Particles: AddExplosionToBuffer

       Name: AddExplosionToBuffer                                    [Show more]
       Type: Subroutine
   Category: Particles
    Summary: Create a big explosion of particles and add it to the particle
             data buffer
  Deep dive: Particles and particle clouds
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * AddShipExplosionToBuffer calls AddExplosionToBuffer
             * AddSmallExplosionToBuffer calls AddExplosionToBuffer
             * LoseLife calls AddExplosionToBuffer
             * ProcessObjectDestruction calls AddExplosionToBuffer


 Arguments:

   R8                               The number of particle clusters in the
                                    explosion (there are four particles per
                                    cluster)


.AddExplosionToBuffer

 STMFD   R13!, {R3-R9, R14}         \ Store the registers that we want to use on
                                    \ the stack so they can be preserved

.expl1

                                    \ Each cluster is made up of four particles,
                                    \ so we now add them to the particle data
                                    \ buffer

 BL      AddSparkParticleToBuffer   \ Add a spark particle to the particle data
                                    \ buffer (one that fades from white to red)

 BL      AddDebrisParticleToBuffer  \ Add a spark particle to the particle data
                                    \ buffer (a purple-brownish-green particle
                                    \ that flies out and bounces on the ground)

 BL      AddSmokeParticleToBuffer   \ Add a smoke particle to the particle data
                                    \ buffer (a grey particle that slowly rises)

 BL      AddSparkParticleToBuffer   \ Add another spark particle to the particle
                                    \ data buffer  (one that fades from white to
                                    \ red)

 SUBS    R8, R8, #1                 \ Decrement the particle cluster counter in
                                    \ R8

 BPL     expl1                      \ Loop back until we have drawn all R8
                                    \ particle clusters in the explosion

 LDMFD   R13!, {R3-R9, PC}          \ Retrieve the registers that we stored on
                                    \ the stack and return from the subroutine