Routines
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46267: Play Footsteps Sound
Used by the routine at HandleWalking.
Plays the footsteps of the player walking, but only on every other frame of the walking animation. The number of cycles comes from the position of the player on the screen. The entry point at PlayFootstepsSound_EveryFrame plays them on every frame.
Input
IX Address of the object
Play on even frames of the walking animation.
PlayFootstepsSound 46267 LD A,(IX+0) Fetch the graphic number of the object.
46270 AND %00000001 Test whether it is an odd frame of the animation.
46272 RET NZ Return if it is.
This entry point is used by the routine at HandleTurning.
PlayFootstepsSound_EveryFrame 46273 LD B,96 Set the pitch.
46275 LD A,(23458) Fetch the frame counter from FrameCounter.
This entry point is used by the routine at PlayGuardFootstepsSound.
One time in two the pitch is made from the height of the object instead.
PlayFootstepsSound_Position 46278 BIT 1,A Jump to PlayFootstepsSound_Cycles if a random bit of the seed is not set.
46280 JR Z,PlayFootstepsSound_Cycles
46282 LD A,(IX+3) Fetch the Z coordinate of the object.
46285 CPL Invert it.
46286 SRL A Halve it.
46288 LD B,A Use it as the pitch.
The number of cycles is the high nibble of half of the X coordinate added to half of the negated Y coordinate, which is the horizontal position on the screen.
PlayFootstepsSound_Cycles 46289 LD A,(IX+1) Fetch the X coordinate of the object.
46292 SRL A Halve it.
46294 LD C,A Stash it in C.
46295 LD A,(IX+2) Fetch the Y coordinate of the object.
46298 NEG Negate it.
46300 SRL A Halve it.
46302 ADD A,C Add the halved X coordinate.
46303 RRCA Move the high nibble into the low nibble.
46304 RRCA
46305 RRCA
46306 RRCA
46307 AND %00001111 Keep the low nibble.
46309 LD C,A Use it as the number of cycles.
View the equivalent code in;
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