skia2/gm/aaxfermodes.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

285 lines
10 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"
#include "SkArithmeticMode.h"
#include "SkPath.h"
#include "SkShader.h"
#include "SkXfermode.h"
enum {
kXfermodeCount = SkXfermode::kLastMode + 2, // All xfermodes plus arithmetic mode.
kShapeSize = 22,
kShapeSpacing = 36,
kShapeTypeSpacing = 4 * kShapeSpacing / 3,
kPaintSpacing = 4 * kShapeTypeSpacing,
kLabelSpacing = 3 * kShapeSize,
kMargin = kShapeSpacing / 2,
kXfermodeTypeSpacing = kLabelSpacing + 2 * kPaintSpacing + kShapeTypeSpacing,
kTitleSpacing = 3 * kShapeSpacing / 4,
kSubtitleSpacing = 5 * kShapeSpacing / 8
};
constexpr SkColor kBGColor = 0xc8d2b887;
constexpr SkColor kShapeColors[2] = {
0x82ff0080, // input color unknown
0xff00ffff, // input color opaque
};
enum Shape {
kSquare_Shape,
kDiamond_Shape,
kOval_Shape,
kConcave_Shape,
kLast_Shape = kConcave_Shape
};
namespace skiagm {
/**
* Verifies AA works properly on all Xfermodes, including arithmetic, with both opaque and unknown
* src colors.
*/
class AAXfermodesGM : public GM {
public:
AAXfermodesGM() {}
protected:
enum DrawingPass {
kCheckerboard_Pass,
kBackground_Pass,
kShape_Pass
};
SkString onShortName() override {
return SkString("aaxfermodes");
}
SkISize onISize() override {
return SkISize::Make(2 * kMargin + 2 * kXfermodeTypeSpacing -
(kXfermodeTypeSpacing - (kLabelSpacing + 2 * kPaintSpacing)),
2 * kMargin + kTitleSpacing + kSubtitleSpacing +
(1 + SkXfermode::kLastCoeffMode) * kShapeSpacing);
}
void onOnceBeforeDraw() override {
fLabelPaint.setAntiAlias(true);
sk_tool_utils::set_portable_typeface(&fLabelPaint);
fLabelPaint.setTextSize(5 * kShapeSize/8);
fLabelPaint.setSubpixelText(true);
constexpr SkScalar radius = -1.4f * kShapeSize/2;
SkPoint pts[4] = {
{-radius, 0},
{0, -1.33f * radius},
{radius, 0},
{0, 1.33f * radius}
};
fOval.moveTo(pts[0]);
fOval.quadTo(pts[1], pts[2]);
fOval.quadTo(pts[3], pts[0]);
fConcave.moveTo(-radius, 0);
fConcave.quadTo(0, 0, 0, -radius);
fConcave.quadTo(0, 0, radius, 0);
fConcave.quadTo(0, 0, 0, radius);
fConcave.quadTo(0, 0, -radius, 0);
fConcave.close();
}
void draw_pass(SkCanvas* canvas, DrawingPass drawingPass) {
SkRect clipRect =
{ -kShapeSize*11/16, -kShapeSize*11/16, kShapeSize*11/16, kShapeSize*11/16 };
canvas->save();
if (kCheckerboard_Pass == drawingPass) {
canvas->translate(kMargin, kMargin);
}
canvas->translate(0, kTitleSpacing);
for (size_t xfermodeSet = 0; xfermodeSet < 2; xfermodeSet++) {
size_t firstMode = (SkXfermode::kLastCoeffMode + 1) * xfermodeSet;
canvas->save();
if (kShape_Pass == drawingPass) {
fLabelPaint.setTextAlign(SkPaint::kCenter_Align);
canvas->drawText("Src Unknown", sizeof("Src Unknown") - 1,
kLabelSpacing + kShapeTypeSpacing * 1.5f + kShapeSpacing / 2,
kSubtitleSpacing / 2 + fLabelPaint.getTextSize() / 3, fLabelPaint);
canvas->drawText("Src Opaque", sizeof("Src Opaque") - 1,
kLabelSpacing + kShapeTypeSpacing * 1.5f + kShapeSpacing / 2 +
kPaintSpacing, kSubtitleSpacing / 2 + fLabelPaint.getTextSize() / 3,
fLabelPaint);
}
canvas->translate(0, kSubtitleSpacing + kShapeSpacing/2);
for (size_t m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
SkXfermode::Mode mode = static_cast<SkXfermode::Mode>(firstMode + m);
canvas->save();
if (kShape_Pass == drawingPass) {
this->drawModeName(canvas, mode);
}
canvas->translate(kLabelSpacing + kShapeSpacing/2, 0);
for (size_t colorIdx = 0; colorIdx < SK_ARRAY_COUNT(kShapeColors); colorIdx++) {
SkPaint paint;
this->setupShapePaint(canvas, kShapeColors[colorIdx], mode, &paint);
SkASSERT(colorIdx == 0 || 255 == paint.getAlpha());
canvas->save();
for (size_t shapeIdx = 0; shapeIdx <= kLast_Shape; shapeIdx++) {
if (kShape_Pass != drawingPass) {
canvas->save();
canvas->clipRect(clipRect);
if (kCheckerboard_Pass == drawingPass) {
sk_tool_utils::draw_checkerboard(canvas, 0xffffffff, 0xffc6c3c6,
10);
} else {
SkASSERT(kBackground_Pass == drawingPass);
canvas->drawColor(kBGColor, SkXfermode::kSrc_Mode);
}
canvas->restore();
} else {
this->drawShape(canvas, static_cast<Shape>(shapeIdx), paint, mode);
}
canvas->translate(kShapeTypeSpacing, 0);
}
canvas->restore();
canvas->translate(kPaintSpacing, 0);
}
canvas->restore();
canvas->translate(0, kShapeSpacing);
}
canvas->restore();
canvas->translate(kXfermodeTypeSpacing, 0);
}
canvas->restore();
}
void onDraw(SkCanvas* canvas) override {
draw_pass(canvas, kCheckerboard_Pass);
canvas->saveLayer(nullptr, nullptr);
canvas->translate(kMargin, kMargin);
draw_pass(canvas, kBackground_Pass);
SkPaint titlePaint(fLabelPaint);
titlePaint.setTextSize(9 * titlePaint.getTextSize() / 8);
titlePaint.setFakeBoldText(true);
titlePaint.setTextAlign(SkPaint::kCenter_Align);
canvas->drawText("Porter Duff", sizeof("Porter Duff") - 1,
kLabelSpacing + 4 * kShapeTypeSpacing,
kTitleSpacing / 2 + titlePaint.getTextSize() / 3, titlePaint);
canvas->drawText("Advanced", sizeof("Advanced") - 1,
kXfermodeTypeSpacing + kLabelSpacing + 4 * kShapeTypeSpacing,
kTitleSpacing / 2 + titlePaint.getTextSize() / 3, titlePaint);
draw_pass(canvas, kShape_Pass);
canvas->restore();
}
void drawModeName(SkCanvas* canvas, SkXfermode::Mode mode) {
const char* modeName = mode <= SkXfermode::kLastMode ? SkXfermode::ModeName(mode)
: "Arithmetic";
fLabelPaint.setTextAlign(SkPaint::kRight_Align);
canvas->drawText(modeName, strlen(modeName), kLabelSpacing - kShapeSize / 4,
fLabelPaint.getTextSize() / 4, fLabelPaint);
}
void setupShapePaint(SkCanvas* canvas, GrColor color, SkXfermode::Mode mode, SkPaint* paint) {
paint->setColor(color);
if (mode == SkXfermode::kPlus_Mode) {
// Check for overflow, otherwise we might get confusing AA artifacts.
int maxSum = SkTMax(SkTMax(SkColorGetA(kBGColor) + SkColorGetA(color),
SkColorGetR(kBGColor) + SkColorGetR(color)),
SkTMax(SkColorGetG(kBGColor) + SkColorGetG(color),
SkColorGetB(kBGColor) + SkColorGetB(color)));
if (maxSum > 255) {
SkPaint dimPaint;
dimPaint.setAntiAlias(false);
dimPaint.setXfermode(SkXfermode::Make(SkXfermode::kDstIn_Mode));
if (255 != paint->getAlpha()) {
// Dim the src and dst colors.
dimPaint.setARGB(255 * 255 / maxSum, 0, 0, 0);
paint->setAlpha(255 * paint->getAlpha() / maxSum);
} else {
// Just clear the dst, we need to preserve the paint's opacity.
dimPaint.setARGB(0, 0, 0, 0);
}
canvas->drawRectCoords(-kShapeSpacing/2, -kShapeSpacing/2,
kShapeSpacing/2 + 3 * kShapeTypeSpacing,
kShapeSpacing/2, dimPaint);
}
}
}
void drawShape(SkCanvas* canvas, Shape shape, const SkPaint& paint, SkXfermode::Mode mode) {
SkPaint shapePaint(paint);
shapePaint.setAntiAlias(kSquare_Shape != shape);
sk_sp<SkXfermode> xfermode;
if (mode <= SkXfermode::kLastMode) {
xfermode = SkXfermode::Make(mode);
} else {
xfermode = SkArithmeticMode::Make(+1.0f, +0.25f, -0.5f, +0.1f);
}
shapePaint.setXfermode(std::move(xfermode));
switch (shape) {
case kSquare_Shape:
canvas->drawRectCoords(-kShapeSize/2, -kShapeSize/2, kShapeSize/2, kShapeSize/2,
shapePaint);
break;
case kDiamond_Shape:
canvas->save();
canvas->rotate(45);
canvas->drawRectCoords(-kShapeSize/2, -kShapeSize/2, kShapeSize/2, kShapeSize/2,
shapePaint);
canvas->restore();
break;
case kOval_Shape:
canvas->save();
canvas->rotate(static_cast<SkScalar>((511 * mode + 257) % 360));
canvas->drawPath(fOval, shapePaint);
canvas->restore();
break;
case kConcave_Shape:
canvas->drawPath(fConcave, shapePaint);
break;
default:
SkFAIL("Invalid shape.");
}
}
private:
SkPaint fLabelPaint;
SkPath fOval;
SkPath fConcave;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static GM* MyFactory(void*) { return new AAXfermodesGM; }
static GMRegistry reg(MyFactory);
}