Referencing an Array outside its range - c++

Question

this program creates an image with 100 boxes, after the box is created, it's 4 coordinates are stored in the index of the class array Tile so I can refernce each tile later in my code. This works fine, excpect that I can not reference the Tile array in my main function, only in the Draw() function where it is created. Any solutions would be appreciated.
EDIT: Making Tiles* Tile[100] global does not seem to solve the issue.
Simplified Code:
#include <iostream>
class Tiles {
public:
Tiles() : mA (1){}
double mA;
};
void Function1() {
Tiles Tile[5];
Tile[1].mA = 10;
}
int main(int iArgc, char** cppArgv) {
Function1();
Tile[1].mA = 2; // ERROR "Tile" is unidentified.
return 0;
}
Full Code:
#include <iostream>
#include <glut.h>
class Tiles {
public:
Tiles() : mA () , mB() , mC() , mD() , mCP(){}
double mA[2] , mB[2] , mC[2] , mD[2] , mCP[2];
};
void Draw() {
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0, 1.0, 1.0);
double dX1 = 0.0, dY1 = 0.0, dMidX = 0.0, dMidY = 0.0, dXC = 0.0, dYC = 0.0;
int sq = 0, row = 1, CoordMap = 0;
Tiles Tile[100];
//Tiles* Tile = new Tiles[100]; doesnt seem to be any different..
for (int i=0; i < 10;i++ ) { // ROWS
for (int i2=0; i2 < 10; i2++) { // BOXES
glBegin(GL_LINE_STRIP);
glVertex3f(dX1, dY1, 0.0);
Tile[sq].mA[1] = dX1;
Tile[sq].mA[2] = dY1;// Bottom Left
dX1 = dX1 + .1;
dXC = dX1;
dYC = dY1;
glVertex3f(dX1, dY1, 0.0);
Tile[sq].mB[1] = dX1;
Tile[sq].mB[2] = dY1;// Bottom Right
dY1 = dY1 + .1;
glVertex3f(dX1, dY1, 0.0);
Tile[sq].mC[1] = dX1;
Tile[sq].mC[2] = dY1;// Top Left
dX1 = dX1 - .1;
glVertex3f(dX1, dY1, 0.0);
Tile[sq].mD[1] = dX1;
Tile[sq].mD[2] = dY1;// Top Right
glEnd();
glBegin(GL_POINTS);
glVertex3f((dX1 + .05) , (dY1 - .05), 0.0);
glEnd();
++sq;
dX1 = dXC;
dY1 = dYC;
}
row++;
dX1 = 0.0;
dY1 = ((row * .1) - .1);
}
glFlush();
}
void Initialize() {
glClearColor(0.0, 0.0, 0.0, 0.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
}
int main(int iArgc, char** cppArgv) {
glutInit(&iArgc, cppArgv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(250, 250);
glutInitWindowPosition(200, 200);
glutCreateWindow("XoaX.net");
Initialize();
glutDisplayFunc(Draw);
glutMainLoop();
//Tile[2].mA[1] = 2; //
return 0;
}
This code is modified from it's orginal version written by XoaX - Michael Hall.
Thank you

Answer 1

To make your Tiles array accesible from main() you must declare Tiles within the main() scope. For example, move your declaration Tiles Tile[100]; to global scope, i.e. just before void Draw() { line.

Answer 2

If you want to make it accessible from main, the answer is to move it to global scope, but..
You're using openGL and glut here, and you're calling glutMainLoop just before accessing Tile in main().. as written in the specification, glutMainLoop never return once called..
if by chances, you're trying to cout the value before the call to glutMainLoop, the draw method will not have been called, since it was called from within glutMainLoop.. which make the value to still be 0..
references : http://www.opengl.org/documentation/specs/glut/spec3/node14.html