Add modify_slipperiness power

src/main/java/alluysl/alluyslorigins/mixin/BoatEntityMixin.java

@@ -0,0 +1,40 @@
+package alluysl.alluyslorigins.mixin;
+
+import alluysl.alluyslorigins.power.ModifySlipperinessPower;
+import io.github.apace100.origins.component.OriginComponent;
+import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.vehicle.BoatEntity;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(BoatEntity.class)
+public abstract class BoatEntityMixin extends Entity {
+
+    public BoatEntityMixin(EntityType<?> type, World world){
+        super(type, world);
+    }
+
+    @Shadow @Nullable public abstract Entity getPrimaryPassenger();
+
+    @Redirect(method = "method_7548", at = @At(value = "INVOKE", target = "Lnet/minecraft/block/Block;getSlipperiness()F"))
+    private float modifySlipperiness(Block block){
+        float base = block.getSlipperiness();
+
+        Entity passenger = getPrimaryPassenger();
+
+        if (passenger instanceof LivingEntity)
+            for (ModifySlipperinessPower power : OriginComponent.getPowers(passenger, ModifySlipperinessPower.class))
+                if (power.doesModify(getVelocityAffectingPos(), true))
+                    base = MathHelper.lerp(power.getValue(), base, 1.0F);
+
+        return base;
+    }
+}

src/main/java/alluysl/alluyslorigins/mixin/LivingEntityMixin.java

@@ -0,0 +1,32 @@
+package alluysl.alluyslorigins.mixin;
+
+import alluysl.alluyslorigins.power.ModifySlipperinessPower;
+import io.github.apace100.origins.component.OriginComponent;
+import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(LivingEntity.class)
+public abstract class LivingEntityMixin extends Entity {
+
+    public LivingEntityMixin(EntityType<?> type, World world){
+        super(type, world);
+    }
+
+    @Redirect(method = "travel", at = @At(value = "INVOKE", target = "Lnet/minecraft/block/Block;getSlipperiness()F"))
+    private float modifySlipperiness(Block block){
+        float base = block.getSlipperiness();
+
+        for (ModifySlipperinessPower power : OriginComponent.getPowers(this, ModifySlipperinessPower.class))
+            if (power.doesModify(getVelocityAffectingPos(), false))
+                base = MathHelper.lerp(power.getValue(), base, 1.0F);
+
+        return base;
+    }
+}

src/main/java/alluysl/alluyslorigins/power/AlluyslOriginsPowers.java

@@ -2,9 +2,11 @@
 
 import alluysl.alluyslorigins.AlluyslOrigins;
 import io.github.apace100.origins.power.factory.PowerFactory;
+import io.github.apace100.origins.power.factory.condition.ConditionFactory;
 import io.github.apace100.origins.registry.ModRegistries;
 import io.github.apace100.origins.util.SerializableData;
 import io.github.apace100.origins.util.SerializableDataType;
+import net.minecraft.block.pattern.CachedBlockPosition;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.registry.Registry;
 
@@ -109,6 +111,19 @@ public static void register(){
                             data.getBoolean("static_ratio_threshold_inclusive"))
         ).allowCondition());
 
+        //noinspection unchecked
+        register(new PowerFactory<>(
+                new Identifier(AlluyslOrigins.MODID, "modify_slipperiness"),
+                new SerializableData()
+                        .add("value", SerializableDataType.FLOAT)
+                        .add("block_condition", SerializableDataType.BLOCK_CONDITION, null)
+                        .add("affect_boats", SerializableDataType.BOOLEAN, false),
+                data -> (type, player) -> new ModifySlipperinessPower(type, player,
+                        data.getFloat("value"),
+                        (ConditionFactory<CachedBlockPosition>.Instance)data.get("block_condition"),
+                        data.getBoolean("affect_boats"))
+        ).allowCondition());
+
         System.out.println("[Alluysl's Origins] Powers registered.");
     }
 

src/main/java/alluysl/alluyslorigins/power/ModifySlipperinessPower.java

@@ -0,0 +1,40 @@
+package alluysl.alluyslorigins.power;
+
+import io.github.apace100.origins.power.Power;
+import io.github.apace100.origins.power.PowerType;
+import io.github.apace100.origins.power.factory.condition.ConditionFactory;
+import net.minecraft.block.pattern.CachedBlockPosition;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.math.BlockPos;
+
+import java.util.function.Predicate;
+
+public class ModifySlipperinessPower extends Power {
+
+    private final float value;
+    private final Predicate<CachedBlockPosition> blockCondition;
+    private final boolean affectBoats;
+
+    public ModifySlipperinessPower(PowerType<Power> type, PlayerEntity player, float value, ConditionFactory<CachedBlockPosition>.Instance blockCondition, boolean affectBoats){
+        super(type, player);
+        this.value = value;
+        this.blockCondition = blockCondition;
+        this.affectBoats = affectBoats;
+    }
+
+    public float getValue(){
+        return value;
+    }
+
+    public boolean doesModify(BlockPos pos, boolean isBoat){
+        return doesModify(new CachedBlockPosition(player.world, pos, true), isBoat);
+    }
+
+    public boolean doesModify(CachedBlockPosition pos, boolean isBoat){
+        if (isBoat && !affectBoats)
+            return false;
+        if (blockCondition == null)
+            return true;
+        return blockCondition.test(pos);
+    }
+}

src/main/resources/alluyslorigins.mixins.json

@@ -4,6 +4,8 @@
   "package": "alluysl.alluyslorigins.mixin",
   "compatibilityLevel": "JAVA_8",
   "mixins": [
+    "BoatEntityMixin",
+    "LivingEntityMixin"
   ],
   "client": [
     "GameRendererMixin"