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Lander on the Acorn Archimedes

Particles: AddSparkCloudToBuffer

Name: AddSparkCloudToBuffer [Show more] Type: Subroutine Category: Particles Summary: An unused routine that adds a cloud of 150 spark particles to the particle data buffer, just in front of the player's ship Deep dive: Unused code in Lander
Context: See this subroutine in context in the source code References: No direct references to this subroutine in this source file
.AddSparkCloudToBuffer STMFD R13!, {R6-R9, R14} \ Store the registers that we want to use on \ the stack so they can be preserved MOV R8, #150 \ Set R8 = 150 so the explosion contains 150 \ clusters of four particles \ Now we add an explosion to the particle \ buffer at coordinates (R0, R1, R2), which \ are set to PLAYER_FRONT_Z tiles forwards \ from the camera coordinates, so that's \ just in front of the ship (when the ship \ is not close to the ground, in which case \ the explosion would be above the ship as \ the ship moves down the screen) LDR R0, [R11, #xCamera] \ Set R0 = xCamera MOV R1, #0 \ Set R1 = 0 LDR R2, [R11, #zCamera] \ Set R2 = zCamera - PLAYER_FRONT_Z SUB R2, R2, #PLAYER_FRONT_Z .spcl1 BL AddSparkParticleToBuffer \ Add a spark particle to the particle data \ buffer (one that fades from white to red) SUBS R8, R8, #1 \ Decrement the particle counter in R8 BPL spcl1 \ Loop back until we have drawn all R8 \ particles LDMFD R13!, {R6-R9, PC} \ Retrieve the registers that we stored on \ the stack and return from the subroutine