skia2/gm/bitmappremul.cpp
Mike Reed 6dbeac51b4 Begin to hide drawBitmap
... now that bitmap
- converts to image with just bitmap.asImage()
- canvas *always* converts bitmaps to images before they are drawn

Bug: skia:10037
Change-Id: I24292f62e0fd072b3b810d974d0fe5c6d9b9a68d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353582
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2021-01-13 19:40:45 +00:00

120 lines
3.5 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/gm.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkBlendMode.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorPriv.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkPaint.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypes.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;
static void init_bitmap(SkColorType ct, SkBitmap* bitmap) {
bitmap->allocPixels(SkImageInfo::Make(SLIDE_SIZE, SLIDE_SIZE, ct,
kPremul_SkAlphaType));
bitmap->eraseColor(SK_ColorWHITE);
}
static sk_sp<SkImage> make_argb8888_gradient() {
SkBitmap bitmap;
init_bitmap(kN32_SkColorType, &bitmap);
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(y, y, y, y);
}
}
return bitmap.asImage();
}
static sk_sp<SkImage> make_argb4444_gradient() {
SkBitmap bitmap;
init_bitmap(kARGB_4444_SkColorType, &bitmap);
// Using draw rather than readPixels to suppress dither
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc);
SkCanvas{ bitmap }.drawImage(make_argb8888_gradient(), 0, 0, &paint);
return bitmap.asImage();
}
static sk_sp<SkImage> 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.asImage();
}
static sk_sp<SkImage> make_argb4444_stripes() {
SkBitmap bitmap;
init_bitmap(kARGB_4444_SkColorType, &bitmap);
// Using draw rather than readPixels to suppress dither
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc);
SkCanvas{ bitmap }.drawImage(make_argb8888_stripes(), 0, 0, &paint);
return bitmap.asImage();
}
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->drawImage(make_argb8888_gradient(), 0, 0);
canvas->drawImage(make_argb4444_gradient(), slideSize, 0);
canvas->drawImage(make_argb8888_stripes(), 0, slideSize);
canvas->drawImage(make_argb4444_stripes(), slideSize, slideSize);
}
private:
using INHERITED = GM;
};
DEF_GM( return new BitmapPremulGM; )
} // namespace skiagm