ch19p1_grammar.txt

游戏开发特殊技巧-special.effects.game.programming

BNF Grammar for Particle System Script:

Script ::= 			<ParticleSystem>

ParticleSystem ::= 		ParticleSystem <VersionNumber> <Name> "{" {<SysProperty>} {<EventSequence>} "}"

VersionNumber ::=		RealNumber

Name ::=			"{ --< char >-- }"

Number ::=			<RealNumber> | Random(<RealNumber>,<RealNumber>)

RealNumber ::=			--< float >--

SysProperty ::= 		<VectorProperty> = <Vector> 

SysVectorProperty ::= 		Position

Vector ::= 			XYZ(<Number>,<Number>,<Number>)

EventSequence ::=		EventSequence <Name> "{" {<SeqProperty>} {Event} "}"

SeqProperty ::= 		<SeqNumberProperty> = <Number> | 
				<SeqVectorProperty> = <Vector> |
				<SysAlphaBlendModeProperty> = <AlphaBlendMode> |
				Texture = <Name>

SeqNumberProperty ::=		EmitRate | LifeTime | NumParticles

SeqVectorProperty ::=		SpawnDir | EmitRadius | Gravity

SeqAlphaBlendModeProperty ::= 	SourceBlendMode | DestBlendMode

AlphaBlendMode ::= 		D3DBLEND_ZERO | D3DBLEND_ONE | D3DBLEND_SRCCOLOR | 
                                D3DBLEND_INVSRCCOLOR | D3DBLEND_SRCALPHA |
				D3DBLEND_INVSRCALPHA | D3DBLEND_DESTALPHA | 
                                D3DBLEND_INVDESTALPHA | D3DBLEND_DESTCOLOR |
				D3DBLEND_INVDESTCOLOR | D3DBLEND_SRCALPHASAT

Event ::=			<Time> <ParticleNumericProp> = <Number> |
				<Time> <ParticleColorProp> = <Color> |
				<Time> <ParticleVectorProp> = <Vector> |

Time ::=			[Fade so] at <Number> | initial | [Fade so] Final

ParticleNumericProp ::=		Size | EventTimer | RedColor | GreenColor | BlueColor | Alpha
				
ParticleVectorProp ::=		Velocity

ParticleColorProp ::=		Color

Color ::=			RGBA(<Number>,<Number>,<Number>,<Number>)