skia2/samplecode/SampleAtlas.cpp

257 lines
7.8 KiB
C++
Raw Normal View History

/*
* Copyright 2015 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 "SkPath.h"
#include "SkRandom.h"
#include "SkRSXform.h"
#include "SkSurface.h"
typedef void (*DrawAtlasProc)(SkCanvas*, SkImage*, const SkRSXform[], const SkRect[],
const SkColor[], int, const SkRect*, const SkPaint*);
static void draw_atlas(SkCanvas* canvas, SkImage* atlas, const SkRSXform xform[],
const SkRect tex[], const SkColor colors[], int count, const SkRect* cull,
const SkPaint* paint) {
canvas->drawAtlas(atlas, xform, tex, colors, count, SkBlendMode::kModulate, cull, paint);
}
static void draw_atlas_sim(SkCanvas* canvas, SkImage* atlas, const SkRSXform xform[],
const SkRect tex[], const SkColor colors[], int count, const SkRect* cull,
const SkPaint* paint) {
for (int i = 0; i < count; ++i) {
SkMatrix matrix;
matrix.setRSXform(xform[i]);
canvas->save();
canvas->concat(matrix);
canvas->drawImageRect(atlas, tex[i], tex[i].makeOffset(-tex[i].x(), -tex[i].y()), paint,
SkCanvas::kFast_SrcRectConstraint);
canvas->restore();
}
}
static sk_sp<SkImage> make_atlas(int atlasSize, int cellSize) {
SkImageInfo info = SkImageInfo::MakeN32Premul(atlasSize, atlasSize);
auto surface(SkSurface::MakeRaster(info));
SkCanvas* canvas = surface->getCanvas();
SkPaint paint;
paint.setAntiAlias(true);
SkRandom rand;
const SkScalar half = cellSize * SK_ScalarHalf;
const char* s = "01234567890!@#$%^&*=+<>?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
paint.setTextSize(28);
paint.setTextAlign(SkPaint::kCenter_Align);
int i = 0;
for (int y = 0; y < atlasSize; y += cellSize) {
for (int x = 0; x < atlasSize; x += cellSize) {
paint.setColor(rand.nextU());
paint.setAlpha(0xFF);
int index = i % strlen(s);
canvas->drawText(&s[index], 1, x + half, y + half + half/2, paint);
i += 1;
}
}
return surface->makeImageSnapshot();
}
class DrawAtlasDrawable : public SkDrawable {
enum {
kMaxScale = 2,
kCellSize = 32,
kAtlasSize = 512,
};
struct Rec {
SkPoint fCenter;
SkVector fVelocity;
SkScalar fScale;
SkScalar fDScale;
SkScalar fRadian;
SkScalar fDRadian;
SkScalar fAlpha;
SkScalar fDAlpha;
void advance(const SkRect& bounds) {
fCenter += fVelocity;
if (fCenter.fX > bounds.right()) {
SkASSERT(fVelocity.fX > 0);
fVelocity.fX = -fVelocity.fX;
} else if (fCenter.fX < bounds.left()) {
SkASSERT(fVelocity.fX < 0);
fVelocity.fX = -fVelocity.fX;
}
if (fCenter.fY > bounds.bottom()) {
if (fVelocity.fY > 0) {
fVelocity.fY = -fVelocity.fY;
}
} else if (fCenter.fY < bounds.top()) {
if (fVelocity.fY < 0) {
fVelocity.fY = -fVelocity.fY;
}
}
fScale += fDScale;
if (fScale > 2 || fScale < SK_Scalar1/2) {
fDScale = -fDScale;
}
fRadian += fDRadian;
fRadian = SkScalarMod(fRadian, 2 * SK_ScalarPI);
fAlpha += fDAlpha;
if (fAlpha > 1) {
fAlpha = 1;
fDAlpha = -fDAlpha;
} else if (fAlpha < 0) {
fAlpha = 0;
fDAlpha = -fDAlpha;
}
}
SkRSXform asRSXform() const {
return SkRSXform::MakeFromRadians(fScale, fRadian, fCenter.x(), fCenter.y(),
SkScalarHalf(kCellSize), SkScalarHalf(kCellSize));
}
};
DrawAtlasProc fProc;
enum {
N = 256,
};
sk_sp<SkImage> fAtlas;
Rec fRec[N];
SkRect fTex[N];
SkRect fBounds;
bool fUseColors;
public:
DrawAtlasDrawable(DrawAtlasProc proc, const SkRect& r)
: fProc(proc), fBounds(r), fUseColors(false)
{
SkRandom rand;
fAtlas = make_atlas(kAtlasSize, kCellSize);
const SkScalar kMaxSpeed = 5;
const SkScalar cell = SkIntToScalar(kCellSize);
int i = 0;
for (int y = 0; y < kAtlasSize; y += kCellSize) {
for (int x = 0; x < kAtlasSize; x += kCellSize) {
const SkScalar sx = SkIntToScalar(x);
const SkScalar sy = SkIntToScalar(y);
fTex[i].setXYWH(sx, sy, cell, cell);
fRec[i].fCenter.set(sx + cell/2, sy + 3*cell/4);
fRec[i].fVelocity.fX = rand.nextSScalar1() * kMaxSpeed;
fRec[i].fVelocity.fY = rand.nextSScalar1() * kMaxSpeed;
fRec[i].fScale = 1;
fRec[i].fDScale = rand.nextSScalar1() / 16;
fRec[i].fRadian = 0;
fRec[i].fDRadian = rand.nextSScalar1() / 8;
fRec[i].fAlpha = rand.nextUScalar1();
fRec[i].fDAlpha = rand.nextSScalar1() / 10;
i += 1;
}
}
}
void toggleUseColors() {
fUseColors = !fUseColors;
}
protected:
void onDraw(SkCanvas* canvas) override {
SkRSXform xform[N];
SkColor colors[N];
for (int i = 0; i < N; ++i) {
fRec[i].advance(fBounds);
xform[i] = fRec[i].asRSXform();
if (fUseColors) {
colors[i] = SkColorSetARGB((int)(fRec[i].fAlpha * 0xFF), 0xFF, 0xFF, 0xFF);
}
}
SkPaint paint;
paint.setFilterQuality(kLow_SkFilterQuality);
const SkRect cull = this->getBounds();
const SkColor* colorsPtr = fUseColors ? colors : nullptr;
fProc(canvas, fAtlas.get(), xform, fTex, colorsPtr, N, &cull, &paint);
}
SkRect onGetBounds() override {
const SkScalar border = kMaxScale * kCellSize;
SkRect r = fBounds;
r.outset(border, border);
return r;
}
private:
typedef SkDrawable INHERITED;
};
class DrawAtlasView : public SampleView {
const char* fName;
DrawAtlasDrawable* fDrawable;
public:
DrawAtlasView(const char name[], DrawAtlasProc proc) : fName(name) {
fDrawable = new DrawAtlasDrawable(proc, SkRect::MakeWH(640, 480));
}
~DrawAtlasView() override {
fDrawable->unref();
}
protected:
bool onQuery(SkEvent* evt) override {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, fName);
return true;
}
SkUnichar uni;
if (SampleCode::CharQ(*evt, &uni)) {
switch (uni) {
case 'C': fDrawable->toggleUseColors(); this->inval(nullptr); return true;
default: break;
}
}
return this->INHERITED::onQuery(evt);
}
void onDrawContent(SkCanvas* canvas) override {
canvas->drawDrawable(fDrawable);
}
bool onAnimate(const SkAnimTimer&) override {
return true;
}
#if 0
// TODO: switch over to use this for our animation
bool onAnimate(const SkAnimTimer& timer) override {
SkScalar angle = SkDoubleToScalar(fmod(timer.secs() * 360 / 24, 360));
fAnimatingDrawable->setSweep(angle);
return true;
}
#endif
private:
typedef SampleView INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_SAMPLE( return new DrawAtlasView("DrawAtlas", draw_atlas); )
DEF_SAMPLE( return new DrawAtlasView("DrawAtlasSim", draw_atlas_sim); )