ui_cats.c File Reference

The pick of a cat among the poses that fit a screen's spots, its drawing, and the random source. See include/ui_cats.h. More...

#include "ui_cats.h"
#include <stddef.h>

Functions
void	ui_cats_set_random (ui_cats_random_fn fn)
	Name the source ui_cats_roll() reads.
void	ui_cats_seed (uint32_t seed)
	Seed the built-in xorshift.
uint32_t	ui_cats_roll (void)
	The next random number from the source.
void	ui_cats_force (int pose)
	Put one pose, or none, in place of the random pick.
int	ui_cats_forced (void)
	The pose ui_cats_force() set.
gfx_rect_t	ui_cat_rect (int pose, const ui_cat_spot_t *spot)
	The box pose pose covers in spot.
static uint32_t	clear_spots (int pose, const ui_cat_spot_t *spots, int n, ui_cat_clear_fn clear)
	The spots of spots that pose pose may take and that are clear, as a mask of indexes.
static int	nth_bit (uint32_t m, unsigned k)
	The index of the k-th set bit of m, counting from 0.
static unsigned	bits (uint32_t m)
	The set bits of m.
ui_cat_pick_t	ui_cats_pick (const ui_cat_spot_t *spots, int n, ui_cat_clear_fn clear, uint32_t roll)
	Pick a pose among the ones with a clear spot, and that spot.
gfx_rect_t	ui_cats_draw (gfx_canvas_t *c, ui_cat_pick_t pick, const ui_cat_spot_t *spots, int n)
	Draw a pick.

Variables
static ui_cats_random_fn	s_random
	The source ui_cats_roll() reads; NULL for the xorshift.
static uint32_t	s_state = 1u
	The xorshift's state, never 0.
static int	s_forced = UI_CAT_RANDOM
	The pose ui_cats_force() set, UI_CAT_RANDOM by default.

Detailed Description

The pick of a cat among the poses that fit a screen's spots, its drawing, and the random source. See include/ui_cats.h.

SPDX-License-Identifier: MIT

Function Documentation

bits()

unsigned bits ( uint32_t m )

static

The set bits of m.

Parameters

m

the mask

Returns

how many

clear_spots()

uint32_t clear_spots ( int pose, const ui_cat_spot_t * spots, int n, ui_cat_clear_fn clear )

static

The spots of spots that pose pose may take and that are clear, as a mask of indexes.

Parameters

pose	index into ui_cat_poses[]
spots	the screen's spots
n	how many, at most 32
clear	the screen's test of a box

Returns

bit i set for spots[i]

nth_bit()

int nth_bit ( uint32_t m, unsigned k )

static

The index of the k-th set bit of m, counting from 0.

Parameters

m	the mask, with more than k bits set
k	which set bit

Returns

its index

ui_cat_rect()

gfx_rect_t ui_cat_rect	(	int	pose,
		const ui_cat_spot_t *	spot )

The box pose pose covers in spot.

Parameters

pose	index into ui_cat_poses[]
spot	the spot

Returns

the box; empty for a pose out of range or a NULL spot

ui_cats_draw()

gfx_rect_t ui_cats_draw	(	gfx_canvas_t *	c,
		ui_cat_pick_t	pick,
		const ui_cat_spot_t *	spots,
		int	n )

Draw a pick.

Parameters

c	the canvas
pick	the pick
spots	the list its spot indexes
n	how many

Returns

the box drawn, empty for none

ui_cats_force()

void ui_cats_force

(

int

pose

)

Put one pose, or none, in place of the random pick.

Parameters

pose	index into ui_cat_poses[], UI_CAT_RANDOM or UI_CAT_NONE; anything else is UI_CAT_NONE

ui_cats_forced()

int ui_cats_forced

(

void

)

The pose ui_cats_force() set.

Returns

the pose, UI_CAT_RANDOM or UI_CAT_NONE

ui_cats_pick()

ui_cat_pick_t ui_cats_pick	(	const ui_cat_spot_t *	spots,
		int	n,
		ui_cat_clear_fn	clear,
		uint32_t	roll )

Pick a pose among the ones with a clear spot, and that spot.

A pose counts when one of the n spots is one it may take and clear says its box there is clear. roll picks among them, and among the clear spots of the pose picked: pose roll mod P, spot (roll / P) mod S. A forced pose (ui_cats_force()) is the only one looked at; UI_CAT_NONE forced picks none.

Parameters

spots	the screen's spots
n	how many, at most 32
clear	the screen's test of a box
roll	the random number

Returns

the pick, or UI_CAT_PICK_NONE when no pose fits

ui_cats_roll()

uint32_t ui_cats_roll

(

void

)

The next random number from the source.

Returns

the number

ui_cats_seed()

void ui_cats_seed

(

uint32_t

seed

)

Seed the built-in xorshift.

Parameters

seed	the seed; 0 is taken as 1, which xorshift needs nonzero

ui_cats_set_random()

void ui_cats_set_random

(

ui_cats_random_fn

fn

)

Name the source ui_cats_roll() reads.

Parameters

fn	the source, esp_random() on the panel; NULL for the built-in xorshift