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Routines |
| Prev: 40905 | Up: Map | Next: 41035 |
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Used by the routine at 39047.
See also analogous routine at 41173 (RLE terrain interaction data painting)
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| 40937 | PUSH HL | Store HL (pointer to entry in lookup table for RLE attribute data) | ||||||||
| 40938 | LD HL,23410 | Modify instruction at 40983 to load x-coordinate of graphic's right edge into A... | ||||||||
| 40941 | LD (40984),HL | ...i.e. set end x-coordinate for painting left-to-right | ||||||||
| 40944 | LD HL,41004 | Modify instruction at 40987 to jump to 41004... | ||||||||
| 40947 | LD (40988),HL | ...i.e. advance HL down one character row in attribute file | ||||||||
| 40950 | LD A,35 | Modify instruction at 40990 with opcode 35 (INC HL)... | ||||||||
| 40952 | LD (40990),A | ... | ||||||||
| 40955 | POP HL | Restore HL (pointer to entry in lookup table for RLE attribute data) | ||||||||
| 40956 | CALL 41035 | Store coordinates of area to be coloured and point IX at RLE attribute data | ||||||||
| 40959 | LD BC,(23408) | Load BC with x- and y-coordinates (top-left) defined in current room layout data entry | ||||||||
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This entry point is used by the routines at 40845, 40873 and 40905.
At this point, BC holds the initial coordinates in characters, from which to start painting attributes. IX points to the required RLE attribute data.
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| 40963 | PUSH BC | Store BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 40964 | CALL 63219 | Point HL at attribute file address for character coordinates (C, B) | ||||||||
| 40967 | LD A,(IX+0) | Load A with repeat count value | ||||||||
| 40970 | OR A | If repeat count is zero... | ||||||||
| 40971 | JP Z,41000 | ...then jump to 41000 | ||||||||
| 40974 | LD B,A | Load B with repeat count | ||||||||
| 40975 | LD C,(IX+1) | Load C with attribute to paint | ||||||||
| 40978 | LD (HL),C | Apply attribute in C to current attribute file location in HL | ||||||||
| 40979 | LD A,L | Load E with x-coordinate (characters) of current attribute file location... | ||||||||
| 40980 | AND 31 | ... | ||||||||
| 40982 | LD E,A | ... | ||||||||
| 40983 | LD A,(23410) | Load A with end x-coordinate for painting... | ||||||||
| 40986 | CP E | ...and if this is the same as the x-coordinate... | ||||||||
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The operand of the instruction at 40987 (i.e. the destination of the jump) is modified by the instructions at 40855, 40883, 40915 and 40947 to be 41025 (move up one character row), 41025 (move up one character row), 41004 (move down one character row) or 41004 (move down one character row) respectively.
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| 40987 | JP Z,41004 | ...then jump to routine to move up or down one character row | ||||||||
| 40990 | INC HL | Advance HL to next (or previous) byte in attribute file | ||||||||
| 40991 | DJNZ 40978 | Decrease B (repeat count) and loop back to 40978 if not zero | ||||||||
| 40993 | INC IX | Advance IX by two bytes in RLE attribute data... | ||||||||
| 40995 | INC IX | ... | ||||||||
| 40997 | JP 40967 | Loop back to 40967 for this new data | ||||||||
| 41000 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 41001 | JP 39158 | Advance to next room layout data entry and paint its attributes | ||||||||
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Move down one character row
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| 41004 | EXX | Switch registers | ||||||||
| 41005 | LD A,(23411) | Load A with one more than y-coordinate of bottom edge of area to paint... | ||||||||
| 41008 | INC A | ... | ||||||||
| 41009 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 41010 | INC B | Increase B (i.e. move down a character row) | ||||||||
| 41011 | PUSH BC | Store BC (B = updated y-coordinate, C = initial x-coordinate) | ||||||||
| 41012 | CP B | If B is the same as A (i.e. we are now outside the area to be painted)... | ||||||||
| 41013 | JP Z,41000 | ...then jump to 41000 | ||||||||
| 41016 | CALL 63219 | Load HL with attribute file address for coordinates (C, B) and load E with x-coordinate (characters) | ||||||||
| 41019 | PUSH HL | Store HL (new attribute file address) | ||||||||
| 41020 | EXX | Switch registers | ||||||||
| 41021 | POP HL | Restore HL (new attribute file address) | ||||||||
| 41022 | JP 40991 | Jump back to 40991 and continue painting | ||||||||
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Move up one character row
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| 41025 | EXX | Switch registers | ||||||||
| 41026 | LD A,(23409) | Load A with one less than y-coordinate of top edge of area to paint... | ||||||||
| 41029 | DEC A | ... | ||||||||
| 41030 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 41031 | DEC B | Increase B (i.e. move down a character row) | ||||||||
| 41032 | JP 41011 | Jump back to 41011 | ||||||||
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