I'am making this post because i have for the first time of my life an incomprehensible error from visual studio community 2017 :
I simply can't use others members of std then "nullptr_t" in all my classes except in the main.cpp ....
The auto-completion of visual only suggest me "nullptr_t" when I write "std::" except in the main.cpp. It's incomprehensible.
main.cpp code:
#include <SFML/Graphics.hpp>
int main()
{
return 0;
}
Point class code :
#pragma once
class Point
{
private:
float _x;
float _y;
public:
Point();
Point(float x, float y);
Point(const Point& p);
~Point();
float getx() { return _x; }
float gety() { return _y; }
void setx(float x) { _x = x; }
void sety(float y) { _y = y; }
};
/************************************************************************/
#include "pch.h"
#include "Point.h"
Point::Point()
{
_x = 0.0;
_y = 0.0;
}
Point::Point(float x, float y)
{
_x = x;
_y = y;
}
Point::Point(const Point& p)
{
_x = p._x;
_y = p._y;
}
Point::~Point()
{
}
Hexagon class :
#pragma once
class Hexagon
{
private:
Point _center;
float _diameter;
public:
Hexagon();
Hexagon(Point center, float diameter);
~Hexagon();
};
/***********************************************************************/
#include "pch.h"
#include "Hexagon.h"
#include "Point.h"
Hexagon::Hexagon() : _center()
{
_diameter = 10;
}
Hexagon::Hexagon(Point center, float diameter) : _center(center)
{
_diameter = diameter;
}
Hexagon::~Hexagon()
{
}
You just need to include the iostream library or add this line of code where you need it to the includes.
#include<iostream>
Related
To start off with, I'll mention I come mainly from a Java background. I do have exposure with C and understand most concepts behind C++. I'm trying to help myself learn more about the language and can't seem to figure out headers. I understand why to use them in addition to cpp files and all of that. My problem is trying to actually manage working with them. For example, defining a Vector3 header with private float variables and then overload operating. My problem comes in when I attempt to define the constructor and methods in the cpp file. I can't seem to figure out how to get access to the private variables without specifically defining the functions and the constructor in the header, which more or less leads me to believe I don't need both a header and cpp file in this instance.
Here's how I've defined the header file currently (which works, but isn't undefined as it should be):
#pragma once
#ifndef __Vector_3_H__
#define __Vector_3_H__
namespace VectorMath {
class Vector3 {
public:
Vector3(float x, float y, float z) {
this->x = x;
this->y = y;
this->z = z;
}
Vector3 operator+(Vector3 vector) {
return Vector3(x + vector.x, y + vector.y, z + vector.z);
}
Vector3 operator-(Vector3 vector) {
return Vector3(x - vector.x, y - vector.y, z - vector.z);
}
Vector3 operator*(Vector3 vector) {
return Vector3(x * vector.x, y * vector.y, z * vector.z);
}
Vector3 operator/(Vector3 vector) {
return Vector3(x / vector.x, y / vector.y, z / vector.z);
}
float getX() {
return x;
}
float getY() {
return y;
}
float getZ() {
return z;
}
private:
float x;
float y;
float z;
};
}
#endif
It needs to look more like this instead:
Vector_3.h:
#ifndef Vector_3_H
#define Vector_3_H
#pragma once
namespace VectorMath {
class Vector3 {
public:
Vector3(float x, float y, float z);
Vector3 operator+(Vector3 vector);
Vector3 operator-(Vector3 vector);
Vector3 operator*(Vector3 vector);
Vector3 operator/(Vector3 vector);
float getX();
float getY();
float getZ();
private:
float x;
float y;
float z;
};
}
#endif
Vector_3.cpp:
#include "Vector_3.h"
namespace VectorMath {
Vector3::Vector3(float x, float y, float z) {
this->x = x;
this->y = y;
this->z = z;
}
Vector3 Vector3::operator+(Vector3 vector) {
return Vector3(x + vector.x, y + vector.y, z + vector.z);
}
Vector3 Vector3::operator-(Vector3 vector) {
return Vector3(x - vector.x, y - vector.y, z - vector.z);
}
Vector3 Vector3::operator*(Vector3 vector) {
return Vector3(x * vector.x, y * vector.y, z * vector.z);
}
Vector3 Vector3::operator/(Vector3 vector) {
return Vector3(x / vector.x, y / vector.y, z / vector.z);
}
float Vector3::getX() {
return x;
}
float Vector3::getY() {
return y;
}
float Vector3::getZ() {
return z;
}
}
If you want to use a cpp file for your constructor you should write
// File Vector3.cpp
#include "Vector3.h"
namespace VectorMath {
Vector3::Vector3 (float x, float y, float z)
{
this->x=x;
//...
}
The addition should be implemented as follows if you keep it in the same namespace
Vector3 Vector3::operator+(const Vector3& v)
{
return Vector3 (x+v.x,y+v.y,z+v.z);
}
}
If you want to move the implementations of member functions away from the header file, you still need to declare them in the definition of the class. For example:
// Vector1.h
#pragma once
#ifndef VectorMath_Vector1_H
#define VectorMath_Vector1_H
namespace VectorMath {
class Vector1 {
public: // Methods:
// This is a definition for a default constructor:
Vector1() noexcept : m_x(0) {}
// This is a declaration for another constructor:
Vector1(float x) noexcept;
// This is a declaration of a member function:
Vector1 operator+(Vector1 const & rhs) const noexcept;
private: // Fields:
float m_x;
}; // class Vector1
} // namespace VectorMath {
#endif // VectorMath_Vector1_H
// Vector1.cpp
#include "Vector1.h"
namespace VectorMath {
// Definition of the other constructor:
Vector1::Vector1(float x) noexcept
: m_x(x)
{}
// Definition of the binary + operator:
Vector1 Vector1::operator+(Vector1 const & rhs) const noexcept
{ return m_x + rhs.m_x; }
} // namespace VectorMath {
Multiple markers at this line
- candidates are:
- no matching function for call to
'Coordinate::Coordinate()'
I am getting this error in the constructor of my class and I don't understand why. Here is the code involved:
RadialScan header
#ifndef RADIALSCAN_H_
#define RADIALSCAN_H_
#include "EasyBMP/EasyBMP.h"
#include <vector>
#include "Coordinate.h"
using namespace std;
class RadialScan {
vector<int> distanceTimeSeries;
vector<Coordinate> timeSeries;
BMP image;
Coordinate center;
Coordinate getNextPoint(Coordinate c);
bool isBlack(Coordinate c);
void computeTimeSeries();
public:
RadialScan(char* filename);
vector<int> getDistances();
vector<Coordinate> getCoordinates();
};
#endif
RadialScan class (all the methods are implemented, but the error is in the constructor and that's the code I'm providing):
#include "RadialScan.h"
RadialScan::RadialScan(char* filename){
image.ReadFromFile(filename);
int centerX = image.TellWidth()/2;
int centerY = image.TellHeight()/2;
center = Coordinate(centerX, centerY);
}
...
The error seems to be in the constructor. If I remove the constructor everything seems to compile correctly. If I delete the code inside the constructor I'm still getting the error. I don't understand why it keeps asking me for the Coordinate::Coordinate() constructor even when I don't have a coordinate object defined in the RadialScan(char* filename) constructor.
Additionally, these are the files for the Coordinate class:
header:
#ifndef COORDINATE_H_
#define COORDINATE_H_
class Coordinate {
int x;
int y;
public:
Coordinate(int x, int y);
void setX(int oneX);
void setY(int oneY);
int getX();
int getY();
double getMagnitude();
Coordinate operator-(const Coordinate&);
bool operator==(const Coordinate&);
Coordinate operator=(const Coordinate&);
};
#endif
cpp class:
#include "Coordinate.h"
#include <math.h>
Coordinate::Coordinate(int oneX, int oneY) {
x = oneX;
y = oneY;
}
//Setters
void Coordinate::setX(int oneX) {
x = oneX;
}
void Coordinate::setY(int oneY) {
y = oneY;
}
//Getters
int Coordinate::getX() {
return x;
}
int Coordinate::getY() {
return y;
}
double Coordinate::getMagnitude() {
return sqrt(x * x + y * y);
}
Coordinate Coordinate::operator-(const Coordinate& p) {
return Coordinate(x - p.x, y - p.y);
}
bool Coordinate::operator==(const Coordinate& p) {
return x == p.x && y == p.y;
}
Coordinate Coordinate::operator=(const Coordinate& p) {
return Coordinate(p.x, p.y);
}
Your constructor must look like
RadialScan::RadialScan(char* filename) : center (0, 0) {
image.ReadFromFile(filename);
int centerX = image.TellWidth()/2;
int centerY = image.TellHeight()/2;
center = Coordinate(centerX, centerY);
}
this because you did not implement default constructor and you can not create center object by default, so the only way is to call explicity Coordinate constructor with some default values.
I am learning OpenGL w/ C++. I am building the asteroids game as an exercise. I'm not quite sure how to override the constructors:
projectile.h
class projectile
{
protected:
float x;
float y;
public:
projectile();
projectile(float, float);
float get_x() const;
float get_y() const;
void move();
};
projectile.cpp
projectile::projectile()
{
x = 0.0f;
y = 0.0f;
}
projectile::projectile(float X, float Y)
{
x = X;
y = Y;
}
float projectile::get_x() const
{
return x;
}
float projectile::get_y() const
{
return y;
}
void projectile::move()
{
x += 0.5f;
y += 0.5f;
}
asteroid.h
#include "projectile.h"
class asteroid : public projectile
{
float radius;
public:
asteroid();
asteroid(float X, float Y);
float get_radius();
};
main.cpp
#include <iostream>
#include "asteroid.h"
using namespace std;
int main()
{
asteroid a(1.0f, 2.0f);
cout << a.get_x() << endl;
cout << a.get_y() << endl;
}
error I'm getting:
main.cpp:(.text+0x20): undefined reference to `asteroid::asteroid(float, float)'
You can use the : syntax to call the parent's constructor:
asteroid(float X, float Y) : projectile (x ,y);
Ok, just figured it out.
I actually don't have asteroid constructors defined because I thought they would inherit. But I think I have to do the following in asteroid.h:
asteroid(float X, float Y) : projectile(X, Y){];
You need a asteroid.cpp.
Even though inheriting from projectile, for non-default constructors (i.e., asteroid(float,float)), you still need to define the child class constructor.
You'll also need to define get_radius, as it's not defined in your base class.
Here's how that might look (I've taken the liberty of passing values for radius into both ctors):
#include "asteroid.h"
asteroid::asteroid(float r)
: projectile()
{
radius = r;
}
asteroid::asteroid(float x, float y, float r)
: projectile(x, y)
{
radius = r;
}
float asteroid::get_radius()
{
return radius;
}
I'm trying to fill a vector of an object Point 3D. My app read a csv file to load the vector by the three cordinate x, y, z. I use the type float.
This is my code.
main.cpp
int main(int argc, char** argv) {
char *theFileName = "file.csv"; //[100];
vector<Point> v = getPointCloud(theFileName);
for (int i = 0; i < v.size(); ++i) {
v.at(i).print(cout);
}
}
getPointCloud
vector<Point> getPointCloud(char *fileName) {
string line;
string token;
vector<Point> v;
double tab[3];
ifstream file(fileName);
if (file.is_open()) {
while (getline(file, line)) {
int cpt = 0;
stringstream stream(line);
while (getline(stream, token, ',')) {
tab[cpt] = ::atof(token.c_str());
cpt++;
}
Point p(tab[0], tab[1], tab[2]);
p.print(cout); <-- the display works
p.setColor(255, 0, 0);
v.push_back(p);
}
file.close();
} else {
cout << "Unable to open " << fileName << '\n';
exit(0);
}
return v;
}
I have two problems:
1 - when I try to display points in the main method, I found that the three coordinates are null ( == 0) but in the displaying in the getPointCloud method works very well.
2 - Can someone give a simple method to conserve my coordinates without loss precision after mathematical operations. I have searched in the net but I don't understand haw to solve it. I'm newbie with c++.
Point.h
#ifndef POINT_H
#define POINT_H
#include <math.h>
#include <iostream>
class Point {
protected:
float x;
float y;
float z;
// color RGB
float r;
float g;
float b;
public:
// Constructors
Point();
// Point(const Point& orig);
Point(std::ostream &strm);
Point(float x, float y, float z);
Point(const Point& orig);
virtual ~Point();
//getters
float getX() const {
return this->x;
}
float getY() const {
return this->y;
}
float getZ() const {
return this->z;
}
float getR() const {
return this->r;
}
float getG() const {
return this->g;
}
float getB() const {
return this->b;
}
//setters
void setX(float x) {
this->x = x;
}
void setY(float y) {
this->y = y;
}
void setZ(float z) {
this->z = z;
}
void setR(float r) {
this->r = r;
}
void setG(float g) {
this->g = g;
}
void setB(float b) {
this->b = b;
}
void setColor(float r, float g, float b) {
this->r = r;
this->g = g;
this->b = b;
}
/**
* Print the point
* #param strm
*/
void print(std::ostream &strm);
//Other methods
float dist2D(Point &other);
float dist3D(Point &other);
Point swap(Point p);
// Point operator-(const Point &other) const;
};
#endif /* POINT_H */
Point.cpp
#include <iostream>
#include <math.h>
#include <ostream>
using namespace std;
#include "Point.h"
Point::Point(const Point& orig) {
}
Point::Point(ostream &strm) {
strm << "Type the abscissa: ", cin >> this->x;
strm << "Type the ordinate: ", cin >> this->y;
strm << "Type the applicate: ", cin >> this->z;
}
Point::Point(float x, float y, float z) : x(x), y(y), z(z) {
// The default point color is blue
this->r = 0;
this->g = 0;
this->b = 255;
}
/**
* Destructor
*/
Point::~Point() {
}
//Other methods
float Point::dist2D(Point &other) {
float xd = x - other.x;
float yd = y - other.y;
return sqrt(xd * xd + yd * yd);
}
float Point::dist3D(Point &other) {
float xd = x - other.x;
float yd = y - other.y;
float zd = z - other.z;
return sqrt(xd * xd + yd * yd + zd * zd);
}
Point Point::swap(Point p) {
Point aux(x, y, z);
x = p.x;
y = p.y;
z = p.z;
return aux;
}
//Point Point::operator-(const Point &other) const {
// return Point(other.getX() - this->x, other.getY() - this->y, other.getZ() - this->z);
//}
void Point::print(ostream &strm) {
strm << "Point(" << this->x << "," << y << "," << z << ")" << endl;
}
Thanks in advance.
Point::Point(const Point& orig) {
}
is incorrect.
It does not copy data from orig to *this
Please copy each of the member in this constructor.
This would look like this:
Point::Point(const Point& orig) {
x = orig.x ;
y = orig.y ;
x = orig.z ;
r = orig.r ;
g = orig.g ;
b = orig.b ;
}
Ok, I'm having this problem with my Sprite class. Basically the sprite class should have a object of class Vector as its member with Vector being a class with both angle and speed. The Vector class has a Vector(double,double) constructor so the speed and angle can be set at its initialization but when I make my sprite class. It sends an error that its calling Vector(), a blank constructor, and that it doesn't exist. I'm trying to figure out why its calling Vector(). Here is my code from both the Sprite and Vector classes.
#Vector.h
#ifndef VECTOR_H
#define VECTOR_H
class Vector
{
public:
Vector(double,double);
double getX();
double getY();
double getSpeed();
double getAngle();
void setSpeed(double);
void setAngle(double);
private:
double speed,angle;
};
#endif
#Vector.h
#include "SDL/SDL.h"
#include "vector.h"
#include "math.h"
Vector::Vector(double speed,double angle)
{
this -> speed = speed;
this -> angle = angle;
}
double Vector::getX()
{
return speed*cos(angle);
}
double Vector::getY()
{
return speed*sin(angle);
}
double Vector::getSpeed()
{
return speed;
}
double Vector::getAngle()
{
return angle;
}
void Vector::setAngle(double angle)
{
this -> angle = angle;
}
void Vector::setSpeed(double speed)
{
this -> speed = speed;
}
#Sprite.h:
#ifndef SPRITE_H
#define SPRITE_H
#include "vector.h"
class Sprite
{
public:
Sprite(int x,int y);
SDL_Rect getRect();
SDL_Surface* getImage();
void setRect(SDL_Rect);
void move();
void draw(SDL_Surface*);
private:
Vector movement;
double x,y,lastX,lastY,angle,speed;
SDL_Rect rect;
SDL_Surface* image;
};
#endif
#Sprite.cpp:
#include "SDL/SDL.h"
#include "sprite.h"
#include "functions.h"
#include <cmath>
Sprite::Sprite(int x, int y)
{
this -> x = x;
this -> y = y;
lastX = x;
lastY = y;
image = loadImage("box.png");
rect.x = x;
rect.y = y;
rect.w = image->w;
rect.h = image->h;
speed = 1;
angle = 0;
}
SDL_Rect Sprite::getRect()
{
return rect;
}
SDL_Surface* Sprite::getImage()
{
return image;
}
void Sprite::setRect(SDL_Rect rect)
{
this -> rect = rect;
}
void Sprite::move()
{
lastX = x;
lastY = y;
x += speed*cos(angle);
y += speed*sin(angle);
rect.x = int(x);
rect.y = int(y);
}
void Sprite::draw(SDL_Surface* dest)
{
blit(image,dest,int(x),int(y));
}
Your Sprite class has a Vector member that will be constructed when the Sprite is constructed. At the moment, the Vector will be initialized with the default constructor because you haven't specified otherwise. If you want a specific constructor of Vector to be used, you need to add an initialization list to the constructor of Sprite:
Sprite::Sprite(int x, int y)
: movement(1.0, 0.0)
{
// ...
}
This will initialise movement with arguments 1 and 0. In fact, you might as well add other members to your initialization list too:
Sprite::Sprite(int x, int y)
: movement(1.0, 0.0), x(x), y(y), lastX(x), lastY(y) // and so on...
{
// ...
}
The Vector is created in Sprite::Sprite(int x, int y). The blank constructor for Vector is called because you do not call a constructor in the initializer list: in fact, you leave the Vector movement completely uninitialized!
Do this:
Sprite::Sprite(int x, int y):
movement(3.14, 2.7)
{
...
}
to construct movement using a two argument constructor. I would pick better values than 3.14 and 2.7, those are just sample values.
I would also consider creating a public no-argument constructor on Vector for ease of use that initalizes speed and angle to zero.