SkTiledImageUtils Namespace Reference

Functions
SK_API void	DrawImageRect (SkCanvas *canvas, const SkImage *image, const SkRect &src, const SkRect &dst, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
void	DrawImageRect (SkCanvas *canvas, const sk_sp< SkImage > &image, const SkRect &src, const SkRect &dst, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
void	DrawImageRect (SkCanvas *canvas, const SkImage *image, const SkRect &dst, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
void	DrawImageRect (SkCanvas *canvas, const sk_sp< SkImage > &image, const SkRect &dst, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
void	DrawImage (SkCanvas *canvas, const SkImage *image, SkScalar x, SkScalar y, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
void	DrawImage (SkCanvas *canvas, const sk_sp< SkImage > &image, SkScalar x, SkScalar y, const SkSamplingOptions &sampling={}, const SkPaint *paint=nullptr, SkCanvas::SrcRectConstraint constraint=SkCanvas::kFast_SrcRectConstraint)
SK_API void	GetImageKeyValues (const SkImage *image, uint32_t keyValues[kNumImageKeyValues])

Variables
static constexpr int	kNumImageKeyValues = 6

Detailed Description

SkTiledImageUtils' DrawImage/DrawImageRect methods are intended to be direct replacements for their SkCanvas equivalents. The SkTiledImageUtils calls will break SkBitmap-backed SkImages into smaller tiles and draw them if the original image is too large to be uploaded to the GPU. If the original image doesn't need tiling or is already gpu-backed the DrawImage/DrawImageRect calls will fall through to the matching SkCanvas call.

Function Documentation

DrawImage() [1/2]

void SkTiledImageUtils::DrawImage ( SkCanvas *  canvas, const sk_sp< SkImage > &  image, SkScalar  x, SkScalar  y, const SkSamplingOptions &  sampling = {}, const SkPaint *  paint = nullptr, SkCanvas::SrcRectConstraint  constraint = SkCanvas::kFast_SrcRectConstraint  )

inline

Definition at line 95 of file SkTiledImageUtils.h.

                                                          {},
                      const SkPaint* paint = nullptr,
                      SkCanvas::SrcRectConstraint constraint =
                              SkCanvas::kFast_SrcRectConstraint) {
    DrawImage(canvas, image.get(), x, y, sampling, paint, constraint);
}

DrawImage() [2/2]

void SkTiledImageUtils::DrawImage ( SkCanvas *  canvas, const SkImage *  image, SkScalar  x, SkScalar  y, const SkSamplingOptions &  sampling = {}, const SkPaint *  paint = nullptr, SkCanvas::SrcRectConstraint  constraint = SkCanvas::kFast_SrcRectConstraint  )

inline

Definition at line 78 of file SkTiledImageUtils.h.

                                                          {},
                      const SkPaint* paint = nullptr,
                      SkCanvas::SrcRectConstraint constraint =
                              SkCanvas::kFast_SrcRectConstraint) {
    if (!image) {
        return;
    }
 
    SkRect src = SkRect::MakeIWH(image->width(), image->height());
    SkRect dst = SkRect::MakeXYWH(x, y, image->width(), image->height());
 
    DrawImageRect(canvas, image, src, dst, sampling, paint, constraint);
}

DrawImageRect() [1/4]

void SkTiledImageUtils::DrawImageRect ( SkCanvas *  canvas, const sk_sp< SkImage > &  image, const SkRect &  dst, const SkSamplingOptions &  sampling = {}, const SkPaint *  paint = nullptr, SkCanvas::SrcRectConstraint  constraint = SkCanvas::kFast_SrcRectConstraint  )

inline

Definition at line 68 of file SkTiledImageUtils.h.

                                                              {},
                          const SkPaint* paint = nullptr,
                          SkCanvas::SrcRectConstraint constraint =
                                  SkCanvas::kFast_SrcRectConstraint) {
    DrawImageRect(canvas, image.get(), dst, sampling, paint, constraint);
}

DrawImageRect() [2/4]

void SkTiledImageUtils::DrawImageRect ( SkCanvas *  canvas, const sk_sp< SkImage > &  image, const SkRect &  src, const SkRect &  dst, const SkSamplingOptions &  sampling = {}, const SkPaint *  paint = nullptr, SkCanvas::SrcRectConstraint  constraint = SkCanvas::kFast_SrcRectConstraint  )

inline

Definition at line 41 of file SkTiledImageUtils.h.

                                                              {},
                          const SkPaint* paint = nullptr,
                          SkCanvas::SrcRectConstraint constraint =
                                  SkCanvas::kFast_SrcRectConstraint) {
    DrawImageRect(canvas, image.get(), src, dst, sampling, paint, constraint);
}

DrawImageRect() [3/4]

void SkTiledImageUtils::DrawImageRect ( SkCanvas *  canvas, const SkImage *  image, const SkRect &  dst, const SkSamplingOptions &  sampling = {}, const SkPaint *  paint = nullptr, SkCanvas::SrcRectConstraint  constraint = SkCanvas::kFast_SrcRectConstraint  )

inline

Definition at line 52 of file SkTiledImageUtils.h.

                                                              {},
                          const SkPaint* paint = nullptr,
                          SkCanvas::SrcRectConstraint constraint =
                                  SkCanvas::kFast_SrcRectConstraint) {
    if (!image) {
        return;
    }
 
    SkRect src = SkRect::MakeIWH(image->width(), image->height());
 
    DrawImageRect(canvas, image, src, dst, sampling, paint, constraint);
}

DrawImageRect() [4/4]

void SkTiledImageUtils::DrawImageRect	(	SkCanvas *	canvas,
		const SkImage *	image,
		const SkRect &	src,
		const SkRect &	dst,
		const SkSamplingOptions &	sampling = {},
		const SkPaint *	paint = nullptr,
		SkCanvas::SrcRectConstraint	constraint = SkCanvas::kFast_SrcRectConstraint
	)

Definition at line 24 of file SkTiledImageUtils.cpp.

                                                         {
    if (!image || !canvas) {
        return;
    }
 
    SkPaint p;
    if (paint) {
        p = *paint;
    }
    if (!SkCanvasPriv::TopDevice(canvas)->drawAsTiledImageRect(
                canvas, image, &src, dst, sampling, p, constraint)) {
        // Either the image didn't require tiling or this is a raster-backed
        // canvas. In either case fall back to a default draw.
        canvas->drawImageRect(image, src, dst, sampling, paint, constraint);
    }
}

GetImageKeyValues()

void SkTiledImageUtils::GetImageKeyValues	(	const SkImage *	image,
		uint32_t	keyValues[kNumImageKeyValues]
	)

Retrieves a set of values that can be used as part of a cache key for the provided image.

Unfortunately, SkImage::uniqueID isn't sufficient as an SkImage cache key. In particular, SkBitmap-backed SkImages can share a single SkBitmap and refer to different subsets of it. In this situation the optimal key is based on the SkBitmap's generation ID and the subset rectangle. For Picture-backed images this method will attempt to generate a concise internally-based key (i.e., containing picture ID, matrix translation, width and height, etc.). For complicated Picture-backed images (i.e., those w/ a paint or a full matrix) it will fall back to using 'image's unique key.

Parameters

image	The image for which key values are desired
keyValues	The resulting key values

Definition at line 47 of file SkTiledImageUtils.cpp.

                                                                                     {
    if (!image || !keyValues) {
        if (keyValues) {
            memset(keyValues, 0, kNumImageKeyValues * sizeof(uint32_t));
        }
        return;
    }
 
    const SkImage_Base* imageBase = as_IB(image);
    if (const SkBitmap* bm = imageBase->onPeekBitmap()) {
        keyValues[0] = bm->pixelRef()->getGenerationID();
        SkIRect subset = image->bounds();
        subset.offset(bm->pixelRefOrigin());
 
        SkASSERT(SkTFitsIn<uint32_t>(subset.fLeft));
        SkASSERT(SkTFitsIn<uint32_t>(subset.fTop));
        SkASSERT(SkTFitsIn<uint32_t>(subset.fRight));
        SkASSERT(SkTFitsIn<uint32_t>(subset.fBottom));
 
        keyValues[1] = 0;              // This empty slot is to disambiguate picture IDs
        keyValues[2] = subset.fLeft;
        keyValues[3] = subset.fTop;
        keyValues[4] = subset.fRight;
        keyValues[5] = subset.fBottom;
        return;
    }
 
    if (imageBase->type() == SkImage_Base::Type::kLazyPicture) {
        const SkImage_Picture* pictureImage = static_cast<const SkImage_Picture*>(imageBase);
        if (pictureImage->getImageKeyValues(keyValues)) {
            return;
        }
    }
 
    keyValues[0] = image->uniqueID();
    memset(&keyValues[1], 0, (kNumImageKeyValues-1) * sizeof(uint32_t));
}

Variable Documentation

kNumImageKeyValues

constexpr int SkTiledImageUtils::kNumImageKeyValues = 6

staticconstexpr

Definition at line 105 of file SkTiledImageUtils.h.