Routines
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58476: Animation routine for when Maroc is out of energy
Routine called from 55885 when Maroc is out of energy. He spins towards the top of the screen, with a decreasing pitch sound.
Maroc animation when drained of energy
58476 LD A,(60097) Maroc's vertical (Y-axis) screen position, in pixels
58479 LD (60114),A Copy into data buffer
58482 LD HL,(60098) Maroc's sprite address pointer in table at 38851
58485 LD (60109),HL Copy into data buffer
58488 LD A,(60096) Get Maroc's horizontal (X-axis) screen position, in half character (4-pixel) steps
58491 RLA Multiply by 4 to convert to horizontal pixel position
58492 RLA
58493 AND 252 Filter out any carry bits that may have appeared from the SLA
58495 LD (60115),A ...and store horizontal pixel position in data buffer
58498 LD A,0 Set high byte of horizontal graphic position to indicate that it's within the current screen (viewport) rather than to the left (255) or right (1)
58500 LD (60116),A
Play sound:
58503 LD A,(60114) Get vertical graphic (pixel) position
58506 NEG The sound pitch/speed is based on Maroc's vertical position as he spins upwards, so would naturally increase in pitch. By using NEG this decreases the pitch instead, as Maroc ascends.
58508 SRA A Halve the value to reduce the pitch change slightly
58510 LD C,A Store in C register as a loop counter
58511 LD E,64
58513 LD A,0 Start loop with speaker off
58515 XOR 16 Toggle the speaker bit
58517 OUT (254),A Play sound
58519 LD B,C Inner loop - short pause
58520 DJNZ 58520
58522 DEC E Outer loop - short pause
58523 JR NZ,58515
Erase Maroc's graphic:
58525 LD A,0 Set draw/erase flag to ERASE
58527 LD (60111),A
58530 LD HL,(60109) Get graphic address pointer
58533 CALL 56216 Erase Maroc's sprite
Rotate Maroc's sprite clockwise
58536 LD A,(60163) Rotation value - for 8 different directions, in increments of 32
58539 ADD A,32 Rotate Maroc's sprite clockwise one graphics frame
58541 LD (60163),A Re-store new graphics frame
58544 RRA Rotate rotation bits into bits 1-3
58545 RRA
58546 RRA
58547 RRA
58548 AND 14 ...and filter out other unwanted bits caused by the rotate. Value is now an even number and in the range 0-14.
58550 LD E,A This corresponds to Maroc's frame (0-7) x 2. Transfer this offset to DE
58551 LD D,0
58553 LD HL,(60266) Get sprite graphic address pointer
58556 ADD HL,DE Add the offset, which now points to Maroc's new frame (from 38851)
58557 LD (60109),HL ...and store as address pointer in graphic data buffer.
The following code sets Maroc's attribute colours. Maroc's INK attribute colour is supposed to change as he spins upwards.
However, the attribute print routine at 57888 references the byte at 60097 for Maroc's normal vertical screen position, rather than the one at 60071, which changes as Maroc ascends.
This means that the colour change/rotation is only applied at Maroc's base screen position, so once he starts rising he retains the standard screen colour. You can see this in the animated image at the top of this page.
58560 LD A,(60071) Get Maroc's attribute colour (usually 71 - bright white)
58563 DEC A Decrement (Maroc is supposed to change colour as he rises)
58564 AND 7 Only need INK colour so filter out PAPER, BRIGHT and FLASH bits
58566 LD (60071),A ...and store.
58569 LD A,(60114) Get Maroc's vertical position (in pixels)
58572 SUB 4 Reduce by 4 (Maroc moves upwards in half character squares)
58574 LD (60114),A
58577 CALL 57888 Set/change Maroc's attributes (INK colour)
Draw Maroc at his new screen position:
58580 LD A,1 Set draw/erase flag to DRAW
58582 LD (60111),A
58585 LD HL,(60109) Get sprite graphics address pointer
58588 CALL 56216 Draw Maroc sprite
58591 LD A,(60117) Flag indicating whether (any part of) graphic is visible on screen
58594 CP 0 Check if Maroc has disappeared off the top of the screen
58596 JR NZ,58503 If not, continue to spin him upwards and play sound.
58598 RET
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