skia2/gm/bitmappremul.cpp

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/*
* 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 "SkColorData.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; )
}