common: add GrenadeProjectile.Velocity() function (#286)

Author: markus-wa

pkg/demoinfocs/common/common.go

@@ -79,6 +79,11 @@ func (g *GrenadeProjectile) Position() r3.Vector {
 	return g.Entity.Position()
 }
 
+// Velocity returns the projectile's velocity.
+func (g *GrenadeProjectile) Velocity() r3.Vector {
+	return g.Entity.PropertyValueMust("m_vecVelocity").VectorVal
+}
+
 // UniqueID returns the unique id of the grenade.
 // The unique id is a random int generated internally by this library and can be used to differentiate
 // grenades from each other. This is needed because demo-files reuse entity ids.

pkg/demoinfocs/common/common_test.go

@@ -32,6 +32,20 @@ func TestGrenadeProjectileUniqueID(t *testing.T) {
 	assert.NotEqual(t, NewGrenadeProjectile().UniqueID(), NewGrenadeProjectile().UniqueID(), "UniqueIDs of different grenade projectiles should be different")
 }
 
+func TestGrenadeProjectile_Velocity(t *testing.T) {
+	expected := r3.Vector{
+		X: 1,
+		Y: 2,
+		Z: 3,
+	}
+
+	p := GrenadeProjectile{
+		Entity: entityWithProperty("m_vecVelocity", st.PropertyValue{VectorVal: expected}),
+	}
+
+	assert.Equal(t, expected, p.Velocity())
+}
+
 func TestDemoHeader(t *testing.T) {
 	header := DemoHeader{
 		PlaybackFrames: 256,