bool SkDCubic::controlsContainedByEnds() const {
SkDVector startTan = fPts[1] - fPts[0];
if (startTan.fX == 0 && startTan.fY == 0) {
startTan = fPts[2] - fPts[0];
}
SkDVector endTan = fPts[2] - fPts[3];
if (endTan.fX == 0 && endTan.fY == 0) {
endTan = fPts[1] - fPts[3];
}
if (startTan.dot(endTan) >= 0) {
return false;
}
SkDLine startEdge = {{fPts[0], fPts[0]}};
startEdge[1].fX -= startTan.fY;
startEdge[1].fY += startTan.fX;
SkDLine endEdge = {{fPts[3], fPts[3]}};
endEdge[1].fX -= endTan.fY;
endEdge[1].fY += endTan.fX;
double leftStart1 = startEdge.isLeft(fPts[1]);
if (leftStart1 * startEdge.isLeft(fPts[2]) < 0) {
return false;
}
double leftEnd1 = endEdge.isLeft(fPts[1]);
if (leftEnd1 * endEdge.isLeft(fPts[2]) < 0) {
return false;
}
return leftStart1 * leftEnd1 >= 0;
}
static void pointFinder(const SkDQuad& q1, const SkDQuad& q2) {
for (int index = 0; index < 3; ++index) {
double t = q1.nearestT(q2[index]);
SkDPoint onQuad = q1.ptAtT(t);
SkDebugf("%s t=%1.9g (%1.9g,%1.9g) dist=%1.9g\n", __FUNCTION__, t, onQuad.fX, onQuad.fY,
onQuad.distance(q2[index]));
double left[3];
left[0] = ((const SkDLine&) q1[0]).isLeft(q2[index]);
left[1] = ((const SkDLine&) q1[1]).isLeft(q2[index]);
SkDLine diag = {{q1[0], q1[2]}};
left[2] = diag.isLeft(q2[index]);
SkDebugf("%s left=(%d, %d, %d) inHull=%s\n", __FUNCTION__, floatSign(left[0]),
floatSign(left[1]), floatSign(left[2]),
q1.pointInHull(q2[index]) ? "true" : "false");
}
SkDebugf("\n");
}