anchor.diff:                Absolute = absolute
                 Blend = blend
                 Image = image
  -              Life = { StartTime = time; LifeTimeOpt = lifeTimeOpt }
  +              Life = Life.make time lifeTimeOpt
                 ParticleLifeTimeOpt = particleLifeTimeOpt
                 ParticleRate = particleRate
                 ParticleIndex = 0
  
positive.code:         let makeDefault time lifeTimeOpt particleLifeTimeOpt particleRate particleMax =
              let image = asset Assets.Default.PackageName Assets.Default.ImageName
              let particleSeed =
                  { Life = { StartTime = 0L; LifeTimeOpt = 60L }
                    Body = Body.defaultBody
                    Size = Constants.Engine.ParticleSizeDefault
                    Offset = v2Dup 0.5f
  
negative.code:             if particleIndex > emitter.ParticleWatermark then emitter.ParticleWatermark <- particleIndex
              emitter.ParticleIndex <- particleIndex
              let particle = &emitter.ParticleBuffer.[particleIndex]
              particle.Life <- Life.make time particle.Life.LifeTimeOpt
              particle <- emitter.ParticleInitializer time constrain emitter
  
          /// Determine emitter's liveness.
  