remove unused SkXRay functions
BUG=skia: TBR= Review URL: https://codereview.chromium.org/1016263002
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@ -8,61 +8,6 @@
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#include "SkGeometry.h"
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#include "SkGeometry.h"
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#include "SkMatrix.h"
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#include "SkMatrix.h"
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bool SkXRayCrossesLine(const SkXRay& pt,
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const SkPoint pts[2],
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bool* ambiguous) {
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if (ambiguous) {
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*ambiguous = false;
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}
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// Determine quick discards.
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// Consider query line going exactly through point 0 to not
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// intersect, for symmetry with SkXRayCrossesMonotonicCubic.
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if (pt.fY == pts[0].fY) {
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if (ambiguous) {
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*ambiguous = true;
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}
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return false;
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}
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if (pt.fY < pts[0].fY && pt.fY < pts[1].fY)
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return false;
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if (pt.fY > pts[0].fY && pt.fY > pts[1].fY)
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return false;
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if (pt.fX > pts[0].fX && pt.fX > pts[1].fX)
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return false;
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// Determine degenerate cases
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if (SkScalarNearlyZero(pts[0].fY - pts[1].fY))
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return false;
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if (SkScalarNearlyZero(pts[0].fX - pts[1].fX)) {
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// We've already determined the query point lies within the
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// vertical range of the line segment.
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if (pt.fX <= pts[0].fX) {
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if (ambiguous) {
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*ambiguous = (pt.fY == pts[1].fY);
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}
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return true;
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}
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return false;
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}
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// Ambiguity check
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if (pt.fY == pts[1].fY) {
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if (pt.fX <= pts[1].fX) {
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if (ambiguous) {
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*ambiguous = true;
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}
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return true;
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}
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return false;
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}
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// Full line segment evaluation
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SkScalar delta_y = pts[1].fY - pts[0].fY;
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SkScalar delta_x = pts[1].fX - pts[0].fX;
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SkScalar slope = SkScalarDiv(delta_y, delta_x);
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SkScalar b = pts[0].fY - SkScalarMul(slope, pts[0].fX);
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// Solve for x coordinate at y = pt.fY
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SkScalar x = SkScalarDiv(pt.fY - b, slope);
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return pt.fX <= x;
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}
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/** If defined, this makes eval_quad and eval_cubic do more setup (sometimes
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/** If defined, this makes eval_quad and eval_cubic do more setup (sometimes
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involving integer multiplies by 2 or 3, but fewer calls to SkScalarMul.
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involving integer multiplies by 2 or 3, but fewer calls to SkScalarMul.
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May also introduce overflow of fixed when we compute our setup.
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May also introduce overflow of fixed when we compute our setup.
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@ -949,130 +894,6 @@ int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
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return count + 1;
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return count + 1;
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}
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}
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bool SkXRayCrossesMonotonicCubic(const SkXRay& pt, const SkPoint cubic[4],
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bool* ambiguous) {
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if (ambiguous) {
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*ambiguous = false;
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}
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// Find the minimum and maximum y of the extrema, which are the
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// first and last points since this cubic is monotonic
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SkScalar min_y = SkMinScalar(cubic[0].fY, cubic[3].fY);
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SkScalar max_y = SkMaxScalar(cubic[0].fY, cubic[3].fY);
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if (pt.fY == cubic[0].fY
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|| pt.fY < min_y
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|| pt.fY > max_y) {
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// The query line definitely does not cross the curve
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if (ambiguous) {
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*ambiguous = (pt.fY == cubic[0].fY);
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}
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return false;
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}
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bool pt_at_extremum = (pt.fY == cubic[3].fY);
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SkScalar min_x =
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SkMinScalar(
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SkMinScalar(
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SkMinScalar(cubic[0].fX, cubic[1].fX),
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cubic[2].fX),
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cubic[3].fX);
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if (pt.fX < min_x) {
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// The query line definitely crosses the curve
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if (ambiguous) {
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*ambiguous = pt_at_extremum;
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}
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return true;
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}
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SkScalar max_x =
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SkMaxScalar(
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SkMaxScalar(
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SkMaxScalar(cubic[0].fX, cubic[1].fX),
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cubic[2].fX),
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cubic[3].fX);
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if (pt.fX > max_x) {
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// The query line definitely does not cross the curve
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return false;
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}
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// Do a binary search to find the parameter value which makes y as
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// close as possible to the query point. See whether the query
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// line's origin is to the left of the associated x coordinate.
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// kMaxIter is chosen as the number of mantissa bits for a float,
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// since there's no way we are going to get more precision by
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// iterating more times than that.
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const int kMaxIter = 23;
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SkPoint eval;
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int iter = 0;
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SkScalar upper_t;
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SkScalar lower_t;
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// Need to invert direction of t parameter if cubic goes up
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// instead of down
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if (cubic[3].fY > cubic[0].fY) {
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upper_t = SK_Scalar1;
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lower_t = 0;
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} else {
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upper_t = 0;
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lower_t = SK_Scalar1;
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}
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do {
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SkScalar t = SkScalarAve(upper_t, lower_t);
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SkEvalCubicAt(cubic, t, &eval, NULL, NULL);
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if (pt.fY > eval.fY) {
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lower_t = t;
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} else {
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upper_t = t;
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}
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} while (++iter < kMaxIter
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&& !SkScalarNearlyZero(eval.fY - pt.fY));
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if (pt.fX <= eval.fX) {
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if (ambiguous) {
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*ambiguous = pt_at_extremum;
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}
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return true;
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}
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return false;
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}
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int SkNumXRayCrossingsForCubic(const SkXRay& pt,
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const SkPoint cubic[4],
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bool* ambiguous) {
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int num_crossings = 0;
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SkPoint monotonic_cubics[10];
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int num_monotonic_cubics = SkChopCubicAtYExtrema(cubic, monotonic_cubics);
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if (ambiguous) {
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*ambiguous = false;
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}
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bool locally_ambiguous;
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if (SkXRayCrossesMonotonicCubic(pt,
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&monotonic_cubics[0],
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&locally_ambiguous))
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++num_crossings;
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if (ambiguous) {
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*ambiguous |= locally_ambiguous;
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}
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if (num_monotonic_cubics > 0)
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if (SkXRayCrossesMonotonicCubic(pt,
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&monotonic_cubics[3],
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&locally_ambiguous))
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++num_crossings;
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if (ambiguous) {
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*ambiguous |= locally_ambiguous;
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}
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if (num_monotonic_cubics > 1)
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if (SkXRayCrossesMonotonicCubic(pt,
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&monotonic_cubics[6],
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&locally_ambiguous))
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++num_crossings;
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if (ambiguous) {
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*ambiguous |= locally_ambiguous;
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}
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return num_crossings;
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}
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///////////////////////////////////////////////////////////////////////////////
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///////////////////////////////////////////////////////////////////////////////
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/* Find t value for quadratic [a, b, c] = d.
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/* Find t value for quadratic [a, b, c] = d.
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@ -10,21 +10,6 @@
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#include "SkMatrix.h"
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#include "SkMatrix.h"
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/** An XRay is a half-line that runs from the specific point/origin to
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+infinity in the X direction. e.g. XRay(3,5) is the half-line
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(3,5)....(infinity, 5)
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*/
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typedef SkPoint SkXRay;
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/** Given a line segment from pts[0] to pts[1], and an xray, return true if
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they intersect. Optional outgoing "ambiguous" argument indicates
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whether the answer is ambiguous because the query occurred exactly at
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one of the endpoints' y coordinates, indicating that another query y
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coordinate is preferred for robustness.
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*/
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bool SkXRayCrossesLine(const SkXRay& pt, const SkPoint pts[2],
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bool* ambiguous = NULL);
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/** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
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/** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
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equation.
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equation.
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*/
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*/
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@ -159,36 +144,6 @@ int SkFindCubicMaxCurvature(const SkPoint src[4], SkScalar tValues[3]);
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int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
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int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
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SkScalar tValues[3] = NULL);
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SkScalar tValues[3] = NULL);
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/** Given a monotonic cubic bezier, determine whether an xray intersects the
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cubic.
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By definition the cubic is open at the starting point; in other
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words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
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left of the curve, the line is not considered to cross the curve,
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but if it is equal to cubic[3].fY then it is considered to
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cross.
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Optional outgoing "ambiguous" argument indicates whether the answer is
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ambiguous because the query occurred exactly at one of the endpoints' y
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coordinates, indicating that another query y coordinate is preferred
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for robustness.
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*/
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bool SkXRayCrossesMonotonicCubic(const SkXRay& pt, const SkPoint cubic[4],
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bool* ambiguous = NULL);
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/** Given an arbitrary cubic bezier, return the number of times an xray crosses
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the cubic. Valid return values are [0..3]
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By definition the cubic is open at the starting point; in other
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words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
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left of the curve, the line is not considered to cross the curve,
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but if it is equal to cubic[3].fY then it is considered to
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cross.
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Optional outgoing "ambiguous" argument indicates whether the answer is
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ambiguous because the query occurred exactly at one of the endpoints' y
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coordinates or at a tangent point, indicating that another query y
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coordinate is preferred for robustness.
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*/
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int SkNumXRayCrossingsForCubic(const SkXRay& pt, const SkPoint cubic[4],
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bool* ambiguous = NULL);
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enum SkCubicType {
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enum SkCubicType {
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kSerpentine_SkCubicType,
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kSerpentine_SkCubicType,
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kCusp_SkCubicType,
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kCusp_SkCubicType,
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