I'm trying to draw quadratic bezier curve (as line). I approximate quadratic bezier curve as parabola ($y=x^2$), according to this document http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html
There, in section "25.5 Antialiasing" Loop/Blinn claims that signed distance from point (x,y) to the curve $f$(which is $y=x^2$) is:
Is this correct? [I read, that it is impossible to have another "parallel" bezier curve]
I ask this because, if I want to detect distance more than 1-2 pixels, and have a high
triangle base/height ratio, than "distance" shrinks on the base direction.
For example, here is 50px distance from inner side of the curve filled green, all other red (all ok):
And this one shrunken (pay attention, that distance on height axis still is correct):
Curve drawing in triangle with coordinates (0,0) (0.5,0) (1,1). Which is 1st quadrant.