|
Routines |
| Prev: 28882 | Up: Map | Next: 28985 |
|
Erases the sprite of an actor from where it was last drawn (the old state held in the actor buffer at Actor_Position_X) and draws it at its new position. Both sprites are handled a line at a time by MaskSprite, but if the old and the new Y positions are different then the lines of one sprite that stick out below the other are handled first.
|
||||||||||||
| DisplayEntity | 28929 | LD A,(24098) | Fetch the sprite ID of the old sprite (Actor_SpriteID). | |||||||||
| 28932 | AND A | Jump to DrawEntity if there is no old sprite, as there is nothing to erase. | ||||||||||
| 28933 | JP Z,DrawEntity | |||||||||||
| 28936 | CALL PrepareActorSprite | Call PrepareActorSprite to prepare the new sprite. | ||||||||||
| 28939 | EXX | Switch to the shadow registers (to keep the new sprite). | ||||||||||
| 28940 | CALL PrepareOldSprite | Call PrepareOldSprite to prepare the old sprite. | ||||||||||
| 28943 | LD A,(24097) | A=Actor_Position_Y (the old Y position). | ||||||||||
| 28946 | SUB (IX+2) | Subtract the new Y position. | ||||||||||
| 28949 | JP Z,ActorUpdateSize | Jump to ActorUpdateSize if the old and new Y positions are the same. | ||||||||||
| 28952 | JP M,DisplayEntity_NewLower | Jump to DisplayEntity_NewLower if the new sprite is lower down than the old sprite. | ||||||||||
| 28955 | LD C,A | C=the number of lines that the old sprite sticks out below the new sprite. | ||||||||||
| 28956 | LD A,(24101) | A=CurrentSpriteHeight (the number of lines in the old sprite). | ||||||||||
| 28959 | CP C | Jump to ActorUpdateSize if the old sprite has fewer lines than this. | ||||||||||
| 28960 | JP C,ActorUpdateSize | |||||||||||
| 28963 | SUB C | Subtract the lines that stick out. | ||||||||||
| 28964 | LD (24101),A | Write the number of lines left to CurrentSpriteHeight. | ||||||||||
| 28967 | JP MaskSprite | Jump to MaskSprite to erase the lines that stick out. | ||||||||||
|
The new sprite is lower down, so it has some lines to draw before any lines are erased.
|
||||||||||||
| DisplayEntity_NewLower | 28970 | EXX | Switch to the shadow registers (the new sprite). | |||||||||
| 28971 | NEG | Make the result positive. | ||||||||||
| 28973 | LD C,A | C=the number of lines that the new sprite sticks out below the old sprite. | ||||||||||
| 28974 | LD A,(24102) | A=HeightLines (the number of lines in the new sprite). | ||||||||||
| 28977 | CP C | Jump to ActorUpdateSizeFlipReg if the new sprite has fewer lines than this. | ||||||||||
| 28978 | JP C,ActorUpdateSizeFlipReg | |||||||||||
| 28981 | SUB C | Subtract the lines that stick out. | ||||||||||
| 28982 | JP ActorUpdateHeightAndMask | Jump to ActorUpdateHeightAndMask to store the number of lines left and to draw the lines that stick out. | ||||||||||
|
View the equivalent code in;
|
||||||||||||
| Prev: 28882 | Up: Map | Next: 28985 |
