Routines
Prev: BA5E Up: Map Next: BB0F
BA70: Draw Level Objects
Used by the routines at BuildView, ScrollViewLeft and ScrollViewRight.
Draws the objects of the level that are near the player. The nine cells around the position of the player are tried in turn, and the objects of the group in each cell are drawn with DrawGroupObjects. There are two entry points, which choose between two versions of the drawing code that is patched at C3D8.
DrawLevelObjects BA70 LD DE,$C59A Draw each row with DrawBlockRow.
BA73 JR DrawLevelObjects_Start
This entry point is used by the routines at ScrollViewDown and ScrollViewUp.
DrawLevelObjects_Second BA75 LD DE,$C717 Test each row with TestBlockRow instead.
This entry point is used by the routine at CollectBottle.
DrawLevelObjects_Start BA78 LD ($C3D8),DE Give that routine to the shape drawer.
BA7C LD ($C0DF),HL Remember where DrawObject should return.
Records at ObjectRecords whose fifth byte is set are copied, seven bytes each, into the table at CopiedRecords.
BA7F LD A,($BD73) There is nothing to copy when the count is zero.
BA82 AND A
BA83 JR Z,DrawLevelObjects_0
BA85 LD B,A Start with none kept.
BA86 LD C,$00
BA88 LD IY,$BD74 Start at the first record.
BA8C LD DE,$BDBB The copies go into CopiedRecords.
DrawLevelObjects_Loop BA8F PUSH BC Remember how many records remain.
BA90 LD A,(IY+$05) Copy a record whose fifth byte is set.
BA93 AND A
BA94 JR Z,DrawLevelObjects_Empty
BA96 PUSH IY Take the seven bytes.
BA98 POP HL
BA99 LD BC,$0007
BA9C LDIR Copy them.
BA9E PUSH HL Move on to the next source record.
BA9F POP IY
BAA1 POP BC Count the copy.
BAA2 INC C
BAA3 JR DrawLevelObjects_Copied
DrawLevelObjects_Empty BAA5 LD BC,$0007 Skip an empty record.
BAA8 ADD IY,BC
BAAA POP BC Bring the counts back.
DrawLevelObjects_Copied BAAB DJNZ DrawLevelObjects_Loop Repeat for the remaining records.
BAAD LD A,C Remember how many records were copied.
BAAE LD ($BDBA),A
DrawLevelObjects_0 BAB1 LD HL,($5CE7) Remember the horizontal view origin.
BAB4 LD ($B16A),HL
BAB7 LD HL,$BBF7 The next item record is the first one.
BABA LD ($B201),HL
BABD LD HL,$BD74 The object records start at ObjectRecords.
BAC0 LD ($BF42),HL
BAC3 LD A,$CD Draw the block bytes with a call.
BAC5 LD ($C75D),A
BAC8 LD HL,$C76D The call draws the block bytes.
BACB LD ($C75E),HL
BACE LD HL,$FFE6 Restore the shape index so that it masks nothing.
BAD1 LD ($C1A0),HL
BAD4 LD A,$1A The row step-back is 1A.
BAD6 LD ($B530),A
BAD9 XOR A Clear the item count and the record count.
BADA LD ($BBF6),A
BADD LD ($BD73),A
BAE0 PUSH IX Remember the entity.
BAE2 LD C,$00 Start at the first cell.
DrawLevelObjects_1 BAE4 PUSH BC Remember the cell number.
BAE5 CALL GetCellPosition Find the cell around the player.
BAE8 CALL SetCarry Accept the cell.
BAEB JR NC,DrawLevelObjects_Next Leave the cell when it is not accepted.
BAED LD HL,($5CB9) Find the cell position for the group.
BAF0 CALL ClearCarry
BAF3 JR C,DrawLevelObjects_Next Leave the cell when it is rejected.
BAF5 LD HL,($5CB9) Find the group at that cell.
BAF8 CALL FindGroup
BAFB JR C,DrawLevelObjects_Next Leave the cell when there is no group.
BAFD LD ($5CDC),DE Remember the group.
BB01 CALL DrawGroupObjects Draw the objects of the group.
DrawLevelObjects_Next BB04 POP BC Bring the cell number back.
BB05 INC C Step on by two cells.
BB06 INC C
BB07 LD A,C Repeat for the nine cells.
BB08 CP $12
BB0A JR NZ,DrawLevelObjects_1
BB0C POP IX Restore the entity.
BB0E RET Return.
Prev: BA5E Up: Map Next: BB0F