Special Effects

Macros
#define	PA_EnableBgMosaic(screen, bg)   _REG16(REG_BGCNT(screen, bg)) |= (1 << 6)
	Enable the mosaic effect for a given background.
#define	PA_DisableBgMosaic(screen, bg)   _REG16(REG_BGCNT(screen, bg)) &= ~(1 << 6)
	Disable the mosaic effect for a given background.
#define	PA_SetBgMosaicXY(screen, h_size, v_size)   do{PA_REG_MOSAIC(screen) &= 255; PA_REG_MOSAIC(screen) |= ((h_size) + ((v_size) << 4));}while(0)
	Set the Mosaic parameters for the backgrounds.
#define	PA_SetSpriteMosaicXY(screen, h_size, v_size)   do{PA_REG_MOSAIC(screen) &= (255 << 8); PA_REG_MOSAIC(screen) |= (((h_size) << 8) + ((v_size) << 12));}while(0)
	Set the Mosaic parameters for the sprites.
#define	PA_EnableSpecialFx(screen, EffectType, FirstTarget, SecondTarget)   PA_REG_BLDCNT(screen) = ((FirstTarget) + ((SecondTarget) << 8) + ((EffectType) << 6))
	Enable Special Effects and set whether backgrounds and sprites will use them or not. This also sets the type of Effect.
#define	PA_DisableSpecialFx(screen)   PA_REG_BLDCNT(screen) = 0
	Disable Special Effects.
#define	PA_SetSFXAlpha(screen, Coeff1, Coeff2)   PA_REG_BLDALPHA(screen) = (Coeff1) + ((Coeff2) << 8)
	Set the special effect parameters for Alpha-Blending.

Detailed Description

Set the sprite special effects (alpha-blending, luminosity, mosaic effects...)

Macro Definition Documentation

PA_EnableBgMosaic

#define PA_EnableBgMosaic	(		screen,
			bg
	)		_REG16(REG_BGCNT(screen, bg)) |= (1 << 6)

Enable the mosaic effect for a given background.

Parameters

screen	Background screen (0 or 1)
bg	Background number

PA_DisableBgMosaic

#define PA_DisableBgMosaic	(		screen,
			bg
	)		_REG16(REG_BGCNT(screen, bg)) &= ~(1 << 6)

Disable the mosaic effect for a given background.

Parameters

screen	Background screen (0 or 1)
bg	Background number

PA_SetBgMosaicXY

#define PA_SetBgMosaicXY	(		screen,
			h_size,
			v_size
	)		do{PA_REG_MOSAIC(screen) &= 255; PA_REG_MOSAIC(screen) |= ((h_size) + ((v_size) << 4));}while(0)

Set the Mosaic parameters for the backgrounds.

Parameters

screen	Screen...
h_size	Horizontal size of the mosaic (1 for 1 pixel, 2 for 2 pixels, etc...)
v_size	Vertical size of the mosaic (1 for 1 pixel, 2 for 2 pixels, etc...)

PA_SetSpriteMosaicXY

#define PA_SetSpriteMosaicXY	(		screen,
			h_size,
			v_size
	)		do{PA_REG_MOSAIC(screen) &= (255 << 8); PA_REG_MOSAIC(screen) |= (((h_size) << 8) + ((v_size) << 12));}while(0)

Set the Mosaic parameters for the sprites.

Parameters

screen	Screen...
h_size	Horizontal size of the mosaic (1 for 1 pixel, 2 for 2 pixels, etc...)
v_size	Vertical size of the mosaic (1 for 1 pixel, 2 for 2 pixels, etc...)

PA_EnableSpecialFx

#define PA_EnableSpecialFx	(		screen,
			EffectType,
			FirstTarget,
			SecondTarget
	)		PA_REG_BLDCNT(screen) = ((FirstTarget) + ((SecondTarget) << 8) + ((EffectType) << 6))

Enable Special Effects and set whether backgrounds and sprites will use them or not. This also sets the type of Effect.

Parameters

screen	Screen...
EffectType	Effect Type. 0 for non, 1 for alpha-blending, 2 for brightness increase, and 3 for brightness decrease. You can use the macros SFX_NONE, SFX_ALPHA, SFX_BRIGHTINC, SFX_BRIGHTDEC
FirstTarget	Backgrounds and sprites for which to activate the effect. Use the following macro : SFX_BG0 | SFX_BG1 | SFX_BG2 | SFX_BG3 | SFX_OBJ | SFX_BD (back drop)
SecondTarget	Backgrounds and sprites to be seen behind the alpha-blending. Use the following macro : SFX_BG0 | SFX_BG1 | SFX_BG2 | SFX_BG3 | SFX_OBJ | SFX_BD (back drop)

PA_DisableSpecialFx

#define PA_DisableSpecialFx

(

screen

)

PA_REG_BLDCNT(screen) = 0

Disable Special Effects.

Parameters

screen

Screen...

PA_SetSFXAlpha

#define PA_SetSFXAlpha	(		screen,
			Coeff1,
			Coeff2
	)		PA_REG_BLDALPHA(screen) = (Coeff1) + ((Coeff2) << 8)

Set the special effect parameters for Alpha-Blending.

Parameters

screen	Screen...
Coeff1	Coefficient for the first layer, from 0 to 31. Apparently, it's better to set between 0 and 16
Coeff2	Coefficient for the second layer, from 0 to 31. Apparently, it's better to set between 0 and 16