confusing segmentation fault?

dancks (89)
This is a supporting source file of a larger (but still pretty small) game.

Yeah this is kind of a repeat of my earlier thread but I got rid of the linked list and am using 2 vectors. Let me show you:

.h:
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#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include "collarea.h"
#include <vector>
#ifndef EXP_H
#define EXP_H
using std::vector;
class ALLEGRO_BITMAP;
class collarea;
class explosionhandler {
public:
	
	struct explosion {
		int type;
		int seq;
		float x,y;
		float radius;
	};
	vector<struct explosion> explosions;
	struct explosion_type {
		//int type;
		int num_seq;
		//equation: size(#) = a + m*# - e*#^2
		float a,e,m;
		ALLEGRO_BITMAP* exp;
		explosion_type *next;
	};// *type;
	vector<struct explosion_type> type;
	int num_types;
	
	explosionhandler();
	~explosionhandler();
	
	void add(explosion_type* a);
	
	void registerexplosion(int& ttype,ALLEGRO_BITMAP*& b,int seq, float a, float m,float e);

	void createexplosion(int ttype,float x,float y);
	void drawexplosions(ALLEGRO_BITMAP* screen);

	float getfloat(float& a);
	void gettype(explosion_type& a,ALLEGRO_BITMAP*& b,int& nseq, float& aa, float& ee, float& mm);
	
	int checkkill(collarea a);
	
};
#endif


.cpp:
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#include "explosionhandler.h"
#include <math.h>
explosionhandler::explosionhandler()
{
	num_types=0;
}
void explosionhandler::registerexplosion(int& ttype,ALLEGRO_BITMAP*& b,int seq, float a, float m,float e)
{
	explosion_type n;
	n.num_seq=seq;
	n.exp=b;
	n.a=a;
	n.m=m;
	n.e=e;
	ttype = num_types; //right here is the issue
	num_types++;
	type.push_back(n);
}
void explosionhandler::createexplosion(int ttype,float x,float y)
{
	if((ttype < num_types)&&(ttype>-1))
	{
		explosion e;
		e.type=ttype;
		e.x=x;
		e.y=y;
		e.seq=1;
		e.radius = (type.at(ttype).a) + (type.at(ttype).m) - (type.at(ttype).e);
		explosions.push_back(e);
	}
}
float explosionhandler::getfloat(float& a)
{
	return a;
}
void explosionhandler::drawexplosions(ALLEGRO_BITMAP* screen)
{
	al_set_target_bitmap(screen);
	float a,m,e;
	int ttype,seq;
	ALLEGRO_BITMAP *b;
	int hh = explosions.size();
	for(int i=0;i<hh;i++)
	{
		explosion x = explosions[0];
		explosions.erase(explosions.begin());
		gettype(type.at(x.type),b,seq,a,e,m);
		al_draw_scaled_bitmap(b,0,0,al_get_bitmap_width(b),al_get_bitmap_height(b),getfloat(x.x),getfloat(x.y),getfloat(x.radius)*2,getfloat(x.radius)*2,0);
		x.seq++;
		if(x.seq<=seq)
		{
			float oldradius=x.radius;
			x.radius=(a+m*x.seq-e*x.seq*x.seq)/2;
			x.x-=(x.radius-oldradius);
			x.y-=(x.radius-oldradius);
			explosions.push_back(x);
		}
	}
}
void explosionhandler::gettype(explosion_type& a, ALLEGRO_BITMAP*& b, int& nseq, float& aa, float& ee, float& mm)
{
	b=a.exp;
	nseq=a.num_seq;
	aa=a.a;
	ee=a.e;
	mm=a.m;
}
int explosionhandler::checkkill(collarea a)
{
	int yes=0;
	int h=explosions.size();
	for(int i=0;i<h;i++)
	{
		float x = explosions.at(i).x;
		float y = explosions.at(i).y;
		float seq = explosions.at(i).seq;
		if(seq)
		{
			float xx,yy;
			a.toxy(&xx,&yy,a.getbl());
			float bx,by;
			a.toxy(&bx,&by,a.getbr());
			xx  = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			a.toxy(&bx,&by,a.gettl());
			xx = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			a.toxy(&bx,&by,a.gettr());
			xx = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			float dd = sqrt((x-xx)*(x-xx) + (y-yy)*(y-yy));
			if(dd < explosions.at(i).radius)
			{
				yes++;
			}
		}
	}
	return yes;
}


GDB:

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Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000030
[Switching to process 27451]
0x0000000100007413 in explosionhandler::registerexplosion (this=0x0, ttype=@0x10000fa5c, b=@0x10000f960, seq=3, a=120, m=0, e=-18) at explosionhandler.cpp:222
222		ttype = num_types; //there was a lot of code commented out
Peter87 (11256)
It looks like you are calling the registerexplosion function on a null pointer.
dancks (89)
Let me show you where its being used for context:

.h:
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#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include "collarea.h"
#include "explosionhandler.h"
#include <vector>
#ifndef R1_H
#define R1_H
#define PI 3.14159265
class ALLEGRO_BITMAP;
class collarea;
class explosionhandler;
using std::vector;
class rocket
{
public:
	rocket(float sp,float w,float h);
	~rocket();

	collarea area;
	
	struct rk {
		float x,y,dx,dy,theta;
		int seq;
	};
	vector<struct rk> rockets;
	
	explosionhandler *handler;
	
	int limit;
	int launched;
	int internal_ptr;
	
	
	void setlimit(int a);
	
	
	void renew();
	void update();

	void setrocket(ALLEGRO_BITMAP*& a,ALLEGRO_BITMAP*& b, explosionhandler*& h);
	void launch(float xx, float yy,float ttheta);
	void launch(collarea you, collarea other);
	int draw(float *xx, float *yy, float *ttheta);
	void checkexplode(collarea a);
	void move(collarea a);
	
	void setexptype(int a);
	
	int exptype; //this is the variable.
	
private:
	float width, height;
	float speed;
	float killdist;
	//float x,y,dx,dy;
	float dist;
	float destx,desty;
	float ox,oy;
	//int seq;
	int vdist; //for explosion sequence
	
};
#endif


.cpp:

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#include "rocket.h"
#include <math.h>
#include <stdio.h>
#define abs(x) (((x)>0) ? (x) : (-(x)))
#define growth(x) (1+.18*((x)*(x)))
rocket::rocket(float sp,float w,float h)
{
	speed = sp;
	launched=0;
	limit=0;
	internal_ptr=0;
	width=w;
	height=h;
	rockets.resize(0);
	exptype=-1;  //******** this is the variable initialized **********/
	fprintf(stdout,"constructor, # of rockets in vector: %i\n",(int)rockets.size());
}
void rocket::setexptype(int a)
{
	exptype=a;
}
void rocket::setlimit(int a)
{
	limit=a;
	launched=0;
	fprintf(stdout,"Set Limit called, # of rockets in vector: %i\n",(int)rockets.size());
}
void rocket::setrocket(ALLEGRO_BITMAP*& a,ALLEGRO_BITMAP*& b, explosionhandler*& h)
{
	handler = h;
	area.sethitboundaries(a);
	fprintf(stdout,"setrocket, # of rockets in vector: %i\n",(int)rockets.size());
	h->registerexplosion(exptype,b,3,(float)al_get_bitmap_width(b),(float)0,(float)-18); //called function
}
void rocket::launch(float xx, float yy,float ttheta)
{
	fprintf(stdout,"Launched, before: %i\n",(int)rockets.size());
	if(launched<limit)
	{
		struct rk next;
		next.x=xx; next.y=yy; next.theta=ttheta;
		next.dx = speed * cos(ttheta);
		next.dy = speed * sin(ttheta);
		next.seq=0;
		launched++;
		rockets.push_back(next);
	}
	fprintf(stdout,"Launched, after: %i\n",(int)rockets.size());
}
void rocket::launch(collarea you, collarea other)
{
	if(launched<limit)
	{
		//fprintf(stdout,"In launch, in vector, Before: %i\n",(int)rockets.size());
		struct rk next;
		float xx,yy;
		you.getxy(&xx,&yy);
		next.x=xx; next.y=yy;
		other.getxy(&xx,&yy);
		float ratio = (next.y-yy)/(next.x-xx);
		next.theta = atan(ratio);
		next.dx = speed * cos(next.theta);
		next.dy = speed * sin(next.theta);
		next.seq=0;
		launched++;
		rockets.push_back(next);
		//fprintf(stdout,"In launch, in vector, After: %i\n",(int)rockets.size());
	}
}
int rocket::draw(float *xx, float *yy, float *ttheta)
{
	internal_ptr++;
	*xx = -1;
	*yy = -1;
	*ttheta = -1;
	int i=1;
	if(internal_ptr>=rockets.size())
	{
		i=0;
		internal_ptr=-1;
	}
	else if(!rockets.at(i).seq)
	{
		*xx=rockets.at(internal_ptr).x;
		*yy=rockets.at(internal_ptr).y;
		*ttheta=rockets.at(internal_ptr).theta;
		//fprintf(stdout,"In draw, parameters: ptr: %i, x: %f, y: %f, theta: %f\n",internal_ptr,*xx,*yy,*ttheta);
	}
	return i;
}
void rocket::checkexplode(collarea a)
{
	int g = rockets.size();
	fprintf(stdout,"In checkexplode(), rockets fired: %i, launched: %i\n",g,launched);
	for(int i=0;i<g;i++)
	{
		rk temp = rockets.at(0);
		if(!temp.seq)
		{
			float x=temp.x;
			float y=temp.y;
			float xx,yy;
			a.toxy(&xx,&yy,a.getbl());
			float bx,by;
			a.toxy(&bx,&by,a.getbr());
			xx = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			a.toxy(&bx,&by,a.gettl());
			xx = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			a.toxy(&bx,&by,a.gettr());
			xx = (abs(x-xx)<abs(x-bx)) ? xx : bx;
			yy = (abs(y-yy)<abs(y-by)) ? yy : by;
			float dd = sqrt((x-xx)*(x-xx) + (y-yy)*(y-yy));
			//fprintf(stdout,"dd: %f, killdist: %f\n",dd,killdist);
			if(dd < killdist)
			{
				fprintf(stdout,"\n\nRocket should explode\n\n");
				temp.seq=1;
				handler->createexplosion(exptype,x,y);
			}
		}
		rockets.push_back(temp);
	}
}
void rocket::update()
{
	//fprintf(stdout,"In update, in vector: Before: %i\n",(int)rockets.size());
	int g=rockets.size();
	for(int i=0;i<g;i++)
	{
		rk temp = rockets.at(0);
		rockets.erase(rockets.begin());
		if(temp.seq)
		{
			temp.seq++;
		}
		else 
		{
			temp.x+=temp.dx;
			temp.y+=temp.dy;
		}
		rockets.push_back(temp);
	}
	//fprintf(stdout,"In update, in vector: Before: %i\n",(int)rockets.size());
}
void rocket::renew()
{
	//fprintf(stdout,"In renew, in vector: Before: %i\n",(int)rockets.size());
	int j=rockets.size();
	for(int i=0;i<j;i++)
	{
		rk temp = rockets.at(0);
		rockets.erase(rockets.begin());
		if(!((temp.x<0)||(temp.x>width)||(temp.y<0)||(temp.y>height)||(temp.seq>3)))
		{
			rockets.push_back(temp);
		}
	}
	//fprintf(stdout,"In renew, in vector: Before: %i\n",(int)rockets.size());
}
void rocket::move(collarea a)
{
	//fprintf(stdout,"In move, before sequence, in vector: Before: %i\n",(int)rockets.size());
	checkexplode(a);
	renew();
	update();
	//fprintf(stdout,"In move, after sequence, in vector: After: %i\n",(int)rockets.size());
}
rocket::~rocket()
{
	while(rockets.size())
	{
		rockets.erase(rockets.begin());
	}
	rockets.resize(0);
}



I guess I should've just post snippets lol whatever you get the idea.

explosionhandler is a pointer in main passed to rocket. rocket is a global object in main as is explosionhandler.
Peter87 (11256)
h->registerexplosion(exptype,b,3,(float)al_get_bitmap_width(b),(float)0,(float)-18);
Make sure h is not a null pointer.
dancks (89)
it was. I initialized it. Problem Solved. Thanks.
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