image_shader.cpp File Reference

#include "gm/gm.h"
#include "include/codec/SkEncodedImageFormat.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkData.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPicture.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkShader.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkSurface.h"
#include "include/core/SkTileMode.h"
#include "include/core/SkTypes.h"
#include "include/encode/SkPngEncoder.h"
#include "include/gpu/GpuTypes.h"
#include "include/gpu/ganesh/SkSurfaceGanesh.h"
#include <utility>
#include "tools/ToolUtils.h"

Go to the source code of this file.

Classes
class	ImageShaderGM

Typedefs
typedef sk_sp< SkImage >(*	ImageMakerProc) (GrRecordingContext *, SkPicture *, const SkImageInfo &)

Functions
static void	draw_something (SkCanvas *canvas, const SkRect &bounds)
static sk_sp< SkImage >	make_raster (GrRecordingContext *, SkPicture *pic, const SkImageInfo &info)
static sk_sp< SkImage >	make_texture (GrRecordingContext *ctx, SkPicture *pic, const SkImageInfo &info)
static sk_sp< SkImage >	make_pict_gen (GrRecordingContext *, SkPicture *pic, const SkImageInfo &info)
static sk_sp< SkImage >	make_encode_gen (GrRecordingContext *ctx, SkPicture *pic, const SkImageInfo &info)
static sk_sp< SkImage >	make_checker_img (int w, int h, SkColor c0, SkColor c1, int size)
	DEF_SIMPLE_GM (drawimage_sampling, canvas, 500, 500)
	DEF_SIMPLE_GM (textureimage_and_shader, canvas, 100, 50)

Variables
const ImageMakerProc	gProcs []

Typedef Documentation

ImageMakerProc

typedef sk_sp< SkImage >(* ImageMakerProc) (GrRecordingContext *, SkPicture *, const SkImageInfo &)

Definition at line 47 of file image_shader.cpp.

Function Documentation

DEF_SIMPLE_GM() [1/2]

DEF_SIMPLE_GM	(	drawimage_sampling	,
		canvas	,
		500	,
		500
	)

Definition at line 170 of file image_shader.cpp.

                                                    {
    constexpr int N = 256;
    constexpr float kScale = 1.0f/6;
    const SkRect dst = {0, 0, kScale*N, kScale*N};
 
    auto img = make_checker_img(N, N, SK_ColorBLACK, SK_ColorWHITE, 7)->withDefaultMipmaps();
    const SkRect src = SkRect::MakeIWH(img->width(), img->height());
 
    SkMatrix mx = SkMatrix::RectToRect(src, dst);
 
    SkPaint paint;
 
    for (auto mm : {SkMipmapMode::kNone, SkMipmapMode::kNearest, SkMipmapMode::kLinear}) {
        for (auto fm : {SkFilterMode::kNearest, SkFilterMode::kLinear}) {
            SkSamplingOptions sampling(fm, mm);
 
            canvas->save();
 
            canvas->save();
            canvas->concat(mx);
            canvas->drawImage(img.get(), 0, 0, sampling);
            canvas->restore();
 
            canvas->translate(dst.width() + 4, 0);
 
            paint.setShader(img->makeShader(SkTileMode::kClamp, SkTileMode::kClamp, sampling, &mx));
            canvas->drawRect(dst, paint);
 
            canvas->translate(dst.width() + 4, 0);
 
            canvas->drawImageRect(img.get(), src, dst, sampling, nullptr,
                                  SkCanvas::kFast_SrcRectConstraint);
            canvas->restore();
 
            canvas->translate(0, dst.height() + 8);
        }
    }
 
}

DEF_SIMPLE_GM() [2/2]

DEF_SIMPLE_GM	(	textureimage_and_shader	,
		canvas	,
		100	,
		50
	)

Definition at line 211 of file image_shader.cpp.

                                                        {
    canvas->clear(SK_ColorGREEN);
 
    sk_sp<SkImage> image;
    if (canvas->getSurface()) {
        image = canvas->getSurface()->makeImageSnapshot();
        canvas->clear(SK_ColorRED);
    } else {
        auto greenSurface = SkSurfaces::Raster(SkImageInfo::MakeN32Premul(50, 50));
        greenSurface->getCanvas()->clear(SK_ColorGREEN);
        image = greenSurface->makeImageSnapshot();
    }
 
    // At this point, 'image' contains a green image. If our original canvas is GPU-backed, then
    // the snapped image will be a (GPU) texture. We will try to draw that image to a non-GPU
    // surface, to ensure that we get automatic read-back. If all goes well, we will get a pure
    // green result. If either draw fails, we'll get red (most likely).
 
    auto surface = SkSurfaces::Raster(SkImageInfo::MakeN32Premul(50, 50));
 
    // First, use drawImage:
    surface->getCanvas()->clear(SK_ColorRED);
    surface->getCanvas()->drawImage(image, 0, 0);
    canvas->drawImage(surface->makeImageSnapshot(), 0, 0);
 
    // Now, use an image shader:
    SkPaint paint;
    paint.setShader(image->makeShader(SkSamplingOptions()));
    surface->getCanvas()->clear(SK_ColorRED);
    surface->getCanvas()->drawPaint(paint);
    canvas->drawImage(surface->makeImageSnapshot(), 50, 0);
}

draw_something()

static void draw_something ( SkCanvas *  canvas, const SkRect &  bounds  )

static

Definition at line 35 of file image_shader.cpp.

                                                                   {
    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setColor(SK_ColorRED);
    paint.setStyle(SkPaint::kStroke_Style);
    paint.setStrokeWidth(10);
    canvas->drawRect(bounds, paint);
    paint.setStyle(SkPaint::kFill_Style);
    paint.setColor(SK_ColorBLUE);
    canvas->drawOval(bounds, paint);
}

make_checker_img()

static sk_sp< SkImage > make_checker_img ( int  w, int  h, SkColor  c0, SkColor  c1, int  size  )

static

Definition at line 164 of file image_shader.cpp.

                                                                                       {
    SkBitmap bm = ToolUtils::create_checkerboard_bitmap(w, h, c0, c1, size);
    bm.setImmutable();
    return bm.asImage();
}

make_encode_gen()

static sk_sp< SkImage > make_encode_gen ( GrRecordingContext *  ctx, SkPicture *  pic, const SkImageInfo &  info  )

static

Definition at line 84 of file image_shader.cpp.

                                                               {
    sk_sp<SkImage> src(make_raster(ctx, pic, info));
    if (!src) {
        return nullptr;
    }
    sk_sp<SkData> encoded = SkPngEncoder::Encode(nullptr, src.get(), {});
    if (!encoded) {
        return nullptr;
    }
    return SkImages::DeferredFromEncodedData(std::move(encoded));
}

make_pict_gen()

static sk_sp< SkImage > make_pict_gen ( GrRecordingContext *  , SkPicture *  pic, const SkImageInfo &  info  )

static

Definition at line 73 of file image_shader.cpp.

                                                             {
    return SkImages::DeferredFromPicture(sk_ref_sp(pic),
                                         info.dimensions(),
                                         nullptr,
                                         nullptr,
                                         SkImages::BitDepth::kU8,
                                         SkColorSpace::MakeSRGB());
}

make_raster()

static sk_sp< SkImage > make_raster ( GrRecordingContext *  , SkPicture *  pic, const SkImageInfo &  info  )

static

Definition at line 49 of file image_shader.cpp.

                                                           {
    auto surface(SkSurfaces::Raster(info));
    surface->getCanvas()->clear(0);
    surface->getCanvas()->drawPicture(pic);
    return surface->makeImageSnapshot();
}

make_texture()

static sk_sp< SkImage > make_texture ( GrRecordingContext *  ctx, SkPicture *  pic, const SkImageInfo &  info  )

static

Definition at line 58 of file image_shader.cpp.

                                                            {
    if (!ctx) {
        return nullptr;
    }
    auto surface(SkSurfaces::RenderTarget(ctx, skgpu::Budgeted::kNo, info));
    if (!surface) {
        return nullptr;
    }
    surface->getCanvas()->clear(0);
    surface->getCanvas()->drawPicture(pic);
    return surface->makeImageSnapshot();
}

Variable Documentation

gProcs

const ImageMakerProc gProcs[]

Initial value:

= {
    make_raster,
    make_texture,
    make_pict_gen,
    make_encode_gen,
}

Definition at line 98 of file image_shader.cpp.

                                {
    make_raster,
    make_texture,
    make_pict_gen,
    make_encode_gen,
};