stb_truetype: fix SDF handling of multiple move_to commands in a row

This commit is contained in:
Sean Barrett
2021-07-07 01:21:37 -07:00
parent ca0e6d06d8
commit fc5b791228
2 changed files with 38 additions and 11 deletions

View File

@ -4587,18 +4587,17 @@ STBTT_DEF unsigned char * stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float sc
for (i=0; i < num_verts; ++i) {
float x0 = verts[i].x*scale_x, y0 = verts[i].y*scale_y;
// check against every point here rather than inside line/curve primitives -- @TODO: wrong if multiple 'moves' in a row produce a garbage point, and given culling, probably more efficient to do within line/curve
float dist2 = (x0-sx)*(x0-sx) + (y0-sy)*(y0-sy);
if (dist2 < min_dist*min_dist)
min_dist = (float) STBTT_sqrt(dist2);
if (verts[i].type == STBTT_vline) {
if (verts[i].type == STBTT_vline && precompute[i] != 0.0f) {
float x1 = verts[i-1].x*scale_x, y1 = verts[i-1].y*scale_y;
float dist,dist2 = (x0-sx)*(x0-sx) + (y0-sy)*(y0-sy);
if (dist2 < min_dist*min_dist)
min_dist = (float) STBTT_sqrt(dist2);
// coarse culling against bbox
//if (sx > STBTT_min(x0,x1)-min_dist && sx < STBTT_max(x0,x1)+min_dist &&
// sy > STBTT_min(y0,y1)-min_dist && sy < STBTT_max(y0,y1)+min_dist)
float dist = (float) STBTT_fabs((x1-x0)*(y0-sy) - (y1-y0)*(x0-sx)) * precompute[i];
dist = (float) STBTT_fabs((x1-x0)*(y0-sy) - (y1-y0)*(x0-sx)) * precompute[i];
STBTT_assert(i != 0);
if (dist < min_dist) {
// check position along line
@ -4625,7 +4624,7 @@ STBTT_DEF unsigned char * stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float sc
float ax = x1-x0, ay = y1-y0;
float bx = x0 - 2*x1 + x2, by = y0 - 2*y1 + y2;
float mx = x0 - sx, my = y0 - sy;
float res[3],px,py,t,it;
float res[3],px,py,t,it,dist2;
float a_inv = precompute[i];
if (a_inv == 0.0) { // if a_inv is 0, it's 2nd degree so use quadratic formula
float a = 3*(ax*bx + ay*by);
@ -4652,6 +4651,10 @@ STBTT_DEF unsigned char * stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float sc
float d = (mx*ax+my*ay) * a_inv;
num = stbtt__solve_cubic(b, c, d, res);
}
dist2 = (x0-sx)*(x0-sx) + (y0-sy)*(y0-sy);
if (dist2 < min_dist*min_dist)
min_dist = (float) STBTT_sqrt(dist2);
if (num >= 1 && res[0] >= 0.0f && res[0] <= 1.0f) {
t = res[0], it = 1.0f - t;
px = it*it*x0 + 2*t*it*x1 + t*t*x2;