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25539: Check whether Sam has somersaulted onto a banknote
Used by the routine at 25789. Compares Sam's location with those of the two banknotes. If there's a match, and Sam has just finished a somersault, the banknote is added to Sam's cash supply.
HL 58892 (byte 12 of Sam's buffer)
25539 BIT 5,(HL) Byte 12 of Sam's buffer holds the LSB of the current roll/somersault animation phase table entry
25541 RET Z Return if Sam was rolling
25542 LD L,1 Collect Sam's x- and y-coordinates in E and D
25544 LD E,(HL)
25545 INC L
25546 LD D,(HL)
25547 LD B,L B=2 (there are 2 banknotes)
25548 DEC H H=228 or 229
25549 LD A,D A=Sam's y-coordinate
25550 CP (HL) Compare it with the banknote's y-coordinate
25551 DEC HL Point HL at byte 1 of the banknote's buffer
25552 JR NZ,25558 Jump unless Sam's y-coordinate matches the banknote's
25554 LD A,E A=Sam's x-coordinate
25555 CP (HL) Has Sam landed on a banknote?
25556 JR Z,25562 Jump if so
25558 INC HL Point HL at byte 2 of the banknote's buffer
25559 DJNZ 25548 Jump back until both banknotes have been checked
25561 RET
Sam has landed on something that is using one of the banknote buffers. Here we check that the object looks like a banknote. But this check is redundant, since no object except a banknote or the hook can use buffer 228 or 229, and Sam cannot land on the hook.
25562 DEC L L=0
25563 LD A,(HL) A=banknote's animatory state
25564 AND 127 Discard bit 7
25566 SUB 62 Is the banknote's animatory state 62 or 190?
25568 JR Z,25573 Jump if so
25570 SUB 8 Is the banknote's animatory state 70 or 198?
25572 RET NZ Return if not (this never happens)
Sam has landed on something that looks like a banknote.
25573 LD L,10 Set byte 10 of the banknote's buffer to 1 to indicate that Sam's just landed on it (see 25420)
25575 INC (HL)
25576 CALL 25039 Add 1, 5, 10 or 20 bucks to Sam's total
Finally we make an appropriate sound effect.
25579 XOR A Prepare the sound effect parameters: A=0 (initial border colour), D=5 (duration), E=249 (initial pitch)
25580 LD DE,1529
25583 INC A Increment the border colour
25584 XOR 16 Flip bit 4 of A
25586 AND 23 Retain only bits 0-2 (border colour) and 4 (speaker state)
25588 OUT (254),A Change the border colour and speaker state
25590 LD B,E Perform the pitch delay
25591 DJNZ 25591
25593 DEC E Decrement the pitch delay
25594 JR NZ,25583 Jump back unless it's zero
25596 DEC D Decrement the duration counter
25597 JR NZ,25583 Jump back unless it's zero
25599 RET
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