bitmappremul.cpp File Reference

#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"

Go to the source code of this file.

Classes
class	skiagm::BitmapPremulGM

Namespaces
namespace	skiagm

Functions
static void	init_bitmap (SkColorType ct, SkBitmap *bitmap)
static sk_sp< SkImage >	make_argb8888_gradient ()
static sk_sp< SkImage >	make_argb4444_gradient ()
static sk_sp< SkImage >	make_argb8888_stripes ()
static sk_sp< SkImage >	make_argb4444_stripes ()
static sk_sp< SkImage >	make_out_of_gamut_image (SkColorType ct)
	DEF_SIMPLE_GM (image_out_of_gamut, canvas, 2 *kBoxSize+3 *kPadding, kBoxSize+2 *kPadding)

Variables
constexpr int	SLIDE_SIZE = 256
static constexpr int	kBoxSize = 31
static constexpr int	kPadding = 5

Function Documentation

DEF_SIMPLE_GM()

DEF_SIMPLE_GM	(	image_out_of_gamut	,
		canvas	,
		2 *kBoxSize+3 *	kPadding,
		kBoxSize+2 *	kPadding
	)

Definition at line 132 of file bitmappremul.cpp.

                                                                                                {
    // This GM draws an image with out-of-gamut colors (RGB > A). Historically, Skia assumed this
    // was impossible, and contained numerous asserts and optimizations that would break if the
    // rule were violated. With color spaces and/or SkSL shaders (among other things), it's no
    // longer reasonable to make this claim. To catch issues with legacy blitters, this draws both
    // RGBA and BGRA. (This ensures that we always hit the N32 -> N32 case).
    canvas->clear(SK_ColorGRAY);
 
    auto rgba = make_out_of_gamut_image(kRGBA_8888_SkColorType),
         bgra = make_out_of_gamut_image(kBGRA_8888_SkColorType);
 
    canvas->translate(kPadding, kPadding);
    canvas->drawImage(rgba, 0, 0);
    canvas->translate(kBoxSize + kPadding, 0);
    canvas->drawImage(bgra, 0, 0);
}

init_bitmap()

static void init_bitmap ( SkColorType  ct, SkBitmap *  bitmap  )

static

Definition at line 32 of file bitmappremul.cpp.

                                                          {
    bitmap->allocPixels(SkImageInfo::Make(SLIDE_SIZE, SLIDE_SIZE, ct,
                                          kPremul_SkAlphaType));
    bitmap->eraseColor(SK_ColorWHITE);
}

make_argb4444_gradient()

static sk_sp< SkImage > make_argb4444_gradient ( )

static

Definition at line 50 of file bitmappremul.cpp.

                                               {
    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, SkSamplingOptions(), &paint);
    return bitmap.asImage();
}

make_argb4444_stripes()

static sk_sp< SkImage > make_argb4444_stripes ( )

static

Definition at line 79 of file bitmappremul.cpp.

                                              {
    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, SkSamplingOptions(), &paint);
    return bitmap.asImage();
}

make_argb8888_gradient()

static sk_sp< SkImage > make_argb8888_gradient ( )

static

Definition at line 38 of file bitmappremul.cpp.

                                               {
    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();
}

make_argb8888_stripes()

static sk_sp< SkImage > make_argb8888_stripes ( )

static

Definition at line 60 of file bitmappremul.cpp.

                                              {
    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();
}

make_out_of_gamut_image()

static sk_sp< SkImage > make_out_of_gamut_image ( SkColorType  ct )

static

Definition at line 120 of file bitmappremul.cpp.

                                                              {
    SkBitmap bmp;
    // Odd dimensions so that we hit the different implementation in the SIMD tail handling
    bmp.allocPixels(SkImageInfo::Make(kBoxSize, kBoxSize, ct, kPremul_SkAlphaType));
    for (int y = 0; y < kBoxSize; ++y) {
        for (int x = 0; x < kBoxSize; ++x) {
            *bmp.getAddr32(x, y) = (0x40000000 | ((x * 8) << 8) | ((y * 8) << 0));
        }
    }
    return bmp.asImage();
}

Variable Documentation

kBoxSize

constexpr int kBoxSize = 31

staticconstexpr

Definition at line 117 of file bitmappremul.cpp.

kPadding

constexpr int kPadding = 5

staticconstexpr

Definition at line 118 of file bitmappremul.cpp.

SLIDE_SIZE

constexpr int SLIDE_SIZE = 256

constexpr

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.

Definition at line 30 of file bitmappremul.cpp.