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Routines |
| Prev: 52714 | Up: Map | Next: 52820 |
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Used when apply-horizontal-mirror flag is reset
Used by the routine at 52714.
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| 52717 | LD A,(23449) | Increase pixel row counter... | ||||||||||||
| 52720 | INC A | ... | ||||||||||||
| 52721 | AND 7 | ...and reset to zero if it exceeds 7... | ||||||||||||
| 52723 | LD (23449),A | ... | ||||||||||||
| 52726 | JR Z,52731 | If we have rolled over to a new character block then advance HL to next character block to be drawn and return | ||||||||||||
| 52728 | INC H | Increase display file address by 256 bytes (i.e. move to next pixel row down) | ||||||||||||
| 52729 | XOR A | Set A to zero | ||||||||||||
| 52730 | RET | Return | ||||||||||||
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This next section advances HL to next character block to be drawn
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| 52731 | LD A,(23450) | Load A with apply-horizontal-mirror and apply-vertical-mirror flags | ||||||||||||
| 52734 | AND 1 | If apply-vertical-mirror flag is set... | ||||||||||||
| 52736 | JP NZ,52793 | ...then skip ahead to 52793 | ||||||||||||
| 52739 | PUSH BC | Store BC | ||||||||||||
| 52740 | LD A,(23444) | Load x-coordinate of character block currently being drawn into A... | ||||||||||||
| 52743 | INC A | ...increase by one... | ||||||||||||
| 52744 | LD B,A | ...and load into B | ||||||||||||
| 52745 | LD A,(23495) | Load (x-coordinate + 1) of right of graphic being drawn into A | ||||||||||||
| 52748 | CP B | If both x-coordinates are the same (i.e. we have moved beyond graphic's right edge)... | ||||||||||||
| 52749 | JR Z,52765 | ...then jump to 52765 | ||||||||||||
| 52751 | LD A,B | Store increased x-coordinate at 23444... | ||||||||||||
| 52752 | LD (23444),A | ... | ||||||||||||
| 52755 | LD BC,(23444) | Load BC with coordinates of new character block to draw | ||||||||||||
| 52759 | CALL 54132 | Move virtual cursor (bitmap) to display file address for coordinates x=C, y=B and load address into HL | ||||||||||||
| 52762 | XOR A | Set A to zero | ||||||||||||
| 52763 | POP BC | Restore BC | ||||||||||||
| 52764 | RET | Return | ||||||||||||
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This next section advances HL to next character row to be drawn
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| 52765 | LD A,(23493) | Load A with x-coordinate of left of graphic to draw... | ||||||||||||
| 52768 | LD (23444),A | ...and set current x-coordinate to match | ||||||||||||
| 52771 | LD A,(23445) | Load current y-coordinate into C, increasing by one... | ||||||||||||
| 52774 | INC A | ... | ||||||||||||
| 52775 | LD C,A | ... | ||||||||||||
| 52776 | LD A,(23496) | Load (y-coordinate + 1) of bottom of graphic being drawn into A | ||||||||||||
| 52779 | CP C | If both y-coordinates are the same (i.e. we have moved beyond graphic's bottom edge)... | ||||||||||||
| 52780 | JR Z,52788 | ...then skip ahead to 52788 | ||||||||||||
| 52782 | LD A,C | Store increased y-coordinate at 23445... | ||||||||||||
| 52783 | LD (23445),A | ... | ||||||||||||
| 52786 | JR 52755 | Move virtual cursor (bitmap) to display file address for coordinates x=C, y=B and load address into HL then return | ||||||||||||
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This entry point is used by the routine at 52820.
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| 52788 | LD A,1 | Load A with 1 | ||||||||||||
| 52790 | OR A | Reset zero flag | ||||||||||||
| 52791 | POP BC | Restore BC | ||||||||||||
| 52792 | RET | Return | ||||||||||||
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This next section advances HL to next character block to be drawn where the apply-vertical-mirror flag is set
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| 52793 | PUSH BC | Store BC | ||||||||||||
| 52794 | LD A,(23444) | Load x-coordinate of character block currently being drawn into A... | ||||||||||||
| 52797 | DEC A | ...decrease by one... | ||||||||||||
| 52798 | LD B,A | ...and load into B | ||||||||||||
| 52799 | LD A,(23493) | Load x-coordinate of left of graphic being drawn into A... | ||||||||||||
| 52802 | DEC A | ...and decrease by one | ||||||||||||
| 52803 | CP B | If both x-coordinates are the same (i.e. we have moved beyond graphic's left edge)... | ||||||||||||
| 52804 | JR Z,52813 | ...then jump to 52813 | ||||||||||||
| 52806 | LD A,B | Store decreased x-coordinate at 23444... | ||||||||||||
| 52807 | LD (23444),A | ... | ||||||||||||
| 52810 | JP 52755 | Move virtual cursor (bitmap) to display file address for coordinates x=C, y=B and load address into HL then return | ||||||||||||
| 52813 | LD A,(23495) | Load x-coordinate of right of graphic being drawn into A... | ||||||||||||
| 52816 | DEC A | ... | ||||||||||||
| 52817 | JP 52768 | Move current character position down one character row and return | ||||||||||||
| Prev: 52714 | Up: Map | Next: 52820 |