Miscellaneous routines

Modules
	DMA
	Timer

Macros
#define	STR(x)   #x
#define	XSTR(x)   STR(x)
	Create text string from a literal.

Variables
const u8	oam_sizes [3][4][2]
const BG_AFFINE	bg_aff_default
COLOR *	vid_page
int	__qran_seed

Sector checking
u32	octant (int x, int y)
	Get the octant that (x, y) is in.
u32	octant_rot (int x0, int y0)
	Get the rotated octant that (x, y) is in.

Random numbers
int	sqran (int seed)
	Quick (and very dirty) pseudo-random number generator.
INLINE int	qran (void)
	Quick (and very dirty) pseudo-random number generator.
INLINE int	qran_range (int min, int max)
	Ranged random number.
#define	QRAN_SHIFT   15
	Quick (and very dirty) pseudo-random number generator.
#define	QRAN_MASK   ((1<<QRAN_SHIFT)-1)
	Quick (and very dirty) pseudo-random number generator.
#define	QRAN_MAX   QRAN_MASK
	Quick (and very dirty) pseudo-random number generator.

Inline assembly
#define	ASM_CMT(str)   asm volatile("@# " str)
	Assembly comment.
#define	ASM_BREAK()   asm volatile("\tmov\t\tr11, r11")
	No$gba breakpoint.
#define	ASM_NOP()   asm volatile("\tnop")
	No-op; wait a bit.

Detailed Description

Macro Definition Documentation

QRAN_MASK

#define QRAN_MASK   ((1<<QRAN_SHIFT)-1)

Quick (and very dirty) pseudo-random number generator.

Returns

random in range [0,8000h>

QRAN_MAX

#define QRAN_MAX   QRAN_MASK

Quick (and very dirty) pseudo-random number generator.

Returns

random in range [0,8000h>

QRAN_SHIFT

#define QRAN_SHIFT   15

Quick (and very dirty) pseudo-random number generator.

Returns

random in range [0,8000h>

Function Documentation

octant()

u32 octant	(	int	x,
		int	y
	)

Get the octant that (x, y) is in.

This function divides the circle in 8 parts. The angle starts at the y=0 line and then moves in the direction of the x=0 line. On the screen, this would be like starting at the 3 o'clock position and moving clockwise

octant_rot()

u32 octant_rot	(	int	x0,
		int	y0
	)

Get the rotated octant that (x, y) is in.

Like octant() but with a twist. The 0-octant starts 22.5° earlier so that 3 o'clock falls in the middle of octant 0, instead of at its start. This can be useful for 8 directional pointing.

qran()

INLINE int qran

(

void

)

Quick (and very dirty) pseudo-random number generator.

Returns

random in range [0,8000h>

References QRAN_MAX.

Referenced by qran_range().

qran_range()

INLINE int qran_range	(	int	min,
		int	max
	)

Ranged random number.

Returns

random in range [min, max>

Note

(max-min) must be lower than 8000h

References max(), min(), qran(), and QRAN_SHIFT.

sqran()

int sqran

(

int

seed

)

Quick (and very dirty) pseudo-random number generator.

Returns

random in range [0,8000h>

References sqran().

Referenced by sqran().