Routines
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39204: Spawn Food
Used by the routine at DrawRoom.
Called by the main loop. When the counter at CounterLow is zero and bit 0 of CounterHigh is reset, the next of the food items from FoodItems to 60888 is looked at (the food pointer in FoodPointer moves on by 8 bytes, and starts again at FoodItems after the last one). If the item is not in the room of the player and is not already in use then it is made one of the foods (sprite IDs 80 to 87), using FRAMES.
SpawnFood 39204 LD A,(24082) Fetch the counter from CounterLow and keep the low byte of the counter in C.
39207 LD C,A
39208 LD A,(24083) Fetch the high byte of the counter from CounterHigh.
39211 AND %00000001 Keep only bit 0.
39213 OR C Return unless the counter is zero and bit 0 of its high byte is reset.
39214 RET NZ
39215 LD HL,(24149) HL=*FoodPointer.
39218 LD DE,8 DE=0008 (the size of a food item).
39221 ADD HL,DE Move HL on to the next food item.
39222 LD (24149),HL Write HL back to FoodPointer.
39225 PUSH HL Copy HL into IX, as the food item.
39226 POP IX
39228 LD DE,60888 DE=60888 (the end of the food items).
39231 AND A Subtract DE from HL.
39232 SBC HL,DE
39234 JR NC,SpawnFood_Restart Jump to SpawnFood_Restart if the food pointer is past the last item.
39236 LD A,(60049) Fetch the room of the player from PlayerRoom.
39239 CP (IX+1) Return if the player is in the same room.
39242 RET Z
39243 LD A,(IX+0) Fetch the sprite ID of the item.
39246 AND A Return if the item is in use.
39247 RET NZ
39248 LD A,(23672) Fetch FRAMES.
39251 AND %00000111 Keep only bits 0-2.
39253 ADD A,80 Add 80 to make the sprite ID of the food.
39255 LD (IX+0),A Update the sprite ID of the item.
39258 RET Return.
SpawnFood_Restart 39259 LD HL,60248 HL=60248.
39262 LD (24149),HL Write HL to FoodPointer.
39265 RET Return.
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