remove unused SkXRay functions
BUG=skia: TBR= Review URL: https://codereview.chromium.org/1016263002
This commit is contained in:
reed
Commit bot
parent
7c44ca926b
commit
562d0e1cd2
@ -8,61 +8,6 @@
|
||||
#include "SkGeometry.h"
|
||||
#include "SkMatrix.h"
|
||||
|
||||
bool SkXRayCrossesLine(const SkXRay& pt,
|
||||
const SkPoint pts[2],
|
||||
bool* ambiguous) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = false;
|
||||
}
|
||||
// Determine quick discards.
|
||||
// Consider query line going exactly through point 0 to not
|
||||
// intersect, for symmetry with SkXRayCrossesMonotonicCubic.
|
||||
if (pt.fY == pts[0].fY) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
if (pt.fY < pts[0].fY && pt.fY < pts[1].fY)
|
||||
return false;
|
||||
if (pt.fY > pts[0].fY && pt.fY > pts[1].fY)
|
||||
return false;
|
||||
if (pt.fX > pts[0].fX && pt.fX > pts[1].fX)
|
||||
return false;
|
||||
// Determine degenerate cases
|
||||
if (SkScalarNearlyZero(pts[0].fY - pts[1].fY))
|
||||
return false;
|
||||
if (SkScalarNearlyZero(pts[0].fX - pts[1].fX)) {
|
||||
// We've already determined the query point lies within the
|
||||
// vertical range of the line segment.
|
||||
if (pt.fX <= pts[0].fX) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = (pt.fY == pts[1].fY);
|
||||
}
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
// Ambiguity check
|
||||
if (pt.fY == pts[1].fY) {
|
||||
if (pt.fX <= pts[1].fX) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = true;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
// Full line segment evaluation
|
||||
SkScalar delta_y = pts[1].fY - pts[0].fY;
|
||||
SkScalar delta_x = pts[1].fX - pts[0].fX;
|
||||
SkScalar slope = SkScalarDiv(delta_y, delta_x);
|
||||
SkScalar b = pts[0].fY - SkScalarMul(slope, pts[0].fX);
|
||||
// Solve for x coordinate at y = pt.fY
|
||||
SkScalar x = SkScalarDiv(pt.fY - b, slope);
|
||||
return pt.fX <= x;
|
||||
}
|
||||
|
||||
/** If defined, this makes eval_quad and eval_cubic do more setup (sometimes
|
||||
involving integer multiplies by 2 or 3, but fewer calls to SkScalarMul.
|
||||
May also introduce overflow of fixed when we compute our setup.
|
||||
@ -949,130 +894,6 @@ int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
|
||||
return count + 1;
|
||||
}
|
||||
|
||||
bool SkXRayCrossesMonotonicCubic(const SkXRay& pt, const SkPoint cubic[4],
|
||||
bool* ambiguous) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = false;
|
||||
}
|
||||
|
||||
// Find the minimum and maximum y of the extrema, which are the
|
||||
// first and last points since this cubic is monotonic
|
||||
SkScalar min_y = SkMinScalar(cubic[0].fY, cubic[3].fY);
|
||||
SkScalar max_y = SkMaxScalar(cubic[0].fY, cubic[3].fY);
|
||||
|
||||
if (pt.fY == cubic[0].fY
|
||||
|| pt.fY < min_y
|
||||
|| pt.fY > max_y) {
|
||||
// The query line definitely does not cross the curve
|
||||
if (ambiguous) {
|
||||
*ambiguous = (pt.fY == cubic[0].fY);
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
bool pt_at_extremum = (pt.fY == cubic[3].fY);
|
||||
|
||||
SkScalar min_x =
|
||||
SkMinScalar(
|
||||
SkMinScalar(
|
||||
SkMinScalar(cubic[0].fX, cubic[1].fX),
|
||||
cubic[2].fX),
|
||||
cubic[3].fX);
|
||||
if (pt.fX < min_x) {
|
||||
// The query line definitely crosses the curve
|
||||
if (ambiguous) {
|
||||
*ambiguous = pt_at_extremum;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
SkScalar max_x =
|
||||
SkMaxScalar(
|
||||
SkMaxScalar(
|
||||
SkMaxScalar(cubic[0].fX, cubic[1].fX),
|
||||
cubic[2].fX),
|
||||
cubic[3].fX);
|
||||
if (pt.fX > max_x) {
|
||||
// The query line definitely does not cross the curve
|
||||
return false;
|
||||
}
|
||||
|
||||
// Do a binary search to find the parameter value which makes y as
|
||||
// close as possible to the query point. See whether the query
|
||||
// line's origin is to the left of the associated x coordinate.
|
||||
|
||||
// kMaxIter is chosen as the number of mantissa bits for a float,
|
||||
// since there's no way we are going to get more precision by
|
||||
// iterating more times than that.
|
||||
const int kMaxIter = 23;
|
||||
SkPoint eval;
|
||||
int iter = 0;
|
||||
SkScalar upper_t;
|
||||
SkScalar lower_t;
|
||||
// Need to invert direction of t parameter if cubic goes up
|
||||
// instead of down
|
||||
if (cubic[3].fY > cubic[0].fY) {
|
||||
upper_t = SK_Scalar1;
|
||||
lower_t = 0;
|
||||
} else {
|
||||
upper_t = 0;
|
||||
lower_t = SK_Scalar1;
|
||||
}
|
||||
do {
|
||||
SkScalar t = SkScalarAve(upper_t, lower_t);
|
||||
SkEvalCubicAt(cubic, t, &eval, NULL, NULL);
|
||||
if (pt.fY > eval.fY) {
|
||||
lower_t = t;
|
||||
} else {
|
||||
upper_t = t;
|
||||
}
|
||||
} while (++iter < kMaxIter
|
||||
&& !SkScalarNearlyZero(eval.fY - pt.fY));
|
||||
if (pt.fX <= eval.fX) {
|
||||
if (ambiguous) {
|
||||
*ambiguous = pt_at_extremum;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
int SkNumXRayCrossingsForCubic(const SkXRay& pt,
|
||||
const SkPoint cubic[4],
|
||||
bool* ambiguous) {
|
||||
int num_crossings = 0;
|
||||
SkPoint monotonic_cubics[10];
|
||||
int num_monotonic_cubics = SkChopCubicAtYExtrema(cubic, monotonic_cubics);
|
||||
if (ambiguous) {
|
||||
*ambiguous = false;
|
||||
}
|
||||
bool locally_ambiguous;
|
||||
if (SkXRayCrossesMonotonicCubic(pt,
|
||||
&monotonic_cubics[0],
|
||||
&locally_ambiguous))
|
||||
++num_crossings;
|
||||
if (ambiguous) {
|
||||
*ambiguous |= locally_ambiguous;
|
||||
}
|
||||
if (num_monotonic_cubics > 0)
|
||||
if (SkXRayCrossesMonotonicCubic(pt,
|
||||
&monotonic_cubics[3],
|
||||
&locally_ambiguous))
|
||||
++num_crossings;
|
||||
if (ambiguous) {
|
||||
*ambiguous |= locally_ambiguous;
|
||||
}
|
||||
if (num_monotonic_cubics > 1)
|
||||
if (SkXRayCrossesMonotonicCubic(pt,
|
||||
&monotonic_cubics[6],
|
||||
&locally_ambiguous))
|
||||
++num_crossings;
|
||||
if (ambiguous) {
|
||||
*ambiguous |= locally_ambiguous;
|
||||
}
|
||||
return num_crossings;
|
||||
}
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
/* Find t value for quadratic [a, b, c] = d.
|
||||
|
||||
@ -10,21 +10,6 @@
|
||||
|
||||
#include "SkMatrix.h"
|
||||
|
||||
/** An XRay is a half-line that runs from the specific point/origin to
|
||||
+infinity in the X direction. e.g. XRay(3,5) is the half-line
|
||||
(3,5)....(infinity, 5)
|
||||
*/
|
||||
typedef SkPoint SkXRay;
|
||||
|
||||
/** Given a line segment from pts[0] to pts[1], and an xray, return true if
|
||||
they intersect. Optional outgoing "ambiguous" argument indicates
|
||||
whether the answer is ambiguous because the query occurred exactly at
|
||||
one of the endpoints' y coordinates, indicating that another query y
|
||||
coordinate is preferred for robustness.
|
||||
*/
|
||||
bool SkXRayCrossesLine(const SkXRay& pt, const SkPoint pts[2],
|
||||
bool* ambiguous = NULL);
|
||||
|
||||
/** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
|
||||
equation.
|
||||
*/
|
||||
@ -159,36 +144,6 @@ int SkFindCubicMaxCurvature(const SkPoint src[4], SkScalar tValues[3]);
|
||||
int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
|
||||
SkScalar tValues[3] = NULL);
|
||||
|
||||
/** Given a monotonic cubic bezier, determine whether an xray intersects the
|
||||
cubic.
|
||||
By definition the cubic is open at the starting point; in other
|
||||
words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
|
||||
left of the curve, the line is not considered to cross the curve,
|
||||
but if it is equal to cubic[3].fY then it is considered to
|
||||
cross.
|
||||
Optional outgoing "ambiguous" argument indicates whether the answer is
|
||||
ambiguous because the query occurred exactly at one of the endpoints' y
|
||||
coordinates, indicating that another query y coordinate is preferred
|
||||
for robustness.
|
||||
*/
|
||||
bool SkXRayCrossesMonotonicCubic(const SkXRay& pt, const SkPoint cubic[4],
|
||||
bool* ambiguous = NULL);
|
||||
|
||||
/** Given an arbitrary cubic bezier, return the number of times an xray crosses
|
||||
the cubic. Valid return values are [0..3]
|
||||
By definition the cubic is open at the starting point; in other
|
||||
words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
|
||||
left of the curve, the line is not considered to cross the curve,
|
||||
but if it is equal to cubic[3].fY then it is considered to
|
||||
cross.
|
||||
Optional outgoing "ambiguous" argument indicates whether the answer is
|
||||
ambiguous because the query occurred exactly at one of the endpoints' y
|
||||
coordinates or at a tangent point, indicating that another query y
|
||||
coordinate is preferred for robustness.
|
||||
*/
|
||||
int SkNumXRayCrossingsForCubic(const SkXRay& pt, const SkPoint cubic[4],
|
||||
bool* ambiguous = NULL);
|
||||
|
||||
enum SkCubicType {
|
||||
kSerpentine_SkCubicType,
|
||||
kCusp_SkCubicType,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user