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Routines |
| Prev: 28906 | Up: Map | Next: 29036 |
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Used by the routine at 27951.
See also analogous routine at 29174 (RLE terrain interaction data painting)
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| 28938 | PUSH HL | Store HL (pointer to entry in lookup table for RLE attribute data) | ||||||||
| 28939 | LD HL,23495 | Modify instruction at 28984 to load x-coordinate of graphic's right edge into A... | ||||||||
| 28942 | LD (28985),HL | ...i.e. set end x-coordinate for painting left-to-right | ||||||||
| 28945 | LD HL,29005 | Modify instruction at 28988 to jump to 29005... | ||||||||
| 28948 | LD (28989),HL | ...i.e. advance HL down one character row in attribute file | ||||||||
| 28951 | LD A,35 | Modify instruction at 28991 with opcode 35 (INC HL)... | ||||||||
| 28953 | LD (28991),A | ... | ||||||||
| 28956 | POP HL | Restore HL (pointer to entry in lookup table for RLE attribute data) | ||||||||
| 28957 | CALL 29036 | Store coordinates of area to be coloured and point IX at RLE attribute data | ||||||||
| 28960 | LD BC,(23493) | 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 28846, 28874 and 28906.
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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| 28964 | PUSH BC | Store BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 28965 | CALL 54148 | Point HL at attribute file address for character coordinates (C, B) | ||||||||
| 28968 | LD A,(IX+0) | Load A with repeat count value | ||||||||
| 28971 | OR A | If repeat count is zero... | ||||||||
| 28972 | JP Z,29001 | ...then jump to 29001 | ||||||||
| 28975 | LD B,A | Load B with repeat count | ||||||||
| 28976 | LD C,(IX+1) | Load C with attribute to paint | ||||||||
| 28979 | LD (HL),C | Apply attribute in C to current attribute file location in HL | ||||||||
| 28980 | LD A,L | Load E with x-coordinate (characters) of current attribute file location... | ||||||||
| 28981 | AND 31 | ... | ||||||||
| 28983 | LD E,A | ... | ||||||||
| 28984 | LD A,(23495) | Load A with end x-coordinate for painting... | ||||||||
| 28987 | CP E | ...and if this is the same as the x-coordinate... | ||||||||
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The operand of the instruction at 28988 (i.e. the destination of the jump) is modified by the instructions at 28856, 28884, 28916 and 28948 to be 29026 (move up one character row), 29026 (move up one character row), 29005 (move down one character row) or 29005 (move down one character row) respectively.
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| 28988 | JP Z,29005 | ...then jump to routine to move up or down one character row | ||||||||
| 28991 | INC HL | Advance HL to next (or previous) byte in attribute file | ||||||||
| 28992 | DJNZ 28979 | Decrease B (repeat count) and loop back to 28979 if not zero | ||||||||
| 28994 | INC IX | Advance IX by two bytes in RLE attribute data... | ||||||||
| 28996 | INC IX | ... | ||||||||
| 28998 | JP 28968 | Loop back to 28968 for this new data | ||||||||
| 29001 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 29002 | JP 28070 | Advance to next room layout data entry and paint its attributes | ||||||||
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Move down one character row
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| 29005 | EXX | Switch registers | ||||||||
| 29006 | LD A,(23496) | Load A with one more than y-coordinate of bottom edge of area to paint... | ||||||||
| 29009 | INC A | ... | ||||||||
| 29010 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 29011 | INC B | Increase B (i.e. move down a character row) | ||||||||
| 29012 | PUSH BC | Store BC (B = updated y-coordinate, C = initial x-coordinate) | ||||||||
| 29013 | CP B | If B is the same as A (i.e. we are now outside the area to be painted)... | ||||||||
| 29014 | JP Z,29001 | ...then jump to 29001 | ||||||||
| 29017 | CALL 54148 | Load HL with attribute file address for coordinates (C, B) and load E with x-coordinate (characters) | ||||||||
| 29020 | PUSH HL | Store HL (new attribute file address) | ||||||||
| 29021 | EXX | Switch registers | ||||||||
| 29022 | POP HL | Restore HL (new attribute file address) | ||||||||
| 29023 | JP 28992 | Jump back to 28992 and continue painting | ||||||||
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Move up one character row
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| 29026 | EXX | Switch registers | ||||||||
| 29027 | LD A,(23494) | Load A with one less than y-coordinate of top edge of area to paint... | ||||||||
| 29030 | DEC A | ... | ||||||||
| 29031 | POP BC | Restore BC (B = current y-coordinate, C = initial x-coordinate) | ||||||||
| 29032 | DEC B | Increase B (i.e. move down a character row) | ||||||||
| 29033 | JP 29012 | Jump back to 29012 | ||||||||
| Prev: 28906 | Up: Map | Next: 29036 |