You're plotting individual points here, not a proper data graph. Even if you need a cloud of points, it's not enough, since you need to have different sizes and types of points that may have different sizes based on another data column, and definitely need to be drawn with antialiasing, even if they're simple squares.
Then, to draw something like this imgur.com/a/mXvEBzl (ADS-B data, ~10 million points iirc), you need to connect points with (antialiased) lines, where individual pixel should be blended into plot with respect of line opacity. Also, lines can be of different thickness, so it multiplies your `o[w x p+p] += 1` again.
I'm not even talking about multiple layers that are quite standard.
I use my own plotting app, it takes a lot more than just slap a bunch of points into "float *o". Try to write your own, you will figure it out pretty quickly, unless you're ok with black blobs that resemble the input data.
Then, to draw something like this imgur.com/a/mXvEBzl (ADS-B data, ~10 million points iirc), you need to connect points with (antialiased) lines, where individual pixel should be blended into plot with respect of line opacity. Also, lines can be of different thickness, so it multiplies your `o[w x p+p] += 1` again.
I'm not even talking about multiple layers that are quite standard.
I use my own plotting app, it takes a lot more than just slap a bunch of points into "float *o". Try to write your own, you will figure it out pretty quickly, unless you're ok with black blobs that resemble the input data.