Daily SMB HL Disassembly Post #5

Presented with little comment: This is how SMB decides if you have completed a castle correctly (World 4, 7 and 8).

01 ; loop command data 02 LoopCmdWorldNumber: ; world number is one less than world displayed 03 .byte $03, $03, $06, $06, $06, $06, $06, $06, $07, $07, $07 04 LoopCmdPageNumber: 05 .byte $05, $09, $04, $05, $06, $08, $09, $0a, $06, $0b, $10 06 LoopCmdYPosition: 07 .byte $40, $b0, $b0, $80, $40, $40, $80, $40, $f0, $f0, $f0 08 09 .code 10 11 .proc ExecGameLoopback 12 13 mb Player_PageLoc := Player_PageLoc - #4 ; send player back 4 pages 14 mb CurrentPageLoc := CurrentPageLoc - #4 ; send current page back 4 pages 15 mb ScreenLeft_PageLoc := ScreenLeft_PageLoc - #4 ; ..etc 16 mb ScreenRight_PageLoc := ScreenRight_PageLoc - #4 17 mb AreaObjectPageLoc := AreaObjectPageLoc - #4 18 19 lda #$00 ; initialize page select for both 20 sta EnemyObjectPageSel ; area and enemy objects 21 sta AreaObjectPageSel 22 sta EnemyDataOffset ; initialize enemy object data offset 23 sta EnemyObjectPageLoc ; and enemy object page control 24 25 mb AreaDataOffset := AreaDataOfsLoopback[ y ] ; adjust area object offset based on which loop command we encountered 26 27 rts 28 29 .endproc 30 31 32 .proc ProcLoopCommand 33 34 if LoopCommand && CurrentColumnPos == zero ; check if loop command was found 35 36 ldy #$0b ; start at the end of each set of loop data 37 38 repeat 39 40 if dey == negative goto ChkEnemyFrenzy ; if no matching loops, do next 41 42 ; check to see if one of the world numbers matches our current world number AND 43 ; if one of the page numbers matches the page we're currently on: 44 45 until WorldNumber = LoopCmdWorldNumber[ y ] && CurrentPageLoc = LoopCmdPageNumber[ y ] 46 47 ; fall through to check player postion: 48 ; if the player is at the correct position AND on solid ground (i.e. not jumping or falling) 49 if Player_Y_Position = LoopCmdYPosition[ y ] && Player_State = #0 50 51 ; are we in world 7? 52 if WorldNumber <> #World7 goto InitMultLoop 53 54 inc MultiLoopCorrectCntr ; increment counter for correct progression 55 56 IncLoopPass: 57 58 inc MultiLoopPassCntr ; increment master multi-part counter 59 if MultiLoopPassCntr <> #3 goto InitLCmd ; have we done all three parts? 60 if MultiLoopCorrectCntr = #3 goto InitMultLoop ; if so, have we done them all correctly? 61 62 else Z clear 63 if WorldNumber = #World7 goto IncLoopPass ; are we in world 7? 64 endif 65 66 67 jsr ExecGameLoopback ; if player is not in right place, loop back 68 jsr KillAllEnemies 69 70 InitMultLoop: 71 72 lda #$00 ; initialize counters used for multi-part loop commands 73 sta MultiLoopPassCntr 74 sta MultiLoopCorrectCntr 75 76 InitLCmd: 77 78 lda #$00 ; initialize loop command flag 79 sta LoopCommand 80 81 endif 82 83 .endproc