1 files changed, 189 insertions, 0 deletions
diff --git a/src/body.c b/src/body.c
new file mode 100644
index 0000000..bfee083
--- /dev/null
+++ b/src/body.c
@@ -0,0 +1,189 @@
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "../include/body.h"
+
+typedef struct node{
+	int x;
+	int y;
+	struct node *next;
+} NODE;
+
+typedef struct snake{
+	NODE *head; //"head" will be the physical tail of the snake
+	NODE *tail; //"tail" will be the physical head of the snake
+	int length;
+} SNAKE;
+
+//private prototypes
+NODE *makeNode(int x, int y);
+void deleteNode(NODE *np);
+void increaseSnake(SNAKE *sp);
+
+//public functions
+SNAKE *makeSnake(int startx, int starty, int len){
+	SNAKE *new = malloc(sizeof(SNAKE));
+	NODE *np;
+
+	assert(new != NULL);
+
+	new->length = len;
+
+	new->head = makeNode(startx-len+1, starty);
+	np = new->head;
+	len--;
+
+	while(len > 0){
+		np->next = makeNode(startx-len+1, starty);
+		np = np->next;
+		len--;
+	}
+
+	new->tail = np;
+
+	return new;
+}
+
+void deleteSnake(SNAKE *sp){
+	NODE *hold;
+
+	if(sp != NULL){
+		while(sp->head != NULL){
+			hold = sp->head;
+			sp->head = sp->head->next;
+			deleteNode(hold);
+		}
+	}
+
+	free(sp);
+	return;
+}
+
+void updateSnake(SNAKE *sp, int dir, int maxx, int maxy, bool *collision, int *fruit_loc, bool *fruit, int *score){
+	NODE *np;
+
+	if(sp == NULL) return;
+
+	//move the "back" to the "front" (note that sp->tail will not be set until after np->x and np->y are set)
+	np = sp->head;
+	sp->head = sp->head->next;
+	sp->tail->next = np;
+	np->next = NULL;
+
+	//dir decides direction the snake is moving
+	switch(dir){
+		case(0): //snake is moving up
+			np->x = sp->tail->x;
+			np->y = sp->tail->y-1;
+			break;
+
+		case(1): //snake is moving right
+			np->x = sp->tail->x+1;
+			np->y = sp->tail->y;
+			break;
+
+		case(2): //snake is moving down
+			np->x = sp->tail->x;
+			np->y = sp->tail->y+1;
+			break;
+
+		case(3): //snake is moving left
+			np->x = sp->tail->x-1;
+			np->y = sp->tail->y;
+	}
+
+	//update tail pointer
+	sp->tail = np;
+
+	//check if eating fruit
+	if(*fruit && sp->tail->x == *fruit_loc && sp->tail->y == *(fruit_loc + 1)){
+		*fruit = false;
+		(*score)++;
+
+		//need to increase snake size
+		increaseSnake(sp);
+	}
+
+	//check collision
+	*collision = checkSnake(sp, maxx, maxy);
+
+	return;
+}
+
+//true = collision, false = no collision
+bool checkSnake(SNAKE *sp, int maxx, int maxy){
+	NODE *np;
+
+	if(sp == NULL) return true;
+
+	//check if oob
+	if(sp->tail->x < 0 || sp->tail->x >= maxx || sp->tail->y < 0 || sp->tail->y >= maxy) return true;
+
+	//check if collision with body (check each cell)
+	np = sp->head;
+	while(np != sp->tail && np != NULL){
+		if(sp->tail->x == np->x && sp->tail->y == np->y) return true;
+		np = np->next;
+	}
+
+	return false;
+}
+
+int getSnakeTailx(SNAKE *sp){
+
+	if(sp != NULL && sp->tail != NULL) return sp->tail->x;
+	return -1;
+
+}
+int getSnakeTaily(SNAKE *sp){
+
+	if(sp != NULL && sp->tail != NULL) return sp->tail->y;
+	return -1;
+
+}
+
+int getSnakeHeadx(SNAKE *sp){
+
+	if(sp != NULL && sp->head != NULL) return sp->head->x;
+	return -1;
+
+}
+
+int getSnakeHeady(SNAKE *sp){
+
+	if(sp != NULL && sp->head != NULL) return sp->head->y;
+	return -1;
+
+}
+			
+//private functions
+NODE *makeNode(int x, int y){
+	NODE *new = malloc(sizeof(NODE));
+	assert(new != NULL);
+
+	new->x = x;
+	new->y = y;
+	new->next = NULL;
+
+	return new;
+}
+
+void deleteNode(NODE *np){
+
+	if(np != NULL) free(np);
+
+	return;
+}
+
+void increaseSnake(SNAKE *sp){
+	int xdiff = sp->head->next->x - sp->head->x;
+	int ydiff = sp->head->next->y - sp->head->y;
+	NODE *new = makeNode(sp->head->x - xdiff, sp->head->y - ydiff);
+
+	new->next = sp->head;
+	sp->head = new;
+	sp->length++;
+
+	return;
+}