blob: e46be1206725b295a3a3888ab6794d51e3c1104a [file] [log] [blame]
/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkAlphaThresholdFilter.h"
#include "SkBitmap.h"
#include "SkColorSpaceXformer.h"
#include "SkReadBuffer.h"
#include "SkSpecialImage.h"
#include "SkWriteBuffer.h"
#include "SkRegion.h"
#if SK_SUPPORT_GPU
#include "GrAlphaThresholdFragmentProcessor.h"
#include "GrContext.h"
#include "GrFixedClip.h"
#include "GrRenderTargetContext.h"
#include "GrTextureProxy.h"
#endif
class SK_API SkAlphaThresholdFilterImpl : public SkImageFilter {
public:
SkAlphaThresholdFilterImpl(const SkRegion& region, SkScalar innerThreshold,
SkScalar outerThreshold, sk_sp<SkImageFilter> input,
const CropRect* cropRect = nullptr);
SK_TO_STRING_OVERRIDE()
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkAlphaThresholdFilterImpl)
friend void SkAlphaThresholdFilter::InitializeFlattenables();
protected:
void flatten(SkWriteBuffer&) const override;
sk_sp<SkSpecialImage> onFilterImage(SkSpecialImage* source, const Context&,
SkIPoint* offset) const override;
sk_sp<SkImageFilter> onMakeColorSpace(SkColorSpaceXformer*) const override;
#if SK_SUPPORT_GPU
sk_sp<GrTextureProxy> createMaskTexture(GrContext*,
const SkMatrix&,
const SkIRect& bounds) const;
#endif
private:
SkRegion fRegion;
SkScalar fInnerThreshold;
SkScalar fOuterThreshold;
typedef SkImageFilter INHERITED;
};
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkAlphaThresholdFilter)
SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkAlphaThresholdFilterImpl)
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
static SkScalar pin_0_1(SkScalar x) {
return SkMinScalar(SkMaxScalar(x, 0), 1);
}
sk_sp<SkImageFilter> SkAlphaThresholdFilter::Make(const SkRegion& region,
SkScalar innerThreshold,
SkScalar outerThreshold,
sk_sp<SkImageFilter> input,
const SkImageFilter::CropRect* cropRect) {
innerThreshold = pin_0_1(innerThreshold);
outerThreshold = pin_0_1(outerThreshold);
if (!SkScalarIsFinite(innerThreshold) || !SkScalarIsFinite(outerThreshold)) {
return nullptr;
}
return sk_sp<SkImageFilter>(new SkAlphaThresholdFilterImpl(region, innerThreshold,
outerThreshold,
std::move(input),
cropRect));
}
sk_sp<SkFlattenable> SkAlphaThresholdFilterImpl::CreateProc(SkReadBuffer& buffer) {
SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
SkScalar inner = buffer.readScalar();
SkScalar outer = buffer.readScalar();
SkRegion rgn;
buffer.readRegion(&rgn);
return SkAlphaThresholdFilter::Make(rgn, inner, outer, common.getInput(0),
&common.cropRect());
}
SkAlphaThresholdFilterImpl::SkAlphaThresholdFilterImpl(const SkRegion& region,
SkScalar innerThreshold,
SkScalar outerThreshold,
sk_sp<SkImageFilter> input,
const CropRect* cropRect)
: INHERITED(&input, 1, cropRect)
, fRegion(region)
, fInnerThreshold(innerThreshold)
, fOuterThreshold(outerThreshold) {
}
#if SK_SUPPORT_GPU
sk_sp<GrTextureProxy> SkAlphaThresholdFilterImpl::createMaskTexture(GrContext* context,
const SkMatrix& inMatrix,
const SkIRect& bounds) const {
sk_sp<GrRenderTargetContext> rtContext(context->makeDeferredRenderTargetContextWithFallback(
SkBackingFit::kApprox, bounds.width(), bounds.height(), kAlpha_8_GrPixelConfig, nullptr));
if (!rtContext) {
return nullptr;
}
GrPaint paint;
paint.setPorterDuffXPFactory(SkBlendMode::kSrc);
SkRegion::Iterator iter(fRegion);
rtContext->clear(nullptr, 0x0, true);
GrFixedClip clip(SkIRect::MakeWH(bounds.width(), bounds.height()));
while (!iter.done()) {
SkRect rect = SkRect::Make(iter.rect());
rtContext->drawRect(clip, std::move(paint), GrAA::kNo, inMatrix, rect);
iter.next();
}
return rtContext->asTextureProxyRef();
}
#endif
void SkAlphaThresholdFilterImpl::flatten(SkWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeScalar(fInnerThreshold);
buffer.writeScalar(fOuterThreshold);
buffer.writeRegion(fRegion);
}
sk_sp<SkSpecialImage> SkAlphaThresholdFilterImpl::onFilterImage(SkSpecialImage* source,
const Context& ctx,
SkIPoint* offset) const {
SkIPoint inputOffset = SkIPoint::Make(0, 0);
sk_sp<SkSpecialImage> input(this->filterInput(0, source, ctx, &inputOffset));
if (!input) {
return nullptr;
}
const SkIRect inputBounds = SkIRect::MakeXYWH(inputOffset.x(), inputOffset.y(),
input->width(), input->height());
SkIRect bounds;
if (!this->applyCropRect(ctx, inputBounds, &bounds)) {
return nullptr;
}
#if SK_SUPPORT_GPU
if (source->isTextureBacked()) {
GrContext* context = source->getContext();
sk_sp<GrTextureProxy> inputProxy(input->asTextureProxyRef(context));
SkASSERT(inputProxy);
offset->fX = bounds.left();
offset->fY = bounds.top();
bounds.offset(-inputOffset);
SkMatrix matrix(ctx.ctm());
matrix.postTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
sk_sp<GrTextureProxy> maskProxy(this->createMaskTexture(context, matrix, bounds));
if (!maskProxy) {
return nullptr;
}
const OutputProperties& outProps = ctx.outputProperties();
sk_sp<GrColorSpaceXform> colorSpaceXform = GrColorSpaceXform::Make(input->getColorSpace(),
outProps.colorSpace());
sk_sp<GrFragmentProcessor> fp(GrAlphaThresholdFragmentProcessor::Make(
std::move(inputProxy),
std::move(colorSpaceXform),
std::move(maskProxy),
fInnerThreshold,
fOuterThreshold,
bounds));
if (!fp) {
return nullptr;
}
return DrawWithFP(context, std::move(fp), bounds, outProps);
}
#endif
SkBitmap inputBM;
if (!input->getROPixels(&inputBM)) {
return nullptr;
}
if (inputBM.colorType() != kN32_SkColorType) {
return nullptr;
}
if (!inputBM.getPixels() || inputBM.width() <= 0 || inputBM.height() <= 0) {
return nullptr;
}
SkMatrix localInverse;
if (!ctx.ctm().invert(&localInverse)) {
return nullptr;
}
SkImageInfo info = SkImageInfo::MakeN32(bounds.width(), bounds.height(),
kPremul_SkAlphaType);
SkBitmap dst;
if (!dst.tryAllocPixels(info)) {
return nullptr;
}
U8CPU innerThreshold = (U8CPU)(fInnerThreshold * 0xFF);
U8CPU outerThreshold = (U8CPU)(fOuterThreshold * 0xFF);
SkColor* dptr = dst.getAddr32(0, 0);
int dstWidth = dst.width(), dstHeight = dst.height();
SkIPoint srcOffset = { bounds.fLeft - inputOffset.fX, bounds.fTop - inputOffset.fY };
for (int y = 0; y < dstHeight; ++y) {
const SkColor* sptr = inputBM.getAddr32(srcOffset.fX, srcOffset.fY+y);
for (int x = 0; x < dstWidth; ++x) {
const SkColor& source = sptr[x];
SkColor outputColor(source);
SkPoint position;
localInverse.mapXY((SkScalar)x + bounds.fLeft, (SkScalar)y + bounds.fTop, &position);
if (fRegion.contains((int32_t)position.x(), (int32_t)position.y())) {
if (SkColorGetA(source) < innerThreshold) {
U8CPU alpha = SkColorGetA(source);
if (alpha == 0) {
alpha = 1;
}
float scale = (float)innerThreshold / alpha;
outputColor = SkColorSetARGB(innerThreshold,
(U8CPU)(SkColorGetR(source) * scale),
(U8CPU)(SkColorGetG(source) * scale),
(U8CPU)(SkColorGetB(source) * scale));
}
} else {
if (SkColorGetA(source) > outerThreshold) {
float scale = (float)outerThreshold / SkColorGetA(source);
outputColor = SkColorSetARGB(outerThreshold,
(U8CPU)(SkColorGetR(source) * scale),
(U8CPU)(SkColorGetG(source) * scale),
(U8CPU)(SkColorGetB(source) * scale));
}
}
dptr[y * dstWidth + x] = outputColor;
}
}
offset->fX = bounds.left();
offset->fY = bounds.top();
return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(bounds.width(), bounds.height()),
dst);
}
sk_sp<SkImageFilter> SkAlphaThresholdFilterImpl::onMakeColorSpace(SkColorSpaceXformer* xformer)
const {
SkASSERT(1 == this->countInputs());
sk_sp<SkImageFilter> input = xformer->apply(this->getInput(0));
if (input.get() != this->getInput(0)) {
return SkAlphaThresholdFilter::Make(fRegion, fInnerThreshold, fOuterThreshold,
std::move(input), this->getCropRectIfSet());
}
return this->refMe();
}
#ifndef SK_IGNORE_TO_STRING
void SkAlphaThresholdFilterImpl::toString(SkString* str) const {
str->appendf("SkAlphaThresholdImageFilter: (");
str->appendf("inner: %f outer: %f", fInnerThreshold, fOuterThreshold);
str->append(")");
}
#endif