Particles: SplashParticleIntoSea

       Name: SplashParticleIntoSea                                   [Show more]
       Type: Subroutine
   Category: Particles
    Summary: Splash a particle into the sea, creating a spray particle
  Deep dive: Particles and particle clouds
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * BounceParticle calls SplashParticleIntoSea


 Arguments:

   (R0, R1, R2)                     Particle coordinates (on the sea's surface)

   R7                               Particle flags


.SplashParticleIntoSea

 TST     R7, #&00040000             \ If bit 18 of the particle flags is clear,
 BEQ     DeleteParticleData         \ jump to DeleteParticleData to delete the
                                    \ particle without splashing

 TST     R7, #&00800000             \ If bit 23 of the particle flags is set,
 MOVNE   R8, #65                    \ set the number of spray particles in R8
 MOVEQ   R8, #4                     \ to 65, otherwise set it to 4

 SUB     R1, R1, #SPLASH_HEIGHT     \ Set R1 to a point just above the sea's
                                    \ surface (R1 is on the surface, so this
                                    \ moves it to SPLASH_HEIGHT above the waves,
                                    \ or 1/16 of a tile size)

.psea1

 BL      AddSprayParticleToBuffer   \ Add a spray particle to the particle data
                                    \ buffer

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

 BNE     psea1                      \ Loop back until we have added all the
                                    \ spray particles

                                    \ Fall through into DeleteParticleData to
                                    \ delete the particle and return from the
                                    \ subroutine, as the particle has now
                                    \ crashed into the sea