I cannot modify the member values of a class object because of the above error:
When I call my initialize function to initialize my "garo" object, I receive the following run-time error,
"Unhandled exception at 0x01323976 in Heretic.exe: 0xC0000005: Access violation reading location 0x00000008."
NOTE: The class Garo is a child of Object.
THE CODE
Garo.h
#pragma once
#include "Object.h"
class Garo : public Object
{
private:
int animationRow;
public:
Garo();
void Destroy();
void Init(ALLEGRO_BITMAP *image = NULL);
void Update();
void Render();
void MoveLeft();
void MoveRight();
void Idle();
void SetAnimationRow(int row);
};
Garo.cpp
#include "Garo.h"
Garo::Garo()
{
Object::Init(20, 200, 3, 0, 0, 0, 16, 24);
}
void Garo::Init(ALLEGRO_BITMAP *image)
{
Object::Init(20, 200, 3, 0, 0, 0, 16, 24);
SetID(PLAYER);
SetAlive(true);
maxFrame = 3;
curFrame = 0;
frameWidth = 32;
frameHeight = 48;
animationColumns = 4;
animationDirection = 1;
animationRow = 0;
if(image != NULL)
Garo::image = image;
}
... the rest has been abbreviated
Object.h
#pragma once
#include <iostream>
#include <allegro5/allegro5.h>
#include <allegro5/allegro_primitives.h>
#include "Globals.h"
class Object
{
private:
int ID;
bool alive;
bool collidable;
protected:
float x;
float y;
float velX;
float velY;
int dirX;
int dirY;
int boundX;
int boundY;
int maxFrame;
int curFrame;
int frameCount;
int frameDelay;
int frameWidth;
int frameHeight;
int animationColumns;
int animationDirection;
ALLEGRO_BITMAP *image;
public:
Object();
void virtual Destroy();
void Init(float x, float y, float velX, float velY, int dirX, int dirY, int boundX, int boundY);
void virtual Update();
void virtual Render();
float GetX() {return x;}
float GetY() {return y;}
void SetX(float x) {Object::x = x;}
void SetY(float y) {Object::y = y;}
int GetBoundX() {return boundX;}
int GetBoundY() {return boundY;}
int GetID() {return ID;}
void SetID(int ID) {Object::ID = ID;}
bool GetAlive() {return alive;}
void SetAlive(bool alive) {Object::alive = alive;}
bool GetCollidable() {return collidable;}
void SetCollidable(bool collidable) {Object::collidable = collidable;}
bool CheckCollisions(Object *otherObject);
void virtual Collided(int objectID);
bool Collidable();
};
Object.cpp
#include "Object.h"
Object::Object()
{
x = 0;
y = 0;
velX = 0;
velY = 0;
dirX = 0;
dirY = 0;
boundX = 0;
boundY = 0;
maxFrame = 0;
curFrame = 0;
frameCount = 0;
frameDelay = 0;
frameWidth = 0;
frameHeight = 0;
animationColumns = 0;
animationDirection = 0;
image = NULL;
alive = true;
collidable = true;
}
void Object::Init(float x, float y, float velX, float velY, int dirX, int dirY, int boundX, int boundY)
{
std::cout << "HERE?" << std::endl;
Object::x = x;
Object::y = y;
Object::velX = velX;
Object::velY = velY;
Object::dirX = dirX;
Object::dirY = dirY;
Object::boundX = boundX;
Object::boundY = boundY;
}
The Calling Code
Garo *garo;
// ...
garo->Init(garo_img);
This is where I receive the run-time error. I'm using Allegro libraries, so feel free to ask about any weird types you may see. I am stilling learning C++, so please help me to understand in rudimentary terms.
You need to instantiate an object instance to operate on. For example:
garo = new Garo();
By missing this out you are trying to invoke methods on an uninitialized variable. You should probably consider using some form of smart pointer to ensure that the object is destroyed.