fx Namespace Reference

Effects: motion maths, the screen shake, and (chgame/Sizzle.h) particles, banners and floating texts. More...

Enumerations
enum	Ease : uint8_t {   LINEAR ,   OUT_CUBIC ,   OUT_BACK ,   IN_OUT ,   OUT_BOUNCE }
	Easing curves for ease(). More...
enum	Kind : uint8_t {   SPARK ,   CONFETTI ,   STAR ,   DUST }
	The particle kinds (the game's switches decide which exist). More...
enum	BannerStyle : uint8_t {   B_RAINBOW ,   B_GOLD ,   B_RED ,   B_CYAN ,   B_WHITE }
	Banner colour styles (the game's SIZZLE_STYLES decide which exist). More...

Functions
int	easeCurve (const int16_t *curve, int t, int n)
	Ease through a curve table.
int	ease (Ease e, int t, int n)
	Ease: progress through a curve.
int	bounce (int t, int n)
	The OUT_BOUNCE curve.
int	isin (int a)
	Integer sine.
int	icos (int a)
	Integer cosine.
uint32_t	rnd ()
	A random number for presentation (xorshift32).
int	rndRange (int lo, int hi)
	A random number in a range, for presentation.
void	reseed ()
	Restart rnd() from its fixed seed.
void	shake (uint8_t frames, uint8_t amplitude)
	Start a screen shake.
bool	shaking ()
	Whether a shake is running.
void	applyShake (int y0, int y1, int fill=-1)
	Shake the finished framebuffer: call after drawing, before the flush.
void	shakeTick ()
	Count the shake down one tick: once per logic tick.
void	shakeStop ()
	Stop the shake at once.
void	spawn (Kind k, int x, int y, int vx16, int vy16, uint8_t life, uint8_t colour)
	Launch one particle.
void	burst (Kind k, int x, int y, uint8_t n, int speed16, uint8_t colour)
	A radial burst: n particles flying out from a point.
void	fountain (int x, int y, uint8_t n)
	A fountain of confetti thrown up from a point (a win).
bool	particles ()
	Whether any particle is still flying.
bool	particlesAlive ()
	The same as particles().
void	banner (const char *text, BannerStyle s, int cy, uint8_t frames=70)
	Show a banner: big centred lettering with an outline that pops in, holds, and blinks out ("BLACKJACK!", "YOU WIN").
void	holdBanner (bool on)
	Keep the banner up (before it blinks out) until let go.
bool	bannerActive ()
	Whether a banner is showing.
void	floatText (const char *text, int x, int y, uint8_t colour)
	A floating text ("+$15") that rises from a point and fades out.
void	drawFloats ()
	Draw the floating texts: while drawing, on top of the scene.
bool	activeRows (int &lo, int &hi)
	The band of rows everything transient covers (particles, floats, banner, shake): what a partial redraw must include.
void	clear ()
	Remove every particle, float and the banner at once (and stop a shake).
void	update ()
	Move everything on by one tick: once per logic tick.
void	drawParticles (uint8_t dust=2)
	Draw the particles: while drawing, on top of the scene.
void	drawBanner ()
	Draw the banner, if one is showing: while drawing, last.

Variables
const int16_t	EASE_CUBIC [17]
	The curves' tables (17 points, 0..256), for easeCurve().

Detailed Description

Effects: motion maths, the screen shake, and (chgame/Sizzle.h) particles, banners and floating texts.

Enumeration Type Documentation

Ease

enum fx::Ease : uint8_t

Easing curves for ease().

Each curve is a 17-point table; ease() is inline, so a call with a constant curve links only that curve's table.

Enumerator
LINEAR	Straight.
OUT_CUBIC	Fast, then slowing to a stop.
OUT_BACK	Overshoots the end, then settles back (goes past 256).
IN_OUT	Slow, fast, slow.
OUT_BOUNCE	Drops and bounces to a stop (overshoots).

Kind

enum fx::Kind : uint8_t

The particle kinds (the game's switches decide which exist).

Enumerator
SPARK	A pixel with a cross-shaped flash for its first 8 ticks, falling slowly.
CONFETTI	A 2 px scrap that flips flat and upright as it falls. Always present.
STAR	A small plus sign, falling slowly.
DUST	A puff that slows to a stop and shrinks to a speck (see SIZZLE_DUST).

BannerStyle

enum fx::BannerStyle : uint8_t

Banner colour styles (the game's SIZZLE_STYLES decide which exist).

Enumerator
B_RAINBOW	The casino rainbow.
B_GOLD	Gold.
B_RED	Red.
B_CYAN	Cyan.
B_WHITE	White.

Function Documentation

easeCurve()

int fx::easeCurve	(	const int16_t *	curve,
		int	t,
		int	n
	)

Ease through a curve table.

Parameters

curve	A 17-point table (EASE_CUBIC ...), or nullptr for linear.
t	Time, 0..n.
n	Duration.

Returns

0 at t <= 0, 256 at t >= n, the curve in between (interpolated).

ease()

int fx::ease ( Ease  e, int  t, int  n  )

inline

Ease: progress through a curve.

Parameters

e	Which curve.
t	Time, 0..n (clamped).
n	Duration (frames, for instance).

Returns

0..256 (OUT_BACK and OUT_BOUNCE overshoot 256 on the way).

bounce()

int fx::bounce ( int  t, int  n  )

inline

The OUT_BOUNCE curve.

Parameters

t	Time, 0..n.
n	Duration.

Returns

0..256 (with the bounces).

isin()

int fx::isin

(

int

a

)

Integer sine.

Parameters

a	Angle in 1/256 turns (any value: it wraps).

Returns

-256..256.

icos()

int fx::icos ( int  a )

inline

Integer cosine.

Parameters

a	Angle in 1/256 turns.

Returns

-256..256.

rnd()

uint32_t fx::rnd

(

)

A random number for presentation (xorshift32).

Presentation-only randomness: sparkle, confetti, shake. It never touches game outcomes (those use the game's own generator), and reseed() restarts it so scripted runs repeat.

Returns

32 random bits.

rndRange()

int fx::rndRange	(	int	lo,
		int	hi
	)

A random number in a range, for presentation.

Parameters

lo	The smallest value.
hi	One past the largest value.

Returns

lo .. hi-1 (lo if hi <= lo).

reseed()

void fx::reseed

(

)

Restart rnd() from its fixed seed.

shake()

void fx::shake	(	uint8_t	frames,
		uint8_t	amplitude
	)

Start a screen shake.

shake() starts it; applyShake() moves the finished frame and shakeTick() counts it down once per logic tick.

Parameters

frames	How many ticks it lasts.
amplitude	The vertical jolt in pixels at 10 ticks left; it scales with the ticks left, so the shake dies away (at least 1 px). It also moves 2 px sideways.

shaking()

bool fx::shaking

(

)

Whether a shake is running.

Returns

true until it has counted down.

applyShake()

void fx::applyShake	(	int	y0,
		int	y1,
		int	fill = -1
	)

Shake the finished framebuffer: call after drawing, before the flush.

Parameters

y0,y1	The band of rows to move (inclusive).
fill	< 0 (default): rows the move uncovers keep their pixels, shifted in place; else they are filled with this colour.

shakeTick()

void fx::shakeTick

(

)

Count the shake down one tick: once per logic tick.

shakeStop()

void fx::shakeStop

(

)

Stop the shake at once.

spawn()

void fx::spawn	(	Kind	k,
		int	x,
		int	y,
		int	vx16,
		int	vy16,
		uint8_t	life,
		uint8_t	colour
	)

Launch one particle.

When the pool is full it takes a random one's place.

Parameters

k	Its kind.
x,y	Where it starts, in pixels.
vx16	Horizontal speed in 1/16 px per tick (-127..127).
vy16	Vertical speed in 1/16 px per tick (-127..127; negative is up).
life	How many ticks it lives.
colour	Its colour.

burst()

void fx::burst	(	Kind	k,
		int	x,
		int	y,
		uint8_t	n,
		int	speed16,
		uint8_t	colour
	)

A radial burst: n particles flying out from a point.

Parameters

k	Their kind.
x,y	The centre.
n	How many.
speed16	Top speed in 1/16 px per tick (each gets half to all of it).
colour	Their colour.

fountain()

void fx::fountain	(	int	x,
		int	y,
		uint8_t	n
	)

A fountain of confetti thrown up from a point (a win).

Parameters

x,y	Where it springs from.
n	How many pieces.

particles()

bool fx::particles

(

)

Whether any particle is still flying.

Returns

true while one is alive.

particlesAlive()

bool fx::particlesAlive ( )

inline

The same as particles().

Returns

true while a particle is alive.

banner()

void fx::banner	(	const char *	text,
		BannerStyle	s,
		int	cy,
		uint8_t	frames = 70
	)

Show a banner: big centred lettering with an outline that pops in, holds, and blinks out ("BLACKJACK!", "YOU WIN").

Parameters

text	The text (copied; at most SIZZLE_BANNER_CHARS - 1 characters).
s	Its style.
cy	The row its centre sits on.
frames	How many ticks it stays up, blinking out at the end (default 70).

One banner at a time: a new one replaces the last.

holdBanner()

void fx::holdBanner

(

bool

on

)

Keep the banner up (before it blinks out) until let go.

Parameters

on	true to hold it; false to let it blink out.

bannerActive()

bool fx::bannerActive

(

)

Whether a banner is showing.

Returns

true until it has blinked out.

floatText()

void fx::floatText	(	const char *	text,
		int	x,
		int	y,
		uint8_t	colour
	)

A floating text ("+$15") that rises from a point and fades out.

Parameters

text	The text (copied; at most SIZZLE_FLOAT_CHARS - 1 characters).
x,y	Where it starts.
colour	Its colour.

Several can be up at once; a new one takes the first free slot (or the first slot when all four are busy). Each lives 50 ticks.

drawFloats()

void fx::drawFloats

(

)

Draw the floating texts: while drawing, on top of the scene.

activeRows()

bool fx::activeRows	(	int &	lo,
		int &	hi
	)

The band of rows everything transient covers (particles, floats, banner, shake): what a partial redraw must include.

Parameters

lo	Gets the top row.
hi	Gets the bottom row.

Returns

false if nothing is moving (lo and hi are then meaningless).

clear()

void fx::clear

(

)

Remove every particle, float and the banner at once (and stop a shake).

update()

void fx::update

(

)

Move everything on by one tick: once per logic tick.

drawParticles()

void fx::drawParticles

(

uint8_t

dust = 2

)

Draw the particles: while drawing, on top of the scene.

Parameters

dust	The size of a DUST puff in pixels (default 2).

drawBanner()

void fx::drawBanner

(

)

Draw the banner, if one is showing: while drawing, last.

Variable Documentation

EASE_CUBIC

const int16_t fx::EASE_CUBIC[17]

extern

The curves' tables (17 points, 0..256), for easeCurve().