Hi. Sorry for the off-topic, but since there are a lot of people that
know about graphics, I thought I might ask. I am trying not to reinvent
the wheel. I am looking to simulate freehand drawing of thick lines
with feathering in opengl for my viewer.
I am looking for a lightweight library (or a class or set of functions)
that would allow me to, given an arbitrary list of points that make a
freehand drawn line, return the vertices of the line drawn with
triangles with UVs (between 0,1 in the width of the line and in the
length of the line). The idea is that then I would render the triangles
with opengl and would use the UVs in a shader to create a feathering effect.
So far, I found:
https://github.com/tyt2y3/vaserenderer.git
The code is messy and it does not use UVs only colors to create
feathering, drawing more than 6 triangles per line segment (slow).
Other than that, this is closer to what I want.
https://github.com/AcademySoftwareFoundation/OpenRV
It has a really neat polyline drawing code, albeit it is too dependent
on several classes in OpenRV itself.
https://github.com/memononen/nanovg
i did not play much with it. It does not allow me to get the list of
points or the UVs but instead just draws the lines in opengl directly.
I prefer to control the drawing, specially since I am working with
OpenGL3 and drawing to a FBO. This looks like I could modify it to
make it work like what I want, but I am not too crazy about its API for
drawing lines.
--
Gonzalo Garramuño
ggar...@gmail.com