pitrix/src/effect_snake.cpp

#include "effect_snake.h"
#include "functions.h"

void SnakeEffect::loop() {
	if (run++ % EFFECT_SNAKE_SLOWDOWN == 0) { // Change the coordinates only on every n-th run.
		uint8_t r = random8(EFFECT_SNAKE_DIRECTION_CHANGE);
		if (r==0 && valid_position(update_position(this->coords, direction+1))) {
			direction++;
		} else if (r==1 && valid_position(update_position(this->coords, direction-1))) {
			direction--;
		} else if (!valid_position(update_position(this->coords, direction))) {
			if (valid_position(update_position(this->coords, direction+1))) {
				direction++;
			} else if (valid_position(update_position(this->coords, direction-1))) {
				direction--;
			}
		}

		this->coords = update_position(this->coords, direction);
	}

	fadeToBlackBy(leds, LED_COUNT, 2);
 	setPixel(window, this->coords.x, this->coords.y, CHSV(hue, 200, 255));
	hue++;
}

Coords SnakeEffect::update_position(Coords original, uint8_t direction) {
	direction = direction % 4;
	if (direction == 0) original.y--;
	else if (direction == 1) original.x++;
	else if (direction == 2) original.y++;
	else if (direction == 3) original.x--;
	return original;
}

boolean SnakeEffect::valid_position(Coords c) {
	return c.x<window.w && c.y<window.h;
}

boolean SnakeEffect::can_be_shown_with_clock() { return true; }