static void test_quad_tangents(skiatest::Reporter* reporter) {
SkPoint pts[] = {
{10, 20}, {10, 20}, {20, 30},
{10, 20}, {15, 25}, {20, 30},
{10, 20}, {20, 30}, {20, 30},
};
int count = (int) SK_ARRAY_COUNT(pts) / 3;
for (int index = 0; index < count; ++index) {
SkConic conic(&pts[index * 3], 0.707f);
SkVector start = SkEvalQuadTangentAt(&pts[index * 3], 0);
SkVector mid = SkEvalQuadTangentAt(&pts[index * 3], .5f);
SkVector end = SkEvalQuadTangentAt(&pts[index * 3], 1);
REPORTER_ASSERT(reporter, start.fX && start.fY);
REPORTER_ASSERT(reporter, mid.fX && mid.fY);
REPORTER_ASSERT(reporter, end.fX && end.fY);
REPORTER_ASSERT(reporter, SkScalarNearlyZero(start.cross(mid)));
REPORTER_ASSERT(reporter, SkScalarNearlyZero(mid.cross(end)));
}
}
void SkEvalQuadAt(const SkPoint src[3], SkScalar t, SkPoint* pt, SkVector* tangent) {
SkASSERT(src);
SkASSERT(t >= 0 && t <= SK_Scalar1);
if (pt) {
pt->set(eval_quad(&src[0].fX, t), eval_quad(&src[0].fY, t));
}
if (tangent) {
*tangent = SkEvalQuadTangentAt(src, t);
}
}
static void test_evalquadat(skiatest::Reporter* reporter) {
SkRandom rand;
for (int i = 0; i < 1000; ++i) {
SkPoint pts[3];
for (int j = 0; j < 3; ++j) {
pts[j].set(rand.nextSScalar1() * 100, rand.nextSScalar1() * 100);
}
const SkScalar dt = SK_Scalar1 / 128;
SkScalar t = dt;
for (int j = 1; j < 128; ++j) {
SkPoint r0;
SkEvalQuadAt(pts, t, &r0);
SkPoint r1 = SkEvalQuadAt(pts, t);
check_pairs(reporter, i, t, "quad-pos", r0.fX, r0.fY, r1.fX, r1.fY);
SkVector v0;
SkEvalQuadAt(pts, t, nullptr, &v0);
SkVector v1 = SkEvalQuadTangentAt(pts, t);
check_pairs(reporter, i, t, "quad-tan", v0.fX, v0.fY, v1.fX, v1.fY);
t += dt;
}
}
}
/// Used inside SkCurveMeasure::getTime's Newton's iteration
static inline SkVector evaluateDerivative(const SkPoint pts[4],
SkSegType segType, SkScalar t) {
SkVector tan;
switch (segType) {
case kQuad_SegType:
tan = SkEvalQuadTangentAt(pts, t);
break;
case kLine_SegType:
tan = pts[1] - pts[0];
break;
case kCubic_SegType:
SkEvalCubicAt(pts, t, nullptr, &tan, nullptr);
break;
case kConic_SegType: {
SkConic conic(pts, pts[3].x());
conic.evalAt(t, nullptr, &tan);
}
break;
default:
UNIMPLEMENTED;
}
return tan;
}
