using memmove to update snake

include/element.hpp

@@ -22,7 +22,7 @@ struct Point {
 };
 
 int get_score();
-void determine_index_zero_pos(Point* (*board)[COL], Point** buffer);
+void determine_index_zero_pos(Point** buffer);
 void move_tail_indicies(Point** buffer);
 void on_fruit_eaten(Point* (*board)[COL], Point** buffer);
 bool segment_overlap(Point** buffer);

src/element.cpp

@@ -1,8 +1,10 @@
 #include "element.hpp"
 #include <cstdlib>
+#include <cstring>
 #include <ctime>
 
 int _score = 0;
+int _snake_size = 3;
 
 int get_score() {
 	return _score;
@@ -13,9 +15,7 @@ void Point::set_new_point(int row, int col) {
 	m_col = col;
 }
 
-void determine_index_zero_pos(Point* (*board)[COL], Point** buffer) {
+void determine_index_zero_pos(Point** buffer) {
-	Point new_point = { buffer[0]->m_row, buffer[0]->m_col, '.' }; 
-
 	if(buffer[1] == nullptr) {
 		buffer[1] = new Point { buffer[0]->m_row, buffer[0]->m_col, '.' };
 	} else {
@@ -23,49 +23,40 @@ void determine_index_zero_pos(Point* (*board)[COL], Point** buffer) {
 	}
 
 	if (buffer[0]->m_dir == LEFT) {
-		if (new_point.m_col <= 0) new_point.m_col = COL - 1;
+		if (buffer[0]->m_col <= 0) buffer[0]->m_col = COL - 1;
-		else new_point.m_col--;
+		else buffer[0]->m_col--;
-	} else if (buffer[0]->m_dir == RIGHT) {
+	}
-		if (new_point.m_col >= COL - 1) new_point.m_col = 0;
+	else if (buffer[0]->m_dir == RIGHT) {
-		else new_point.m_col++;
+		if (buffer[0]->m_col >= COL - 1) buffer[0]->m_col = 0;
-	} else if (buffer[0]->m_dir == UP) {
+		else buffer[0]->m_col++;
-		if (new_point.m_row <= 0) new_point.m_row = ROW - 1;
+	}
-		else new_point.m_row--;
+	else if (buffer[0]->m_dir == UP) {
-	} else if (buffer[0]->m_dir == DOWN) {
+		if (buffer[0]->m_row <= 0) buffer[0]->m_row = ROW - 1;
-		if (new_point.m_row >= ROW - 1) new_point.m_row = 0;
+		else buffer[0]->m_row--;
-		else new_point.m_row++;
+	}
+	else if (buffer[0]->m_dir == DOWN) {
+		if (buffer[0]->m_row >= ROW - 1) buffer[0]->m_row = 0;
+		else buffer[0]->m_row++;
 	}
-	buffer[0]->set_new_point(new_point.m_row, new_point.m_col);
 }
 
 void move_tail_indicies(Point** buffer) {
-	Point* previous_head = buffer[1];
+	if(_snake_size <= 3) return;
 	int new_row = buffer[1]->m_row;
 	int new_col = buffer[1]->m_col;
-	Point* last_point = nullptr;
+	Point* last_point = buffer[_snake_size - 1];
-	for(int i = (ROW * COL) - 1; i > 3; i--) {
+
-		if(buffer[i] == nullptr) {
+	memmove(buffer + 4, buffer + 3, (_snake_size - 4) * sizeof(Point*));
-			last_point = buffer[i - 1];
+
-			continue;
-		}
-		buffer[i] = buffer[i - 1];
-	}
 	buffer[3] = last_point;
 	if(buffer[3] != nullptr) {
 		buffer[3]->set_new_point(new_row, new_col);
 	}
 }
 
-void _append_tail(Point *(*board)[COL], Point** buffer) {
+void _append_tail(Point** buffer) {
-	for(int i = (ROW * COL) - 1; i >= 3; i--) {
+	memmove(buffer + 4, buffer + 3, (_snake_size - 3) * sizeof(Point*));
-		buffer[i] = buffer[i - 1];
+	buffer[3] = new Point { ROW, COL, '@' };
-	}
-	Point* old_tail = buffer[4];
-	if(old_tail != nullptr) {
-		buffer[3] = new Point { old_tail->m_row, old_tail->m_col, '@' };
-	} else {
-		buffer[3] = new Point {};
-	}
 }
 
 void on_fruit_eaten(Point* (*board)[COL], Point** buffer) {
@@ -76,15 +67,16 @@ void on_fruit_eaten(Point* (*board)[COL], Point** buffer) {
 			col = (rand() % COL);
 		} while (board[row][col] != nullptr);
 		buffer[2]->set_new_point(row, col);
-		_append_tail(board, buffer);
+		_append_tail(buffer);
 		_score++;
+		_snake_size++;
 	}
 }
 
 bool segment_overlap(Point** buffer) {
-	for(int i = (ROW * COL) - 1; i > 3; i--) {
+	for(int i = 0; i < _snake_size; i++) {
-		if(buffer[i] == nullptr) continue;
+		if(buffer[i + 3] == nullptr) continue;
-		if(buffer[i]->m_row == buffer[0]->m_row && buffer[i]->m_col == buffer[0]->m_col) {
+		if(buffer[i + 3]->m_row == buffer[0]->m_row && buffer[i + 3]->m_col == buffer[0]->m_col) {
 			return true;
 		}
 	}

src/main.cpp

@@ -9,9 +9,10 @@ int main () {
 	std::srand(std::time(0));
 	Window window;
 	Input input;
+	const int MAX_LEN = (ROW * COL) + 3;
 	bool running = true;
 
-	Point* buffer[(ROW * COL) + 3] = {}; // 2 for head, 1 for fruit, rest for tail
+	Point* buffer[MAX_LEN] = {}; // 2 for head, 1 for fruit, rest for tail
 	buffer[0] = new Point { ROW / 2, COL / 2, '*' }; // Head
 	buffer[2] = new Point { (rand() % ROW), (rand() % COL), 'o' }; // Fruit
 
@@ -19,16 +20,16 @@ int main () {
 
 	while (running) {
 		on_fruit_eaten(window.m_board, buffer);
-		determine_index_zero_pos(window.m_board, buffer);
+		determine_index_zero_pos(buffer);
 		move_tail_indicies(buffer);
 
-		for(int i = (ROW * COL) - 1; i > 3; i--) {
+		for(int i = MAX_LEN - 1; i > 3; i--) {
 			if(buffer[i] == nullptr) break;
-			std::cout << "You win! Score: " << get_score() << std::endl;
+			std::cout << "You filled the whole board and won! Score: " << get_score() << std::endl;
 			running = false;
 		}
 		if(segment_overlap(buffer)) {
-			std::cout << "You died! Score: " << get_score() << std::endl;
+			std::cout << "You collided with yourself and died! Score: " << get_score() << std::endl;
 			running = false;
 		}
 		window.clear_display();
@@ -37,8 +38,7 @@ int main () {
 	}
 
 	input_thread.join();
-	for(int i = ((ROW * COL) + 3) - 1; i > 0; i--) {
+	for(int i = 0; i < MAX_LEN - 1; i++) {
-		if(buffer[i] == nullptr) continue;
 		delete buffer[i];
 	}
 	return 0;

src/window.cpp

@@ -24,11 +24,8 @@ void Window::draw_display(int milliseconds) {
 }
 
 void Window::update_display(Point** buffer) {
-	m_board[buffer[0]->m_row][buffer[0]->m_col] = buffer[0];
+	for(int i = 0; i < ROW * COL; i++) {
-	m_board[buffer[2]->m_row][buffer[2]->m_col] = buffer[2];
+		if(buffer[i] == nullptr || i == 1 || buffer[i]->m_row > ROW - 1 || buffer[i]->m_col > COL - 1) continue;
-	for(int i = 3; i < ROW * COL; i++) {
-		if(buffer[i] != nullptr) {
 		m_board[buffer[i]->m_row][buffer[i]->m_col] = buffer[i];
 	}
 }
-}