Board of 3D cubes, size columns x lines in openGL - c

Question

I am declaring the GLfloat vertices[][3], GLfloat normals[][3] and GLfloat colors[][3] and after I declare the structs for the cube and board according to the following code. I want the cubes to have a gap or 0.1% of the cube size, so scale them by a factor of 0.99. What is failing is to see that gap.
typedef struct cube * Cube;
struct cube {
float x, y, z;
float scale;
};
Cube cube; // cube
Cube *board;
void drawBoard()
{
// Initialize cube and board
cube = (Cube)malloc(sizeof(struct cube));
cube->x = 0.0;
cube->y = 0.0;
cube->z = 0.0;
cube->scale = 1;
board = (Cube*)malloc(sizeof(Cube)*64);
for(int i=0; i<64; i++) {
board[i] = (Cube)malloc(sizeof(struct cube));
board[i]->x = 0.0 + 0.1*(i%8);
board[i]->y = 0.0 - 0.1*(i/8);
board[i]->z = 0.0;
board[i]->scale = 0.99;
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef(cube->x, cube->y, cube->z);
//glScalef(cube->scale, cube->scale, cube->scale);
// Draw board of cubes
for(int i=0; i<64; i++) {
glPushMatrix();
glTranslatef(board[i]->x, board[i]->y, board[i]->z);
glScalef(board[i]->scale, board[i]->scale, board[i]->scale);
drawCube();
glEnd();
glPopMatrix();
}
glPopMatrix();
glFlush();
}
I am expecting to see a board size columns X lines of 3d cubes considering the cubes have a size = 1, with a gap between them of 0.1% of their size.The board is drawned but the cubes seem to be all placed side by side with no gaps.

Answer 1

So you are drawing a bunch of cubes on a grid, and the size of the cube (if you imagine measure from one side to the other side with a ruler) is 0.99 (the actual cube size is 1.0 and you scaled it by 0.99), and the distance between the middle of the first cube and the middle of the second cube is only 0.1.
That means the cubes are overlapping each other by quite a lot. so of course there are no spaces between them. If you want to put cubes on a 0.1 grid with gaps between them, obviously each cube has to be smaller than 0.1.
If you'll pardon the lazy drawing, you think your cubes are like this:
but they are actually more like this:
because the gap between the cubes is way smaller than the size of each cube.