I want to store the byte value of aFloat in pixelsArray for each 3D coordinate, in a 1D array:
float aFloat = 1.0;
unsigned char* pixelsArray = new unsigned char[HEIGHT*WIDTH*3];
for (int i = 0; i < HEIGHT; i++)
{
for (int j = 0; j < WIDTH; j++)
{
for (int k = 0; k < 3; k++)
{
pixelsArray[?] = aFloat;
}
}
}
What would go in the ?? I think it also needs to have + sizeof(float) somewhere in the index if I'm not mistaken.
Your inside line needs to be:
pixelsArray[(i * WIDTH + j) * 3 + k] = (unsigned char)(255.0 * aFloat);
This should give you an all-white image.
Make sure your target is really three bytes per pixel and not four (alpha channel or padding); if it is four, you'll just need to change the 3 above to a 4.
Let's do this with a 2-dimensional array first:
0 1 ... W-1
W W+1 ... 2*W-1
2*W 2*W+1 ... 3*W-1
. . . .
. . . .
. . . .
(H-1)*W (H-1)*W+1 ... H*W-1
So you would accesss this with
unsigned char* array = new unsigned char[H*W];
for(int r=0;r<H;r++)
for (int c=0; c<H; c++)
array[r*w+c]=...;
In your 3-dimensional array, you'd use
i*WIDTH*3 + j*3 + k
You do not need a sizeof(float) anywhere, though you probably need the value conversion that Mike DeSimone suggests.
