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/*
* 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 "gm.h"
#include "SkCanvas.h"
#include "SkRSXform.h"
#include "SkSurface.h"
class DrawAtlasGM : public skiagm::GM {
static sk_sp<SkImage> MakeAtlas(SkCanvas* caller, const SkRect& target) {
SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
auto surface(caller->makeSurface(info));
if (nullptr == surface) {
surface = SkSurface::MakeRaster(info);
}
SkCanvas* canvas = surface->getCanvas();
// draw red everywhere, but we don't expect to see it in the draw, testing the notion
// that drawAtlas draws a subset-region of the atlas.
canvas->clear(SK_ColorRED);
SkPaint paint;
paint.setXfermodeMode(SkXfermode::kClear_Mode);
SkRect r(target);
r.inset(-1, -1);
// zero out a place (with a 1-pixel border) to land our drawing.
canvas->drawRect(r, paint);
paint.setXfermode(nullptr);
paint.setColor(SK_ColorBLUE);
paint.setAntiAlias(true);
canvas->drawOval(target, paint);
return surface->makeImageSnapshot();
}
public:
DrawAtlasGM() {}
protected:
SkString onShortName() override {
return SkString("draw-atlas");
}
SkISize onISize() override {
return SkISize::Make(640, 480);
}
void onDraw(SkCanvas* canvas) override {
const SkRect target = { 50, 50, 80, 90 };
auto atlas = MakeAtlas(canvas, target);
const struct {
SkScalar fScale;
SkScalar fDegrees;
SkScalar fTx;
SkScalar fTy;
void apply(SkRSXform* xform) const {
const SkScalar rad = SkDegreesToRadians(fDegrees);
xform->fSCos = fScale * SkScalarCos(rad);
xform->fSSin = fScale * SkScalarSin(rad);
xform->fTx = fTx;
xform->fTy = fTy;
}
} rec[] = {
{ 1, 0, 10, 10 }, // just translate
{ 2, 0, 110, 10 }, // scale + translate
{ 1, 30, 210, 10 }, // rotate + translate
{ 2, -30, 310, 30 }, // scale + rotate + translate
};
const int N = SK_ARRAY_COUNT(rec);
SkRSXform xform[N];
SkRect tex[N];
SkColor colors[N];
for (int i = 0; i < N; ++i) {
rec[i].apply(&xform[i]);
tex[i] = target;
colors[i] = 0x80FF0000 + (i * 40 * 256);
}
SkPaint paint;
paint.setFilterQuality(kLow_SkFilterQuality);
paint.setAntiAlias(true);
canvas->drawAtlas(atlas.get(), xform, tex, N, nullptr, &paint);
canvas->translate(0, 100);
canvas->drawAtlas(atlas.get(), xform, tex, colors, N, SkXfermode::kSrcIn_Mode, nullptr, &paint);
}
private:
typedef GM INHERITED;
};
DEF_GM( return new DrawAtlasGM; )
///////////////////////////////////////////////////////////////////////////////////////////////////
#include "SkPath.h"
#include "SkPathMeasure.h"
static void draw_text_on_path_rigid(SkCanvas* canvas, const void* text, size_t length,
const SkPoint xy[], const SkPath& path, const SkPaint& paint) {
SkPathMeasure meas(path, false);
int count = paint.countText(text, length);
size_t size = count * (sizeof(SkRSXform) + sizeof(SkScalar));
SkAutoSMalloc<512> storage(size);
SkRSXform* xform = (SkRSXform*)storage.get();
SkScalar* widths = (SkScalar*)(xform + count);
paint.getTextWidths(text, length, widths);
for (int i = 0; i < count; ++i) {
// we want to position each character on the center of its advance
const SkScalar offset = SkScalarHalf(widths[i]);
SkPoint pos;
SkVector tan;
if (!meas.getPosTan(xy[i].x() + offset, &pos, &tan)) {
pos = xy[i];
tan.set(1, 0);
}
xform[i].fSCos = tan.x();
xform[i].fSSin = tan.y();
xform[i].fTx = pos.x() - tan.y() * xy[i].y() - tan.x() * offset;
xform[i].fTy = pos.y() + tan.x() * xy[i].y() - tan.y() * offset;
}
// Compute a conservative bounds so we can cull the draw
const SkRect font = paint.getFontBounds();
const SkScalar max = SkTMax(SkTMax(SkScalarAbs(font.fLeft), SkScalarAbs(font.fRight)),
SkTMax(SkScalarAbs(font.fTop), SkScalarAbs(font.fBottom)));
const SkRect bounds = path.getBounds().makeOutset(max, max);
canvas->drawTextRSXform(text, length, &xform[0], &bounds, paint);
if (true) {
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
canvas->drawRect(bounds, p);
}
}
DEF_SIMPLE_GM(drawTextRSXform, canvas, 860, 860) {
const char text0[] = "ABCDFGHJKLMNOPQRSTUVWXYZ";
const int N = sizeof(text0) - 1;
SkPoint pos[N];
SkPaint paint;
paint.setAntiAlias(true);
paint.setTextSize(100);
SkScalar x = 0;
for (int i = 0; i < N; ++i) {
pos[i].set(x, 0);
x += paint.measureText(&text0[i], 1);
}
SkPath path;
path.addOval(SkRect::MakeXYWH(160, 160, 540, 540));
draw_text_on_path_rigid(canvas, text0, N, pos, path, paint);
paint.setStyle(SkPaint::kStroke_Style);
canvas->drawPath(path, paint);
}
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