#168 Add speed boosts when performing stunts and add a stunt for flying at low altitude.

src/main/java/com/minelittlepony/unicopia/entity/player/FlightStuntUtil.java

@@ -0,0 +1,19 @@
+package com.minelittlepony.unicopia.entity.player;
+
+import com.minelittlepony.unicopia.entity.mob.StormCloudEntity;
+import com.minelittlepony.unicopia.util.MutableVector;
+
+import net.minecraft.util.math.BlockPos;
+
+public class FlightStuntUtil {
+    public static boolean isPerformingDive(Pony pony, MutableVector velocity) {
+        double horizontalSpeed = velocity.horizontalLengthSquared();
+        double verticalSpeed = velocity.y;
+        return horizontalSpeed != 0 && verticalSpeed < -0.3F && (verticalSpeed / horizontalSpeed) < -0.3F;
+    }
+
+    public static boolean isFlyingLow(Pony pony, MutableVector velocity) {
+        BlockPos pos = pony.asEntity().getBlockPos();
+        return velocity.horizontalLengthSquared() > 0.005F && (pos.getY() - StormCloudEntity.findSurfaceBelow(pony.asWorld(), pos).getY()) < 6;
+    }
+}

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerPhysics.java

@@ -60,6 +60,7 @@ public class PlayerPhysics extends EntityPhysics<PlayerEntity> implements Tickab
     private int ticksInAir;
     private int ticksToGlide;
     private int ticksDiving;
+    private int ticksFlyingLow;
 
     private float thrustScale = 0;
     private float prevThrustScale;
@@ -335,28 +336,9 @@ public class PlayerPhysics extends EntityPhysics<PlayerEntity> implements Tickab
                     velocity.y /= 2F;
                 }
 
-                double horizontalSpeed = this.getHorizontalMotion();
+                tickStunts(velocity);
-                double verticalSpeed = velocity.y;
-
-                if (Abilities.RAINBOOM.canUse(pony.getCompositeRace()) && horizontalSpeed != 0 && verticalSpeed < -0.3F && (verticalSpeed / horizontalSpeed) < -0.3F) {
-                    ticksDiving++;
-                } else {
-                    ticksDiving = 0;
-                }
-
-                if (ticksDiving > 0 && ticksDiving % 25 == 0) {
-                    pony.getMagicalReserves().getCharge().addPercent(12.5F);
-                }
             } else {
-                prevStrafe = 0;
+                tickGrounded();
-                strafe = 0;
-                ticksInAir = 0;
-                wallHitCooldown = MAX_WALL_HIT_CALLDOWN;
-                soundPlaying = false;
-                descentRate = 0;
-                ticksDiving = 0;
-                updraft.update(0, 100);
-                windStrength.update(0, 100);
 
                 if (Abilities.RAINBOOM.canUse(pony.getCompositeRace()) && entity.isOnGround()) {
                     pony.getMagicalReserves().getCharge().set(0);
@@ -367,10 +349,7 @@ public class PlayerPhysics extends EntityPhysics<PlayerEntity> implements Tickab
                 }
             }
         } else {
-            descentRate = 0;
+            tickGrounded();
-            soundPlaying = false;
-            updraft.update(0, 100);
-            windStrength.update(0, 100);
         }
 
         if (!entity.isOnGround()) {
@@ -379,6 +358,10 @@ public class PlayerPhysics extends EntityPhysics<PlayerEntity> implements Tickab
             velocity.z /= heavyness;
         }
 
+        float maximum = 1.5F;
+        velocity.x = MathHelper.clamp(velocity.x, -maximum, maximum);
+        velocity.y = MathHelper.clamp(velocity.y, -maximum, maximum);
+        velocity.z = MathHelper.clamp(velocity.z, -maximum, maximum);
         entity.setVelocity(velocity.toImmutable());
 
         if (isFlying() && !entity.isFallFlying() && !pony.getAcrobatics().isHanging() && pony.isClient()) {
@@ -397,6 +380,46 @@ public class PlayerPhysics extends EntityPhysics<PlayerEntity> implements Tickab
         }
     }
 
+    private void tickGrounded() {
+        prevStrafe = 0;
+        strafe = 0;
+        ticksInAir = 0;
+        wallHitCooldown = MAX_WALL_HIT_CALLDOWN;
+        soundPlaying = false;
+        descentRate = 0;
+        ticksDiving = 0;
+        ticksFlyingLow = 0;
+        updraft.update(0, 0);
+        windStrength.update(0, 0);
+    }
+
+    private void tickStunts(MutableVector velocity) {
+        boolean canPerformStunts = Abilities.RAINBOOM.canUse(pony.getCompositeRace());
+        ticksDiving = canPerformStunts && FlightStuntUtil.isPerformingDive(pony, velocity) ? (ticksDiving + 1) : 0;
+        ticksFlyingLow = canPerformStunts && FlightStuntUtil.isFlyingLow(pony, velocity) ? (ticksFlyingLow + 1) : 0;
+
+        if (ticksDiving > 0) {
+            float horDiveScale = MathHelper.clamp(ticksDiving / 100F, 0, 10);
+            float verDiveScale = MathHelper.clamp(ticksDiving / 90F, 0, 5);
+            velocity.multiply(1 + horDiveScale, 1 + verDiveScale, 1 + horDiveScale);
+        }
+
+        if (ticksFlyingLow > 0) {
+            float horDiveScale = MathHelper.clamp(ticksFlyingLow / 1000F, 0, 0.9F);
+            float verDiveScale = MathHelper.clamp(ticksFlyingLow / 900F, 0, 0.5F);
+            velocity.multiply(1 + horDiveScale, 1 + verDiveScale, 1 + horDiveScale);
+        }
+
+        if (pony.asEntity().age % 2 == 0) {
+            if (ticksDiving > 0) {
+                pony.getMagicalReserves().getCharge().addPercent(1F);
+            }
+            if (ticksFlyingLow > 0) {
+                pony.getMagicalReserves().getCharge().addPercent(ticksFlyingLow / 200F);
+            }
+        }
+    }
+
     private void tickFlight(FlightType type, MutableVector velocity) {
         if (type.isArtifical()) {
             tickArtificialFlight(velocity);

src/main/java/com/minelittlepony/unicopia/util/MutableVector.java

@@ -20,6 +20,12 @@ public class MutableVector {
         z = vec.z;
     }
 
+    public void multiply(double x, double y, double z) {
+        this.x *= x;
+        this.y *= y;
+        this.z *= z;
+    }
+
     public void add(Vec3d vector) {
         add(vector.x, vector.y, vector.z);
     }
@@ -38,6 +44,18 @@ public class MutableVector {
         this.z += z;
     }
 
+    public double horizontalLengthSquared() {
+        return x * x + z * z;
+    }
+
+    public double verticalLengthSquared() {
+        return y * y;
+    }
+
+    public double lengthSquared() {
+        return verticalLengthSquared() + horizontalLengthSquared();
+    }
+
     public Vec3d toImmutable() {
         return new Vec3d(x, y, z);
     }