skia2/gm/bitmappremul.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

134 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 "SkColorPriv.h"
/**
* This GM checks that bitmap pixels are unpremultiplied before being exported
* to other formats. If unpremultiplication is implemented properly, this
* GM should come out completely white. If not, this GM looks like a row of two
* greyscale gradients above a row of grey lines.
* This tests both the ARGB4444 and ARGB8888 bitmap configurations.
*/
constexpr int SLIDE_SIZE = 256;
constexpr int PIXEL_SIZE_8888 = SLIDE_SIZE / 256;
constexpr int PIXEL_SIZE_4444 = SLIDE_SIZE / 16;
static void init_bitmap(SkColorType ct, SkBitmap* bitmap) {
bitmap->allocPixels(SkImageInfo::Make(SLIDE_SIZE, SLIDE_SIZE, ct,
kPremul_SkAlphaType));
bitmap->eraseColor(SK_ColorWHITE);
}
static SkBitmap make_argb8888_gradient() {
SkBitmap bitmap;
init_bitmap(kN32_SkColorType, &bitmap);
uint8_t rowColor = 0;
for (int y = 0; y < SLIDE_SIZE; y++) {
uint32_t* dst = bitmap.getAddr32(0, y);
for (int x = 0; x < SLIDE_SIZE; x++) {
dst[x] = SkPackARGB32(rowColor, rowColor,
rowColor, rowColor);
}
if (y % PIXEL_SIZE_8888 == PIXEL_SIZE_8888 - 1) {
rowColor++;
}
}
return bitmap;
}
static SkBitmap make_argb4444_gradient() {
SkBitmap bitmap;
init_bitmap(kARGB_4444_SkColorType, &bitmap);
uint8_t rowColor = 0;
for (int y = 0; y < SLIDE_SIZE; y++) {
uint16_t* dst = bitmap.getAddr16(0, y);
for (int x = 0; x < SLIDE_SIZE; x++) {
dst[x] = SkPackARGB4444(rowColor, rowColor,
rowColor, rowColor);
}
if (y % PIXEL_SIZE_4444 == PIXEL_SIZE_4444 - 1) {
rowColor++;
}
}
return bitmap;
}
static SkBitmap make_argb8888_stripes() {
SkBitmap bitmap;
init_bitmap(kN32_SkColorType, &bitmap);
uint8_t rowColor = 0;
for (int y = 0; y < SLIDE_SIZE; y++) {
uint32_t* dst = bitmap.getAddr32(0, y);
for (int x = 0; x < SLIDE_SIZE; x++) {
dst[x] = SkPackARGB32(rowColor, rowColor,
rowColor, rowColor);
}
if (rowColor == 0) {
rowColor = 255;
} else {
rowColor = 0;
}
}
return bitmap;
}
static SkBitmap make_argb4444_stripes() {
SkBitmap bitmap;
init_bitmap(kARGB_4444_SkColorType, &bitmap);
uint8_t rowColor = 0;
for (int y = 0; y < SLIDE_SIZE; y++) {
uint16_t* dst = bitmap.getAddr16(0, y);
for (int x = 0; x < SLIDE_SIZE; x++) {
dst[x] = SkPackARGB4444(rowColor, rowColor,
rowColor, rowColor);
}
if (rowColor == 0) {
rowColor = 15;
} else {
rowColor = 0;
}
}
return bitmap;
}
namespace skiagm {
class BitmapPremulGM : public GM {
public:
BitmapPremulGM() {
this->setBGColor(SK_ColorWHITE);
}
protected:
SkString onShortName() override {
return SkString("bitmap_premul");
}
SkISize onISize() override {
return SkISize::Make(SLIDE_SIZE * 2, SLIDE_SIZE * 2);
}
void onDraw(SkCanvas* canvas) override {
SkScalar slideSize = SkIntToScalar(SLIDE_SIZE);
canvas->drawBitmap(make_argb8888_gradient(), 0, 0);
canvas->drawBitmap(make_argb4444_gradient(), slideSize, 0);
canvas->drawBitmap(make_argb8888_stripes(), 0, slideSize);
canvas->drawBitmap(make_argb4444_stripes(), slideSize, slideSize);
}
private:
typedef GM INHERITED;
};
DEF_GM( return new BitmapPremulGM; )
}