Routines
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26195: Find Sprite Frame
Used by the routines at SetEntitySize and DrawSprite.
Finds the address of the sprite which shows an entity. The type of the entity selects a table of frames and the frame number of the entity selects one of the sprites in that table.
Input
IX The entity
Output
DE The address of the sprite
FindSpriteFrame 26195 LD E,(IX+0) Fetch the type of the entity.
26198 LD D,0 Clear D.
26200 LD HL,26270 Point HL at SpriteTable.
26203 ADD HL,DE Add the type twice, as the table has two bytes per entry.
26204 ADD HL,DE
26205 LD E,(HL) Fetch the low byte of the address of the frame table of the type.
26206 INC HL Move onto the high byte.
26207 LD D,(HL) Fetch the high byte of the address of the frame table.
26208 LD A,(IX+1) Fetch the frame number of the entity.
26211 AND %00011111 Keep the frame number in the range 0-31.
26213 ADD A,A Double it, as the table has two bytes per frame.
26214 LD L,A Set HL to the frame number multiplied by two.
26215 LD H,0 Clear the high byte.
26217 ADD HL,DE Add the address of the frame table to find the address of the entry.
26218 LD E,(HL) Fetch the low byte of the address of the sprite.
26219 INC HL Move onto the high byte.
26220 LD D,(HL) Fetch the high byte of the address of the sprite.
26221 RET Return.
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