Difference between revisions of "Extend the level index past $10 in Sonic 2"
From Sonic Retro
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You will find a link to the archive with the extra data files (sprite 34 mappings included) at the end of the tutorial. | You will find a link to the archive with the extra data files (sprite 34 mappings included) at the end of the tutorial. | ||
+ | |||
+ | Now we want to locate: | ||
+ | <asm> | ||
+ | ; off_19F4: | ||
+ | PalCycle: | ||
+ | dc.w PalCycle_EHZ - PalCycle ; 0 | ||
+ | dc.w PalCycle_Null - PalCycle ; 1 | ||
+ | dc.w PalCycle_Level2 - PalCycle ; 2 | ||
+ | dc.w PalCycle_Null - PalCycle ; 3 | ||
+ | dc.w PalCycle_MTZ - PalCycle ; 4 | ||
+ | dc.w PalCycle_MTZ - PalCycle ; 5 | ||
+ | dc.w PalCycle_WFZ - PalCycle ; 6 | ||
+ | dc.w PalCycle_HTZ - PalCycle ; 7 | ||
+ | dc.w PalCycle_HPZ - PalCycle ; 8 | ||
+ | dc.w PalCycle_Null - PalCycle ; 9 | ||
+ | dc.w PalCycle_OOZ - PalCycle ; 10 | ||
+ | dc.w PalCycle_MCZ - PalCycle ; 11 | ||
+ | dc.w PalCycle_CNZ - PalCycle ; 12 | ||
+ | dc.w PalCycle_CPZ - PalCycle ; 13 | ||
+ | dc.w PalCycle_CPZ - PalCycle ; 14 | ||
+ | dc.w PalCycle_ARZ - PalCycle ; 15 | ||
+ | dc.w PalCycle_WFZ - PalCycle ; 16 | ||
+ | </asm> | ||
+ | |||
+ | and replace it with: | ||
+ | <asm> | ||
+ | ; off_19F4: | ||
+ | PalCycle: | ||
+ | dc.w PalCycle_EHZ - PalCycle ; 00 | ||
+ | dc.w PalCycle_Null - PalCycle ; 01 | ||
+ | dc.w PalCycle_Level2 - PalCycle ; 02 | ||
+ | dc.w PalCycle_Null - PalCycle ; 03 | ||
+ | dc.w PalCycle_MTZ - PalCycle ; 04 | ||
+ | dc.w PalCycle_MTZ - PalCycle ; 05 | ||
+ | dc.w PalCycle_WFZ - PalCycle ; 06 | ||
+ | dc.w PalCycle_HTZ - PalCycle ; 07 | ||
+ | dc.w PalCycle_HPZ - PalCycle ; 08 | ||
+ | dc.w PalCycle_Null - PalCycle ; 09 | ||
+ | dc.w PalCycle_OOZ - PalCycle ; 0A | ||
+ | dc.w PalCycle_MCZ - PalCycle ; 0B | ||
+ | dc.w PalCycle_CNZ - PalCycle ; 0C | ||
+ | dc.w PalCycle_CPZ - PalCycle ; 0D | ||
+ | dc.w PalCycle_CPZ - PalCycle ; 0E | ||
+ | dc.w PalCycle_ARZ - PalCycle ; 0F | ||
+ | dc.w PalCycle_WFZ - PalCycle ; 10 | ||
+ | dc.w PalCycle_Null - PalCycle ; 11 | ||
+ | dc.w PalCycle_Null - PalCycle ; 12 | ||
+ | dc.w PalCycle_Null - PalCycle ; 13 | ||
+ | dc.w PalCycle_Null - PalCycle ; 14 | ||
+ | dc.w PalCycle_Null - PalCycle ; 15 | ||
+ | dc.w PalCycle_Null - PalCycle ; 16 | ||
+ | dc.w PalCycle_Null - PalCycle ; 17 | ||
+ | dc.w PalCycle_Null - PalCycle ; 18 | ||
+ | dc.w PalCycle_Null - PalCycle ; 19 | ||
+ | dc.w PalCycle_Null - PalCycle ; 1A | ||
+ | dc.w PalCycle_Null - PalCycle ; 1B | ||
+ | dc.w PalCycle_Null - PalCycle ; 1C | ||
+ | dc.w PalCycle_Null - PalCycle ; 1D | ||
+ | dc.w PalCycle_Null - PalCycle ; 1E | ||
+ | dc.w PalCycle_Null - PalCycle ; 1F | ||
+ | dc.w PalCycle_Null - PalCycle ; 20 | ||
+ | </asm> | ||
+ | |||
+ | That inserts empty slots for the cycling palettes of out new levels. |
Revision as of 12:22, 29 April 2008
WARNING: I strongly recommend you port the sonic1 sound driver first before proceeding. A lot of major data shifting will occur in this tutorial and it will make the rom size a lot bigger than it was before. This will break the sonic2 or even sonic2 beta sound driver, thus so you definitely want the sonic 1 sound driver due to the fact that it can take the shifting and still work properly.
You probably noticed that all the indexes in the game stop at $10 and when you try to extend it, by extending the MLLB, you get weird glitches or even crashes, that is because you haven't extended all the indexes that need to be extended.
first we will look at the data that defines the titlecard layout:
<asm>
- word_13CD4
Obj34_TitleCardData: dc.b 8, 0, $80, $1B dc.w $240, $120, $B8
dc.b $A, $11, $40, $1C dc.w $28, $148, $D0
dc.b $C, $12, $18, $1C dc.w $68, $188, $D0
dc.b 2, 0, 0, 0 dc.w 0, 0, 0
dc.b 4, $15, $48, 8 dc.w $2A8, $168,$120
dc.b 6, $16, 8, $15 dc.w $80, $F0, $F0 </asm>
we want to change it to:
<asm>
- word_13CD4
Obj34_TitleCardData: dc.b 8, 0, $80, $1B; Index 0 is the start of Zone names dc.w $240, $120, $B8
dc.b $A, $21, $40, $1C; Use index $21 to load the "ZONE" string dc.w $28, $148, $D0
dc.b $C, $22, $18, $1C; Use index $22 as the index for act 1, $23 for act 2, $24 for act 3 dc.w $68, $188, $D0
dc.b 2, 0, 0, 0; I have no idea what this is. dc.w 0, 0, 0
dc.b 4, $25, $48, 8; Use index $25 for "SONIC THE HEDGEHOG" string dc.w $2A8, $168,$120
dc.b 6, $26, 8, $15; Use index $26 for red panel edge dc.w $80, $F0, $F0 </asm>
That change allows us to make room for our extra 16 levels.
Next we locate: <asm>
- loc_157D2
LoadTitleCard: bsr.s LoadTitleCard0 moveq #0,d0 move.b (Current_Zone).w,d0 move.b byte_15820(pc,d0.w),d0 lea word_15832(pc),a0 lea (a0,d0.w),a0 move.l #$7BC00002,d0 </asm>
and replace it with: <asm>
- loc_157D2
LoadTitleCard: bsr.s LoadTitleCard0 moveq #0,d0 move.b (Current_Zone).w,d0 add.w d0,d0 move.w Off_FontIndexes(pc,d0.w),d0 lea Off_FontIndexes(pc,d0.w),a0 move.l #$7BC00002,d0 </asm>
Next we locate: <asm>
- unknown
byte_15820: dc.b 0, 0, 0, 0,$10,$10,$98,$20,$2C, 0,$3C,$46,$58,$68,$A8,$7A dc.b $8A, 0 ; 16
- unknown
word_15832: dc.w $2A06,$3804, 4,$2604, $C04,$1804,$1C02,$FFFF dc.w $2A06,$4004,$3804,$3004,$2604,$1C02,$3C04,$FFFF; 8 dc.w $1804,$1C02,$2604,$4004,$3004,$FFFF,$1804,$1C02; 16 dc.w $C04,$3004, 4,$2604, $804,$FFFF,$1C02,$2604; 24 dc.w $804, 4,$FFFF,$2A06,$5604,$3C04,$4004,$1C02; 32 dc.w $804, 4,$4804,$FFFF, $804, 4,$3C04,$1C02; 40 dc.w $1404,$1804,$4004,$FFFF, $804,$1804,$2A06,$1C02; 48 dc.w 4,$2604,$3004,$4004,$FFFF, 4,$3404,$4404; 56 dc.w $4004,$1C02, $804,$3804,$FFFF,$3C04,$2204,$5604; 64 dc.w $804,$1804, 4,$FFFF,$4C06,$1C02,$1404,$1004; 72 dc.w $3804,$4004,$3C04,$FFFF, $C04, 4,$4004,$1804; 80 dc.w $1404,$FFFF ; 88 </asm>
and replace it with: <asm>; offset index to loaded artwork index for titlecards Off_FontIndexes: dc.w FontIndex_EHZ-Off_FontIndexes dc.w FontIndex_LZ-Off_FontIndexes dc.w FontIndex_WZ-Off_FontIndexes dc.w FontIndex_DHZ-Off_FontIndexes dc.w FontIndex_MTZ-Off_FontIndexes dc.w FontIndex_MTZ-Off_FontIndexes dc.w FontIndex_WFZ-Off_FontIndexes dc.w FontIndex_HTZ-Off_FontIndexes dc.w FontIndex_HPZ-Off_FontIndexes dc.w FontIndex_GCZ-Off_FontIndexes dc.w FontIndex_OOZ-Off_FontIndexes dc.w FontIndex_MCZ-Off_FontIndexes dc.w FontIndex_CNZ-Off_FontIndexes dc.w FontIndex_CPZ-Off_FontIndexes dc.w FontIndex_DEZ-Off_FontIndexes dc.w FontIndex_ARZ-Off_FontIndexes dc.w FontIndex_SCZ-Off_FontIndexes dc.w FontIndex_Lev11-Off_FontIndexes dc.w FontIndex_Lev12-Off_FontIndexes dc.w FontIndex_Lev13-Off_FontIndexes dc.w FontIndex_Lev14-Off_FontIndexes dc.w FontIndex_Lev15-Off_FontIndexes dc.w FontIndex_Lev16-Off_FontIndexes dc.w FontIndex_Lev17-Off_FontIndexes dc.w FontIndex_Lev18-Off_FontIndexes dc.w FontIndex_Lev19-Off_FontIndexes dc.w FontIndex_Lev1A-Off_FontIndexes dc.w FontIndex_Lev1B-Off_FontIndexes dc.w FontIndex_Lev1C-Off_FontIndexes dc.w FontIndex_Lev1D-Off_FontIndexes dc.w FontIndex_Lev1E-Off_FontIndexes dc.w FontIndex_Lev1F-Off_FontIndexes dc.w FontIndex_Lev20-Off_FontIndexes
- Letters displayed on EHZ titlecard
FontIndex_EHZ: dc.w $2A06,$3804, 4,$2604, $C04,$1804,$1C02,$FFFF
- Letters displayed on LZ titlecard
FontIndex_LZ: dc.w $2604, 4, $404,$3804,$1C02,$4004,$1804,$FFFF
- Letters displayed on WZ titlecard
FontIndex_WZ: dc.w $4C06, $C04,$FFFF
- Letters displayed on DHZ titlecard
FontIndex_DHZ: dc.w $C04,$4404,$3C04,$4004,$1804,$1C02,$2604,$FFFF
- Letters displayed on MTZ titlecard
FontIndex_MTZ: dc.w $2A06,$4004,$3804,$3004,$2604,$1C02,$3C04,$FFFF
- Letters displayed on WFZ titlecard
FontIndex_WFZ: dc.w $4C06,$1C02,$1404,$1004,$3804,$4004,$3C04,$FFFF
- Letters displayed on HTZ titlecard
FontIndex_HTZ: dc.w $1804,$1C02,$2604,$4004,$3004,$FFFF
- Letters displayed on HPZ titlecard
FontIndex_HPZ: dc.w $1804,$1C02, $C04,$3004, 4,$2604, $804,$FFFF
- Letters displayed on GCZ titlecard
FontIndex_GCZ: dc.w $1404, $804,$1C02, $C04,$4004,$5604,$FFFF
- Letters displayed on OOZ titlecard
FontIndex_OOZ: dc.w $1C02,$2604, $804, 4,$FFFF
- Letters displayed on MCZ titlecard
FontIndex_MCZ: dc.w $2A06,$5604,$3C04,$4004,$1C02, $804, 4,$4804 dc.w $FFFF
- Letters displayed on CNZ titlecard
FontIndex_CNZ: dc.w $804, 4,$3C04,$1C02,$1404,$1804,$4004,$FFFF
- Letters displayed on CPZ titlecard
FontIndex_CPZ: dc.w $804,$1804,$2A06,$1C02, 4,$2604,$3004,$4004 dc.w $FFFF
- Letters displayed on DEZ titlecard
FontIndex_DEZ: dc.w $C04, 4,$4004,$1804,$1404,$FFFF
- Letters displayed on ARZ titlecard
FontIndex_ARZ: dc.w 4,$3404,$4404,$4004,$1C02, $804,$3804,$FFFF
- Letters displayed on SCZ titlecard
FontIndex_SCZ: dc.w $3C04,$2204,$5604, $804,$1804, 4,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev11: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev12: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev13: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev14: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev15: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev16: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev17: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev18: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev19: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1A: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1B: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1C: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1D: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1E: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev1F: dc.w $4606,$2604,$4804,$FFFF
- Letters displayed on New Level titlecard
FontIndex_Lev20: dc.w $4606,$2604,$4804,$FFFF </asm>
The original 8-bit proprietary offset index just won't cut it for the scope of this tutorial, so we replaced it with a much friendlier 16-bit relative offset index. also, we changed the order of the text artwork loading data to something much easier to manage, and added not only the ESE names for the empty levels that were already there, and you may choose to change again later, but also the slots for the new levels too. (they will read "NEW LEVEL ZONE" until you give the levels names and change the data here and mappings for those level titlecards.
You will find a link to the archive with the extra data files (sprite 34 mappings included) at the end of the tutorial.
Now we want to locate: <asm>
- off_19F4
PalCycle: dc.w PalCycle_EHZ - PalCycle ; 0 dc.w PalCycle_Null - PalCycle ; 1 dc.w PalCycle_Level2 - PalCycle ; 2 dc.w PalCycle_Null - PalCycle ; 3 dc.w PalCycle_MTZ - PalCycle ; 4 dc.w PalCycle_MTZ - PalCycle ; 5 dc.w PalCycle_WFZ - PalCycle ; 6 dc.w PalCycle_HTZ - PalCycle ; 7 dc.w PalCycle_HPZ - PalCycle ; 8 dc.w PalCycle_Null - PalCycle ; 9 dc.w PalCycle_OOZ - PalCycle ; 10 dc.w PalCycle_MCZ - PalCycle ; 11 dc.w PalCycle_CNZ - PalCycle ; 12 dc.w PalCycle_CPZ - PalCycle ; 13 dc.w PalCycle_CPZ - PalCycle ; 14 dc.w PalCycle_ARZ - PalCycle ; 15 dc.w PalCycle_WFZ - PalCycle ; 16 </asm>
and replace it with: <asm>
- off_19F4
PalCycle: dc.w PalCycle_EHZ - PalCycle ; 00 dc.w PalCycle_Null - PalCycle ; 01 dc.w PalCycle_Level2 - PalCycle ; 02 dc.w PalCycle_Null - PalCycle ; 03 dc.w PalCycle_MTZ - PalCycle ; 04 dc.w PalCycle_MTZ - PalCycle ; 05 dc.w PalCycle_WFZ - PalCycle ; 06 dc.w PalCycle_HTZ - PalCycle ; 07 dc.w PalCycle_HPZ - PalCycle ; 08 dc.w PalCycle_Null - PalCycle ; 09 dc.w PalCycle_OOZ - PalCycle ; 0A dc.w PalCycle_MCZ - PalCycle ; 0B dc.w PalCycle_CNZ - PalCycle ; 0C dc.w PalCycle_CPZ - PalCycle ; 0D dc.w PalCycle_CPZ - PalCycle ; 0E dc.w PalCycle_ARZ - PalCycle ; 0F dc.w PalCycle_WFZ - PalCycle ; 10 dc.w PalCycle_Null - PalCycle ; 11 dc.w PalCycle_Null - PalCycle ; 12 dc.w PalCycle_Null - PalCycle ; 13 dc.w PalCycle_Null - PalCycle ; 14 dc.w PalCycle_Null - PalCycle ; 15 dc.w PalCycle_Null - PalCycle ; 16 dc.w PalCycle_Null - PalCycle ; 17 dc.w PalCycle_Null - PalCycle ; 18 dc.w PalCycle_Null - PalCycle ; 19 dc.w PalCycle_Null - PalCycle ; 1A dc.w PalCycle_Null - PalCycle ; 1B dc.w PalCycle_Null - PalCycle ; 1C dc.w PalCycle_Null - PalCycle ; 1D dc.w PalCycle_Null - PalCycle ; 1E dc.w PalCycle_Null - PalCycle ; 1F dc.w PalCycle_Null - PalCycle ; 20 </asm>
That inserts empty slots for the cycling palettes of out new levels.