Sprite (computer graphics)

For the technique of combining images into a single bitmap, seeTexture atlas.

For the process of drawing sprites, seePixel art.

For other uses, seeSprite (disambiguation).

Tank and rocket sprites fromBroforce

Incomputer graphics,aspriteis atwo-dimensionalbitmapthat is integrated into a larger scene, most often in a 2Dvideo game.Originally, the termspritereferred to fixed-sized objects composited together, by hardware, with a background.Use of the term has since become more general.

Systems with hardware sprites includearcade video gamesof the 1970s and 1980s;game consolesincluding as theAtari VCS(1977),ColecoVision(1982),Famicom(1983),Genesis/Mega Drive(1988); andhome computerssuch as theTI-99/4(1979),Atari 8-bit computers(1979),Commodore 64(1982),MSX(1983),Amiga(1985), andX68000(1987). Hardware varies in the number of sprites supported, the size and colors of each sprite, and special effects such as scaling or reporting pixel-precise overlap.

Hardware composition of sprites occurs as eachscan lineis prepared for the video output device, such as acathode-ray tube,without involvement of the mainCPUand without the need for a full-screenframe buffer.Sprites can be positioned or altered by setting attributes used during the hardware composition process. The number of sprites which can be displayed per scan line is often lower than the total number of sprites a system supports. For example, the Texas InstrumentsTMS9918chip supports 32 sprites, but only four can appear on the same scan line.

The CPUs in modern computers, video game consoles, and mobile devices are fast enough that bitmaps can be drawn into a frame buffer without special hardware assistance. Beyond that,GPUscan render vast numbers of scaled, rotated, antialiased, partially translucent, very high resolution images in parallel with the CPU.

Etymology

According to Karl Guttag, one of two engineers for the 1979Texas Instruments TMS9918video display processor, this use of the wordspritecame from David Ackley, a manager at TI.It was also used byDanny Hillisat Texas Instruments in the late 1970s.The term was derived from the fact that sprites "float" on top of the background image without overwriting it, much like a ghost ormythological sprite.

Some hardware manufacturers used different terms, especially beforespritebecame common:

Player/Missile Graphicswas a term used byAtari, Inc.for hardware sprites in theAtari 8-bit computers(1979) andAtari 5200console (1982).The term reflects the use for both characters ( "players" ) and smaller associated objects ( "missiles" ) that share the same color. The earlierAtari Video Computer Systemand some Atari arcade games usedplayer,missile,andball.

Stampwas used in some arcade hardware in the early 1980s, includingMs. Pac-Man.

Movable Object Block,orMOB,was used inMOS Technology's graphics chip literature.Commodore,the main user of MOS chips and the owner of MOS for most of the chip maker's lifetime, instead used the termspritefor the Commodore 64.

OBJs (short forobjects) is used in the developer manuals for theNES,Super NES,andGame Boy.The region ofvideo RAMused to store sprite attributes and coordinates is calledOAM(Object Attribute Memory). This also applies to theGame Boy AdvanceandNintendo DS.

History

Arcade video games

The use of sprites originated witharcade video games.Nolan Bushnellcame up with the original concept when he developed the first arcade video game,Computer Space(1971). Technical limitations made it difficult to adapt theearly mainframe gameSpacewar!(1962), which performed an entirescreen refreshfor every little movement, so he came up with a solution to the problem: controlling each individual game element with a dedicatedtransistor.Therocketswere essentially hardwiredbitmapsthat moved around the screen independently of the background, an important innovation for producing screen images more efficiently and providing the basis for sprite graphics.

The earliest video games to representplayer charactersas human player sprites were arcadesports video games,beginning withTaito'sTV Basketball,released in April 1974 and licensed toMidway Manufacturingfor release in North America.Designed byTomohiro Nishikado,he wanted to move beyond simplePong-style rectangles to character graphics, by rearranging the rectangle shapes into objects that look likebasketballplayers andbasketball hoops.Ramtekreleased another sports video game in October 1974,Baseball,which similarly displayed human-like characters.

TheNamco Galaxianarcade system board,for the 1979 arcade gameGalaxian,displays animated, multi-colored sprites over a scrolling background.It became the basis forNintendo'sRadar ScopeandDonkey Kongarcade hardware andhome consolessuch as theNintendo Entertainment System.According to Steve Golson fromGeneral Computer Corporation,the term "stamp" was used instead of "sprite" at the time.

Home systems

Signeticsdevised the first chips capable of generating sprite graphics (referred to asobjectsby Signetics) for home systems. The Signetics 2636 video processors were first used in the 19781292 Advanced Programmable Video Systemand later in the 1979Elektor TV Games Computer.

TheAtari VCS,released in 1977, has a hardware sprite implementation where five graphical objects can be moved independently of the game playfield. The termspritewas not in use at the time. The VCS's sprites are calledmovable objectsin the programming manual, further identified as twoplayers,twomissiles,and oneball.These each consist of a single row of pixels that are displayed on ascan line.To produce a two-dimensional shape, the sprite's single-row bitmap is altered by software from one scan line to the next.

The 1979Atari 400 and 800home computers have similar, but more elaborate, circuitry capable of moving eight single-color objects per scan line: four 8-bit wideplayersand four 2-bit widemissiles.Each is the full height of the display—a long, thin strip.DMAfrom a table in memory automatically sets the graphics pattern registers for each scan line. Hardware registers control the horizontal position of each player and missile. Vertical motion is achieved by moving the bitmap data within a player or missile's strip. The feature was calledplayer/missile graphicsby Atari.

Texas Instrumentsdeveloped theTMS9918chip with sprite support for its 1979 TI-99/4 home computer. An updated version is used in the 1981TI-99/4A.

Systems with hardware sprites

These are base hardware specs and do not include additional programming techniques, such as usingraster interruptsto repurpose sprites mid-frame.

System	Sprite hardware	Introduced	Sprites on screen	Sprites per scan line	Max.texelson line	Texturewidth	Texture height	Colors	Zoom	Rotation	Collision detection	Transparency	Source
Amstrad Plus	ASIC	1990	16	16	?	16	16	15	2, 4× vertical, 2, 4× horizontal	No	No	Color key
Atari 2600	TIA	1977	5	5	19	1, 8	262	1	2, 4, 8× horizontal	Horizontal mirroring	Yes	Color key
Atari 8-bit computers	GTIA/ANTIC	1979	8	8	40	2, 8	128, 256	1	2× vertical, 2, 4× horizontal	No	Yes	Color key
Commodore 64	VIC-II	1982	8	8	96, 192	12, 24	21	1, 3	2× integer	No	Yes	Color key
Amiga (OCS)	Denise	1985	8, can be reused horizontally per 4 pixel increments	Arbitrary, 8 unique	Arbitrary	16	Arbitrary	3, 15	Vertical by display list	No	Yes	Color key
Amiga (AGA)	Lisa	1992	8, can be reused horizontally per 2 pixel increments	Arbitrary, 8 unique	Arbitrary	16, 32, 64	Arbitrary	3, 15	Vertical by display list	No	Yes	Color key
ColecoVision	TMS9918A	1983	32	4	64	8, 16	8, 16	1	2× integer	No	Partial	Color key
TI-99/4 & 4A	TMS9918	1979	32	4	64	8, 16	8, 16	1	2× integer	No	Partial	Color key
Gameduino		2011	256	96	1,536	16	16	255	No	Yes	Yes	Color key
Intellivision	STIC AY-3-8900	1979	8	8	64	8	8,16	1	2, 4, 8× vertical, 2× horizontal	Horizontal and vertical mirroring	Yes	Color key
MSX	TMS9918A	1983	32	4	64	8, 16	8, 16	1	2× integer	No	Partial	Color key
MSX2	Yamaha V9938	1986	32	8	128	8, 16	8,16	1, 3, 7, 15 per line	2× integer	No	Partial	Color key
MSX2+/MSX turbo R	Yamaha V9958	1988	32	8	128	8,16	8,16	1, 3, 7, 15 per line	2× integer	No	Partial	Color key
Namco Pac-Man (arcade)	TTL	1980	6	6	96	16	16	3	No	Horizontal and vertical mirroring	No	Color key
TurboGrafx-16	HuC6270A	1987	64	16	256	16, 32	16, 32, 64	15	No	Horizontal and vertical mirroring	Yes	Color key
Namco Galaxian (arcade)	TTL	1979	7	7	112	16	16	3	No	Horizontal and vertical mirroring	No	Color key
NintendoDonkey Kong,Radar Scope (arcade)		1979	128	16	256	16	16	3	Integer	No	Yes	Color key
Nintendo DS	Integrated PPU	2004	128	128	1,210	8, 16, 32, 64	8, 16, 32, 64	65,536	Affine	Affine	No	Color key, blending
NES/Famicom	RicohRP2C0x PPU	1983	64	8	64	8	8, 16	3	No	Horizontal and vertical mirroring	Partial	Color key
Game Boy	Integrated PPU	1989	40	10	80	8	8, 16	3	No	Horizontal and vertical mirroring	No	Color key
Game Boy Advance	Integrated PPU	2001	128	128	1210	8, 16, 32, 64	8, 16, 32, 64	15, 255	Affine	Affine	No	Color key, blending
Master System, Game Gear	YM2602B VDP (TMS9918-derived)	1985	64	8	128	8, 16	8, 16	15	2× integer, 2× vertical	Background tile mirroring	Yes	Color key
Genesis / Mega Drive	YM7101 VDP (SMS VDP-derived)	1988	80	20	320	8, 16, 24, 32	8, 16, 24, 32	15	No	Horizontal and vertical mirroring	Yes	Color key
Sega OutRun(arcade)		1986	128	128	1600	8 to 512	8 to 256	15	Anisotropic	Horizontal and vertical mirroring	Yes	Alpha
X68000	Cynthia jr. (original), Cynthia (later models)	1987	128	32	512	16	16	15	2× integer	Horizontal and vertical mirroring	Partial	Color key
Neo Geo	LSPC2-A2	1990	384	96	1536	16	16 to 512	15	Sprite shrinking	Horizontal and vertical mirroring	Partial	Color key
Super NES / Super Famicom	S-PPU1, S-PPU2	1990	128	34	256	8, 16, 32, 64	8, 16, 32, 64	15	No	Horizontal and vertical mirroring	No	Color key, averaging
System	Sprite hardware	Introduced	Sprites on screen	Sprites on line	Max.texelson line	Texturewidth	Texture height	Colors	Hardware zoom	Rotation	Collision detection	Transparency	Source

See also

• 2.5D