Routines
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E114: Add Map Objects
Used by the routine at LoadMapObjects.
Puts the objects of one column of the map in free slots of the map objects. An object is skipped if the current player has destroyed it (bit 7 of its byte in the table at MapTable is set, or bit 6 for player two), if it is not on one of the two rows that are on the screen or if there is already a slot for it. It is put in the first free slot of the first three slots, or in the fourth if none of them is free. Its column, row, position and kind are set from the tables. The slot holds the index of the object in offsets 18 and 19 so that the object can be marked as destroyed later.
Input
B Number of objects in the column
C Column
HL Address of the first object in MapTable
IX Address of the first object in TerrainData
AddMapObjects E114 AND A Return if A is zero.
E115 RET Z
AddMapObjects_Next2 E116 PUSH BC Stash BC on the stack.
E117 BIT 7,(HL) Jump to AddMapObjects_Skip if bit 7 of the byte at the address in HL is set.
E119 JP NZ,AddMapObjects_Skip
E11C LD A,(IX+$01) Read offset 01 of IX.
E11F AND %00011111 Keep the bits of A that are set in 1F.
E121 LD E,A E=A.
E122 LD A,($CE58) The map row.
E125 CP E Jump to AddMapObjects_Search if A is E.
E126 JR Z,AddMapObjects_Search
E128 INC A Advance A.
E129 CP E Jump to AddMapObjects_Skip if A is not E.
E12A JP NZ,AddMapObjects_Skip
AddMapObjects_Search E12D LD IY,$A80B The map object slots.
E131 LD B,$04 B=04.
AddMapObjects_Search2 E133 LD A,(IY+$00) Read offset 00 of IY.
E136 INC A Advance A.
E137 JR Z,AddMapObjects_Next Jump to AddMapObjects_Next if the zero flag is set.
E139 LD A,(IY+$01) Read offset 01 of IY.
E13C CP C Jump to AddMapObjects_Next if A is not C.
E13D JR NZ,AddMapObjects_Next
E13F LD A,(IY+$04) Read offset 04 of IY.
E142 CP E Jump to AddMapObjects_Skip if A is E.
E143 JP Z,AddMapObjects_Skip
AddMapObjects_Next E146 LD A,E A=E.
E147 LD DE,$001A DE=1A.
E14A ADD IY,DE IY gains DE.
E14C LD E,A E=A.
E14D DJNZ AddMapObjects_Search2 Decrease B and jump to AddMapObjects_Search2 until none remain.
AddMapObjects_Free E14F LD IY,$A80B The map object slots.
E153 LD B,$03 B=03.
AddMapObjects_SearchSecond E155 LD A,(IY+$00) Read offset 00 of IY.
E158 INC A Advance A.
E159 JR Z,AddMapObjects_Fill Jump to AddMapObjects_Fill if the zero flag is set.
E15B LD A,E A=E.
E15C LD DE,$001A DE=1A.
E15F ADD IY,DE IY gains DE.
E161 LD E,A E=A.
E162 DJNZ AddMapObjects_SearchSecond Decrease B and jump to AddMapObjects_SearchSecond until none remain.
AddMapObjects_Fill E164 PUSH IX Stash IX on the stack.
E166 PUSH IY Stash IY on the stack.
E168 POP IX Bring IX back off the stack.
E16A POP IY Bring IY back off the stack.
E16C CALL FreeObjectSlot Call FreeObjectSlot.
E16F PUSH IX Stash IX on the stack.
E171 PUSH IY Stash IY on the stack.
E173 POP IX Bring IX back off the stack.
E175 POP IY Bring IY back off the stack.
E177 LD (IY+$04),E Write E to offset 04 of IY.
E17A LD (IY+$00),$0D Store 0D at offset 00 of IY.
E17E LD A,(HL) Read HL.
E17F AND %00111111 Keep the bits of A that are set in 3F.
E181 LD (IY+$13),A Write A to offset 13 of IY.
E184 PUSH HL Stash HL on the stack.
E185 LD HL,$E205 The object attributes.
E188 CALL AddAToHL Call AddAToHL.
E18B LD A,(HL) Read HL.
E18C LD (IY+$0D),A Write A to offset 0D of IY.
E18F LD HL,$E0FD The object kinds.
E192 LD A,(IY+$13) Read offset 13 of IY.
E195 CALL AddAToHL Call AddAToHL.
E198 LD A,(HL) Read HL.
E199 AND %11100000 Keep the bits of A that are set in E0.
E19B SRL A Shift A right.
E19D SRL A Shift A right.
E19F SRL A Shift A right.
E1A1 SRL A Shift A right.
E1A3 LD (IY+$18),A Write A to offset 18 of IY.
E1A6 BIT 4,(HL) Jump to AddMapObjects_Position if bit 4 of the byte at the address in HL is clear.
E1A8 JR Z,AddMapObjects_Position
E1AA LD A,(HL) Read HL.
E1AB AND %00001111 Keep the bits of A that are set in 0F.
E1AD LD HL,$E10E The special object states.
E1B0 CALL AddAToHL Call AddAToHL.
E1B3 LD A,(HL) Read HL.
E1B4 LD (IY+$13),A Write A to offset 13 of IY.
E1B7 INC HL Advance HL.
E1B8 LD A,(HL) Read HL.
E1B9 LD (IY+$14),A Write A to offset 14 of IY.
E1BC LD (IY+$15),$80 Store 80 at offset 15 of IY.
E1C0 LD (IY+$00),$1B Store 1B at offset 00 of IY.
AddMapObjects_Position E1C4 POP HL Bring HL back off the stack.
E1C5 LD DE,($CE3A) Fetch the word at ScratchValues into DE.
E1C9 LD A,D A=D.
E1CA OR (IY+$18) Set the bits of A that are set in the byte at offset 18 of IY.
E1CD LD (IY+$18),A Write A to offset 18 of IY.
E1D0 LD (IY+$19),E Write E to offset 19 of IY.
E1D3 LD (IY+$01),C Write C to offset 01 of IY.
E1D6 LD A,(IX+$00) Read offset 00 of IX.
E1D9 AND %11111100 Keep the bits of A that are set in FC.
E1DB DEC A Step A back.
E1DC LD (IY+$05),A Write A to offset 05 of IY.
E1DF LD A,(IX+$00) Read offset 00 of IX.
E1E2 AND %00000011 Keep the bits of A that are set in 03.
E1E4 ADD A,A Double A.
E1E5 ADD A,A Double A.
E1E6 ADD A,A Double A.
E1E7 LD E,A E=A.
E1E8 LD A,(IX+$01) Read offset 01 of IX.
E1EB AND %11100000 Keep the bits of A that are set in E0.
E1ED OR E Set the bits of A that are set in E.
E1EE LD (IY+$02),A Write A to offset 02 of IY.
AddMapObjects_Skip E1F1 INC IX Advance IX.
E1F3 INC IX Advance IX.
E1F5 INC HL Advance HL.
E1F6 LD DE,($CE3A) Fetch the word at ScratchValues into DE.
E1FA INC DE Advance DE.
E1FB LD ($CE3A),DE The next object in the column.
E1FF POP BC Bring BC back off the stack.
E200 DEC B Step B back.
E201 JP NZ,AddMapObjects_Next2 Jump to AddMapObjects_Next2 if the zero flag is clear.
E204 RET Return.
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