PixMapImage.opIndexAssign

Assigning a color value to an individual pixel through a one-index indexing operation. Note: It is allowed to use an index greater than the actual length of the array or less than 0, since it is bound to the real length of the internal array of the image.

Typical usage:

// creating image of size 20x20, all pixels are black
auto pmi = new PixMapImage(20, 20);   
// 6th pixel now are green
pmi[5] = new RGBColor(0, 255, 0);