// Modify pts[] in place so that it is clipped in Y to the clip rect
static void chop_cubic_in_Y(SkPoint pts[4], const SkRect& clip) {
SkScalar t;
SkPoint tmp[7]; // for SkChopCubicAt
// are we partially above
if (pts[0].fY < clip.fTop) {
if (chopMonoCubicAtY(pts, clip.fTop, &t)) {
SkChopCubicAt(pts, tmp, t);
// given the imprecision of computing t, we just slam our Y coord
// to the top of the clip. This also saves us in the bad case where
// the t was soooo bad that the entire segment could have been
// below fBottom
tmp[3].fY = clip.fTop;
clamp_ge(tmp[4].fY, clip.fTop);
clamp_ge(tmp[5].fY, clip.fTop);
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 top
for (int i = 0; i < 4; i++) {
clamp_ge(pts[i].fY, clip.fTop);
}
}
}
// are we partially below
if (pts[3].fY > clip.fBottom) {
if (chopMonoCubicAtY(pts, clip.fBottom, &t)) {
SkChopCubicAt(pts, tmp, t);
clamp_le(tmp[1].fY, clip.fBottom);
clamp_le(tmp[2].fY, clip.fBottom);
clamp_le(tmp[3].fY, clip.fBottom);
pts[1] = tmp[1];
pts[2] = tmp[2];
pts[3] = tmp[3];
} else {
// if chopMonoCubicAtY failed, then we may have hit inexact numerics
// so we just clamp against the bottom
for (int i = 0; i < 4; i++) {
clamp_le(pts[i].fY, clip.fBottom);
}
}
}
}
// Modify pts[] in place so that it is clipped in Y to the clip rect
static void chop_quad_in_Y(SkPoint pts[3], const SkRect& clip) {
SkScalar t;
SkPoint tmp[5]; // for SkChopQuadAt
// are we partially above
if (pts[0].fY < clip.fTop) {
if (chopMonoQuadAtY(pts, clip.fTop, &t)) {
// take the 2nd chopped quad
SkChopQuadAt(pts, tmp, t);
clamp_ge(tmp[2].fY, clip.fTop);
clamp_ge(tmp[3].fY, clip.fTop);
pts[0] = tmp[2];
pts[1] = tmp[3];
} else {
// if chopMonoQuadAtY failed, then we may have hit inexact numerics
// so we just clamp against the top
for (int i = 0; i < 3; i++) {
if (pts[i].fY < clip.fTop) {
pts[i].fY = clip.fTop;
}
}
}
}
// are we partially below
if (pts[2].fY > clip.fBottom) {
if (chopMonoQuadAtY(pts, clip.fBottom, &t)) {
SkChopQuadAt(pts, tmp, t);
clamp_le(tmp[1].fY, clip.fBottom);
clamp_le(tmp[2].fY, clip.fBottom);
pts[1] = tmp[1];
pts[2] = tmp[2];
} else {
// if chopMonoQuadAtY failed, then we may have hit inexact numerics
// so we just clamp against the bottom
for (int i = 0; i < 3; i++) {
if (pts[i].fY > clip.fBottom) {
pts[i].fY = clip.fBottom;
}
}
}
}
}
// 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);
}
}
// srcPts[] must be monotonic in X and Y
void SkEdgeClipper::clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip) {
SkPoint pts[3];
bool reverse = sort_increasing_Y(pts, srcPts, 3);
// are we completely above or below
if (pts[2].fY <= clip.fTop || pts[0].fY >= clip.fBottom) {
return;
}
// Now chop so that pts is contained within clip in Y
chop_quad_in_Y(pts, clip);
if (pts[0].fX > pts[2].fX) {
SkTSwap<SkPoint>(pts[0], pts[2]);
reverse = !reverse;
}
SkASSERT(pts[0].fX <= pts[1].fX);
SkASSERT(pts[1].fX <= pts[2].fX);
// Now chop in X has needed, and record the segments
if (pts[2].fX <= clip.fLeft) { // wholly to the left
this->appendVLine(clip.fLeft, pts[0].fY, pts[2].fY, reverse);
return;
}
if (pts[0].fX >= clip.fRight) { // wholly to the right
if (!this->canCullToTheRight()) {
this->appendVLine(clip.fRight, pts[0].fY, pts[2].fY, reverse);
}
return;
}
SkScalar t;
SkPoint tmp[5]; // for SkChopQuadAt
// are we partially to the left
if (pts[0].fX < clip.fLeft) {
if (chopMonoQuadAtX(pts, clip.fLeft, &t)) {
SkChopQuadAt(pts, tmp, t);
this->appendVLine(clip.fLeft, tmp[0].fY, tmp[2].fY, reverse);
// clamp to clean up imprecise numerics in the chop
tmp[2].fX = clip.fLeft;
clamp_ge(tmp[3].fX, clip.fLeft);
pts[0] = tmp[2];
pts[1] = tmp[3];
} else {
// if chopMonoQuadAtY failed, then we may have hit inexact numerics
// so we just clamp against the left
this->appendVLine(clip.fLeft, pts[0].fY, pts[2].fY, reverse);
return;
}
}
// are we partially to the right
if (pts[2].fX > clip.fRight) {
if (chopMonoQuadAtX(pts, clip.fRight, &t)) {
SkChopQuadAt(pts, tmp, t);
// clamp to clean up imprecise numerics in the chop
clamp_le(tmp[1].fX, clip.fRight);
tmp[2].fX = clip.fRight;
this->appendQuad(tmp, reverse);
this->appendVLine(clip.fRight, tmp[2].fY, tmp[4].fY, reverse);
} else {
// if chopMonoQuadAtY failed, then we may have hit inexact numerics
// so we just clamp against the right
this->appendVLine(clip.fRight, pts[0].fY, pts[2].fY, reverse);
}
} else { // wholly inside the clip
this->appendQuad(pts, reverse);
}
}
