83 lines
2.6 KiB
Plaintext
83 lines
2.6 KiB
Plaintext
This folder contains the rendering tuples for the different type of tile rendering modes
|
|
that are defined by both the engine mode and the specific tile attributes. There are
|
|
a *lot* or variants, so they are cataloged here.
|
|
|
|
The top-level TileRender function in the main entry point that defined the overal tile render
|
|
flow as well as the register parameters and calling conventions for each of the modular
|
|
components.
|
|
|
|
There are 5 pluggable functions that make up a rendering mode
|
|
|
|
1. K_TS_BASE_TILE_DISP
|
|
|
|
An address to a function that will render a tile into the code field. There are no
|
|
sprites to handle in this case.
|
|
|
|
Arguments:
|
|
A: TileData/TileMask address
|
|
B: code field bank
|
|
Y: address of the tile in the code bank
|
|
X: TileStore offset
|
|
|
|
Return:
|
|
None
|
|
|
|
If additional TileStore properties are needed for the renderer, they can be read using the X
|
|
register.
|
|
|
|
2. K_TS_SPRITE_TILE_DISP
|
|
|
|
Selects the top-level handler for rendering a tile with a sprite. Currently, this is used to
|
|
select between rendering a sprite above the tile, or under the tile based on the value of the
|
|
TILE_PRIORITY_BIT.
|
|
|
|
Arguments:
|
|
A: TileStore+TS_SPRITE_FLAG
|
|
X: TileStore offset
|
|
|
|
Return:
|
|
Y: TileStore offset
|
|
sprite_ptrX dirct page values set to the sprite VBuff addresses
|
|
|
|
The handler routine is responsible for examining the TS_SPRITE_FLAG value and dispatching
|
|
to an appropriate routine to handle the number of sprites intersecting the tile.
|
|
|
|
3. K_TS_ONE_SPRITE
|
|
|
|
A specialized routine when K_TS_SPRITE_TILE_DISP determines there is only one sprite to render
|
|
it MUST dispatch to this function. The K_TS_ONE_SPRITE routine MAY make use of the K_TS_COPY_TILE_DATA
|
|
and K_TS_APPLY_TILE_DATA functions, but is not required to do so.
|
|
|
|
4. K_TS_COPY_TILE_DATA & K_TS_APPLY_TILE_DATA
|
|
|
|
A pair of function that copye tile data (and possible mask information) into a temporary
|
|
direct page space and then render that workspace into the code field.
|
|
|
|
These functions are used as building blocks by the generic Over/Under multi-sprite
|
|
rendering code.
|
|
|
|
K_TS_COPY_TILE_DATA
|
|
Arguments:
|
|
B: Set to the TileData bank
|
|
Y: Set to the tile address
|
|
Return:
|
|
X: preserve the X register
|
|
|
|
K_TS_APPLY_TILE_DATA
|
|
Arguments:
|
|
B: code field bank
|
|
Y: address of the tile in the code bank
|
|
Return:
|
|
None
|
|
|
|
|
|
|
|
Generic Flow
|
|
|
|
1. Is there a sprite?
|
|
No -> Call K_TS_BASE_TILE_DISP to render a tile into the code field
|
|
|
|
Yes -> Call K_TS_SPRITE_TILE_DISP
|
|
|
|
Over : Copy tile data + mask to DP, Copy sprite data + mask to DP, render tile to code field
|
|
Under : Copy sprite data to DP, |