Tiled Backgrounds

Macros
#define	CBB_CLEAR(cbb)   memset32(&tile_mem[cbb], 0, CBB_SIZE/4)
#define	SBB_CLEAR(sbb)   memset32(&se_mem[sbb], 0, SBB_SIZE/4)
#define	SBB_CLEAR_ROW(sbb, row)    memset32(&se_mem[sbb][(row)*32], 0, 32/2)
#define	__BG_TYPES   ((0x0C7F<<16)|(0x0C40))
#define	BG_IS_AFFINE(n)   ( (__BG_TYPES>>(4*(REG_DISPCNT&7)+(n) ))&1 )
#define	BG_IS_AVAIL(n)   ( (__BG_TYPES>>(4*(REG_DISPCNT&7)+(n)+16))&1 )

Functions
INLINE void	se_fill (SCR_ENTRY *sbb, SCR_ENTRY se)
	Fill screenblock sbb with se.
INLINE void	se_plot (SCR_ENTRY *sbb, int x, int y, SCR_ENTRY se)
	Plot a screen entry at (x,y) of screenblock sbb.
INLINE void	se_rect (SCR_ENTRY *sbb, int left, int top, int right, int bottom, SCR_ENTRY se)
	Fill a rectangle on sbb with se.
INLINE void	se_frame (SCR_ENTRY *sbb, int left, int top, int right, int bottom, SCR_ENTRY se)
	Create a border on sbb with se.
INLINE void	se_hline (SCR_ENTRY *sbb, int x0, int x1, int y, SCR_ENTRY se)
	Draw a horizontal line on sbb with se.
INLINE void	se_vline (SCR_ENTRY *sbb, int x, int y0, int y1, SCR_ENTRY se)
	Draw a vertical line on sbb with se.
void	se_window (SCR_ENTRY *sbb, int left, int top, int right, int bottom, SCR_ENTRY se0)
	Create a framed rectangle.
INLINE void	bg_aff_set (BG_AFFINE *bgaff, FIXED pa, FIXED pb, FIXED pc, FIXED pd)
	Set the elements of an bg affine matrix.
INLINE void	bg_aff_identity (BG_AFFINE *bgaff)
	Set an bg affine matrix to the identity matrix.
INLINE void	bg_aff_scale (BG_AFFINE *bgaff, FIXED sx, FIXED sy)
	Set an bg affine matrix for scaling.
INLINE void	bg_aff_shearx (BG_AFFINE *bgaff, FIXED hx)
INLINE void	bg_aff_sheary (BG_AFFINE *bgaff, FIXED hy)
void	bg_aff_rotate (BG_AFFINE *bgaff, u16 alpha)
	Set bg matrix to counter-clockwise rotation.
void	bg_aff_rotscale (BG_AFFINE *bgaff, int sx, int sy, u16 alpha)
	Set bg matrix to 2d scaling, then counter-clockwise rotation.
void	bg_aff_premul (BG_AFFINE *dst, const BG_AFFINE *src)
	Pre-multiply dst by src: D = S*D.
void	bg_aff_postmul (BG_AFFINE *dst, const BG_AFFINE *src)
	Post-multiply dst by src: D= D*S.
void	bg_aff_rotscale2 (BG_AFFINE *bgaff, const AFF_SRC *as)
	Set bg matrix to 2d scaling, then counter-clockwise rotation.
void	bg_rotscale_ex (BG_AFFINE *bgaff, const AFF_SRC_EX *asx)
	Set bg affine matrix to a rot/scale around an arbitrary point.

Detailed Description

Function Documentation

bg_aff_rotate()

void bg_aff_rotate	(	BG_AFFINE *	bgaff,
		u16	alpha
	)

Set bg matrix to counter-clockwise rotation.

Parameters

bgaff	Object affine struct to set.
alpha	CCW angle. full-circle is 10000h.

References lu_cos(), and lu_sin().

bg_aff_rotscale()

void bg_aff_rotscale	(	BG_AFFINE *	bgaff,
		int	sx,
		int	sy,
		u16	alpha
	)

Set bg matrix to 2d scaling, then counter-clockwise rotation.

Parameters

bgaff	Object affine struct to set.
sx	Horizontal scale (zoom). .8 fixed point.
sy	Vertical scale (zoom). .8 fixed point.
alpha	CCW angle. full-circle is 10000h.

References lu_cos(), and lu_sin().

bg_aff_rotscale2()

void bg_aff_rotscale2	(	BG_AFFINE *	bgaff,
		const AFF_SRC *	as
	)

Set bg matrix to 2d scaling, then counter-clockwise rotation.

Parameters

bgaff	Object affine struct to set.
as	Struct with scales and angle.

References AFF_SRC::alpha, lu_cos(), lu_sin(), AFF_SRC::sx, and AFF_SRC::sy.

bg_rotscale_ex()

void bg_rotscale_ex	(	BG_AFFINE *	bgaff,
		const AFF_SRC_EX *	asx
	)

Set bg affine matrix to a rot/scale around an arbitrary point.

Rotate and scale round an arbitrary point using the asx data.

Parameters

bgaff	BG affine data to set.
asx	Affine source data: screen and texture origins, scales and angle.

References AFF_SRC_EX::alpha, lu_cos(), lu_sin(), AFF_SRC_EX::scr_x, AFF_SRC_EX::scr_y, AFF_SRC_EX::sx, AFF_SRC_EX::sy, AFF_SRC_EX::tex_x, and AFF_SRC_EX::tex_y.

se_window()

void se_window	(	SCR_ENTRY *	sbb,
		int	left,
		int	top,
		int	right,
		int	bottom,
		SCR_ENTRY	se0
	)

Create a framed rectangle.

In contrast to se_frame(), se_frame_ex() uses nine tiles starting at se0 for the frame, which indicate the borders and center for the window.

Note

Rectangle is nor normalized.