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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 "include/core/SkCanvas.h"
- #include "include/core/SkColorFilter.h"
- #include "include/core/SkColorPriv.h"
- #include "include/core/SkImage.h"
- #include "include/core/SkTime.h"
- #include "include/core/SkTypeface.h"
- #include "include/utils/SkRandom.h"
- #include "samplecode/Sample.h"
- #include "src/utils/SkUTF.h"
- #if SK_SUPPORT_GPU
- #include "include/gpu/GrContext.h"
- #include "src/gpu/GrContextPriv.h"
- #endif
- SkRandom gRand;
- static void DrawTheText(SkCanvas* canvas, const char text[], size_t length, SkScalar x, SkScalar y,
- const SkFont& font, const SkPaint& paint) {
- SkFont f(font);
- f.setSubpixel(true);
- canvas->drawSimpleText(text, length, SkTextEncoding::kUTF8, x, y, f, paint);
- }
- // This sample demonstrates the cache behavior of bitmap vs. distance field text
- // It renders variously sized text with an animated scale and rotation.
- // Specifically one should:
- // use 'D' to toggle between bitmap and distance field fonts
- // use '2' to toggle between scaling the image by 2x
- // -- this feature boosts the rendering out of the small point-size
- // SDF-text special case (which falls back to bitmap fonts for small points)
- class AnimatedTextView : public Sample {
- float fScale = 1;
- float fScaleInc = 0.1f;
- float fRotation = 0;
- int fSizeScale = 1;
- SkString name() override { return SkString("AnimatedText"); }
- bool onChar(SkUnichar uni) override {
- if ('2' == uni) {
- if (fSizeScale == 2) {
- fSizeScale = 1;
- } else {
- fSizeScale = 2;
- }
- return true;
- }
- return false;
- }
- void onDrawContent(SkCanvas* canvas) override {
- SkFont font(SkTypeface::MakeFromFile("/skimages/samplefont.ttf"));
- SkPaint paint;
- paint.setAntiAlias(true);
- paint.setFilterQuality(kMedium_SkFilterQuality);
- canvas->save();
- #if SK_SUPPORT_GPU
- GrContext* grContext = canvas->getGrContext();
- if (grContext) {
- sk_sp<SkImage> image = grContext->priv().testingOnly_getFontAtlasImage(
- GrMaskFormat::kA8_GrMaskFormat);
- canvas->drawImageRect(image,
- SkRect::MakeXYWH(512.0f, 10.0f, 512.0f, 512.0f), &paint);
- }
- #endif
- canvas->translate(180, 180);
- canvas->rotate(fRotation);
- canvas->scale(fScale, fScale);
- canvas->translate(-180, -180);
- const char* text = "Hamburgefons";
- size_t length = strlen(text);
- SkScalar y = SkIntToScalar(0);
- for (int i = 12; i <= 26; i++) {
- font.setSize(SkIntToScalar(i*fSizeScale));
- y += font.getSpacing();
- DrawTheText(canvas, text, length, SkIntToScalar(110), y, font, paint);
- }
- canvas->restore();
- font.setSize(16);
- }
- bool onAnimate(double nanos) override {
- // TODO: use nanos
- // We add noise to the scale and rotation animations to
- // keep the font atlas from falling into a steady state
- fRotation += (1.0f + gRand.nextRangeF(-0.1f, 0.1f));
- fScale += (fScaleInc + gRand.nextRangeF(-0.025f, 0.025f));
- if (fScale >= 2.0f) {
- fScaleInc = -0.1f;
- } else if (fScale <= 1.0f) {
- fScaleInc = 0.1f;
- }
- return true;
- }
- };
- DEF_SAMPLE( return new AnimatedTextView(); )
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