Sprites - Revision history

Ped7g: Refresh info about incomplete sprite rendering

2025-12-22T17:33:51Z

Refresh info about incomplete sprite rendering

← Older revision		Revision as of 18:33, 22 December 2025
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	* A nextreg interface allows the copper to move sprites during the video frame		* A nextreg interface allows the copper to move sprites during the video frame

	&dagger; A minimum of 100 16×16 sprites is guaranteed to be displayed in any scanline. Any additional sprites will not be displayed with the hardware ensuring sprites are not partially plotted.		&dagger; A minimum of 100 16×16 (at 1x scale) sprites is guaranteed to be displayed in any scanline. <s>Any additional sprites will not be displayed with the hardware ensuring sprites are not partially plotted.</s> Since core 3.02.02 the HW keeps drawing until full pixel bandwidth is exhausted including incomplete span of sprite. Before core 3.02.02 there was bug in the code preventing incomplete draws, causing less than 100 sprites being shown per line.

	The actual limit is determined by how many 28MHz clock cycles there are in a scanline. The sprite hardware is able to plot one pixel cycle and uses one cycle to qualify each sprite. Since the number of cycles there are in a scanline varies with video timing (HDMI, VGA), the number of pixels that can be plotted also varies but the minimum will be 1600 pixels per line including overhead cycles needed to qualify 100 sprites. Since sprites magnified horizontally involve plotting more pixels, x2 x4 x8 sprites will take more cycles to plot and the presence of these sprites in a line will reduce the total number of sprites that can be plotted.		The actual limit is determined by how many 28MHz clock cycles there are in a scanline. The sprite hardware is able to plot one pixel cycle and uses one cycle to qualify each sprite. Since the number of cycles there are in a scanline varies with video timing (HDMI, VGA), the number of pixels that can be plotted also varies but the minimum will be 1600 pixels per line including overhead cycles needed to qualify 100 sprites. Since sprites magnified horizontally involve plotting more pixels, x2 x4 x8 sprites will take more cycles to plot and the presence of these sprites in a line will reduce the total number of sprites that can be plotted.

Sol HSA: Added padding to the palette offset calculation to make it easier to read

2020-10-05T16:53:51Z

Added padding to the palette offset calculation to make it easier to read

← Older revision		Revision as of 17:53, 5 October 2020
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	<pre>8-bit Sprite		<pre>8-bit Sprite
	PPPP0000		PPPP0000
	+ IIIIIIII		+ IIIIIIII
	----------		----------
	SSSSSSSS		SSSSSSSS

	4-bit Sprite		4-bit Sprite
	PPPP0000		PPPP0000
	+ 0000IIII		+ 0000IIII
	----------		----------
	SSSSSSSS = PPPPIIII</pre>		SSSSSSSS = PPPPIIII</pre>

	Where “PPPP” is the 4-bit palette offset from the sprite’s attributes and the “I”s represent the pixel value from the sprite pattern. The final sprite index is represented by the 8-bit value “SSSSSSSS”.		Where “PPPP” is the 4-bit palette offset from the sprite’s attributes and the “I”s represent the pixel value from the sprite pattern. The final sprite index is represented by the 8-bit value “SSSSSSSS”.

Robpearmain: Changed site of sprite to size of sprite

2019-07-11T20:41:13Z

Changed site of sprite to size of sprite

← Older revision		Revision as of 21:41, 11 July 2019
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	* Minimum of 100 sprites per scanline<sup>&dagger;</sup>		* Minimum of 100 sprites per scanline<sup>&dagger;</sup>
	* Choice of 512 colours for each pixel		* Choice of 512 colours for each pixel
	* ~~Site~~ of each sprite is 16×16 pixels but sprites can be magnified 2x, 4x or 8x horizontally and vertically		* Size of each sprite is 16×16 pixels but sprites can be magnified 2x, 4x or 8x horizontally and vertically
	* Sprites can be mirrored and rotated		* Sprites can be mirrored and rotated
	* Sprites can be grouped together to form larger sprites under the control of a single anchor		* Sprites can be grouped together to form larger sprites under the control of a single anchor

Ped7g: some typos fixed, couple of wording changes, and cross-linked with other wiki pages a bit

2019-05-06T09:16:23Z

some typos fixed, couple of wording changes, and cross-linked with other wiki pages a bit

Show changes

Intrepidis: Fix formatting in the Global Control of Sprites section.

2019-05-05T10:46:43Z

Fix formatting in the Global Control of Sprites section.

Show changes

Intrepidis: Fix formatting in the Programming Sprites section.

2019-05-05T10:39:05Z

Fix formatting in the Programming Sprites section.

Intrepidis: Add bullet points to Composite section.

2019-05-05T10:33:31Z

Add bullet points to Composite section.

← Older revision		Revision as of 11:33, 5 May 2019
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	The sprite module records the following information from the anchor:		The sprite module records the following information from the anchor:

	Anchor.visible		* Anchor.visible
	Anchor.X		* Anchor.X
	Anchor.Y		* Anchor.Y
	Anchor.palette_offset		* Anchor.palette_offset
	Anchor.N (pattern number)		* Anchor.N (pattern number)
	Anchor.H (indicates if the sprite uses 4-bit patterns)		* Anchor.H (indicates if the sprite uses 4-bit patterns)

	These recorded items are not used by composite sprites:		These recorded items are not used by composite sprites:

	Anchor.rotate		* Anchor.rotate
	Anchor.xmirror		* Anchor.xmirror
	Anchor.ymirror		* Anchor.ymirror
	Anchor.xscale		* Anchor.xscale
	Anchor.yscale		* Anchor.yscale

	The anchor determines if all its relative sprites use 4-bit patterns or not.		The anchor determines if all its relative sprites use 4-bit patterns or not.

Intrepidis: Add better formatting to the attribute section.

2019-05-05T10:29:59Z

Add better formatting to the attribute section.

Intrepidis: Add the sprite flags image link.

2019-05-05T10:24:46Z

Add the sprite flags image link.

← Older revision		Revision as of 11:24, 5 May 2019
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	==== Sprite Attribute 2 ====		==== Sprite Attribute 2 ====
	<pre>P P P P XM YM R X8/PR</pre>		<pre>P P P P XM YM R X8/PR</pre>
	P = 4-bit Palette Offset
	XM = 1 to mirror the sprite image horizontally		P = 4-bit Palette Offset<br />
	YM = 1 to mirror the sprite image vertically		XM = 1 to mirror the sprite image horizontally<br />
	R = 1 to rotate the sprite image 90 degrees clockwise		YM = 1 to mirror the sprite image vertically<br />
	X8 = Ninth bit of the sprite’s X coordinate		R = 1 to rotate the sprite image 90 degrees clockwise<br />
			X8 = Ninth bit of the sprite’s X coordinate<br />
	PR = 1 to indicate P is relative to the anchor’s palette offset (relative sprites only)		PR = 1 to indicate P is relative to the anchor’s palette offset (relative sprites only)

	Rotation is applied before mirroring.		Rotation is applied before mirroring.<br />
	Relative sprites, described below, replace X8 with PR.		Relative sprites, described below, replace X8 with PR.

			[[File:Sprite_flags.png\|frame\|center\|All possibilities of Rotate, Mirror X and Mirror Y flags.]]
	All possibilities of Rotate, Mirror X and Mirror Y flags.

	==== Sprite Attribute 3 ====		==== Sprite Attribute 3 ====

Intrepidis: Format the code sections.

2019-05-05T10:19:17Z

Format the code sections.

← Older revision		Revision as of 11:19, 5 May 2019
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	As an example we will use the same sprite image as was given in the 8-bit pattern example. Here only the lower 4 bits of each pixel is retained to confine each pixel’s color to 4-bits:		As an example we will use the same sprite image as was given in the 8-bit pattern example. Here only the lower 4 bits of each pixel is retained to confine each pixel’s color to 4-bits:

	4444444333333333		<pre>4444444333333333
	4FFFFF4333333333		4FFFFF4333333333
	4FBBBF4333333333		4FBBBF4333333333
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	33333334DD434543		33333334DD434543
	33333333443334A4		33333333443334A4
	3333333333333344		3333333333333344</pre>

	0x3 is used as the transparent index.		0x3 is used as the transparent index.

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	The final sprite colour index generated by the sprite hardware is then the sum of the pixel index and the 4-bit palette offset. In pictures using binary math:		The final sprite colour index generated by the sprite hardware is then the sum of the pixel index and the 4-bit palette offset. In pictures using binary math:

	8-bit Sprite		<pre>8-bit Sprite
	PPPP0000		PPPP0000
	+ IIIIIIII		+ IIIIIIII
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	+ 0000IIII		+ 0000IIII
	----------		----------
	SSSSSSSS = PPPPIIII		SSSSSSSS = PPPPIIII</pre>

	Where “PPPP” is the 4-bit palette offset from the sprite’s attributes and the “I”s represent the pixel value from the sprite pattern. The final sprite index is represented by the 8-bit value “SSSSSSSS”.		Where “PPPP” is the 4-bit palette offset from the sprite’s attributes and the “I”s represent the pixel value from the sprite pattern. The final sprite index is represented by the 8-bit value “SSSSSSSS”.

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	==== Sprite Attribute 0 ====		==== Sprite Attribute 0 ====
	X X X X X X X X		<pre>X X X X X X X X</pre>
	The least significant eight bits of the sprite’s X coordinate. The ninth bit is found in sprite attribute 2.		The least significant eight bits of the sprite’s X coordinate. The ninth bit is found in sprite attribute 2.

	==== Sprite Attribute 1 ====		==== Sprite Attribute 1 ====
	Y Y Y Y Y Y Y Y		<pre>Y Y Y Y Y Y Y Y</pre>
	The least significant eight bits of the sprite’s Y coordinate. The ninth bit is optional and is found in attribute 4.		The least significant eight bits of the sprite’s Y coordinate. The ninth bit is optional and is found in attribute 4.

	==== Sprite Attribute 2 ====		==== Sprite Attribute 2 ====
	P P P P XM YM R X8/PR		<pre>P P P P XM YM R X8/PR</pre>
	P = 4-bit Palette Offset		P = 4-bit Palette Offset
	XM = 1 to mirror the sprite image horizontally		XM = 1 to mirror the sprite image horizontally
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	==== Sprite Attribute 3 ====		==== Sprite Attribute 3 ====
	V E N5 N4 N3 N2 N1 N0		<pre>V E N5 N4 N3 N2 N1 N0</pre>
	V = 1 to make the sprite visible		V = 1 to make the sprite visible
	E = 1 to enable attribute byte 4		E = 1 to enable attribute byte 4
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	==== Sprite Attribute 4 ====		==== Sprite Attribute 4 ====
	===== A. Extended Anchor Sprite =====		===== A. Extended Anchor Sprite =====
	H N6 T X X Y Y Y8		<pre>H N6 T X X Y Y Y8</pre>
	H = 1 if the sprite pattern is 4-bit		H = 1 if the sprite pattern is 4-bit
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit
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	===== B. Relative Sprite, Composite Type =====		===== B. Relative Sprite, Composite Type =====
	0 1 N6 X X Y Y PO		<pre>0 1 N6 X X Y Y PO</pre>
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit
	XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)
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	===== C. Relative Sprite, Unified Type =====		===== C. Relative Sprite, Unified Type =====
	0 1 N6 0 0 0 0 PO		<pre>0 1 N6 0 0 0 0 PO</pre>
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit
	PO = 1 to indicate the sprite pattern number is relative to the anchor’s		PO = 1 to indicate the sprite pattern number is relative to the anchor’s
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	Port 0x303B (W)		Port 0x303B (W)

	X S S S S S S S		<pre>X S S S S S S S
	N6 X N N N N N N		N6 X N N N N N N</pre>

	A write to this port has two effects.		A write to this port has two effects.

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	Port 0x303B (R)		Port 0x303B (R)

	0 0 0 0 0 0 M C		<pre>0 0 0 0 0 0 M C</pre>

	M = 1 if the maximum number of sprites per line was exceeded		M = 1 if the maximum number of sprites per line was exceeded
	C = 1 if any two displayed sprites collide on screen		C = 1 if any two displayed sprites collide on screen

← Older revision		Revision as of 11:39, 5 May 2019
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	<pre>0 0 0 0 0 0 M C</pre>		<pre>0 0 0 0 0 0 M C</pre>

	M = 1 if the maximum number of sprites per line was exceeded		M = 1 if the maximum number of sprites per line was exceeded<br />
	C = 1 if any two displayed sprites collide on screen		C = 1 if any two displayed sprites collide on screen

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	Besides the i/o interface, there is a nextreg interface to sprite attributes. The nextreg interface allows the copper to manipulate sprites and grants the program random access to a sprite’s individual attribute bytes.		Besides the i/o interface, there is a nextreg interface to sprite attributes. The nextreg interface allows the copper to manipulate sprites and grants the program random access to a sprite’s individual attribute bytes.

	(R/W) 0x34 (52) => Sprite Number		(R/W) 0x34 (52) => Sprite Number<br />
	If the sprite number is in lockstep with io port 0x303B (nextreg 0x09 bit 4 is set)		If the sprite number is in lockstep with io port 0x303B (nextreg 0x09 bit 4 is set)<br />
	bits 7 = Pattern address offset (Add 128 to pattern address)		bits 7 = Pattern address offset (Add 128 to pattern address)<br />
	bits 6-0 = Sprite number 0-127, Pattern number 0-63		bits 6-0 = Sprite number 0-127, Pattern number 0-63<br />
	Selects which sprite has its attributes connected to the following registers.		Selects which sprite has its attributes connected to the following registers.<br />
	Effectively performs an out to port 0x303B with the same value		Effectively performs an out to port 0x303B with the same value<br />
	Otherwise		Otherwise<br />
	bit 7 = Ignored		bit 7 = Ignored<br />
	bits 6-0 = Sprite number 0-127		bits 6-0 = Sprite number 0-127<br />
	Selects which sprite has its attributes connected to the following registers.		Selects which sprite has its attributes connected to the following registers.<br />
	Bit 7 always reads back as zero.		Bit 7 always reads back as zero.

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	If nextreg 0x09 bit 4 is reset, then the nextreg interface is decoupled from i/o port 0x303B. This nextreg is used to select a particular sprite 0-127 and this is completely independent from the sprite selected for the i/o interface. This independence allows the copper, for example, to manipulate different sprites than the cpu using the i/o interface.		If nextreg 0x09 bit 4 is reset, then the nextreg interface is decoupled from i/o port 0x303B. This nextreg is used to select a particular sprite 0-127 and this is completely independent from the sprite selected for the i/o interface. This independence allows the copper, for example, to manipulate different sprites than the cpu using the i/o interface.

	(W) 0x35 (53) => Sprite Attribute 0		(W) 0x35 (53) => Sprite Attribute 0<br />
	(W) 0x75 (117) => Sprite Attribute 0 with automatic post increment of Sprite Number		(W) 0x75 (117) => Sprite Attribute 0 with automatic post increment of Sprite Number<br />
	bits 7-0 = LSB of X coordinate		bits 7-0 = LSB of X coordinate

	A write to nextreg 0x75 also increases the selected sprite in nextreg 0x34.		A write to nextreg 0x75 also increases the selected sprite in nextreg 0x34.

	(W) 0x36 (54) => Sprite Attribute 1		(W) 0x36 (54) => Sprite Attribute 1<br />
	(W) 0x76 (118) => Sprite Attribute 1 with automatic post increment of Sprite Number		(W) 0x76 (118) => Sprite Attribute 1 with automatic post increment of Sprite Number<br />
	bits 7-0 = LSB of Y coordinate		bits 7-0 = LSB of Y coordinate

	A write to nextreg 0x76 also increases the selected sprite in nextreg 0x34.		A write to nextreg 0x76 also increases the selected sprite in nextreg 0x34.

	(W) 0x37 (55) => Sprite Attribute 2		(W) 0x37 (55) => Sprite Attribute 2<br />
	(W) 0x77 (119) => Sprite Attribute 2 with automatic post increment of Sprite Number		(W) 0x77 (119) => Sprite Attribute 2 with automatic post increment of Sprite Number<br />
	bits 7-4 = Palette offset added to top 4 bits of sprite colour index		bits 7-4 = Palette offset added to top 4 bits of sprite colour index<br />
	bit 3 = X mirror		bit 3 = X mirror<br />
	bit 2 = Y mirror		bit 2 = Y mirror<br />
	bit 1 = Rotate		bit 1 = Rotate<br />
	bit 0 = MSB of X coordinate		bit 0 = MSB of X coordinate

	A write to nextreg 0x77 also increases the selected sprite in nextreg 0x34.		A write to nextreg 0x77 also increases the selected sprite in nextreg 0x34.

	(W) 0x38 (56) => Sprite Attribute 3		(W) 0x38 (56) => Sprite Attribute 3<br />
	(W) 0x78 (120) => Sprite Attribute 3 with automatic post increment of Sprite Number		(W) 0x78 (120) => Sprite Attribute 3 with automatic post increment of Sprite Number<br />
	bit 7 = Visible flag (1 = displayed)		bit 7 = Visible flag (1 = displayed)<br />
	bit 6 = Extended attribute (1 = Sprite Attribute 4 is active)		bit 6 = Extended attribute (1 = Sprite Attribute 4 is active)<br />
	bits 5-0 = Pattern used by sprite (0-63)		bits 5-0 = Pattern used by sprite (0-63)

	A write to nextreg 0x78 also increases the selected sprite in nextreg 0x34.		A write to nextreg 0x78 also increases the selected sprite in nextreg 0x34.

	(W) 0x39 (57) => Sprite Attribute 4		(W) 0x39 (57) => Sprite Attribute 4<br />
	(W) 0x79 (121) => Sprite Attribute 4 with automatic post increment of Sprite Number		(W) 0x79 (121) => Sprite Attribute 4 with automatic post increment of Sprite Number<br />
	4-bit Sprites		4-bit Sprites<br />
	bit 7 = H (1 = sprite uses 4-bit patterns)		bit 7 = H (1 = sprite uses 4-bit patterns)<br />
	bit 6 = N6 (0 = use the first 128 bytes of the pattern else use the last 128 bytes)		bit 6 = N6 (0 = use the first 128 bytes of the pattern else use the last 128 bytes)<br />
	bit 5 = 1 if relative sprites are composite, 0 if relative sprites are unified		bit 5 = 1 if relative sprites are composite, 0 if relative sprites are unified<br />
	Scaling		Scaling<br />
	bits 4-3 = X scaling (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		bits 4-3 = X scaling (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	bits 2-1 = Y scaling (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		bits 2-1 = Y scaling (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	bit 0 = MSB of Y coordinate		bit 0 = MSB of Y coordinate<br />
	A relative mode is enabled if H,N6 = 01. The byte format for relative sprites is described above.		A relative mode is enabled if H,N6 = 01. The byte format for relative sprites is described above.

← Older revision		Revision as of 11:29, 5 May 2019
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	==== Sprite Attribute 3 ====		==== Sprite Attribute 3 ====
	<pre>V E N5 N4 N3 N2 N1 N0</pre>		<pre>V E N5 N4 N3 N2 N1 N0</pre>
	V = 1 to make the sprite visible		V = 1 to make the sprite visible<br />
	E = 1 to enable attribute byte 4		E = 1 to enable attribute byte 4<br />
	N = Sprite pattern to use 0-63		N = Sprite pattern to use 0-63

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	===== A. Extended Anchor Sprite =====		===== A. Extended Anchor Sprite =====
	<pre>H N6 T X X Y Y Y8</pre>		<pre>H N6 T X X Y Y Y8</pre>
	H = 1 if the sprite pattern is 4-bit		H = 1 if the sprite pattern is 4-bit<br />
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit<br />
	T = 0 if relative sprites are composite type else 1 for unified type		T = 0 if relative sprites are composite type else 1 for unified type<br />
	XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	YY = Magnification in the Y direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		YY = Magnification in the Y direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	Y8 = Ninth bit of the sprite’s Y coordinate		Y8 = Ninth bit of the sprite’s Y coordinate

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	===== B. Relative Sprite, Composite Type =====		===== B. Relative Sprite, Composite Type =====
	<pre>0 1 N6 X X Y Y PO</pre>		<pre>0 1 N6 X X Y Y PO</pre>
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit<br />
	XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		XX = Magnification in the X direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	YY = Magnification in the Y direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)		YY = Magnification in the Y direction (00 = 1x, 01 = 2x, 10 = 4x, 11 = 8x)<br />
	PO = 1 to indicate the sprite pattern number is relative to the anchor’s		PO = 1 to indicate the sprite pattern number is relative to the anchor’s

	===== C. Relative Sprite, Unified Type =====		===== C. Relative Sprite, Unified Type =====
	<pre>0 1 N6 0 0 0 0 PO</pre>		<pre>0 1 N6 0 0 0 0 PO</pre>
	N6 = 7th pattern bit if the sprite pattern is 4-bit		N6 = 7th pattern bit if the sprite pattern is 4-bit<br />
	PO = 1 to indicate the sprite pattern number is relative to the anchor’s		PO = 1 to indicate the sprite pattern number is relative to the anchor’s