From 9de77349e830800827d10cc92a6707ec0701bfcb Mon Sep 17 00:00:00 2001
From: Fabian Schlenz <mail@fabianonline.de>
Date: Thu, 30 Apr 2020 06:40:05 +0200
Subject: [PATCH] SnakeEffect now uses a hand-crafted meandering algorithm.
 Still not perfect, but it works as good as the old code while looking more
 "natural".

---
 src/effect_snake.cpp | 42 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/effect_snake.cpp b/src/effect_snake.cpp
index 64c0840..08c999d 100644
--- a/src/effect_snake.cpp
+++ b/src/effect_snake.cpp
@@ -30,10 +30,6 @@ SnakeEffect::~SnakeEffect() {
 }
 
 void SnakeEffect::_place_apple() {
-	if (SNAKE_DEBUG) {
-		_apple = {3, 3};
-		return;
-	}
 	if (_length < _pixels) {
 		uint8_t start = random8(_pixels);
 		for (int i=0; i<_pixels; i++) {
@@ -60,7 +56,7 @@ void SnakeEffect::_decide() {
 	inputs[3] = a_l;
 	inputs[4] = a_s;
 	inputs[5] = a_r;
-	if (SNAKE_DEBUG) LOGln("SnakeEffect * Position: %d, %d - Inputs: %3.1f %3.1f %3.1f %3.1f %3.1f %3.1f", _pos.x, _pos.y, inputs[0], inputs[1], inputs[2], inputs[3], inputs[4], inputs[5]);
+	if (SNAKE_DEBUG) DBG("SnakeEffect * Position: %d, %d - Inputs: %3.1f %3.1f %3.1f %3.1f %3.1f %3.1f", _pos.x, _pos.y, inputs[0], inputs[1], inputs[2], inputs[3], inputs[4], inputs[5]);
 	float* outputs = NULL;
 	uint8_t i=0;
 	for (uint8_t layer=1; layer<_net_layers; layer++) {
@@ -92,7 +88,7 @@ void SnakeEffect::_decide() {
 	decision = decision - 1;
 	delete outputs;
 	
-	if (SNAKE_DEBUG) LOGln("SnakeEffect * Decision: %d", decision);
+	if (SNAKE_DEBUG) DBG("SnakeEffect * Decision: %d", decision);
 
 	_dir += decision;
 	if (_dir < 0) _dir += 4;
@@ -130,6 +126,36 @@ int8_t SnakeEffect::_manual_decision() {
      (2) Having a number smaller than the field the apple is on. (Watch out for "overflows".)
 */
 int8_t SnakeEffect::_manual_decision() {
+	uint8_t head_index = _coords_to_field_id(_pos);
+	uint8_t apple_index = _coords_to_field_id(_apple);
+	uint8_t tail_index = _coords_to_field_id(_tail);
+	if (SNAKE_DEBUG) DBG("SnakeEffect * Decision. head: %d, apple: %d, tail: %d", head_index, apple_index, tail_index);
+	
+	uint16_t best_distance = 0xFFFF;
+	int8_t decision = 0;
+	
+	for (int i=-1; i<=1; i++) { // Test all thre possible directions (left, ahead, right)
+		Coords new_pos = _new_pos(_dir + i);
+		uint8_t new_index = _coords_to_field_id(new_pos);
+		
+		int16_t distance;
+		if (apple_index >= new_index) {
+			distance = apple_index - new_index;
+		} else {
+			distance = (window->width * window->height) - apple_index + new_index;
+		}
+		if (SNAKE_DEBUG) DBG("SnakeEffect *   Decision: %d would have distance %d", i, distance);
+		if (distance < best_distance && _is_free(_dir + i)) {
+			best_distance = distance;
+			decision = i;
+		}
+	}
+	
+	if (SNAKE_DEBUG) DBG("SnakeEffect *   Decision taken: %d with distance %d", decision, best_distance);
+		
+	/*	apple_index > new_index && head_index > apple_index
+		apple_index > new_index && head_index < apple_index && new_index > head_index
+
 	uint16_t head_index = (_head_rounds<<8) | _coords_to_field_id(_pos);
 	uint16_t apple_index = (_head_rounds<<8) | _coords_to_field_id(_apple);
 	uint16_t tail_index = (_tail_rounds<<8) | _coords_to_field_id(_tail);
@@ -148,7 +174,7 @@ int8_t SnakeEffect::_manual_decision() {
 			decision = i;
 			best_dist = dist;
 		}
-	}
+	}*/
 	_dir = (_dir + decision) % 4;
 	return decision;
 }
@@ -242,7 +268,7 @@ void SnakeEffect::_move() {
 	}
 	
 	unsigned long now = millis();
-	if (_last_move_at < now && now - _last_move_at < 0) {
+	if (_last_move_at < now && now - _last_move_at < 50) {
 		return;
 	}
 	_round++;