Mike Harris' Blog - The old Porkchop Express!

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The title of course has nothing to do with my entry.

New update coming soon.
As far as I can tell all mapping bugs have been fixed.
When I upload the new rom then you tell me what you find.

No more going through or getting caught in walls.

Kids...This was a huge pain in the %%%.
The interesting thing is is when I finished and optimized the check routines it seems so simple.
Just like replacing Spock's brain...A child could do it.

The great part is that I can use these routines in all my new games coming.

Still have to incorporate Diagonal movement and then the new rom will be released.
Next will be optimize pick up routine which I plan to have directional pickup.
As in pick up from the left then item will be on the right and so forth.

Here is a sample of my movement code.
NORTH:
LD A, 01
LD (DIRECTION_RAM), A

 

LD A,(SPRTBL)
SUB A, 02 ; Y Offset
LD (SPRTBL),A
CALL MAP_TO_SPRITE ; Get Pattern, Wall?
AND A
JP NZ, WALL_NORTH ; Hit North Wall
LD A,(SPRTBL+1)
ADD A, 09 ; X Offset
LD (SPRTBL+1),A
CALL MAP_TO_SPRITE ; Get Pattern, Wall?
AND A
JP NZ, WALL_NORTH_2 ; Hit North Wall Offset

 

LD A,(SPRTBL+1)
SUB A, 09 ; Return X Value
LD (SPRTBL+1),A

 

LD A,(SPRTBL)
DEC A ; Return Y Value + Move North
CP 02 ; Check Screen Edge
JP C, GOING_NORTH ; Going North
RET
WALL_NORTH:
LD A,(SPRTBL)
ADD A, 03 ; Bounce Player, Return Y Value
LD (SPRTBL),A
RET
WALL_NORTH_2:
LD A,(SPRTBL+1)
SUB A, 09 ; Return X Value
LD (SPRTBL+1),A
LD A,(SPRTBL)
ADD A, 03 ; Bounce Player, Return Y Value
LD (SPRTBL),A
RET
GOING_NORTH:
LD A, 182
LD (SPRTBL),A ; Player to the Bottom
LD C, 01
CALL PRINT_ROOM
RET

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