
@@ -219,11 +225,16 @@ public class StructureUtility {
         @Override
         public PlaceResult survivalPlaceBlock(Object o, World world, int x, int y, int z, ItemStack trigger,
                 AutoPlaceEnvironment env) {
-            if (check(o, world, x, y, z)) return PlaceResult.SKIP;
+            int mode = ItemConstructableTrigger.getMode(trigger);
+            if (mode < 2 && check(o, world, x, y, z)) return PlaceResult.SKIP;
             // user should place anything here.
             // maybe make this configurable, but for now we try to take some cobble from user
             if (env.getSource().takeOne(new ItemStack(Blocks.cobblestone), false)) {
-                world.setBlock(x, y, z, Blocks.cobblestone, 0, 2);
+                placeRemoveOrUpdate(
+                        trigger,
+                        () -> world.setBlock(x, y, z, Blocks.cobblestone, 0, 2),
+                        () -> world.setBlock(x, y, z, Blocks.cobblestone, 0, 2),
+                        () -> world.setBlock(x, y, z, Blocks.air, 0, 2));
             }
             return PlaceResult.REJECT;
         }
@@ -330,29 +341,75 @@ public class StructureUtility {
     public static PlaceResult survivalPlaceBlock(Block block, int meta, World world, int x, int y, int z, IItemSource s,
             EntityPlayer actor, Consumer<IChatComponent> chatter) {
         if (block == null) throw new NullPointerException();
-        if (!StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        int mode = 0;
+        if (actor.getHeldItem() != null && actor.getHeldItem().getItem() instanceof ItemConstructableTrigger) {
+            // best effort lookup if the item in the player's hand is a trigger, and if it is, get the mode from the
+            // ...trigger instead of assuming default behavior
+            mode = ItemConstructableTrigger.getMode(actor.getHeldItem());
+        }
+        if (mode == 0 && !StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        if (mode == 1 && world.getTileEntity(x, y, z) instanceof TileEntity) {
+            // We're in updating mode and the block we're looking at might be important, so let's just leave it alone
+            // since it's probably not something we want to replace with something else
+            return PlaceResult.SKIP;
+        }
         Item itemBlock = Item.getItemFromBlock(block);
         int itemMeta = itemBlock instanceof ISpecialItemBlock
                 ? ((ISpecialItemBlock) itemBlock).getItemMetaFromBlockMeta(block, meta)
                 : meta;
         ItemStack stack = new ItemStack(itemBlock, 1, itemMeta);
-        if (!s.takeOne(stack, true)) {
+        if (mode == 1 && !world.isAirBlock(x, y, z)) {
+            Block blockInWorld = world.getBlock(x, y, z);
+            if (blockInWorld.isAssociatedBlock(block) && blockInWorld.getDamageValue(world, x, y, z) == meta) {
+                // This is the block we are looking for, move along
+                return PlaceResult.SKIP;
+            }
+        }
+        if (mode < 2 && !s.takeOne(stack, true)) {
             if (chatter != null) chatter.accept(
                     new ChatComponentTranslation(
                             "structurelib.autoplace.error.no_simple_block",
                             stack.func_151000_E()));
             return PlaceResult.REJECT;
         }
-        if (block instanceof ICustomBlockSetting) {
-            ICustomBlockSetting blockCustom = (ICustomBlockSetting) block;
-            blockCustom.setBlock(world, x, y, z, meta);
-        } else if (!stack.copy()
-                .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
+        if (mode < 2) {
+            if (block instanceof ICustomBlockSetting) {
+                ICustomBlockSetting blockCustom = (ICustomBlockSetting) block;
+                blockCustom.setBlock(world, x, y, z, meta);
+            } else {
+                if (mode == 1 && !world.isAirBlock(x, y, z)) {
+                    // We're in updating mode and there's a block in our way (grr), so let's remove whatever is there
+                    // ...and drop it to the player
+                    ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+                    toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
+                    if (!world.setBlock(x, y, z, Blocks.air, 0, 4) || !tryGiveOrDropItem(world, actor, toGive)) {
+                        // We either weren't able to give the player the block that was there, or we weren't able to
+                        // remove
+                        // the block, either way, we need to reject the update. Also, since we hid the block update from
+                        // the client in an effort to make the exchange as seamless as possible, we need to now notify
+                        // the client if we did successfully remove the block.
+                        if (world.isAirBlock(x, y, z)) world.notifyBlockChange(x, y, z, Blocks.air);
+                        return PlaceResult.REJECT;
+                    }
+                }
+                if (!stack.copy()
+                        .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
                     return PlaceResult.REJECT;
                 }
-        if (!s.takeOne(stack, false)) {
-            // rollback
+            }
+        }
+        if (mode == 2 && world.isAirBlock(x, y, z)) {
+            return PlaceResult.SKIP;
+        }
+        if (mode == 2 || !s.takeOne(stack, false)) {
+            // If the user didn't have the item in their inventory, or we're in removing mode, we set it to air
+            ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+            toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
             world.setBlockToAir(x, y, z);
+            if (mode == 2 && !tryGiveOrDropItem(world, actor, toGive)) {
+                // Something went wrong while trying to give the player the block we removed, let's just fail for now
+                return PlaceResult.REJECT;
+            }
         }
         return PlaceResult.ACCEPT;
     }
@@ -444,24 +501,74 @@ public class StructureUtility {
         if (stack == null) throw new NullPointerException();
         if (stack.stackSize != 1) throw new IllegalArgumentException();
         if (!(stack.getItem() instanceof ItemBlock)) throw new IllegalArgumentException();
-        if (!StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
-        if (!assumeStackPresent && !s.takeOne(stack, true)) {
+        int mode = 0;
+        if (actor.getHeldItem() != null && actor.getHeldItem().getItem() instanceof ItemConstructableTrigger) {
+            // best effort lookup if the item in the player's hand is a trigger, and if it is, get the mode from the
+            // ...trigger instead of assuming default behavior
+            mode = ItemConstructableTrigger.getMode(actor.getHeldItem());
+        }
+        if (mode == 1 && !world.isAirBlock(x, y, z)) {
+            if (world.getTileEntity(x, y, z) instanceof TileEntity) {
+                // We're in updating mode and the block we're looking at might be important, so let's just leave it
+                // alone
+                // since it's probably not something we want to replace with something else
+                return PlaceResult.SKIP;
+            }
+            Block blockInWorld = world.getBlock(x, y, z);
+            ItemStack blockInWorldItem = new ItemStack(blockInWorld);
+            blockInWorldItem.setItemDamage(blockInWorld.getDamageValue(world, x, y, z));
+            if (blockInWorldItem.isItemEqual(stack)) {
+                // This is the block we are looking for, move along
+                return PlaceResult.SKIP;
+            }
+        }
+        if (mode == 0 && !StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        if (mode < 2 && !assumeStackPresent && !s.takeOne(stack, true)) {
             if (chatter != null) chatter.accept(
                     new ChatComponentTranslation("structurelib.autoplace.error.no_item_stack", stack.func_151000_E()));
             return PlaceResult.REJECT;
         }
-        if (!stack.copy().tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f))
-            return PlaceResult.REJECT;
-        if (!s.takeOne(stack, false))
-            // this is bad! probably an exploit somehow. Let's nullify the block we just placed instead
+        if (mode < 2) {
+            if (mode == 1 && !world.isAirBlock(x, y, z)) {
+                // We're in updating mode and there's a block in our way (grr), so let's remove whatever is there
+                // ...and drop it to the player
+                ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+                toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
+                if (!world.setBlock(x, y, z, Blocks.air, 0, 4) || !tryGiveOrDropItem(world, actor, toGive)) {
+                    // We either weren't able to give the player the block that was there, or we weren't able to remove
+                    // the block, either way, we need to reject the update. Also, since we hid the block update from
+                    // the client in an effort to make the exchange as seamless as possible, we need to now notify
+                    // the client if we did successfully remove the block.
+                    if (world.isAirBlock(x, y, z)) world.notifyBlockChange(x, y, z, Blocks.air);
+                    return PlaceResult.REJECT;
+                }
+            }
+            if (!stack.copy()
+                    .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
+                return PlaceResult.REJECT;
+            }
+        }
+        if (mode == 2 && world.isAirBlock(x, y, z)) {
+            return PlaceResult.SKIP;
+        }
+        if (mode == 2 || !s.takeOne(stack, false)) {
+            // If the user didn't have the item in their inventory, or we're in removing mode, we set it to air
+            ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+            toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
             world.setBlockToAir(x, y, z);
+            if (mode == 2 && !tryGiveOrDropItem(world, actor, toGive)) {
+                // We were in removing mode and something went wrong while trying to give the player the block we
+                // ...removed, let's just fail for now
+                return PlaceResult.REJECT;
+            }
+        }
         return PlaceResult.ACCEPT;
     }
 
     /**
      * Return a structure element that only allow air (or air equivalents, like Railcraft hidden blocks). You usually
-     * don't need to call this yourselves. Use {@code -} in shape to automatically use this. Provided nontheless in case
-     * you want this as a fallback to something else.
+     * don't need to call this yourselves. Use {@code -} in shape to automatically use this. Provided nonetheless in
+     * case you want this as a fallback to something else.
      */
     @SuppressWarnings("unchecked")
     public static <T> IStructureElement<T> isAir() {
@@ -470,8 +577,8 @@ public class StructureUtility {
 
     /**
      * Return a structure element that allow anything but air (or air equivalents, like Railcraft hidden blocks). You
-     * usually don't need to call this yourselves. Use {@code +} in shape to automatically use this. Provided nontheless
-     * in case you want this as a fallback to something else.
+     * usually don't need to call this yourselves. Use {@code +} in shape to automatically use this. Provided
+     * nonetheless in case you want this as a fallback to something else.
      */
     @SuppressWarnings("unchecked")
     public static <T> IStructureElement<T> notAir() {
@@ -637,20 +744,7 @@ public class StructureUtility {
      * given tier, then player will be allowed to use multiple kinds of blocks, but their tier is guaranteed to be the
      * same.
      * <p>
-     * <h3>WARNING</h3> <b>You SHOULD NOT return notSet from your tierExtractor.</b> If you do so, we will have this
-     * chain of events:
-     * <ul>
-     * <li>at check start, tier is reset to notSet
-     * <li>the tier extractor returns notSet for first block, so since ofBlocksTiered finds your current tier is notSet,
-     * and the new block's tier is the same as that, so it's accepted
-     * <li>at 2nd, 3rd..., same thing in 2 happens
-     * <li>at last occurrence, player placed a valid block with a tier not notSet. ofBlocksTiered now sets your current
-     * tier to this tier, and accept the block
-     * <li>check got notified structure is sound, and tier is not notSet. it marks the structure as complete and start
-     * doing its business
-     * <li>Player enjoy a (probably) hilariously shaped multi and (probably) reduced build cost.
-     * </ul>
-     * <h3>Example Implementation</h3>
+     * <b>Example Implementation:</b>
      * <p>
      * Assume you have 16 tier, each map to one particular block's 16 different meta. You will usually want something
      * like this
@@ -677,7 +771,7 @@ public class StructureUtility {
      * }
      * </pre>
      *
-     * Important bits of this example implementation:
+     * Important bits:
      * <ul>
      * <li>The supplied ITierConverter returns null for an invalid block</li>
      * <li>Possible tier returned by ITierConverter is Integer object 0 to 15.</li>
@@ -686,8 +780,19 @@ public class StructureUtility {
      * <li>notSet is never a tier returned by ITierConverter.</li>
      * </ul>
      * <p>
-     * As a friendly reminder, the above characteristics are only for this simply demo, not as a general restriction
-     * imposed by ofBlocksTiered.
+     * <p>
+     * <b>You SHOULD NOT return notSet from your tierExtractor.</b> If you do so, we will have this chain of events:
+     * <ul>
+     * <li>at check start, tier is reset to notSet
+     * <li>the tier extractor returns notSet for first block, so since ofBlocksTiered finds your current tier is notSet,
+     * and the new block's tier is the same as that, so it's accepted
+     * <li>at 2nd, 3rd..., same thing in 2 happens
+     * <li>at last occurrence, player placed a valid block with a tier not notSet. ofBlocksTiered now sets your current
+     * tier to this tier, and accept the block
+     * <li>check got notified structure is sound, and tier is not notSet. it marks the structure as complete and start
+     * doing its business
+     * <li>Player enjoy a (probably) hilariously shaped multi and (probably) reduced build cost.
+     * </ul>
      *
      * @param tierExtractor a function to extract tier info from a block. This function can return null and will never
      *                      be passed a null block or an invalid block meta. If this function returns null, then the
@@ -709,7 +814,7 @@ public class StructureUtility {
         List<Pair<Block, Integer>> hints = allKnownTiers == null ? Collections.emptyList() : allKnownTiers;
         if (hints.stream().anyMatch(Objects::isNull)) throw new IllegalArgumentException();
         IStructureElementCheckOnly<T> check = ofBlocksTiered(tierExtractor, notSet, setter, getter);
-        return new StructureElement_Bridge<T>() {
+        return new StructureElement_Bridge<>() {
 
             @Override
             public boolean check(T t, World world, int x, int y, int z) {
@@ -766,12 +871,13 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
+                int mode = ItemConstructableTrigger.getMode(trigger);
                 Pair<Block, Integer> hint = getHint(trigger);
                 if (hint == null) return PlaceResult.REJECT; // TODO or SKIP?
                 Block block = world.getBlock(x, y, z);
                 int meta = world.getBlockMetadata(x, y, z);
                 TIER tier = tierExtractor.convert(block, meta);
-                if (Objects.equals(tier, tierExtractor.convert(hint.getKey(), hint.getValue())))
+                if (mode < 2 && Objects.equals(tier, tierExtractor.convert(hint.getKey(), hint.getValue())))
                     return PlaceResult.SKIP;
                 return StructureUtility.survivalPlaceBlock(
                         hint.getKey(),
@@ -861,7 +967,8 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (getBlock() == null) return PlaceResult.REJECT;
                 return StructureUtility.survivalPlaceBlock(
                         getBlock(),
@@ -948,7 +1055,8 @@ public class StructureUtility {
             @Deprecated
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     IItemSource s, EntityPlayerMP actor, Consumer<IChatComponent> chatter) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (init()) return StructureUtility.survivalPlaceBlock(block, meta, world, x, y, z, s, actor, chatter);
                 return fallback.survivalPlaceBlock(t, world, x, y, z, trigger, s, actor, chatter);
             }
@@ -956,7 +1064,8 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (init()) return StructureUtility.survivalPlaceBlock(
                         block,
                         meta,
@@ -1584,7 +1693,9 @@ public class StructureUtility {
                 @Deprecated
                 public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                         AutoPlaceEnvironment env) {
-                    if (world.getBlock(x, y, z) == defaultBlock && world.getBlockMetadata(x, y, z) == defaultMeta)
+                    int mode = ItemConstructableTrigger.getMode(trigger);
+                    if (mode < 2 && world.getBlock(x, y, z) == defaultBlock
+                            && world.getBlockMetadata(x, y, z) == defaultMeta)
                         return PlaceResult.SKIP;
                     return StructureUtility.survivalPlaceBlock(
                             defaultBlock,
@@ -1630,7 +1741,9 @@ public class StructureUtility {
                 @Deprecated
                 public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                         AutoPlaceEnvironment env) {
-                    if (world.getBlock(x, y, z) == defaultBlock && world.getBlockMetadata(x, y, z) == defaultMeta)
+                    int mode = ItemConstructableTrigger.getMode(trigger);
+                    if (mode < 2 && world.getBlock(x, y, z) == defaultBlock
+                            && world.getBlockMetadata(x, y, z) == defaultMeta)
                         return PlaceResult.SKIP;
                     return StructureUtility.survivalPlaceBlock(
                             defaultBlock,
@@ -1890,7 +2003,8 @@ public class StructureUtility {
             @Deprecated
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     IItemSource s, EntityPlayerMP actor, Consumer<IChatComponent> chatter) {
-                if (predicate.test(t))
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode == 2 || predicate.test(t))
                     return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, s, actor, chatter);
                 return placeResultWhenDisabled;
             }
@@ -1898,7 +2012,9 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (predicate.test(t)) return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, env);
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode == 2 || predicate.test(t))
+                    return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, env);
                 return placeResultWhenDisabled;
             }
         };
@@ -3265,4 +3381,35 @@ public class StructureUtility {
         }
         return shape;
     }
+
+    /**
+     * Performs a creation, removal, or update operation at the given position
+     *
+     * @param trigger  ItemStack for the trigger item
+     * @param onCreate Operation to be performed when the mode of the trigger is set to building mode
+     * @param onUpdate Operation to be performed when the mode of the trigger is set to updating mode
+     * @param onRemove Operation to be performed when the mode of the trigger is set to removing mode
+     */
+    public static void placeRemoveOrUpdate(ItemStack trigger, Runnable onCreate, Runnable onUpdate, Runnable onRemove) {
+        int mode = ItemConstructableTrigger.getMode(trigger);
+        switch (mode) {
+            case 0:
+                onCreate.run();
+                break;
+            case 1:
+                onUpdate.run();
+                break;
+            case 2:
+                onRemove.run();
+                break;
+        }
+    }
+
+    public static boolean tryGiveOrDropItem(World world, EntityPlayer actor, ItemStack stack) {
+        if (actor.inventory.addItemStackToInventory(stack)) {
+            actor.inventoryContainer.detectAndSendChanges();
+            return true;
+        }
+        return world.spawnEntityInWorld(new EntityItem(world, actor.posX, actor.posY, actor.posZ, stack));
+    }
 }

src/main/resources/assets/structurelib/lang/en_US.lang

@@ -22,6 +22,9 @@ item.structurelib.frontRotationTool.desc.1=Rotates only the front panel,
 item.structurelib.frontRotationTool.desc.2=which allows structure rotation.
 
 item.structurelib.constructableTrigger.name=Multiblock Structure Hologram Projector
+item.structurelib.constructableTrigger.modes.0=Building Mode
+item.structurelib.constructableTrigger.modes.1=Updating Mode
+item.structurelib.constructableTrigger.modes.2=Removing Mode
 item.structurelib.constructableTrigger.desc.0=Triggers Constructable Interface
 item.structurelib.constructableTrigger.desc.1=Shows multiblock construction schematic,
 item.structurelib.constructableTrigger.desc.2=use on the multiblock controller.
@@ -30,20 +33,23 @@ item.structurelib.constructableTrigger.desc.4=Quantity of schematics in item sta
 item.structurelib.constructableTrigger.desc.5=Hold §l[LSHIFT]§r to display channel data
 item.structurelib.constructableTrigger.desc.lshift.0=Contain %d sub channel.
 item.structurelib.constructableTrigger.too_fast=Please wait %d milliseconds before another autoplace...
-item.structurelib.constructableTrigger.gui.title=Sub Channels
 item.structurelib.constructableTrigger.gui.key=Key:
 item.structurelib.constructableTrigger.gui.value=Value:
 item.structurelib.constructableTrigger.gui.add=Add
 item.structurelib.constructableTrigger.gui.set=Set
 item.structurelib.constructableTrigger.gui.unset=Unset
 item.structurelib.constructableTrigger.gui.wipe=§4Wipe
+item.structurelib.constructableTrigger.gui.error.show=Show Errors
+item.structurelib.constructableTrigger.gui.error.hide=Hide Errors
+item.structurelib.constructableTrigger.gui.gt_no_hatch.enable=No Hatch
+item.structurelib.constructableTrigger.gui.gt_no_hatch.disable=Hatches
+item.structurelib.constructableTrigger.keyCategory=Multiblock Structure Hologram Projector Keys
+item.structurelib.constructableTrigger.keys.cycleMode=Cycle Projector Mode
 item.structurelib.constructableTrigger.gui.channels.from=§rMod: §9§o%s
-item.structurelib.constructableTrigger.gui.info=Many multiblocks support some degree of variation in its structure and use sub channels to indicate which variant to use.\n Sub channels are has a sequence of lower case characters as key and a positive integer as value. Most known sub channels should be available as typeahead completions.\nYou can also drag and drop items from NEI to set the corresponding sub channel value. These items all have a tooltip of §oIndicates value X for sub channel Y§r.
 
 channels.structurelib.show_errors=When set, will highlight parts of the multiblock that is definitely wrong
 
 structurelib.tooltip.channelvalue=§7Indicates value §6%d§r§7 for sub channel §6%s
-structurelib.tooltip.indicator_dnd=Drop into GUI to select this value for this channel
 
 structurelib.autoplace.built_stat=Built %s blocks
 structurelib.autoplace.complete=§aThis multiblock has completed!

src/main/resources/assets/structurelib/lang/zh_CN.lang

@@ -30,7 +30,6 @@ item.structurelib.constructableTrigger.desc.4=此物品堆叠数量会影响显
 item.structurelib.constructableTrigger.desc.5=按下 §l[左SHIFT]§r 以显示子信道
 item.structurelib.constructableTrigger.desc.lshift.0=包含 %d 个子信道
 item.structurelib.constructableTrigger.too_fast=请在下一次自动搭建前等待 %d 毫秒...
-item.structurelib.constructableTrigger.gui.title=子信道
 item.structurelib.constructableTrigger.gui.key=信道名:
 item.structurelib.constructableTrigger.gui.value=值:
 item.structurelib.constructableTrigger.gui.add=添加
@@ -38,12 +37,10 @@ item.structurelib.constructableTrigger.gui.set=替换
 item.structurelib.constructableTrigger.gui.unset=删除
 item.structurelib.constructableTrigger.gui.wipe=§4全部清空
 item.structurelib.constructableTrigger.gui.channels.from=§r模组: §9§o%s
-item.structurelib.constructableTrigger.gui.info=许多多方块的结构都是可变的，在自动放置时，可以使用子信道来向多方块指明该使用哪一个变体。\n子信道由一个字符串标识、并拥有一个正整数作为值。这个GUI中的信道名支持自动补全到绝大多数已知的子信道。\n你也可以将部分物品从NEI中拖拽至GUI内来设置子信道值为该物品表示的值。这些物品的物品说明中都带有§o表示子信道 X 为 Y§r。
 
 channels.structurelib.show_errors=添加后，在投影时会高亮标出必然错误的部分
 
 structurelib.tooltip.channelvalue=§7表示子信道 §6%2$s§r§7 为 §6%d§r
-structurelib.tooltip.indicator_dnd=拖入GUI中来选择该值
 
 structurelib.autoplace.built_stat=已放置 %s 个方块
 structurelib.autoplace.complete=§a这个多方块结构已经完成自动搭建！