diff options
Diffstat (limited to 'src/sdf/ftbsdf.c')
| -rw-r--r-- | src/sdf/ftbsdf.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/sdf/ftbsdf.c b/src/sdf/ftbsdf.c index e26f18cb7..696d54999 100644 --- a/src/sdf/ftbsdf.c +++ b/src/sdf/ftbsdf.c @@ -187,11 +187,12 @@ /* distance of the pixel to edge pretty accurately. A real */ /* simple approximation is ( 0.5f - alpha ), assuming that */ /* the outline is parallel to the x or y axis. But in this */ - /* algorithm that is pretty accurate the edge distance. */ + /* algorithm we use a different approximation which is qui- */ + /* te accurate even for non axis aligned edges. */ /* */ /* * The only remaining piece of information that we cannot */ /* approximate directly from the alpha is the direction of */ - /* the edge. That is where we use the Sobel's operator to */ + /* the edge. This is where we use the Sobel's operator to */ /* compute the gradient of the pixel. The gradient give us */ /* a pretty good approximation of the edge direction. */ /* We use a 3x3 kernel filter to compute the gradient. */ |