ddt/include/dd_animation.h

#ifndef DD_ANIMATION_H
#define DD_ANIMATION_H

/* Used for creating animations
 * Counts from 0 to given value
 * Can check if animation is increasing or decreasing
 * `update()` moves animation until it ends (reach max or 0)
 	returns true if updated, false otherwise
 * `interpolate()` takes a float (usually a distance)
 	and calculates the interpolated value from 0 to that float
 */

/* so far, 255 values were enough for an animation, I don't know
 * if I'll change it later on
 */
typedef unsigned char anim_size;

/* Animation struct */
struct dd_animation {
	/* Counters */
	anim_size counter, max;

	/* Boolean */
	char positive;
};

/* initializes an animation struct */
void dd_animation_init(struct dd_animation *a, anim_size max_value);

/* updates animation */
int dd_animation_update(struct dd_animation *a);

/* Start animation 
 * the `0` version starts from 0 and moves positively 
 * the `max` version starts from max and moves negatively
 * flip just changes the direction of the update
 */
void dd_animation_start0(struct dd_animation *a);
void dd_animation_startmax(struct dd_animation *a);
void dd_animation_flip(struct dd_animation *a);

/* Get an interpolated value, from 0 to value
 * taken from animation's size
 */
float dd_animation_interpolate(struct dd_animation *a, float value);

/* issers */
int dd_animation_isrunning(struct dd_animation *a);

#endif