Routines
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54883: Draw Tile Pixels
Used by the routines at DrawReward and DrawTile.
Draws the pixels of a tile of eight by eight pixels. Bit 7 of the number of the tile says that it is reflected vertically and bit 6 that it is reflected horizontally.
Input
A The number of the tile, with bits 6 and 7 which say how to reflect it
BC The address of the tile set
HL The screen address
Find the pixels of the tile.
DrawTilePixels 54883 PUSH BC Save the registers.
54884 PUSH DE
54885 PUSH HL
54886 PUSH AF
54887 EX DE,HL Keep the screen address in DE.
54888 AND %00111111 Keep the number of the tile.
54890 LD L,A Move it to HL.
54891 LD H,0
54893 ADD HL,HL Multiply it by eight.
54894 ADD HL,HL
54895 ADD HL,HL
54896 ADD HL,BC Add the address of the tile set.
54897 EX DE,HL Put the address of the tile in DE and the screen address in HL.
Choose how to reflect it.
54898 POP AF Restore the number of the tile.
54899 RLCA Move bits 6 and 7 to bits 0 and 1.
54900 RLCA
54901 AND %00000011 Keep them.
54903 JR Z,DrawTilePixels_Normal Jump to draw the tile as it is if neither is set.
54905 DEC A Count down.
54906 JR Z,DrawTilePixels_Horizontal Jump to draw it reflected horizontally if that was one.
54908 DEC A Count down.
54909 JR Z,DrawTilePixels_Vertical Jump to draw it reflected vertically if that was two.
54911 CALL DrawTileBoth Otherwise draw it reflected both ways.
DrawTilePixels_Done 54914 POP HL Restore the registers and return.
54915 POP DE
54916 POP BC
54917 RET
DrawTilePixels_Normal 54918 CALL DrawTileNormal Draw the tile as it is.
54921 JR DrawTilePixels_Done
DrawTilePixels_Horizontal 54923 CALL DrawTileHorizontal Draw the tile reflected horizontally.
54926 JR DrawTilePixels_Done
DrawTilePixels_Vertical 54928 CALL DrawTileVertical Draw the tile reflected vertically.
54931 JR DrawTilePixels_Done
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