Sprite Attribute 4 Register: Difference between revisions

Latest revision as of 10:52, 14 October 2025

Number	TBRegisterNumber::$39
Readable	TBRegisterReadable::No
Writable	TBRegisterWritable::Yes
Short Description	[[ShortDesc::Nextreg port-mirror to write directly into "byte 5" of {{#ask: PortNumber::$xx57 }} ($xx57{{#ask: PortNumber::$xx57 \|mainlabel=- \|headers=hide \|intro= / \|?NumberDec#- }}).]]

Byte 5 is bitmapped:

For anchor sprites:

Bit	Description
7-6	"H N6" - "H" is 4/8 bit graphics selector, "N6" is sub-pattern selector for 4 bit modes. %00 = 8-bit colour patterns (256 bytes), this sprite is "anchor" %01 = this sprite is "relative" (4/8-bit colour is selected by "anchor" sprite) → see tables below %10 = 4-bit colour pattern (128 bytes) using bytes 0..127 of pattern slot, this sprite is "anchor" %11 = 4-bit colour pattern (128 bytes) using bytes 128..255 of pattern slot, this sprite is "anchor"
5	Type for following relative sprites: 0 = "composite", 1 = "big sprite"
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

For composite relative sprites:

Bit	Description
7-6	%01 = relative sprite
5	"N6" bit, in 4-bit colour mode 0 = using bytes 0..127 of pattern slot, 1 = using bytes 128..255 of pattern slot. In 8-bit mode use 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	Enable relative pattern offset (1 = Pattern index is added to anchor pattern index, 0 = independent pattern index)

For big-sprite relative sprites:

Bit	Description
7-6	%01 = relative sprite
5	"N6" bit, in 4-bit colour mode 0 = using bytes 0..127 of pattern slot, 1 = using bytes 128..255 of pattern slot. In 8-bit mode use 0.
4-1	use 0 (scaling is defined by anchor sprite)
0	Enable relative pattern offset (1 = Pattern index is added to anchor pattern index, 0 = independent pattern index)

See {{#ask: PortNumber::$xx57 }} ($xx57{{#ask: PortNumber::$xx57 |mainlabel=- |headers=hide |intro= / |?NumberDec#- }}) for extra notes about anchor/relative sprites, coordinates and clipping.

@@ Line 6: / Line 6: @@
 }}
 Byte 5 is bitmapped:
+:For '''anchor''' sprites:
 {|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)
+| 7-6 || "H N6" - "H" is 4/8 bit graphics selector, "N6" is sub-pattern selector for 4 bit modes.<br />
+%00 = 8-bit colour patterns (256 bytes), this sprite is "'''anchor'''"<br />
+%01 = this sprite is "'''relative'''" (4/8-bit colour is selected by "anchor" sprite) → see tables below<br />
+%10 = 4-bit colour pattern (128 bytes) using bytes 0..127 of pattern slot, this sprite is "'''anchor'''"<br />
+%11 = 4-bit colour pattern (128 bytes) using bytes 128..255 of pattern slot, this sprite is "'''anchor'''"
 |-
-| 6 || (if bit 7 = 1): Chooses top/bottom part of pattern slot when 4-bit colour pattern
+| 5 || Type for following '''relative''' sprites: 0 = "composite", 1 = "big sprite"
-will target bytes 0..127 of pattern "Name" (byte 4), 1 will target bytes 128..255 of pattern "Name".
-(if bit 7 = 0): make this sprite "relative" one: 1 = relative, 0 = normal (anchor) type
 |-
-| 5 || (if bit 7-6 = %01) for "relative" sprite, this bit chooses top/bottom part of pattern slot for 4-bit colour mode (4 or 8 bit mode is set by anchor sprite, relative sprite can't switch the colour mode). See Bit 6 description above, if anchor sprite is in 4-bit mode. If anchor sprite is in 8-bit mode, use always 0
+| 4-3 || x-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
-(else) For normal (anchor) sprites this is reserved, use always 0
+|-
+| 2-1 || y-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
+|-
+| 0 || MSB of Y coordinate
+|}
+:For '''composite relative''' sprites:
+{|class="wikitable"
+! Bit !! Description
+|-
+| 7-6 ||%01 = relative sprite
+|-
+| 5 || "N6" bit, in 4-bit colour mode 0 = using bytes 0..127 of pattern slot, 1 = using bytes 128..255 of pattern slot. In 8-bit mode use 0.
 |-
 | 4-3 || x-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
@@ Line 23: / Line 36: @@
 | 2-1 || y-axis scale factor: %00 = 1x (16 pixels), %01 = 2x, %10 = 4x, %11 = 8x (128 pixels)
 |-
-| 0 || MSB of Y coordinate
+| 0 || Enable relative pattern offset (1 = Pattern index is added to anchor pattern index, 0 = independent pattern index)
+|}
+:For '''big-sprite relative''' sprites:
+{|class="wikitable"
+! Bit !! Description
+|-
+| 7-6 ||%01 = relative sprite
+|-
+| 5 || "N6" bit, in 4-bit colour mode 0 = using bytes 0..127 of pattern slot, 1 = using bytes 128..255 of pattern slot. In 8-bit mode use 0.
+|-
+| 4-1 || use 0 (scaling is defined by '''anchor''' sprite)
+|-
+| 0 || Enable relative pattern offset (1 = Pattern index is added to anchor pattern index, 0 = independent pattern index)
 |}
 See {{PortNo|$xx57}} for extra notes about anchor/relative sprites, coordinates and clipping.