skia2/include/core/SkCrossContextImageData.h
Brian Osman 2c2bc11aea Add GrExternalTextureData and SkCrossContextImageData
GrExternalTextureData is an API for exporting the backend-specific
information about a texture in a type-safe way, and without pointing
into the GrTexture. The new detachBackendTexture API lets us release
ownership of a texture to the client.

SkCrossContextImageData is the public API that lets clients upload
textures on one thread/GrContext, then safely transfer ownership to
another thread and GrContext for rendering.

Only GL is implemented/supported right now. Vulkan support requires
that we add thread-safe memory pools, or otherwise transfer the
actual memory block containing the texture to the new context.

Re-land of https://skia-review.googlesource.com/c/8529/

BUG=skia:

Change-Id: I48ebd57d1ea0cfd3a1db10c475f2903afb821966
Reviewed-on: https://skia-review.googlesource.com/8960
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2017-02-28 20:59:57 +00:00

69 lines
2.4 KiB
C++

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkCrossContextImageData_DEFINED
#define SkCrossContextImageData_DEFINED
#include "SkImage.h"
#if SK_SUPPORT_GPU
#include "GrExternalTextureData.h"
#endif
class SK_API SkCrossContextImageData : SkNoncopyable {
public:
/**
* Decodes and uploads the encoded data to a texture using the supplied GrContext, then
* returns an instance of SkCrossContextImageData that can be used to transport that texture
* to a different GrContext, across thread boundaries. The GrContext used here, and the one
* used to reconstruct the texture-backed image later must be in the same GL share group,
* or otherwise be able to share resources. After calling this, you *must* construct exactly
* one SkImage from the returned value, using SkImage::MakeFromCrossContextImageData.
*
* The texture will be decoded and uploaded to be suitable for use with surfaces that have the
* supplied destination color space. The color space of the texture itself will be determined
* from the encoded data.
*/
static std::unique_ptr<SkCrossContextImageData> MakeFromEncoded(
GrContext*, sk_sp<SkData>, SkColorSpace* dstColorSpace);
private:
SkCrossContextImageData(sk_sp<SkImage> image) : fImage(std::move(image)) {
SkASSERT(!fImage->isTextureBacked());
}
#if SK_SUPPORT_GPU
SkCrossContextImageData(const GrBackendTextureDesc& desc,
std::unique_ptr<GrExternalTextureData> textureData,
SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace)
: fAlphaType(alphaType)
, fColorSpace(std::move(colorSpace))
, fDesc(desc)
, fTextureData(std::move(textureData)) {
// Point our texture desc at our copy of the backend information
fDesc.fTextureHandle = fTextureData->getBackendObject();
}
#endif
// For non-GPU backed images
sk_sp<SkImage> fImage;
#if SK_SUPPORT_GPU
// GPU-backed images store some generic information (needed to reconstruct the SkImage),
// and some backend-specific info (to reconstruct the texture).
SkAlphaType fAlphaType;
sk_sp<SkColorSpace> fColorSpace;
GrBackendTextureDesc fDesc;
std::unique_ptr<GrExternalTextureData> fTextureData;
#endif
friend class SkImage;
};
#endif