skia2/gm/clippedbitmapshaders.cpp
mtklein dbfd7ab108 Replace a lot of 'static const' with 'constexpr' or 'const'.
'static const' means, there must be at most one of these, and initialize it at
compile time if possible or runtime if necessary.  This leads to unexpected
code execution, and TSAN* will complain about races on the guard variables.

Generally 'constexpr' or 'const' are better choices.  Neither can cause races:
they're either intialized at compile time (constexpr) or intialized each time
independently (const).

This CL prefers constexpr where possible, and uses const where not.  It even
prefers constexpr over const where they don't make a difference... I want to have
lots of examples of constexpr for people to see and mimic.

The scoped-to-class static has nothing to do with any of this, and is not changed.

* Not yet on the bots, which use an older TSAN.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300623005

Review-Url: https://codereview.chromium.org/2300623005
2016-09-01 11:24:54 -07:00

126 lines
3.8 KiB
C++

/*
* Copyright 2013 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 "SkBitmap.h"
#include "SkCanvas.h"
#include "SkColor.h"
#include "SkShader.h"
namespace skiagm {
// This GM draws a 3x3 grid (with the center element excluded) of rectangles
// filled with a bitmap shader. The bitmap shader is transformed so that the
// pattern cell is at the center (excluded) region.
//
// In Repeat and Mirror mode, this tests that the bitmap shader still draws
// even though the pattern cell is outside the clip.
//
// In Clamp mode, this tests that the clamp is handled properly. For PDF,
// (and possibly other exported formats) this also "tests" that the image itself
// is not stored (well, you'll need to open it up with an external tool to
// verify that).
static SkBitmap create_bitmap() {
SkBitmap bmp;
bmp.allocN32Pixels(2, 2);
uint32_t* pixels = reinterpret_cast<uint32_t*>(bmp.getPixels());
pixels[0] = SkPreMultiplyColor(SK_ColorRED);
pixels[1] = SkPreMultiplyColor(SK_ColorGREEN);
pixels[2] = SkPreMultiplyColor(SK_ColorBLACK);
pixels[3] = SkPreMultiplyColor(SK_ColorBLUE);
return bmp;
}
constexpr SkScalar RECT_SIZE = 64;
constexpr SkScalar SLIDE_SIZE = 300;
class ClippedBitmapShadersGM : public GM {
public:
ClippedBitmapShadersGM(SkShader::TileMode mode, bool hq=false)
: fMode(mode), fHQ(hq) {
}
protected:
SkShader::TileMode fMode;
bool fHQ;
virtual SkString onShortName() {
SkString descriptor;
switch (fMode) {
case SkShader::kRepeat_TileMode:
descriptor = "tile";
break;
case SkShader::kMirror_TileMode:
descriptor = "mirror";
break;
case SkShader::kClamp_TileMode:
descriptor = "clamp";
break;
default:
SkASSERT(false);
}
descriptor.prepend("clipped-bitmap-shaders-");
if (fHQ) {
descriptor.append("-hq");
}
return descriptor;
}
virtual SkISize onISize() {
return SkISize::Make(300, 300);
}
virtual void onDraw(SkCanvas* canvas) {
SkBitmap bmp = create_bitmap();
SkMatrix s;
s.reset();
s.setScale(8, 8);
s.postTranslate(SLIDE_SIZE / 2, SLIDE_SIZE / 2);
SkPaint paint;
paint.setShader(SkShader::MakeBitmapShader(bmp, fMode, fMode, &s));
if (fHQ) {
paint.setFilterQuality(kHigh_SkFilterQuality);
}
SkScalar margin = (SLIDE_SIZE / 3 - RECT_SIZE) / 2;
for (int i = 0; i < 3; i++) {
SkScalar yOrigin = SLIDE_SIZE / 3 * i + margin;
for (int j = 0; j < 3; j++) {
SkScalar xOrigin = SLIDE_SIZE / 3 * j + margin;
if (i == 1 && j == 1) {
continue; // skip center element
}
SkRect rect = SkRect::MakeXYWH(xOrigin, yOrigin,
RECT_SIZE, RECT_SIZE);
canvas->save();
canvas->clipRect(rect);
canvas->drawRect(rect, paint);
canvas->restore();
}
}
}
private:
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kRepeat_TileMode); )
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kMirror_TileMode); )
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kClamp_TileMode); )
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kRepeat_TileMode, true); )
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kMirror_TileMode, true); )
DEF_GM( return new ClippedBitmapShadersGM(SkShader::kClamp_TileMode, true); )
}