Tweak gravity and player physics

pkg/balance/numbers.go

@@ -32,18 +32,19 @@ var (
 	}
 
 	// Player speeds
-	PlayerMaxVelocity    float64 = 7
+	PlayerMaxVelocity       float64 = 7
-	PlayerJumpVelocity   float64 = -23
+	PlayerJumpVelocity      float64 = -15
-	PlayerAcceleration   float64 = 0.04 // 0.12
+	PlayerAcceleration      float64 = 0.04 // 0.12
-	PlayerFriction       float64 = 0.1
+	PlayerFriction          float64 = 0.1
-	SlipperyAcceleration float64 = 0.02
+	SlipperyAcceleration    float64 = 0.02
-	SlipperyFriction     float64 = 0.02
+	SlipperyFriction        float64 = 0.02
-	Gravity              float64 = 7
+	GravityMaximum          float64 = 7    // max pull of gravity
-	GravityAcceleration  float64 = 0.1
+	GravityAcceleration     float64 = 0.25 // normal gravity acceleration downward
-	SwimGravity          float64 = 3
+	GravityJumpAcceleration float64 = 0.05 // gravity while jumping upward (smoother jumps)
-	SwimJumpVelocity     float64 = -12
+	SwimGravity             float64 = 3
-	SwimJumpCooldown     uint64  = 24 // number of frames of cooldown between swim-jumps
+	SwimJumpVelocity        float64 = -12
-	SlopeMaxHeight               = 8  // max pixel height for player to walk up a slope
+	SwimJumpCooldown        uint64  = 24 // number of frames of cooldown between swim-jumps
+	SlopeMaxHeight                  = 8  // max pixel height for player to walk up a slope
 
 	// Number of game ticks to insist the canvas follows the player at the start
 	// of a level - to overcome Anvils settling into their starting positions so

pkg/uix/actor_collision.go

@@ -73,14 +73,23 @@ func (w *Canvas) loopActorCollision() error {
 			// Apply gravity to the actor's velocity.
 			if a.hasGravity && !a.Grounded() { //v.Y >= 0 {
 				if !a.Grounded() {
-					var gravity = balance.Gravity
+					var (
+						gravity      = balance.GravityMaximum
+						acceleration = balance.GravityAcceleration
+					)
 					if a.IsWet() {
 						gravity = balance.SwimGravity
 					}
+
+					// If the actor is jumping/moving upwards, apply softer gravity.
+					if v.Y < 0 {
+						acceleration = balance.GravityJumpAcceleration
+					}
+
 					v.Y = physics.Lerp(
 						v.Y,     // current speed
 						gravity, // target max gravity falling downwards
-						balance.GravityAcceleration,
+						acceleration,
 					)
 				} else {
 					v.Y = 0