// srcPts[] must be monotonic in X and Y
void SkEdgeClipper::clipMonoCubic(const SkPoint src[4], const SkRect& clip) {
SkPoint pts[4];
bool reverse = sort_increasing_Y(pts, src, 4);
// are we completely above or below
if (pts[3].fY <= clip.fTop || pts[0].fY >= clip.fBottom) {
return;
}
// Now chop so that pts is contained within clip in Y
chop_cubic_in_Y(pts, clip);
if (pts[0].fX > pts[3].fX) {
SkTSwap<SkPoint>(pts[0], pts[3]);
SkTSwap<SkPoint>(pts[1], pts[2]);
reverse = !reverse;
}
// Now chop in X has needed, and record the segments
if (pts[3].fX <= clip.fLeft) { // wholly to the left
this->appendVLine(clip.fLeft, pts[0].fY, pts[3].fY, reverse);
return;
}
if (pts[0].fX >= clip.fRight) { // wholly to the right
this->appendVLine(clip.fRight, pts[0].fY, pts[3].fY, reverse);
return;
}
SkScalar t;
SkPoint tmp[7];
// are we partially to the left
if (pts[0].fX < clip.fLeft) {
if (chopMonoCubicAtX(pts, clip.fLeft, &t)) {
SkChopCubicAt(pts, tmp, t);
this->appendVLine(clip.fLeft, tmp[0].fY, tmp[3].fY, reverse);
clamp_ge(tmp[3].fX, clip.fLeft);
clamp_ge(tmp[4].fX, clip.fLeft);
clamp_ge(tmp[5].fX, clip.fLeft);
pts[0] = tmp[3];
pts[1] = tmp[4];
pts[2] = tmp[5];
} else {
// if chopMonocubicAtY failed, then we may have hit inexact numerics
// so we just clamp against the left
this->appendVLine(clip.fLeft, pts[0].fY, pts[3].fY, reverse);
return;
}
}
// are we partially to the right
if (pts[3].fX > clip.fRight) {
if (chopMonoCubicAtX(pts, clip.fRight, &t)) {
SkChopCubicAt(pts, tmp, t);
clamp_le(tmp[1].fX, clip.fRight);
clamp_le(tmp[2].fX, clip.fRight);
clamp_le(tmp[3].fX, clip.fRight);
this->appendCubic(tmp, reverse);
this->appendVLine(clip.fRight, tmp[3].fY, tmp[6].fY, reverse);
} else {
// if chopMonoCubicAtX failed, then we may have hit inexact numerics
// so we just clamp against the right
this->appendVLine(clip.fRight, pts[0].fY, pts[3].fY, reverse);
}
} else { // wholly inside the clip
this->appendCubic(pts, reverse);
}
}
// srcPts[] must be monotonic in X and Y
void SkEdgeClipper::clipMonoCubic(const SkPoint src[4], const SkRect& clip) {
SkPoint pts[4];
bool reverse = sort_increasing_Y(pts, src, 4);
// are we completely above or below
if (pts[3].fY <= clip.fTop || pts[0].fY >= clip.fBottom) {
return;
}
// Now chop so that pts is contained within clip in Y
chop_cubic_in_Y(pts, clip);
if (pts[0].fX > pts[3].fX) {
SkTSwap<SkPoint>(pts[0], pts[3]);
SkTSwap<SkPoint>(pts[1], pts[2]);
reverse = !reverse;
}
// Now chop in X has needed, and record the segments
if (pts[3].fX <= clip.fLeft) { // wholly to the left
this->appendVLine(clip.fLeft, pts[0].fY, pts[3].fY, reverse);
return;
}
if (pts[0].fX >= clip.fRight) { // wholly to the right
if (!this->canCullToTheRight()) {
this->appendVLine(clip.fRight, pts[0].fY, pts[3].fY, reverse);
}
return;
}
// are we partially to the left
if (pts[0].fX < clip.fLeft) {
SkPoint tmp[7];
chop_mono_cubic_at_x(pts, clip.fLeft, tmp);
this->appendVLine(clip.fLeft, tmp[0].fY, tmp[3].fY, reverse);
// tmp[3, 4].fX should all be to the right of clip.fLeft.
// Since we can't trust the numerics of
// the chopper, we force those conditions now
tmp[3].fX = clip.fLeft;
clamp_ge(tmp[4].fX, clip.fLeft);
pts[0] = tmp[3];
pts[1] = tmp[4];
pts[2] = tmp[5];
}
// are we partially to the right
if (pts[3].fX > clip.fRight) {
SkPoint tmp[7];
chop_mono_cubic_at_x(pts, clip.fRight, tmp);
tmp[3].fX = clip.fRight;
clamp_le(tmp[2].fX, clip.fRight);
this->appendCubic(tmp, reverse);
this->appendVLine(clip.fRight, tmp[3].fY, tmp[6].fY, reverse);
} else { // wholly inside the clip
this->appendCubic(pts, reverse);
}
}
