common: add Player.IsAirborne() utility function (#132)

Author: markus-wa

common/player.go

@@ -8,6 +8,13 @@ import (
 	st "github.com/markus-wa/demoinfocs-golang/sendtables"
 )
 
+const (
+	maxEdictBits                 = 11
+	entityHandleSerialNumberBits = 10
+	entityHandleBits             = maxEdictBits + entityHandleSerialNumberBits
+	invalidEntityHandle          = (1 << entityHandleBits) - 1
+)
+
 // Player contains mostly game-relevant player information.
 type Player struct {
 	demoInfoProvider demoInfoProvider // provider for demo info such as tick-rate or current tick
@@ -66,6 +73,17 @@ func (p *Player) IsBlinded() bool {
 	return p.FlashDurationTimeRemaining() > 0
 }
 
+// IsAirborne returns true if the player is jumping or falling.
+func (p *Player) IsAirborne() bool {
+	if p.Entity == nil {
+		return false
+	}
+
+	groundEntityHandle := p.Entity.FindPropertyI("m_hGroundEntity").Value().IntVal
+
+	return groundEntityHandle == invalidEntityHandle
+}
+
 // FlashDurationTime returns the duration of the blinding effect as time.Duration instead of float32 in seconds.
 // Will return 0 if IsBlinded() returns false.
 func (p *Player) FlashDurationTime() time.Duration {

common/player_test.go

@@ -190,6 +190,22 @@ func TestPlayer_IsScoped(t *testing.T) {
 	assert.True(t, pl.IsScoped())
 }
 
+func TestPlayer_IsAirborne_NilEntity(t *testing.T) {
+	pl := new(Player)
+
+	assert.False(t, pl.IsAirborne())
+}
+
+func TestPlayer_IsAirborne(t *testing.T) {
+	pl := playerWithProperty("m_hGroundEntity", st.PropertyValue{IntVal: 0})
+
+	assert.False(t, pl.IsAirborne())
+
+	pl = playerWithProperty("m_hGroundEntity", st.PropertyValue{IntVal: 2097151})
+
+	assert.True(t, pl.IsAirborne())
+}
+
 func newPlayer(tick int) *Player {
 	return NewPlayer(mockDemoInfoProvider(128, tick))
 }

demoinfocs_test.go

@@ -115,6 +115,14 @@ func TestDemoInfoCs(t *testing.T) {
 		}
 	})
 
+	// airborne checks
+	// we don't check RoundStart or RoundFreezetimeEnd since players may spawn airborne
+	p.RegisterEventHandler(func(plantBegin events.BombPlantBegin) {
+		if plantBegin.Player.IsAirborne() {
+			t.Error("Player is airborne during plant")
+		}
+	})
+
 	// Check some things at match start
 	p.RegisterEventHandler(func(events.MatchStart) {
 		participants := gs.Participants()