Hi there, sorry for de delay, I was trying to understand how to generate a VBO by "hand". I've made some progress by constructing a mesh with the following structure:
For two particles with a trail of 4 points
index0, index1, index1, index2, index2, index3
index4, index5, index6, index6, index6, index7
But for some reason the last point get's connected to the first point of the next particle ( or vec2(0.f,0.f) , like the picture below shows
(drawing with immediate mode is fine)
I've updated the gist: https://gist.github.com/Hperigo/c70d1970a7244f8e367abdfc8d717425
I also did some tests trying to draw 60000 vertices and the performance was not good, so either I'm doing something wrong with the VBO or this is the wrong approach.
Some time ago I did manage to draw multiple lines using instancing, but I'm not sure how I would control each individual vertex position for each instance, maybe with a 32f Texture?