skia2/gm/anisotropic.cpp

114 lines
3.7 KiB
C++

/*
* 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"
namespace skiagm {
// This GM exercises HighQuality anisotropic filtering.
class AnisotropicGM : public GM {
public:
AnisotropicGM() : fFilterQuality(kHigh_SkFilterQuality) {
this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
}
protected:
SkString onShortName() override { return SkString("anisotropic_hq"); }
SkISize onISize() override {
return SkISize::Make(2*kImageSize + 3*kSpacer,
kNumVertImages*kImageSize + (kNumVertImages+1)*kSpacer);
}
// Create an image consisting of lines radiating from its center
void onOnceBeforeDraw() override {
static const int kNumLines = 100;
static const SkScalar kAngleStep = 360.0f / kNumLines;
static const int kInnerOffset = 10;
fBM.allocN32Pixels(kImageSize, kImageSize, true);
SkCanvas canvas(fBM);
canvas.clear(SK_ColorWHITE);
SkPaint p;
p.setAntiAlias(true);
SkScalar angle = 0.0f, sin, cos;
canvas.translate(kImageSize/2.0f, kImageSize/2.0f);
for (int i = 0; i < kNumLines; ++i, angle += kAngleStep) {
sin = SkScalarSinCos(angle, &cos);
canvas.drawLine(cos * kInnerOffset, sin * kInnerOffset,
cos * kImageSize/2, sin * kImageSize/2, p);
}
}
void draw(SkCanvas* canvas, int x, int y, int xSize, int ySize) {
SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y),
SkIntToScalar(xSize), SkIntToScalar(ySize));
SkPaint p;
p.setFilterQuality(fFilterQuality);
canvas->drawBitmapRect(fBM, r, &p);
}
void onDraw(SkCanvas* canvas) override {
SkScalar gScales[] = { 0.9f, 0.8f, 0.75f, 0.6f, 0.5f, 0.4f, 0.25f, 0.2f, 0.1f };
SkASSERT(kNumVertImages-1 == (int)SK_ARRAY_COUNT(gScales)/2);
// Minimize vertically
for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
int height = SkScalarFloorToInt(fBM.height() * gScales[i]);
int yOff;
if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
yOff = kSpacer + i * (fBM.height() + kSpacer);
} else {
// Position the more highly squashed images with their less squashed counterparts
yOff = (SK_ARRAY_COUNT(gScales) - i) * (fBM.height() + kSpacer) - height;
}
this->draw(canvas, kSpacer, yOff, fBM.width(), height);
}
// Minimize horizontally
for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
int width = SkScalarFloorToInt(fBM.width() * gScales[i]);
int xOff, yOff;
if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
xOff = fBM.width() + 2*kSpacer;
yOff = kSpacer + i * (fBM.height() + kSpacer);
} else {
// Position the more highly squashed images with their less squashed counterparts
xOff = fBM.width() + 2*kSpacer + fBM.width() - width;
yOff = kSpacer + (SK_ARRAY_COUNT(gScales) - i - 1) * (fBM.height() + kSpacer);
}
this->draw(canvas, xOff, yOff, width, fBM.height());
}
}
private:
static const int kImageSize = 256;
static const int kSpacer = 10;
static const int kNumVertImages = 5;
SkBitmap fBM;
SkFilterQuality fFilterQuality;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM(return new AnisotropicGM;)
}