skia2/bench/Matrix44Bench.cpp
Michael Ludwig daa9b8e4d9 Add mapRect function and RectToRect constructor to SkM44
The SkM44::RectToRect function matches the semantics of
SkMatrix::RectToRect(kFill_ScaleToFit). No other ScaleToFit variants are
ported over to SkM44.

skottie uses some instances of kCenter_ScaleToFit so that functionality
may need to be added in the future (in SkM44 or in skottie). There are
no current usages of the kStart and kEnd_ScaleToFit semantics.

The SkM44::mapRect() function is implemented to correspond to the
SkMatrix::mapRect() that returns the mapped rect (instead of modifying a
pointer) and always has ApplyPerspectiveClip::kYes. This was chosen to
keep its behavior simple and because perspective clipping is almost
always the right thing to do. In the new implementation there is no
longer a performance cliff to worry about (see below). For the timebeing
mapRect is hidden behind SkMatrixPriv::MapRect().

Performance:
I added benchmarks for mapRect() on SkM44 and SkMatrix that use the same
matrices to get a fair comparison on their different specializations.
SkMatrix has a very efficient mapRect when it's scale+translate or
simpler, then another impl. for affine matrices, and then falls back to
SkPath clipping when there's perspective. On the other hand, SkM44 only
has 2 modes: affine and perspective.

On my desktop, with a Ryzen 9 3900X, here are the times for 100,000 calls
to mapRect for different types of matrices:
                         SkMatrix    SkM44
scale+translate           0.35 ms    0.42 ms
rotate                    1.70 ms    0.42 ms
perspective              63.90 ms    0.66 ms
clipped-perspective      138.0 ms    0.96 ms

To summarize, the SkM44::mapRect is almost as fast as the s+t specialization
in SkMatrix, but for all non-perspective matrices. For perspective matrices
it's only 2x slower than that specialization when no vertices are clipped,
and still almost 2x faster than the affine specialization when vertices are
clipped (and 100x faster than falling back to SkPath).

Given that, there's the open question of whether or not keeping an affine
specialization is worth it for SkM44's code size.

Bug: skia:11720
Change-Id: I6771956729ed64f3b287a9de503513375c9f42a0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/402957
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
2021-05-05 19:57:26 +00:00

260 lines
6.6 KiB
C++

/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "bench/Benchmark.h"
#include "include/core/SkM44.h"
#include "include/core/SkString.h"
#include "include/utils/SkRandom.h"
#include "src/core/SkMatrixPriv.h"
class M4Bench : public Benchmark {
SkString fName;
public:
M4Bench(const char name[]) {
fName.printf("m4_%s", name);
SkRandom rand;
float value[32];
for (auto& v : value) {
v = rand.nextF();
}
fM1 = SkM44::ColMajor(value + 0);
fM2 = SkM44::ColMajor(value + 16);
}
bool isSuitableFor(Backend backend) override {
return backend == kNonRendering_Backend;
}
virtual void performTest() = 0;
protected:
SkM44 fM0, fM1, fM2;
virtual int mulLoopCount() const { return 1; }
const char* onGetName() override {
return fName.c_str();
}
void onDraw(int loops, SkCanvas*) override {
for (int i = 0; i < loops; i++) {
this->performTest();
}
}
private:
using INHERITED = Benchmark;
};
class M4NEQ : public M4Bench {
public:
M4NEQ() : INHERITED("neq") {}
protected:
void performTest() override {
for (int i = 0; i < 10000; ++i) {
fEQ = (fM2 == fM1); // should always be false
}
}
private:
bool fEQ;
using INHERITED = M4Bench;
};
class M4EQ : public M4Bench {
public:
M4EQ() : INHERITED("eq") {}
protected:
void performTest() override {
fM2 = fM1;
for (int i = 0; i < 10000; ++i) {
fEQ = (fM2 == fM1); // should always be true
}
}
private:
bool fEQ;
using INHERITED = M4Bench;
};
class M4Concat : public M4Bench {
public:
M4Concat() : INHERITED("op_concat") {}
protected:
void performTest() override {
for (int i = 0; i < 10000; ++i) {
fM0 = SkM44(fM1, fM2);
}
}
private:
using INHERITED = M4Bench;
};
class M4SetConcat : public M4Bench {
public:
M4SetConcat() : INHERITED("set_concat") {}
protected:
void performTest() override {
for (int i = 0; i < 10000; ++i) {
fM0.setConcat(fM1, fM2);
}
}
private:
using INHERITED = M4Bench;
};
DEF_BENCH( return new M4EQ(); )
DEF_BENCH( return new M4NEQ(); )
DEF_BENCH( return new M4Concat(); )
DEF_BENCH( return new M4SetConcat(); )
class M4_map4 : public M4Bench {
public:
M4_map4() : INHERITED("map4") {}
protected:
void performTest() override {
SkV4 v = {1, 2, 3, 4};
for (int i = 0; i < 100000; ++i) {
fV = fM0 * v;
}
}
private:
SkV4 fV;
using INHERITED = M4Bench;
};
DEF_BENCH( return new M4_map4(); )
class M4_map2 : public M4Bench {
public:
M4_map2() : INHERITED("map2") {}
protected:
void performTest() override {
SkMatrix m;
m.setRotate(1);
for (int i = 0; i < 100000; ++i) {
fV = m.mapXY(5, 6);
}
}
private:
SkPoint fV;
using INHERITED = M4Bench;
};
DEF_BENCH( return new M4_map2(); )
enum class MapMatrixType {
kTranslateOnly,
kScaleTranslate,
kRotate,
kPerspective,
kPerspectiveClipped
};
class MapRectBench : public Benchmark {
SkString fName;
public:
MapRectBench(MapMatrixType type, const char name[]) {
SkRandom rand;
const char* typeName;
switch(type) {
case MapMatrixType::kTranslateOnly:
typeName = "t";
fM = SkM44::Translate(rand.nextF(), rand.nextF());
break;
case MapMatrixType::kScaleTranslate:
typeName = "s+t";
fM = SkM44::Scale(rand.nextF(), rand.nextF());
fM.postTranslate(rand.nextF(), rand.nextF());
break;
case MapMatrixType::kRotate:
typeName = "r";
fM = SkM44::Rotate({0.f, 0.f, 1.f}, SkDegreesToRadians(45.f));
break;
case MapMatrixType::kPerspective:
typeName = "p";
// Hand chosen to have all corners with w > 0 and w != 1
fM = SkM44::Perspective(0.01f, 10.f, SK_ScalarPI / 3.f);
fM.preTranslate(0.f, 5.f, -0.1f);
fM.preConcat(SkM44::Rotate({0.f, 1.f, 0.f}, 0.008f /* radians */));
break;
case MapMatrixType::kPerspectiveClipped:
typeName = "pc";
// Hand chosen to have some corners with w > 0 and some with w < 0
fM = SkM44();
fM.setRow(3, {-.2f, -.6f, 0.f, 8.f});
break;
}
fS = SkRect::MakeXYWH(10.f * rand.nextF(), 10.f * rand.nextF(),
150.f * rand.nextF(), 150.f * rand.nextF());
fName.printf("mapRect_%s_%s", name, typeName);
}
bool isSuitableFor(Backend backend) override { return backend == kNonRendering_Backend; }
virtual void performTest() = 0;
protected:
SkM44 fM;
SkRect fS, fD;
virtual int mulLoopCount() const { return 1; }
const char* onGetName() override { return fName.c_str(); }
void onDraw(int loops, SkCanvas*) override {
for (int i = 0; i < loops; i++) {
this->performTest();
}
}
private:
using INHERITED = Benchmark;
};
class M4_mapRectBench : public MapRectBench {
public:
M4_mapRectBench(MapMatrixType type) : INHERITED(type, "m4") {}
protected:
void performTest() override {
for (int i = 0; i < 100000; ++i) {
fD = SkMatrixPriv::MapRect(fM, fS);
}
}
private:
using INHERITED = MapRectBench;
};
DEF_BENCH(return new M4_mapRectBench(MapMatrixType::kTranslateOnly);)
DEF_BENCH(return new M4_mapRectBench(MapMatrixType::kScaleTranslate);)
DEF_BENCH(return new M4_mapRectBench(MapMatrixType::kRotate);)
DEF_BENCH(return new M4_mapRectBench(MapMatrixType::kPerspective);)
DEF_BENCH(return new M4_mapRectBench(MapMatrixType::kPerspectiveClipped);)
class M33_mapRectBench : public MapRectBench {
public:
M33_mapRectBench(MapMatrixType type) : INHERITED(type, "m33") {
fM33 = fM.asM33();
}
protected:
void performTest() override {
for (int i = 0; i < 100000; ++i) {
fD = fM33.mapRect(fS);
}
}
private:
SkMatrix fM33;
using INHERITED = MapRectBench;
};
DEF_BENCH(return new M33_mapRectBench(MapMatrixType::kTranslateOnly);)
DEF_BENCH(return new M33_mapRectBench(MapMatrixType::kScaleTranslate);)
DEF_BENCH(return new M33_mapRectBench(MapMatrixType::kRotate);)
DEF_BENCH(return new M33_mapRectBench(MapMatrixType::kPerspective);)
DEF_BENCH(return new M33_mapRectBench(MapMatrixType::kPerspectiveClipped);)