skia2/samplecode/SampleHT.cpp
bungeman 7438bfc080 Factor code to rotate a canvas about a point.
SkMatrix::scale and ::rotate take a point around which to scale or rotate.
Canvas lacks these helpers, so the code to rotate a canvas around a
point has been duplicated many times. Factor all of these
implementations into SkCanvas::rotate.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2142033002

Review-Url: https://codereview.chromium.org/2142033002
2016-07-12 15:01:19 -07:00

185 lines
4.9 KiB
C++

/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SampleCode.h"
#include "SkAnimTimer.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkDrawable.h"
#include "SkInterpolator.h"
#include "SkPictureRecorder.h"
#include "SkRandom.h"
const SkRect gUnitSquare = { -1, -1, 1, 1 };
static void color_to_floats(SkColor c, SkScalar f[4]) {
f[0] = SkIntToScalar(SkColorGetA(c));
f[1] = SkIntToScalar(SkColorGetR(c));
f[2] = SkIntToScalar(SkColorGetG(c));
f[3] = SkIntToScalar(SkColorGetB(c));
}
static SkColor floats_to_color(const SkScalar f[4]) {
return SkColorSetARGB(SkScalarRoundToInt(f[0]),
SkScalarRoundToInt(f[1]),
SkScalarRoundToInt(f[2]),
SkScalarRoundToInt(f[3]));
}
static bool oval_contains(const SkRect& r, SkScalar x, SkScalar y) {
SkMatrix m;
m.setRectToRect(r, gUnitSquare, SkMatrix::kFill_ScaleToFit);
SkPoint pt;
m.mapXY(x, y, &pt);
return pt.lengthSqd() <= 1;
}
static SkColor rand_opaque_color(uint32_t seed) {
SkRandom rand(seed);
return rand.nextU() | (0xFF << 24);
}
class HTDrawable : public SkDrawable {
SkRect fR;
SkColor fColor;
SkInterpolator* fInterp;
SkMSec fTime;
public:
HTDrawable(SkRandom& rand) {
fR = SkRect::MakeXYWH(rand.nextRangeF(0, 640), rand.nextRangeF(0, 480),
rand.nextRangeF(20, 200), rand.nextRangeF(20, 200));
fColor = rand_opaque_color(rand.nextU());
fInterp = nullptr;
fTime = 0;
}
void spawnAnimation(SkMSec now) {
this->setTime(now);
delete fInterp;
fInterp = new SkInterpolator(5, 3);
SkScalar values[5];
color_to_floats(fColor, values); values[4] = 0;
fInterp->setKeyFrame(0, now, values);
values[0] = 0; values[4] = 180;
fInterp->setKeyFrame(1, now + 1000, values);
color_to_floats(rand_opaque_color(fColor), values); values[4] = 360;
fInterp->setKeyFrame(2, now + 2000, values);
fInterp->setMirror(true);
fInterp->setRepeatCount(3);
this->notifyDrawingChanged();
}
bool hitTest(SkScalar x, SkScalar y) {
return oval_contains(fR, x, y);
}
void setTime(SkMSec time) { fTime = time; }
void onDraw(SkCanvas* canvas) override {
SkAutoCanvasRestore acr(canvas, false);
SkPaint paint;
paint.setAntiAlias(true);
if (fInterp) {
SkScalar values[5];
SkInterpolator::Result res = fInterp->timeToValues(fTime, values);
fColor = floats_to_color(values);
canvas->save();
canvas->rotate(values[4], fR.centerX(), fR.centerY());
switch (res) {
case SkInterpolator::kFreezeEnd_Result:
delete fInterp;
fInterp = nullptr;
break;
default:
break;
}
}
paint.setColor(fColor);
canvas->drawRect(fR, paint);
}
SkRect onGetBounds() override { return fR; }
};
class HTView : public SampleView {
public:
enum {
N = 50,
W = 640,
H = 480,
};
struct Rec {
HTDrawable* fDrawable;
};
Rec fArray[N];
sk_sp<SkDrawable> fRoot;
SkMSec fTime;
HTView() {
SkRandom rand;
SkPictureRecorder recorder;
SkCanvas* canvas = recorder.beginRecording(SkRect::MakeWH(W, H));
for (int i = 0; i < N; ++i) {
fArray[i].fDrawable = new HTDrawable(rand);
canvas->drawDrawable(fArray[i].fDrawable);
fArray[i].fDrawable->unref();
}
fRoot = recorder.finishRecordingAsDrawable();
}
protected:
bool onQuery(SkEvent* evt) override {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, "HT");
return true;
}
return this->INHERITED::onQuery(evt);
}
void onDrawContent(SkCanvas* canvas) override {
canvas->drawDrawable(fRoot.get());
}
bool onAnimate(const SkAnimTimer& timer) override {
fTime = timer.msec();
for (int i = 0; i < N; ++i) {
fArray[i].fDrawable->setTime(fTime);
}
return true;
}
SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
// search backwards to find the top-most
for (int i = N - 1; i >= 0; --i) {
if (fArray[i].fDrawable->hitTest(x, y)) {
fArray[i].fDrawable->spawnAnimation(fTime);
break;
}
}
this->inval(nullptr);
return nullptr;
}
private:
typedef SampleView INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static SkView* MyFactory() { return new HTView; }
static SkViewRegister reg(MyFactory);