Thread: Segfaults - again

Hi, I just had a go at starting on a program. It makes 2 points which seems to work until I try and print the data at which point it segfaults. Heres my main:

Code:

#include <stdio.h>	
#include "vector.h"

int main()
{
	Polygon *line;
	NewLine(line, 10, 10, 20, 20);
	PrintPoints(line);
	DeletePolygon(line);
	return 0;
}

vector.h:

Code:

#include <stdlib.h>
#include <stdio.h>

#define true 1
#define false 0

#ifndef Uint8
	#define Uint8 unsigned char
#endif 
#ifndef Uint32
	#define Uint32 unsigned long
#endif 


#define POLYGON_IS_SPLINE 128
#define POLYGON_SPLINE_IS_CUBIC 64		//Must be spline to be cubic
#define POLYGON_IS_CLOSED 32
#define POLYGON_IS_FILLED 16 			//Must be closed to be filled and have size > 2

typedef struct
{
	int x, y;	  // Point position
	float vx, vy; // Independant point velocity 
}Point;

typedef struct
{
	Uint8 flags;  
	Uint32 size;
	Point *point; // List of points
	float vx, vy; // Polygon velocity
}Polygon;

int DeletePolygon(Polygon *p);
int NewPoint(Point *p, int x, int y);
int NewLine(Polygon *p, int x1, int y1, int x2, int y2);
void PrintPoints(Polygon *poly);

and vector.c:

Code:

#include "vector.h"

int NewPoint(Point *p, int x, int y)
{
	p = malloc(sizeof(Point));
	if(p == NULL) return false;	
	p->x = x; p->y = y;
	return true;
}


int NewLine(Polygon *p, int x1, int y1, int x2, int y2)
{
	p = malloc(sizeof(Polygon));
	if(p == NULL) return false;
	p->size = 2;	
	p->flags = 0;
	p->point = malloc(sizeof(int*)*2);
	Point *temp = p->point;
	if( NewPoint(temp, x1, y1) == false) 
	{
		free(p);
		return false;
	}
	temp++;
	if( NewPoint(temp, x2, y2) == false)
	{
		free((--temp));
		free(p);
		return false;
	}
	return true;
}

void PrintPoints(Polygon *poly)
{
	Point *p = poly->point;
	for(int i=0; i<poly->size; i++, p++)
		printf("%c(%d, %d)\n", 'A'+i, p->x, p->y);
}


int DeletePolygon(Polygon *p)
{
	Point *temp = p->point;
	for(int i=0; i < p->size; i++, temp++)
		free(temp);	
	return true;
}

Its segfauting somewhere in the red, but that could be because I havent created my structs propery or something. What am I doing wrong?

Cheers.

Whoops, yeah I have been here before, lol. Thanks MacGuyver; I added the extra pointy bit and it works now