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ccpr: Don't call calcCubicInverseTransposePowerBasisMatrix

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We only need a few values from this Matrix, so it doesn't make sense to
spend time solving the entire thing.

Bug: skia:
Change-Id: Id56d6f593a9a5afe1455bf2c93f6a51b1b9f1642
Reviewed-on: https://skia-review.googlesource.com/122130
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
This commit is contained in:
Chris Dalton 2018-04-18 14:13:45 -06:00 committed by Skia Commit-Bot
parent e6a67f1487
commit 4229b35c3e
1 changed files with 32 additions and 16 deletions
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48
src/gpu/ccpr/GrCCGeometry.cpp
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@ -8,7 +8,7 @@
#include "GrCCGeometry.h"
#include "GrTypes.h"
#include "GrPathUtils.h"
#include "SkGeometry.h"
#include <algorithm>
#include <cmath>
#include <cstdlib>
@ -229,7 +229,10 @@ static inline bool is_cubic_nearly_quadratic(const Sk2f& p0, const Sk2f& p1, con
return ((c1 - c2).abs() <= 1).allTrue();
}
using ExcludedTerm = GrPathUtils::ExcludedTerm;
enum class ExcludedTerm : bool {
kQuadraticTerm,
kLinearTerm
};
// Finds where to chop a non-loop around its inflection points. The resulting cubic segments will be
// chopped such that a box of radius 'padRadius', centered at any point along the curve segment, is
@ -241,11 +244,14 @@ using ExcludedTerm = GrPathUtils::ExcludedTerm;
// A serpentine cubic has two inflection points, so this method takes Sk2f and computes the padding
// for both in SIMD.
static inline void find_chops_around_inflection_points(float padRadius, Sk2f tl, Sk2f sl,
const SkMatrix& CIT, ExcludedTerm skipTerm,
const Sk2f& C0, const Sk2f& C1,
ExcludedTerm skipTerm, float Cdet,
SkSTArray<4, float>* chops) {
SkASSERT(chops->empty());
SkASSERT(padRadius >= 0);
padRadius /= std::abs(Cdet); // Scale this single value rather than all of C^-1 later on.
// The homogeneous parametric functions for distance from lines L & M are:
//
// l(t,s) = (t*sl - s*tl)^3
@ -275,8 +281,10 @@ static inline void find_chops_around_inflection_points(float padRadius, Sk2f tl,
// L = C^-1 * (l excluding skipTerm)
//
// (See comments for GrPathUtils::calcCubicInverseTransposePowerBasisMatrix.)
Sk2f Lx = CIT[0] * l3 + CIT[3] * l2or1;
Sk2f Ly = CIT[1] * l3 + CIT[4] * l2or1;
// We are only interested in the normal to L, so only need the upper 2x2 of C^-1. And rather
// than divide by determinant(C) here, we have already performed this divide on padRadius.
Sk2f Lx = C1[1]*l3 - C0[1]*l2or1;
Sk2f Ly = -C1[0]*l3 + C0[0]*l2or1;
// A box of radius "padRadius" is touching line L if "center dot L" is less than the Manhattan
// with of L. (See rationale in are_collinear.)
@ -321,11 +329,14 @@ static inline void swap_if_greater(float& a, float& b) {
// A loop intersection falls at two different T values, so this method takes Sk2f and computes the
// padding for both in SIMD.
static inline void find_chops_around_loop_intersection(float padRadius, Sk2f t2, Sk2f s2,
const SkMatrix& CIT, ExcludedTerm skipTerm,
const Sk2f& C0, const Sk2f& C1,
ExcludedTerm skipTerm, float Cdet,
SkSTArray<4, float>* chops) {
SkASSERT(chops->empty());
SkASSERT(padRadius >= 0);
padRadius /= std::abs(Cdet); // Scale this single value rather than all of C^-1 later on.
// The parametric functions for distance from lines L & M are:
//
// l(T) = (T - Td)^2 * (T - Te)
@ -355,9 +366,11 @@ static inline void find_chops_around_loop_intersection(float padRadius, Sk2f t2,
// L = C^-1 * (l excluding skipTerm)
//
// (See comments for GrPathUtils::calcCubicInverseTransposePowerBasisMatrix.)
// We are only interested in the normal to L, so only need the upper 2x2 of C^-1. And rather
// than divide by determinant(C) here, we have already performed this divide on padRadius.
Sk2f l2or1 = (ExcludedTerm::kLinearTerm == skipTerm) ? l2 : l1;
Sk2f Lx = CIT[3] * l2or1 + CIT[0]; // l3 is always 1.
Sk2f Ly = CIT[4] * l2or1 - CIT[1];
Sk2f Lx = -C0[1]*l2or1 + C1[1]; // l3 is always 1.
Sk2f Ly = C0[0]*l2or1 - C1[0];
// A box of radius "padRadius" is touching line L if "center dot L" is less than the Manhattan
// with of L. (See rationale in are_collinear.)
@ -476,18 +489,21 @@ void GrCCGeometry::cubicTo(const SkPoint P[4], float inflectPad, float loopInter
Sk2f t = Sk2f(static_cast<float>(tt[0]), static_cast<float>(tt[1]));
Sk2f s = Sk2f(static_cast<float>(ss[0]), static_cast<float>(ss[1]));
SkMatrix CIT;
ExcludedTerm skipTerm = GrPathUtils::calcCubicInverseTransposePowerBasisMatrix(P, &CIT);
SkASSERT(ExcludedTerm::kNonInvertible != skipTerm); // Should have been caught above.
SkASSERT(0 == CIT[6]);
SkASSERT(0 == CIT[7]);
SkASSERT(1 == CIT[8]);
ExcludedTerm skipTerm = (std::abs(D[2]) > std::abs(D[1]))
? ExcludedTerm::kQuadraticTerm
: ExcludedTerm::kLinearTerm;
Sk2f C0 = SkNx_fma(Sk2f(3), p1 - p2, p3 - p0);
Sk2f C1 = (ExcludedTerm::kLinearTerm == skipTerm
? SkNx_fma(Sk2f(-2), p1, p0 + p2)
: p1 - p0) * 3;
Sk2f C0x1 = C0 * SkNx_shuffle<1,0>(C1);
float Cdet = C0x1[0] - C0x1[1];
SkSTArray<4, float> chops;
if (SkCubicType::kLoop != fCurrCubicType) {
find_chops_around_inflection_points(inflectPad, t, s, CIT, skipTerm, &chops);
find_chops_around_inflection_points(inflectPad, t, s, C0, C1, skipTerm, Cdet, &chops);
} else {
find_chops_around_loop_intersection(loopIntersectPad, t, s, CIT, skipTerm, &chops);
find_chops_around_loop_intersection(loopIntersectPad, t, s, C0, C1, skipTerm, Cdet, &chops);
}
if (4 == chops.count() && chops[1] >= chops[2]) {
// This just the means the KLM roots are so close that their paddings overlap. We will