Sprite Attribute Upload: Difference between revisions

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Core 2.00.22 changes.
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{{Port
{{Port
|Number=$xx57
|Number=$xx57
|ShortDesc=Uploads sprite positions, visibility and effect flags.
|ShortDesc=Uploads sprite positions, visibility, colour type and effect flags.
|PortMask=%---- ---- 0101 0111
|PortMask=%---- ---- 0101 0111
|Readable=No
|Readable=No
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|Subsystem=Sprites
|Subsystem=Sprites
}}
}}
Uploads attributes of the sprite slot selected by {{PortNo|$303B}}. Attributes are in 4 byte blocks sent in the following order; after sending 4 bytes the address auto-increments to the next sprite. This auto-increment is independent of other sprite ports. The 4 bytes are as follows:
Uploads attributes of the sprite slot selected by {{PortNo|$303B}}. Attributes are in 4-5 byte blocks sent in the following order; after sending 4 or 5 bytes the address auto-increments to the next sprite. This auto-increment is independent of other sprite ports. The 4-5 bytes are as follows:


Byte 1 is the low bits of the X position. Legal X positions are 0-319 if sprites are allowed over the border or 32-287 if not. The MSB is in byte 3.
Byte 1 is the low bits of the X position. Legal X positions are 0-319 if sprites are allowed over the border or 32-287 if not. The MSB is in byte 3.


Byte 2 is the Y position. Legal Y positions are 0-255 if sprites are allowed over the border or 32-223 if not.
Byte 2 is the Y position. Legal Y positions are 0-255 if sprites are allowed over the border or 32-223 if not (with "core 2.00.22" there's now Y8 bit in b0 of byte 5, allowing for positions 0-511, but I'm not sure at this moment what are legal values).


Byte 3 is bitmapped:
Byte 3 is bitmapped:
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|}
|}


Byte 4 is also bitmapped:
Byte 4 is bitmapped:
{|class="wikitable"
{|class="wikitable"
! Bit !! Description
! Bit !! Description
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| 7 || Enable visibility
| 7 || Enable visibility
|-
|-
| 6 || Reserved
| 6 || If 1, the optional 5th attribute byte should follow. If 0, only four attribute bytes are expected.
|-
|-
| 5-0 || Pattern index ("Name")
| 5-0 || Pattern index ("Name")
|}
Optional (when bit 6 is set in byte 4) byte 5 is bitmapped:
{|class="wikitable"
! Bit !! Description
|-
| 7 || If 1, the pattern will be treated as 4-bit colour one (128 bytes), 0 is for 8-bit colour patterns (256 bytes)
|-
| 6 || Chooses top/bottom part of pattern slot (for 4-bit colour patterns)
|-
| 5 || Reserved, use always 0
|-
| 4-3 || x-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
|-
| 2-1 || y-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
|-
| 0 || MSB of Y coordinate
|}
|}

Revision as of 02:49, 20 December 2018

Number PortNumber::$xx57
Decimal NumberDec::
Short desc. ShortDesc::Uploads sprite positions, visibility, colour type and effect flags.
Bit Mask PortMask::%---- ---- 0101 0111
Readable Readable::No
Writable Writable::Yes
Subsystem Subsystem::Sprites

Uploads attributes of the sprite slot selected by {{#ask: PortNumber::$303B }} ($303B{{#ask: PortNumber::$303B |mainlabel=- |headers=hide |intro= /  |?NumberDec#- }}). Attributes are in 4-5 byte blocks sent in the following order; after sending 4 or 5 bytes the address auto-increments to the next sprite. This auto-increment is independent of other sprite ports. The 4-5 bytes are as follows:

Byte 1 is the low bits of the X position. Legal X positions are 0-319 if sprites are allowed over the border or 32-287 if not. The MSB is in byte 3.

Byte 2 is the Y position. Legal Y positions are 0-255 if sprites are allowed over the border or 32-223 if not (with "core 2.00.22" there's now Y8 bit in b0 of byte 5, allowing for positions 0-511, but I'm not sure at this moment what are legal values).

Byte 3 is bitmapped:

Bit Description
4-7 Palette offset, added to each palette index from pattern before drawing
3 Enable X mirror
2 Enable Y mirror
1 Enable rotation
0 MSB of X coordinate

Byte 4 is bitmapped:

Bit Description
7 Enable visibility
6 If 1, the optional 5th attribute byte should follow. If 0, only four attribute bytes are expected.
5-0 Pattern index ("Name")

Optional (when bit 6 is set in byte 4) byte 5 is bitmapped:

Bit Description
7 If 1, the pattern will be treated as 4-bit colour one (128 bytes), 0 is for 8-bit colour patterns (256 bytes)
6 Chooses top/bottom part of pattern slot (for 4-bit colour patterns)
5 Reserved, use always 0
4-3 x-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
2-1 y-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
0 MSB of Y coordinate