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* Copyright 2016 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrTextureProducer_DEFINED
#define GrTextureProducer_DEFINED
#include "GrSamplerParams.h"
#include "GrResourceKey.h"
class GrColorSpaceXform;
class GrTexture;
class GrTextureProxy;
* Different GPUs and API extensions have different requirements with respect to what texture
* sampling parameters may be used with textures of various types. This class facilitates making
* texture compatible with a given GrSamplerParams. There are two immediate subclasses defined
* below. One is a base class for sources that are inherently texture-backed (e.g. a texture-backed
* SkImage). It supports subsetting the original texture. The other is for use cases where the
* source can generate a texture that represents some content (e.g. cpu pixels, SkPicture, ...).
class GrTextureProducer : public SkNoncopyable {
struct CopyParams {
GrSamplerParams::FilterMode fFilter;
int fWidth;
int fHeight;
enum FilterConstraint {
* Helper for creating a fragment processor to sample the texture with a given filtering mode.
* It attempts to avoid making texture copies or using domains whenever possible.
* @param textureMatrix Matrix used to access the texture. It is applied to
* the local coords. The post-transformed coords should
* be in texel units (rather than normalized) with
* respect to this Producer's bounds (width()/height()).
* @param constraintRect A rect that represents the area of the texture to be
* sampled. It must be contained in the Producer's
* bounds as defined by width()/height().
* @param filterConstriant Indicates whether filtering is limited to
* constraintRect.
* @param coordsLimitedToConstraintRect Is it known that textureMatrix*localCoords is bound
* by the portion of the texture indicated by
* constraintRect (without consideration of filter
* width, just the raw coords).
* @param filterOrNullForBicubic If non-null indicates the filter mode. If null means
* use bicubic filtering.
virtual sk_sp<GrFragmentProcessor> createFragmentProcessor(
const SkMatrix& textureMatrix,
const SkRect& constraintRect,
FilterConstraint filterConstraint,
bool coordsLimitedToConstraintRect,
const GrSamplerParams::FilterMode* filterOrNullForBicubic,
SkColorSpace* dstColorSpace) = 0;
virtual ~GrTextureProducer() {}
int width() const { return fWidth; }
int height() const { return fHeight; }
bool isAlphaOnly() const { return fIsAlphaOnly; }
virtual SkAlphaType alphaType() const = 0;
friend class GrTextureProducer_TestAccess;
GrTextureProducer(int width, int height, bool isAlphaOnly)
: fWidth(width)
, fHeight(height)
, fIsAlphaOnly(isAlphaOnly) {}
/** Helper for creating a key for a copy from an original key. */
static void MakeCopyKeyFromOrigKey(const GrUniqueKey& origKey,
const CopyParams& copyParams,
GrUniqueKey* copyKey) {
if (origKey.isValid()) {
static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
GrUniqueKey::Builder builder(copyKey, origKey, kDomain, 3);
builder[0] = copyParams.fFilter;
builder[1] = copyParams.fWidth;
builder[2] = copyParams.fHeight;
* If we need to make a copy in order to be compatible with GrTextureParams producer is asked to
* return a key that identifies its original content + the CopyParms parameter. If the producer
* does not want to cache the stretched version (e.g. the producer is volatile), this should
* simply return without initializing the copyKey. If the texture generated by this producer
* depends on the destination color space, then that information should also be incorporated
* in the key.
virtual void makeCopyKey(const CopyParams&, GrUniqueKey* copyKey,
SkColorSpace* dstColorSpace) = 0;
* If a stretched version of the texture is generated, it may be cached (assuming that
* makeCopyKey() returns true). In that case, the maker is notified in case it
* wants to note that for when the maker is destroyed.
virtual void didCacheCopy(const GrUniqueKey& copyKey) = 0;
enum DomainMode {
static sk_sp<GrTextureProxy> CopyOnGpu(GrContext*, sk_sp<GrTextureProxy> inputProxy,
const SkIRect* subset, const CopyParams& copyParams);
static DomainMode DetermineDomainMode(
const SkRect& constraintRect,
FilterConstraint filterConstraint,
bool coordsLimitedToConstraintRect,
const SkIRect* textureContentArea,
const GrSamplerParams::FilterMode* filterModeOrNullForBicubic,
SkRect* domainRect);
static sk_sp<GrFragmentProcessor> CreateFragmentProcessorForDomainAndFilter(
sk_sp<GrTextureProxy> proxy,
const SkMatrix& textureMatrix,
const SkRect& domain,
const GrSamplerParams::FilterMode* filterOrNullForBicubic);
const int fWidth;
const int fHeight;
const bool fIsAlphaOnly;
typedef SkNoncopyable INHERITED;