combat folia anti-cheat

src/main/java/com/github/sebseb7/autotrade/event/AutoTradeClientTick.java

@@ -37,10 +37,12 @@ import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.trading.MerchantOffer;
 import net.minecraft.world.item.trading.MerchantOffers;
+import net.minecraft.world.level.ClipContext;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.phys.AABB;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.EntityHitResult;
+import net.minecraft.world.phys.HitResult;
 import net.minecraft.world.phys.Vec3;
 
 final class AutoTradeClientTick {
@@ -68,6 +70,16 @@ final class AutoTradeClientTick {
 	private int outputContainerHighlightTicks = 0;
 	private int postMerchantInventorySyncTicks = 0;
 
+	/**
+	 * Entity we have already snapped the camera onto and are waiting for line of
+	 * sight to clear on. Prevents re-rotating to the same villager every tick
+	 * while a block briefly obstructs the view; reset once we interact (or after
+	 * a timeout) so the next villager can be acquired.
+	 */
+	private int rotatingTargetId = -1;
+	private int rotatingTargetTicks = 0;
+	private static final int LOS_TIMEOUT_TICKS = 60;
+
 	/**
 	 * Entity to draw in-world highlight for; {@code null} when inactive or unknown
 	 * id.
@@ -157,20 +169,38 @@ final class AutoTradeClientTick {
 					if (!found) {
 						if (!newVillagersInRange.contains(entity)) {
 							found = true;
-							newVillagersInRange.add(entity);
 							// Paper/Folia rejects entity-interact packets unless the player is
-							// actually facing the entity, so align the look vector first and
+							// actually facing a visible part of the entity hitbox. Aim at any
-							// mirror vanilla's full INTERACT_AT + INTERACT + swing sequence.
+							// point we have a clean line of sight to (eyes, head, chest, feet);
+							// if none of them are visible yet, wait without flooding the camera
+							// with re-rotations every tick.
+							Vec3 aimPoint = firstVisiblePoint(mc, entity);
+							if (rotatingTargetId != entity.getId()) {
+								rotatingTargetId = entity.getId();
+								rotatingTargetTicks = 0;
+								Vec3 lookAt = aimPoint != null ? aimPoint : entity.getEyePosition();
 								Vec3 eyePos = mc.player.getEyePosition();
-							Vec3 targetEye = entity.getEyePosition();
+								Vec3 delta = lookAt.subtract(eyePos);
-							Vec3 delta = targetEye.subtract(eyePos);
 								double horiz = Math.sqrt(delta.x * delta.x + delta.z * delta.z);
 								float yaw = (float) (Math.toDegrees(Math.atan2(delta.z, delta.x)) - 90.0);
 								float pitch = (float) -Math.toDegrees(Math.atan2(delta.y, horiz));
 								mc.player.setYRot(yaw);
 								mc.player.setXRot(pitch);
 								mc.player.yHeadRot = yaw;
-							EntityHitResult ehr = new EntityHitResult(entity, targetEye);
+							} else {
+								rotatingTargetTicks++;
+							}
+							if (aimPoint == null) {
+								if (rotatingTargetTicks > LOS_TIMEOUT_TICKS) {
+									// Give up so the player can move past this villager.
+									newVillagersInRange.add(entity);
+									rotatingTargetId = -1;
+								}
+								break;
+							}
+							newVillagersInRange.add(entity);
+							rotatingTargetId = -1;
+							EntityHitResult ehr = new EntityHitResult(entity, aimPoint);
 							AutoTrade.autoInteracting = true;
 							try {
 								//? if mc26 {
@@ -459,6 +489,38 @@ final class AutoTradeClientTick {
 		traderGlowTicksRemaining = TRADER_HIGHLIGHT_TICKS;
 	}
 
+	/**
+	 * Returns the first point on {@code target}'s bounding box (eyes, head,
+	 * chest, feet, or one of the four upper corners) that has an unobstructed
+	 * block ray-cast from the player's eyes; {@code null} when the entire body
+	 * is occluded.
+	 */
+	private static Vec3 firstVisiblePoint(Minecraft mc, Entity target) {
+		Vec3 eye = mc.player.getEyePosition();
+		AABB box = target.getBoundingBox();
+		double cx = (box.minX + box.maxX) * 0.5;
+		double cz = (box.minZ + box.maxZ) * 0.5;
+		Vec3[] candidates = {
+				target.getEyePosition(),
+				new Vec3(cx, (box.minY + box.maxY) * 0.5, cz),
+				new Vec3(cx, box.maxY - 0.05, cz),
+				new Vec3(cx, box.minY + 0.1, cz),
+				new Vec3(box.minX + 0.05, box.maxY - 0.2, box.minZ + 0.05),
+				new Vec3(box.maxX - 0.05, box.maxY - 0.2, box.minZ + 0.05),
+				new Vec3(box.minX + 0.05, box.maxY - 0.2, box.maxZ - 0.05),
+				new Vec3(box.maxX - 0.05, box.maxY - 0.2, box.maxZ - 0.05),
+		};
+		for (Vec3 p : candidates) {
+			BlockHitResult hit = mc.level.clip(new ClipContext(eye, p, ClipContext.Block.COLLIDER,
+					ClipContext.Fluid.NONE, mc.player));
+			if (hit.getType() == HitResult.Type.MISS
+					|| eye.distanceToSqr(hit.getLocation()) >= eye.distanceToSqr(p) - 1.0E-4) {
+				return p;
+			}
+		}
+		return null;
+	}
+
 	private static Entity findEntityById(Minecraft mc, int entityId) {
 		for (Entity e : mc.level.entitiesForRendering()) {
 			if (e.getId() == entityId) {

src/main/java/com/github/sebseb7/autotrade/gui/MerchantScreenButtonInjector.java

@@ -12,6 +12,7 @@ import net.fabricmc.fabric.api.client.screen.v1.ScreenEvents;
 import net.fabricmc.fabric.api.client.screen.v1.Screens;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.components.StringWidget;
 import net.minecraft.client.gui.screens.Screen;
 import net.minecraft.client.gui.screens.inventory.MerchantScreen;
 import net.minecraft.network.chat.Component;
@@ -48,36 +49,55 @@ public final class MerchantScreenButtonInjector {
 		// Position buttons safely to the right of the merchant GUI (276 px wide, centered).
 		int x = scaledWidth / 2 + 140;
 		int y = scaledHeight / 2 - 83;
-		int w = 160;
+		int bw = 160;
+		int lw = 110;
 		int h = 20;
 		int gap = 2;
+		int labelX = x + bw + 4;
 
 		Button openSettings = Button
-				.builder(Component.literal("Open Settings"), btn -> GuiBase.openGui(new GuiConfigs()))
+				.builder(Component.literal("Open Settings"), btn -> {
-				.bounds(x, y, w, h).build();
+					// vanilla Screen.onClose -> setScreen(null) sends the container-close
+					// packet; switching the screen out from under the merchant GUI via
+					// GuiBase.openGui skips that path, so the server still thinks we are
+					// trading with this villager and rejects the next interact packet.
+					if (client.player != null) {
+						client.player.closeContainer();
+					}
+					GuiBase.openGui(new GuiConfigs());
+				})
+				.bounds(x, y, bw, h).build();
 
 		Button selectSell = Button
-				.builder(sellButtonLabel(), btn -> applySelectedTradeAsSell(client, merchantScreen))
+				.builder(sellButtonLabel(null), btn -> onSellButton(client, merchantScreen))
-				.bounds(x, y + (h + gap), w, h).build();
+				.bounds(x, y + (h + gap), bw, h).build();
+		StringWidget sellCurrent = new StringWidget(labelX, y + (h + gap), lw, h,
+				currentSellLabel(), client.font);
 
 		Button selectBuy = Button
-				.builder(buyButtonLabel(), btn -> applySelectedTradeAsBuy(client, merchantScreen))
+				.builder(buyButtonLabel(null), btn -> onBuyButton(client, merchantScreen))
-				.bounds(x, y + 2 * (h + gap), w, h).build();
+				.bounds(x, y + 2 * (h + gap), bw, h).build();
+		StringWidget buyCurrent = new StringWidget(labelX, y + 2 * (h + gap), lw, h,
+				currentBuyLabel(), client.font);
 
 		Button enableAutotrade = Button
 				.builder(autotradeButtonLabel(), btn -> toggleAutotrade(btn))
-				.bounds(x, y + 3 * (h + gap), w, h).build();
+				.bounds(x, y + 3 * (h + gap), bw, h).build();
 
 		Screen asScreen = merchantScreen;
 		//? if mc26 {
 		Screens.getWidgets(asScreen).add(openSettings);
 		Screens.getWidgets(asScreen).add(selectSell);
+		Screens.getWidgets(asScreen).add(sellCurrent);
 		Screens.getWidgets(asScreen).add(selectBuy);
+		Screens.getWidgets(asScreen).add(buyCurrent);
 		Screens.getWidgets(asScreen).add(enableAutotrade);
 		//?} else {
 		Screens.getButtons(asScreen).add(openSettings);
 		Screens.getButtons(asScreen).add(selectSell);
+		Screens.getButtons(asScreen).add(sellCurrent);
 		Screens.getButtons(asScreen).add(selectBuy);
+		Screens.getButtons(asScreen).add(buyCurrent);
 		Screens.getButtons(asScreen).add(enableAutotrade);
 		//?}
 
@@ -93,27 +113,74 @@ public final class MerchantScreenButtonInjector {
 			}
 
 			MerchantOffer current = currentSelectedOffer(merchantScreen);
-			selectSell.active = current != null && isSellOffer(current);
+			MerchantOffer sellOffer = (current != null && isSellOffer(current)) ? current : null;
-			selectBuy.active = current != null && isBuyOffer(current);
+			MerchantOffer buyOffer = (current != null && isBuyOffer(current)) ? current : null;
-			selectSell.setMessage(sellButtonLabel());
+			boolean sellOn = Configs.Generic.ENABLE_SELL.getBooleanValue();
-			selectBuy.setMessage(buyButtonLabel());
+			boolean buyOn = Configs.Generic.ENABLE_BUY.getBooleanValue();
+			// Button doubles as a "Disable" toggle when no applicable trade is selected
+			// but the corresponding ENABLE flag is currently on — so the user can turn
+			// it off without leaving the merchant screen.
+			selectSell.active = sellOffer != null || sellOn;
+			selectBuy.active = buyOffer != null || buyOn;
+			selectSell.setMessage(sellOffer != null ? sellButtonLabel(sellOffer)
+					: (sellOn ? Component.literal("Disable sell") : sellButtonLabel(null)));
+			selectBuy.setMessage(buyOffer != null ? buyButtonLabel(buyOffer)
+					: (buyOn ? Component.literal("Disable buy") : buyButtonLabel(null)));
+			sellCurrent.setMessage(currentSellLabel());
+			buyCurrent.setMessage(currentBuyLabel());
 			enableAutotrade.setMessage(autotradeButtonLabel());
 		});
 	}
 
+	private static void onSellButton(Minecraft client, MerchantScreen screen) {
+		MerchantOffer offer = currentSelectedOffer(screen);
+		if (offer != null && isSellOffer(offer)) {
+			applySelectedTradeAsSell(client, screen);
+			return;
+		}
+		if (Configs.Generic.ENABLE_SELL.getBooleanValue()) {
+			Configs.Generic.ENABLE_SELL.setBooleanValue(false);
+			Configs.saveToFile();
+		}
+	}
+
+	private static void onBuyButton(Minecraft client, MerchantScreen screen) {
+		MerchantOffer offer = currentSelectedOffer(screen);
+		if (offer != null && isBuyOffer(offer)) {
+			applySelectedTradeAsBuy(client, screen);
+			return;
+		}
+		if (Configs.Generic.ENABLE_BUY.getBooleanValue()) {
+			Configs.Generic.ENABLE_BUY.setBooleanValue(false);
+			Configs.saveToFile();
+		}
+	}
+
 	private static Component autotradeButtonLabel() {
 		boolean on = Configs.Generic.ENABLED.getBooleanValue();
 		return Component.literal(on ? "Disable Autotrade" : "Enable Autotrade");
 	}
 
-	private static Component sellButtonLabel() {
+	/** Button label previews the item that would be written if clicked. */
-		String enabled = Configs.Generic.ENABLE_SELL.getBooleanValue() ? "" : " (off)";
+	private static Component sellButtonLabel(MerchantOffer offer) {
-		return Component.literal("Sell: " + describeSpec(Configs.Generic.SELL_ITEM.getStringValue()) + enabled);
+		String item = offer == null ? "-" : describeSpec(TradeItemSpec.encodeFromStack(offer.getCostA()));
+		return Component.literal("Set " + item + " as sell item");
 	}
 
-	private static Component buyButtonLabel() {
+	private static Component buyButtonLabel(MerchantOffer offer) {
-		String enabled = Configs.Generic.ENABLE_BUY.getBooleanValue() ? "" : " (off)";
+		String item = offer == null ? "-" : describeSpec(TradeItemSpec.encodeFromStack(offer.getResult()));
-		return Component.literal("Buy: " + describeSpec(Configs.Generic.BUY_ITEM.getStringValue()) + enabled);
+		return Component.literal("Set " + item + " as buy item");
+	}
+
+	/** Side-label shows the currently-configured sell/buy item from config. */
+	private static Component currentSellLabel() {
+		String off = Configs.Generic.ENABLE_SELL.getBooleanValue() ? "" : " (off)";
+		return Component.literal(describeSpec(Configs.Generic.SELL_ITEM.getStringValue()) + off);
+	}
+
+	private static Component currentBuyLabel() {
+		String off = Configs.Generic.ENABLE_BUY.getBooleanValue() ? "" : " (off)";
+		return Component.literal(describeSpec(Configs.Generic.BUY_ITEM.getStringValue()) + off);
 	}
 
 	/**