src/gpu/GrBlurUtils.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "src/gpu/GrBlurUtils.h"

 #include "include/gpu/GrDirectContext.h"
 #include "include/gpu/GrRecordingContext.h"
 #include "src/gpu/GrBitmapTextureMaker.h"
 #include "src/gpu/GrCaps.h"
 #include "src/gpu/GrDirectContextPriv.h"
 #include "src/gpu/GrFixedClip.h"
 #include "src/gpu/GrProxyProvider.h"
 #include "src/gpu/GrRecordingContextPriv.h"
 #include "src/gpu/GrSoftwarePathRenderer.h"
 #include "src/gpu/GrStyle.h"
 #include "src/gpu/GrSurfaceDrawContext.h"
 #include "src/gpu/GrTextureProxy.h"
 #include "src/gpu/GrThreadSafeCache.h"
 #include "src/gpu/effects/GrTextureEffect.h"
 #include "src/gpu/geometry/GrStyledShape.h"

 #include "include/core/SkPaint.h"
 #include "src/core/SkDraw.h"
 #include "src/core/SkMaskFilterBase.h"
 #include "src/core/SkMatrixProvider.h"
 #include "src/core/SkTLazy.h"
 #include "src/gpu/SkGr.h"

 static bool clip_bounds_quick_reject(const SkIRect& clipBounds, const SkIRect& rect) {
     return clipBounds.isEmpty() || rect.isEmpty() || !SkIRect::Intersects(clipBounds, rect);
 }

 static constexpr auto kMaskOrigin = kTopLeft_GrSurfaceOrigin;

 // Draw a mask using the supplied paint. Since the coverage/geometry
 // is already burnt into the mask this boils down to a rect draw.
 // Return true if the mask was successfully drawn.
 static bool draw_mask(GrSurfaceDrawContext* surfaceDrawContext,
                       const GrClip* clip,
                       const SkMatrix& viewMatrix,
                       const SkIRect& maskBounds,
                       GrPaint&& paint,
                       GrSurfaceProxyView mask) {
     SkMatrix inverse;
     if (!viewMatrix.invert(&inverse)) {
         return false;
     }

     mask.concatSwizzle(GrSwizzle("aaaa"));

     SkMatrix matrix = SkMatrix::Translate(-SkIntToScalar(maskBounds.fLeft),
                                           -SkIntToScalar(maskBounds.fTop));
     matrix.preConcat(viewMatrix);
     paint.setCoverageFragmentProcessor(
             GrTextureEffect::Make(std::move(mask), kUnknown_SkAlphaType, matrix));

     surfaceDrawContext->fillPixelsWithLocalMatrix(clip, std::move(paint), maskBounds, inverse);
     return true;
 }

 static void mask_release_proc(void* addr, void* /*context*/) {
     SkMask::FreeImage(addr);
 }

 // This stores the mapping from an unclipped, integerized, device-space, shape bounds to
 // the filtered mask's draw rect.
 struct DrawRectData {
     SkIVector fOffset;
     SkISize   fSize;
 };

 static sk_sp<SkData> create_data(const SkIRect& drawRect, const SkIRect& origDevBounds) {

     DrawRectData drawRectData { {drawRect.fLeft - origDevBounds.fLeft,
                                  drawRect.fTop - origDevBounds.fTop},
                                 drawRect.size() };

     return SkData::MakeWithCopy(&drawRectData, sizeof(drawRectData));
 }

 static SkIRect extract_draw_rect_from_data(SkData* data, const SkIRect& origDevBounds) {
     auto drawRectData = static_cast<const DrawRectData*>(data->data());

     return SkIRect::MakeXYWH(origDevBounds.fLeft + drawRectData->fOffset.fX,
                              origDevBounds.fTop + drawRectData->fOffset.fY,
                              drawRectData->fSize.fWidth,
                              drawRectData->fSize.fHeight);
 }

 static GrSurfaceProxyView sw_create_filtered_mask(GrRecordingContext* rContext,
                                                   const SkMatrix& viewMatrix,
                                                   const GrStyledShape& shape,
                                                   const SkMaskFilter* filter,
                                                   const SkIRect& unclippedDevShapeBounds,
                                                   const SkIRect& clipBounds,
                                                   SkIRect* drawRect,
                                                   GrUniqueKey* key) {
     SkASSERT(filter);
     SkASSERT(!shape.style().applies());

     auto threadSafeCache = rContext->priv().threadSafeCache();

     GrSurfaceProxyView filteredMaskView;
     sk_sp<SkData> data;

     if (key->isValid()) {
         std::tie(filteredMaskView, data) = threadSafeCache->findWithData(*key);
     }

     if (filteredMaskView) {
         SkASSERT(data);
         SkASSERT(kMaskOrigin == filteredMaskView.origin());

         *drawRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
     } else {
         SkStrokeRec::InitStyle fillOrHairline = shape.style().isSimpleHairline()
                                                         ? SkStrokeRec::kHairline_InitStyle
                                                         : SkStrokeRec::kFill_InitStyle;

         // TODO: it seems like we could create an SkDraw here and set its fMatrix field rather
         // than explicitly transforming the path to device space.
         SkPath devPath;

         shape.asPath(&devPath);

         devPath.transform(viewMatrix);

         SkMask srcM, dstM;
         if (!SkDraw::DrawToMask(devPath, &clipBounds, filter, &viewMatrix, &srcM,
                                 SkMask::kComputeBoundsAndRenderImage_CreateMode, fillOrHairline)) {
             return {};
         }
         SkAutoMaskFreeImage autoSrc(srcM.fImage);

         SkASSERT(SkMask::kA8_Format == srcM.fFormat);

         if (!as_MFB(filter)->filterMask(&dstM, srcM, viewMatrix, nullptr)) {
             return {};
         }
         // this will free-up dstM when we're done (allocated in filterMask())
         SkAutoMaskFreeImage autoDst(dstM.fImage);

         if (clip_bounds_quick_reject(clipBounds, dstM.fBounds)) {
             return {};
         }

         // we now have a device-aligned 8bit mask in dstM, ready to be drawn using
         // the current clip (and identity matrix) and GrPaint settings
         SkBitmap bm;
         if (!bm.installPixels(SkImageInfo::MakeA8(dstM.fBounds.width(), dstM.fBounds.height()),
                               autoDst.release(), dstM.fRowBytes, mask_release_proc, nullptr)) {
             return {};
         }
         bm.setImmutable();

         GrBitmapTextureMaker maker(rContext, bm, SkBackingFit::kApprox);
         filteredMaskView = maker.view(GrMipmapped::kNo);
         if (!filteredMaskView.proxy()) {
             return {};
         }

         SkASSERT(kMaskOrigin == filteredMaskView.origin());

         *drawRect = dstM.fBounds;

         if (key->isValid()) {
             key->setCustomData(create_data(*drawRect, unclippedDevShapeBounds));
             std::tie(filteredMaskView, data) = threadSafeCache->addWithData(*key, filteredMaskView);
             // If we got a different view back from 'addWithData' it could have a different drawRect
             *drawRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
         }
     }

     return filteredMaskView;
 }

 // Create a mask of 'shape' and return the resulting surfaceDrawContext
 static std::unique_ptr<GrSurfaceDrawContext> create_mask_GPU(GrRecordingContext* context,
                                                              const SkIRect& maskRect,
                                                              const SkMatrix& origViewMatrix,
                                                              const GrStyledShape& shape,
                                                              int sampleCnt) {
     // Use GrResourceProvider::MakeApprox to implement our own approximate size matching, but demand
     // a "SkBackingFit::kExact" size match on the actual render target. We do this because the
     // filter will reach outside the src bounds, so we need to pre-clear these values to ensure a
     // "decal" sampling effect (i.e., ensure reads outside the src bounds return alpha=0).
     //
     // FIXME: Reads outside the left and top edges will actually clamp to the edge pixel. And in the
     // event that MakeApprox does not change the size, reads outside the right and/or bottom will do
     // the same. We should offset our filter within the render target and expand the size as needed
     // to guarantee at least 1px of padding on all sides.
     auto approxSize = GrResourceProvider::MakeApprox(maskRect.size());
     auto rtContext = GrSurfaceDrawContext::MakeWithFallback(
             context, GrColorType::kAlpha_8, nullptr, SkBackingFit::kExact, approxSize, sampleCnt,
             GrMipmapped::kNo, GrProtected::kNo, kMaskOrigin);
     if (!rtContext) {
         return nullptr;
     }

     rtContext->clear(SK_PMColor4fTRANSPARENT);

     GrPaint maskPaint;
     maskPaint.setCoverageSetOpXPFactory(SkRegion::kReplace_Op);

     // setup new clip
     GrFixedClip clip(rtContext->dimensions(), SkIRect::MakeWH(maskRect.width(), maskRect.height()));

     // Draw the mask into maskTexture with the path's integerized top-left at the origin using
     // maskPaint.
     SkMatrix viewMatrix = origViewMatrix;
     viewMatrix.postTranslate(-SkIntToScalar(maskRect.fLeft), -SkIntToScalar(maskRect.fTop));
     rtContext->drawShape(&clip, std::move(maskPaint), GrAA::kYes, viewMatrix, GrStyledShape(shape));
     return rtContext;
 }

 static bool get_unclipped_shape_dev_bounds(const GrStyledShape& shape, const SkMatrix& matrix,
                                            SkIRect* devBounds) {
     SkRect shapeBounds = shape.styledBounds();
     if (shapeBounds.isEmpty()) {
         return false;
     }
     SkRect shapeDevBounds;
     matrix.mapRect(&shapeDevBounds, shapeBounds);
     // Even though these are "unclipped" bounds we still clip to the int32_t range.
     // This is the largest int32_t that is representable exactly as a float. The next 63 larger ints
     // would round down to this value when cast to a float, but who really cares.
     // INT32_MIN is exactly representable.
     static constexpr int32_t kMaxInt = 2147483520;
     if (!shapeDevBounds.intersect(SkRect::MakeLTRB(INT32_MIN, INT32_MIN, kMaxInt, kMaxInt))) {
         return false;
     }
     // Make sure that the resulting SkIRect can have representable width and height
     if (SkScalarRoundToInt(shapeDevBounds.width()) > kMaxInt ||
         SkScalarRoundToInt(shapeDevBounds.height()) > kMaxInt) {
         return false;
     }
     shapeDevBounds.roundOut(devBounds);
     return true;
 }

 // Gets the shape bounds, the clip bounds, and the intersection (if any). Returns false if there
 // is no intersection.
 static bool get_shape_and_clip_bounds(GrSurfaceDrawContext* surfaceDrawContext,
                                       const GrClip* clip,
                                       const GrStyledShape& shape,
                                       const SkMatrix& matrix,
                                       SkIRect* unclippedDevShapeBounds,
                                       SkIRect* devClipBounds) {
     // compute bounds as intersection of rt size, clip, and path
     *devClipBounds = clip ? clip->getConservativeBounds()
                           : SkIRect::MakeWH(surfaceDrawContext->width(),
                                             surfaceDrawContext->height());

     if (!get_unclipped_shape_dev_bounds(shape, matrix, unclippedDevShapeBounds)) {
         *unclippedDevShapeBounds = SkIRect::MakeEmpty();
         return false;
     }

     return true;
 }

 // The key and clip-bounds are computed together because the caching decision can impact the
 // clip-bound - since we only cache un-clipped masks the clip can be removed entirely.
 // A 'false' return value indicates that the shape is known to be clipped away.
 static bool compute_key_and_clip_bounds(GrUniqueKey* maskKey,
                                         SkIRect* boundsForClip,
                                         const GrCaps* caps,
                                         const SkMatrix& viewMatrix,
                                         bool inverseFilled,
                                         const SkMaskFilterBase* maskFilter,
                                         const GrStyledShape& shape,
                                         const SkIRect& unclippedDevShapeBounds,
                                         const SkIRect& devClipBounds) {
     *boundsForClip = devClipBounds;

 #ifndef SK_DISABLE_MASKFILTERED_MASK_CACHING
     // To prevent overloading the cache with entries during animations we limit the cache of masks
     // to cases where the matrix preserves axis alignment.
     bool useCache = !inverseFilled && viewMatrix.preservesAxisAlignment() &&
                     shape.hasUnstyledKey() && as_MFB(maskFilter)->asABlur(nullptr);

     if (useCache) {
         SkIRect clippedMaskRect, unClippedMaskRect;
         maskFilter->canFilterMaskGPU(shape, unclippedDevShapeBounds, devClipBounds,
                                      viewMatrix, &clippedMaskRect);
         maskFilter->canFilterMaskGPU(shape, unclippedDevShapeBounds, unclippedDevShapeBounds,
                                      viewMatrix, &unClippedMaskRect);
         if (clippedMaskRect.isEmpty()) {
             return false;
         }

         // Use the cache only if >50% of the filtered mask is visible.
         int unclippedWidth = unClippedMaskRect.width();
         int unclippedHeight = unClippedMaskRect.height();
         int64_t unclippedArea = sk_64_mul(unclippedWidth, unclippedHeight);
         int64_t clippedArea = sk_64_mul(clippedMaskRect.width(), clippedMaskRect.height());
         int maxTextureSize = caps->maxTextureSize();
         if (unclippedArea > 2 * clippedArea || unclippedWidth > maxTextureSize ||
             unclippedHeight > maxTextureSize) {
             useCache = false;
         } else {
             // Make the clip not affect the mask
             *boundsForClip = unclippedDevShapeBounds;
         }
     }

     if (useCache) {
         static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
         GrUniqueKey::Builder builder(maskKey, kDomain, 5 + 2 + shape.unstyledKeySize(),
                                      "Mask Filtered Masks");

         // We require the upper left 2x2 of the matrix to match exactly for a cache hit.
         SkScalar sx = viewMatrix.get(SkMatrix::kMScaleX);
         SkScalar sy = viewMatrix.get(SkMatrix::kMScaleY);
         SkScalar kx = viewMatrix.get(SkMatrix::kMSkewX);
         SkScalar ky = viewMatrix.get(SkMatrix::kMSkewY);
         SkScalar tx = viewMatrix.get(SkMatrix::kMTransX);
         SkScalar ty = viewMatrix.get(SkMatrix::kMTransY);
         // Allow 8 bits each in x and y of subpixel positioning. But, note that we're allowing
         // reuse for integer translations.
         SkFixed fracX = SkScalarToFixed(SkScalarFraction(tx)) & 0x0000FF00;
         SkFixed fracY = SkScalarToFixed(SkScalarFraction(ty)) & 0x0000FF00;

         builder[0] = SkFloat2Bits(sx);
         builder[1] = SkFloat2Bits(sy);
         builder[2] = SkFloat2Bits(kx);
         builder[3] = SkFloat2Bits(ky);
         // Distinguish between hairline and filled paths. For hairlines, we also need to include
         // the cap. (SW grows hairlines by 0.5 pixel with round and square caps). Note that
         // stroke-and-fill of hairlines is turned into pure fill by SkStrokeRec, so this covers
         // all cases we might see.
         uint32_t styleBits = shape.style().isSimpleHairline()
                                     ? ((shape.style().strokeRec().getCap() << 1) | 1)
                                     : 0;
         builder[4] = fracX | (fracY >> 8) | (styleBits << 16);

         SkMaskFilterBase::BlurRec rec;
         SkAssertResult(as_MFB(maskFilter)->asABlur(&rec));

         builder[5] = rec.fStyle;  // TODO: we could put this with the other style bits
         builder[6] = SkFloat2Bits(rec.fSigma);
         shape.writeUnstyledKey(&builder[7]);
     }
 #endif

     return true;
 }

 static GrSurfaceProxyView hw_create_filtered_mask(GrDirectContext* dContext,
                                                   GrSurfaceDrawContext* surfaceDrawContext,
                                                   const SkMatrix& viewMatrix,
                                                   const GrStyledShape& shape,
                                                   const SkMaskFilterBase* filter,
                                                   const SkIRect& unclippedDevShapeBounds,
                                                   const SkIRect& clipBounds,
                                                   SkIRect* maskRect,
                                                   GrUniqueKey* key) {
     if (!filter->canFilterMaskGPU(shape,
                                   unclippedDevShapeBounds,
                                   clipBounds,
                                   viewMatrix,
                                   maskRect)) {
         return {};
     }

     if (clip_bounds_quick_reject(clipBounds, *maskRect)) {
         // clipped out
         return {};
     }

     auto threadSafeCache = dContext->priv().threadSafeCache();

     GrSurfaceProxyView lazyView;
     sk_sp<GrThreadSafeCache::Trampoline> trampoline;

     if (key->isValid()) {
         // In this case, we want GPU-filtered masks to have priority over SW-generated ones so
         // we pre-emptively add a lazy-view to the cache and fill it in later.
         std::tie(lazyView, trampoline) = GrThreadSafeCache::CreateLazyView(
                 dContext, GrColorType::kAlpha_8, maskRect->size(),
                 kMaskOrigin, SkBackingFit::kApprox);
         if (!lazyView) {
             return {}; // fall back to a SW-created mask - 'create_mask_GPU' probably won't succeed
         }

         key->setCustomData(create_data(*maskRect, unclippedDevShapeBounds));
         auto [cachedView, data] = threadSafeCache->findOrAddWithData(*key, lazyView);
         if (cachedView != lazyView) {
             // In this case, the gpu-thread lost out to a recording thread - use its result.
             SkASSERT(data);
             SkASSERT(cachedView.asTextureProxy());
             SkASSERT(cachedView.origin() == kMaskOrigin);

             *maskRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
             return cachedView;
         }
     }

     std::unique_ptr<GrSurfaceDrawContext> maskRTC(create_mask_GPU(
                                                             dContext,
                                                             *maskRect,
                                                             viewMatrix,
                                                             shape,
                                                             surfaceDrawContext->numSamples()));
     if (!maskRTC) {
         if (key->isValid()) {
             // It is very unlikely that 'create_mask_GPU' will fail after 'CreateLazyView'
             // succeeded but, if it does, remove the lazy-view from the cache and fallback to
             // a SW-created mask. Note that any recording threads that glommed onto the
             // lazy-view will have to, later, drop those draws.
             threadSafeCache->remove(*key);
         }
         return {};
     }

     auto filteredMaskView = filter->filterMaskGPU(dContext,
                                                   maskRTC->readSurfaceView(),
                                                   maskRTC->colorInfo().colorType(),
                                                   maskRTC->colorInfo().alphaType(),
                                                   viewMatrix,
                                                   *maskRect);
     if (!filteredMaskView) {
         if (key->isValid()) {
             // Remove the lazy-view from the cache and fallback to a SW-created mask. Note that
             // any recording threads that glommed onto the lazy-view will have to, later, drop
             // those draws.
             threadSafeCache->remove(*key);
         }
         return {};
     }

     if (key->isValid()) {
         SkASSERT(filteredMaskView.dimensions() == lazyView.dimensions());
         SkASSERT(filteredMaskView.swizzle() == lazyView.swizzle());
         SkASSERT(filteredMaskView.origin() == lazyView.origin());

         trampoline->fProxy = filteredMaskView.asTextureProxyRef();
         return lazyView;
     }

     return filteredMaskView;
 }

 static void draw_shape_with_mask_filter(GrRecordingContext* rContext,
                                         GrSurfaceDrawContext* surfaceDrawContext,
                                         const GrClip* clip,
                                         GrPaint&& paint,
                                         const SkMatrix& viewMatrix,
                                         const SkMaskFilterBase* maskFilter,
                                         const GrStyledShape& origShape) {
     SkASSERT(maskFilter);

     const GrStyledShape* shape = &origShape;
     SkTLazy<GrStyledShape> tmpShape;

     if (origShape.style().applies()) {
         SkScalar styleScale =  GrStyle::MatrixToScaleFactor(viewMatrix);
         if (styleScale == 0) {
             return;
         }

         tmpShape.init(origShape.applyStyle(GrStyle::Apply::kPathEffectAndStrokeRec, styleScale));
         if (tmpShape->isEmpty()) {
             return;
         }

         shape = tmpShape.get();
     }

     if (maskFilter->directFilterMaskGPU(rContext, surfaceDrawContext, std::move(paint), clip,
                                         viewMatrix, *shape)) {
         // the mask filter was able to draw itself directly, so there's nothing
         // left to do.
         return;
     }
     assert_alive(paint);

     // If the path is hairline, ignore inverse fill.
     bool inverseFilled = shape->inverseFilled() &&
                          !GrPathRenderer::IsStrokeHairlineOrEquivalent(shape->style(),
                                                                        viewMatrix, nullptr);

     SkIRect unclippedDevShapeBounds, devClipBounds;
     if (!get_shape_and_clip_bounds(surfaceDrawContext, clip, *shape, viewMatrix,
                                    &unclippedDevShapeBounds, &devClipBounds)) {
         // TODO: just cons up an opaque mask here
         if (!inverseFilled) {
             return;
         }
     }

     GrUniqueKey maskKey;
     SkIRect boundsForClip;
     if (!compute_key_and_clip_bounds(&maskKey, &boundsForClip,
                                      surfaceDrawContext->caps(),
                                      viewMatrix, inverseFilled,
                                      maskFilter, *shape,
                                      unclippedDevShapeBounds,
                                      devClipBounds)) {
         return; // 'shape' was entirely clipped out
     }

     GrSurfaceProxyView filteredMaskView;
     SkIRect maskRect;

     if (auto dContext = rContext->asDirectContext()) {
         filteredMaskView = hw_create_filtered_mask(dContext, surfaceDrawContext,
                                                    viewMatrix, *shape, maskFilter,
                                                    unclippedDevShapeBounds, boundsForClip,
                                                    &maskRect, &maskKey);
         if (filteredMaskView) {
             if (draw_mask(surfaceDrawContext, clip, viewMatrix, maskRect, std::move(paint),
                           std::move(filteredMaskView))) {
                 // This path is completely drawn
                 return;
             }
             assert_alive(paint);
         }
     }

     // Either HW mask rendering failed or we're in a DDL recording thread
     filteredMaskView = sw_create_filtered_mask(rContext,
                                                viewMatrix, *shape, maskFilter,
                                                unclippedDevShapeBounds, boundsForClip,
                                                &maskRect, &maskKey);
     if (filteredMaskView) {
         if (draw_mask(surfaceDrawContext, clip, viewMatrix, maskRect, std::move(paint),
                       std::move(filteredMaskView))) {
             return;
         }
         assert_alive(paint);
     }
 }

 void GrBlurUtils::drawShapeWithMaskFilter(GrRecordingContext* context,
                                           GrSurfaceDrawContext* surfaceDrawContext,
                                           const GrClip* clip,
                                           const GrStyledShape& shape,
                                           GrPaint&& paint,
                                           const SkMatrix& viewMatrix,
                                           const SkMaskFilter* mf) {
     draw_shape_with_mask_filter(context, surfaceDrawContext, clip, std::move(paint),
                                 viewMatrix, as_MFB(mf), shape);
 }

 void GrBlurUtils::drawShapeWithMaskFilter(GrRecordingContext* context,
                                           GrSurfaceDrawContext* surfaceDrawContext,
                                           const GrClip* clip,
                                           const SkPaint& paint,
                                           const SkMatrixProvider& matrixProvider,
                                           const GrStyledShape& shape) {
     if (context->abandoned()) {
         return;
     }

     GrPaint grPaint;
     if (!SkPaintToGrPaint(context, surfaceDrawContext->colorInfo(), paint, matrixProvider,
                           &grPaint)) {
         return;
     }

     const SkMatrix& viewMatrix(matrixProvider.localToDevice());
     SkMaskFilterBase* mf = as_MFB(paint.getMaskFilter());
     if (mf && !mf->hasFragmentProcessor()) {
         // The MaskFilter wasn't already handled in SkPaintToGrPaint
         draw_shape_with_mask_filter(context, surfaceDrawContext, clip, std::move(grPaint),
                                     viewMatrix, mf, shape);
     } else {
         surfaceDrawContext->drawShape(clip, std::move(grPaint), context->priv().chooseAA(paint),
                                       viewMatrix, GrStyledShape(shape));
     }
 }
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "src/gpu/GrBlurUtils.h"

	#include "include/gpu/GrDirectContext.h"
	#include "include/gpu/GrRecordingContext.h"
	#include "src/gpu/GrBitmapTextureMaker.h"
	#include "src/gpu/GrCaps.h"
	#include "src/gpu/GrDirectContextPriv.h"
	#include "src/gpu/GrFixedClip.h"
	#include "src/gpu/GrProxyProvider.h"
	#include "src/gpu/GrRecordingContextPriv.h"
	#include "src/gpu/GrSoftwarePathRenderer.h"
	#include "src/gpu/GrStyle.h"
	#include "src/gpu/GrSurfaceDrawContext.h"
	#include "src/gpu/GrTextureProxy.h"
	#include "src/gpu/GrThreadSafeCache.h"
	#include "src/gpu/effects/GrTextureEffect.h"
	#include "src/gpu/geometry/GrStyledShape.h"

	#include "include/core/SkPaint.h"
	#include "src/core/SkDraw.h"
	#include "src/core/SkMaskFilterBase.h"
	#include "src/core/SkMatrixProvider.h"
	#include "src/core/SkTLazy.h"
	#include "src/gpu/SkGr.h"

	static bool clip_bounds_quick_reject(const SkIRect& clipBounds, const SkIRect& rect) {
	return clipBounds.isEmpty() \|\| rect.isEmpty() \|\| !SkIRect::Intersects(clipBounds, rect);
	}

	static constexpr auto kMaskOrigin = kTopLeft_GrSurfaceOrigin;

	// Draw a mask using the supplied paint. Since the coverage/geometry
	// is already burnt into the mask this boils down to a rect draw.
	// Return true if the mask was successfully drawn.
	static bool draw_mask(GrSurfaceDrawContext* surfaceDrawContext,
	const GrClip* clip,
	const SkMatrix& viewMatrix,
	const SkIRect& maskBounds,
	GrPaint&& paint,
	GrSurfaceProxyView mask) {
	SkMatrix inverse;
	if (!viewMatrix.invert(&inverse)) {
	return false;
	}

	mask.concatSwizzle(GrSwizzle("aaaa"));

	SkMatrix matrix = SkMatrix::Translate(-SkIntToScalar(maskBounds.fLeft),
	-SkIntToScalar(maskBounds.fTop));
	matrix.preConcat(viewMatrix);
	paint.setCoverageFragmentProcessor(
	GrTextureEffect::Make(std::move(mask), kUnknown_SkAlphaType, matrix));

	surfaceDrawContext->fillPixelsWithLocalMatrix(clip, std::move(paint), maskBounds, inverse);
	return true;
	}

	static void mask_release_proc(void* addr, void* /context/) {
	SkMask::FreeImage(addr);
	}

	// This stores the mapping from an unclipped, integerized, device-space, shape bounds to
	// the filtered mask's draw rect.
	struct DrawRectData {
	SkIVector fOffset;
	SkISize fSize;
	};

	static sk_sp<SkData> create_data(const SkIRect& drawRect, const SkIRect& origDevBounds) {

	DrawRectData drawRectData { {drawRect.fLeft - origDevBounds.fLeft,
	drawRect.fTop - origDevBounds.fTop},
	drawRect.size() };

	return SkData::MakeWithCopy(&drawRectData, sizeof(drawRectData));
	}

	static SkIRect extract_draw_rect_from_data(SkData* data, const SkIRect& origDevBounds) {
	auto drawRectData = static_cast<const DrawRectData*>(data->data());

	return SkIRect::MakeXYWH(origDevBounds.fLeft + drawRectData->fOffset.fX,
	origDevBounds.fTop + drawRectData->fOffset.fY,
	drawRectData->fSize.fWidth,
	drawRectData->fSize.fHeight);
	}

	static GrSurfaceProxyView sw_create_filtered_mask(GrRecordingContext* rContext,
	const SkMatrix& viewMatrix,
	const GrStyledShape& shape,
	const SkMaskFilter* filter,
	const SkIRect& unclippedDevShapeBounds,
	const SkIRect& clipBounds,
	SkIRect* drawRect,
	GrUniqueKey* key) {
	SkASSERT(filter);
	SkASSERT(!shape.style().applies());

	auto threadSafeCache = rContext->priv().threadSafeCache();

	GrSurfaceProxyView filteredMaskView;
	sk_sp<SkData> data;

	if (key->isValid()) {
	std::tie(filteredMaskView, data) = threadSafeCache->findWithData(*key);
	}

	if (filteredMaskView) {
	SkASSERT(data);
	SkASSERT(kMaskOrigin == filteredMaskView.origin());

	*drawRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
	} else {
	SkStrokeRec::InitStyle fillOrHairline = shape.style().isSimpleHairline()
	? SkStrokeRec::kHairline_InitStyle
	: SkStrokeRec::kFill_InitStyle;

	// TODO: it seems like we could create an SkDraw here and set its fMatrix field rather
	// than explicitly transforming the path to device space.
	SkPath devPath;

	shape.asPath(&devPath);

	devPath.transform(viewMatrix);

	SkMask srcM, dstM;
	if (!SkDraw::DrawToMask(devPath, &clipBounds, filter, &viewMatrix, &srcM,
	SkMask::kComputeBoundsAndRenderImage_CreateMode, fillOrHairline)) {
	return {};
	}
	SkAutoMaskFreeImage autoSrc(srcM.fImage);

	SkASSERT(SkMask::kA8_Format == srcM.fFormat);

	if (!as_MFB(filter)->filterMask(&dstM, srcM, viewMatrix, nullptr)) {
	return {};
	}
	// this will free-up dstM when we're done (allocated in filterMask())
	SkAutoMaskFreeImage autoDst(dstM.fImage);

	if (clip_bounds_quick_reject(clipBounds, dstM.fBounds)) {
	return {};
	}

	// we now have a device-aligned 8bit mask in dstM, ready to be drawn using
	// the current clip (and identity matrix) and GrPaint settings
	SkBitmap bm;
	if (!bm.installPixels(SkImageInfo::MakeA8(dstM.fBounds.width(), dstM.fBounds.height()),
	autoDst.release(), dstM.fRowBytes, mask_release_proc, nullptr)) {
	return {};
	}
	bm.setImmutable();

	GrBitmapTextureMaker maker(rContext, bm, SkBackingFit::kApprox);
	filteredMaskView = maker.view(GrMipmapped::kNo);
	if (!filteredMaskView.proxy()) {
	return {};
	}

	SkASSERT(kMaskOrigin == filteredMaskView.origin());

	*drawRect = dstM.fBounds;

	if (key->isValid()) {
	key->setCustomData(create_data(*drawRect, unclippedDevShapeBounds));
	std::tie(filteredMaskView, data) = threadSafeCache->addWithData(*key, filteredMaskView);
	// If we got a different view back from 'addWithData' it could have a different drawRect
	*drawRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
	}
	}

	return filteredMaskView;
	}

	// Create a mask of 'shape' and return the resulting surfaceDrawContext
	static std::unique_ptr<GrSurfaceDrawContext> create_mask_GPU(GrRecordingContext* context,
	const SkIRect& maskRect,
	const SkMatrix& origViewMatrix,
	const GrStyledShape& shape,
	int sampleCnt) {
	// Use GrResourceProvider::MakeApprox to implement our own approximate size matching, but demand
	// a "SkBackingFit::kExact" size match on the actual render target. We do this because the
	// filter will reach outside the src bounds, so we need to pre-clear these values to ensure a
	// "decal" sampling effect (i.e., ensure reads outside the src bounds return alpha=0).
	//
	// FIXME: Reads outside the left and top edges will actually clamp to the edge pixel. And in the
	// event that MakeApprox does not change the size, reads outside the right and/or bottom will do
	// the same. We should offset our filter within the render target and expand the size as needed
	// to guarantee at least 1px of padding on all sides.
	auto approxSize = GrResourceProvider::MakeApprox(maskRect.size());
	auto rtContext = GrSurfaceDrawContext::MakeWithFallback(
	context, GrColorType::kAlpha_8, nullptr, SkBackingFit::kExact, approxSize, sampleCnt,
	GrMipmapped::kNo, GrProtected::kNo, kMaskOrigin);
	if (!rtContext) {
	return nullptr;
	}

	rtContext->clear(SK_PMColor4fTRANSPARENT);

	GrPaint maskPaint;
	maskPaint.setCoverageSetOpXPFactory(SkRegion::kReplace_Op);

	// setup new clip
	GrFixedClip clip(rtContext->dimensions(), SkIRect::MakeWH(maskRect.width(), maskRect.height()));

	// Draw the mask into maskTexture with the path's integerized top-left at the origin using
	// maskPaint.
	SkMatrix viewMatrix = origViewMatrix;
	viewMatrix.postTranslate(-SkIntToScalar(maskRect.fLeft), -SkIntToScalar(maskRect.fTop));
	rtContext->drawShape(&clip, std::move(maskPaint), GrAA::kYes, viewMatrix, GrStyledShape(shape));
	return rtContext;
	}

	static bool get_unclipped_shape_dev_bounds(const GrStyledShape& shape, const SkMatrix& matrix,
	SkIRect* devBounds) {
	SkRect shapeBounds = shape.styledBounds();
	if (shapeBounds.isEmpty()) {
	return false;
	}
	SkRect shapeDevBounds;
	matrix.mapRect(&shapeDevBounds, shapeBounds);
	// Even though these are "unclipped" bounds we still clip to the int32_t range.
	// This is the largest int32_t that is representable exactly as a float. The next 63 larger ints
	// would round down to this value when cast to a float, but who really cares.
	// INT32_MIN is exactly representable.
	static constexpr int32_t kMaxInt = 2147483520;
	if (!shapeDevBounds.intersect(SkRect::MakeLTRB(INT32_MIN, INT32_MIN, kMaxInt, kMaxInt))) {
	return false;
	}
	// Make sure that the resulting SkIRect can have representable width and height
	if (SkScalarRoundToInt(shapeDevBounds.width()) > kMaxInt \|\|
	SkScalarRoundToInt(shapeDevBounds.height()) > kMaxInt) {
	return false;
	}
	shapeDevBounds.roundOut(devBounds);
	return true;
	}

	// Gets the shape bounds, the clip bounds, and the intersection (if any). Returns false if there
	// is no intersection.
	static bool get_shape_and_clip_bounds(GrSurfaceDrawContext* surfaceDrawContext,
	const GrClip* clip,
	const GrStyledShape& shape,
	const SkMatrix& matrix,
	SkIRect* unclippedDevShapeBounds,
	SkIRect* devClipBounds) {
	// compute bounds as intersection of rt size, clip, and path
	*devClipBounds = clip ? clip->getConservativeBounds()
	: SkIRect::MakeWH(surfaceDrawContext->width(),
	surfaceDrawContext->height());

	if (!get_unclipped_shape_dev_bounds(shape, matrix, unclippedDevShapeBounds)) {
	*unclippedDevShapeBounds = SkIRect::MakeEmpty();
	return false;
	}

	return true;
	}

	// The key and clip-bounds are computed together because the caching decision can impact the
	// clip-bound - since we only cache un-clipped masks the clip can be removed entirely.
	// A 'false' return value indicates that the shape is known to be clipped away.
	static bool compute_key_and_clip_bounds(GrUniqueKey* maskKey,
	SkIRect* boundsForClip,
	const GrCaps* caps,
	const SkMatrix& viewMatrix,
	bool inverseFilled,
	const SkMaskFilterBase* maskFilter,
	const GrStyledShape& shape,
	const SkIRect& unclippedDevShapeBounds,
	const SkIRect& devClipBounds) {
	*boundsForClip = devClipBounds;

	#ifndef SK_DISABLE_MASKFILTERED_MASK_CACHING
	// To prevent overloading the cache with entries during animations we limit the cache of masks
	// to cases where the matrix preserves axis alignment.
	bool useCache = !inverseFilled && viewMatrix.preservesAxisAlignment() &&
	shape.hasUnstyledKey() && as_MFB(maskFilter)->asABlur(nullptr);

	if (useCache) {
	SkIRect clippedMaskRect, unClippedMaskRect;
	maskFilter->canFilterMaskGPU(shape, unclippedDevShapeBounds, devClipBounds,
	viewMatrix, &clippedMaskRect);
	maskFilter->canFilterMaskGPU(shape, unclippedDevShapeBounds, unclippedDevShapeBounds,
	viewMatrix, &unClippedMaskRect);
	if (clippedMaskRect.isEmpty()) {
	return false;
	}

	// Use the cache only if >50% of the filtered mask is visible.
	int unclippedWidth = unClippedMaskRect.width();
	int unclippedHeight = unClippedMaskRect.height();
	int64_t unclippedArea = sk_64_mul(unclippedWidth, unclippedHeight);
	int64_t clippedArea = sk_64_mul(clippedMaskRect.width(), clippedMaskRect.height());
	int maxTextureSize = caps->maxTextureSize();
	if (unclippedArea > 2 * clippedArea \|\| unclippedWidth > maxTextureSize \|\|
	unclippedHeight > maxTextureSize) {
	useCache = false;
	} else {
	// Make the clip not affect the mask
	*boundsForClip = unclippedDevShapeBounds;
	}
	}

	if (useCache) {
	static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
	GrUniqueKey::Builder builder(maskKey, kDomain, 5 + 2 + shape.unstyledKeySize(),
	"Mask Filtered Masks");

	// We require the upper left 2x2 of the matrix to match exactly for a cache hit.
	SkScalar sx = viewMatrix.get(SkMatrix::kMScaleX);
	SkScalar sy = viewMatrix.get(SkMatrix::kMScaleY);
	SkScalar kx = viewMatrix.get(SkMatrix::kMSkewX);
	SkScalar ky = viewMatrix.get(SkMatrix::kMSkewY);
	SkScalar tx = viewMatrix.get(SkMatrix::kMTransX);
	SkScalar ty = viewMatrix.get(SkMatrix::kMTransY);
	// Allow 8 bits each in x and y of subpixel positioning. But, note that we're allowing
	// reuse for integer translations.
	SkFixed fracX = SkScalarToFixed(SkScalarFraction(tx)) & 0x0000FF00;
	SkFixed fracY = SkScalarToFixed(SkScalarFraction(ty)) & 0x0000FF00;

	builder[0] = SkFloat2Bits(sx);
	builder[1] = SkFloat2Bits(sy);
	builder[2] = SkFloat2Bits(kx);
	builder[3] = SkFloat2Bits(ky);
	// Distinguish between hairline and filled paths. For hairlines, we also need to include
	// the cap. (SW grows hairlines by 0.5 pixel with round and square caps). Note that
	// stroke-and-fill of hairlines is turned into pure fill by SkStrokeRec, so this covers
	// all cases we might see.
	uint32_t styleBits = shape.style().isSimpleHairline()
	? ((shape.style().strokeRec().getCap() << 1) \| 1)
	: 0;
	builder[4] = fracX \| (fracY >> 8) \| (styleBits << 16);

	SkMaskFilterBase::BlurRec rec;
	SkAssertResult(as_MFB(maskFilter)->asABlur(&rec));

	builder[5] = rec.fStyle; // TODO: we could put this with the other style bits
	builder[6] = SkFloat2Bits(rec.fSigma);
	shape.writeUnstyledKey(&builder[7]);
	}
	#endif

	return true;
	}

	static GrSurfaceProxyView hw_create_filtered_mask(GrDirectContext* dContext,
	GrSurfaceDrawContext* surfaceDrawContext,
	const SkMatrix& viewMatrix,
	const GrStyledShape& shape,
	const SkMaskFilterBase* filter,
	const SkIRect& unclippedDevShapeBounds,
	const SkIRect& clipBounds,
	SkIRect* maskRect,
	GrUniqueKey* key) {
	if (!filter->canFilterMaskGPU(shape,
	unclippedDevShapeBounds,
	clipBounds,
	viewMatrix,
	maskRect)) {
	return {};
	}

	if (clip_bounds_quick_reject(clipBounds, *maskRect)) {
	// clipped out
	return {};
	}

	auto threadSafeCache = dContext->priv().threadSafeCache();

	GrSurfaceProxyView lazyView;
	sk_sp<GrThreadSafeCache::Trampoline> trampoline;

	if (key->isValid()) {
	// In this case, we want GPU-filtered masks to have priority over SW-generated ones so
	// we pre-emptively add a lazy-view to the cache and fill it in later.
	std::tie(lazyView, trampoline) = GrThreadSafeCache::CreateLazyView(
	dContext, GrColorType::kAlpha_8, maskRect->size(),
	kMaskOrigin, SkBackingFit::kApprox);
	if (!lazyView) {
	return {}; // fall back to a SW-created mask - 'create_mask_GPU' probably won't succeed
	}

	key->setCustomData(create_data(*maskRect, unclippedDevShapeBounds));
	auto [cachedView, data] = threadSafeCache->findOrAddWithData(*key, lazyView);
	if (cachedView != lazyView) {
	// In this case, the gpu-thread lost out to a recording thread - use its result.
	SkASSERT(data);
	SkASSERT(cachedView.asTextureProxy());
	SkASSERT(cachedView.origin() == kMaskOrigin);

	*maskRect = extract_draw_rect_from_data(data.get(), unclippedDevShapeBounds);
	return cachedView;
	}
	}

	std::unique_ptr<GrSurfaceDrawContext> maskRTC(create_mask_GPU(
	dContext,
	*maskRect,
	viewMatrix,
	shape,
	surfaceDrawContext->numSamples()));
	if (!maskRTC) {
	if (key->isValid()) {
	// It is very unlikely that 'create_mask_GPU' will fail after 'CreateLazyView'
	// succeeded but, if it does, remove the lazy-view from the cache and fallback to
	// a SW-created mask. Note that any recording threads that glommed onto the
	// lazy-view will have to, later, drop those draws.
	threadSafeCache->remove(*key);
	}
	return {};
	}

	auto filteredMaskView = filter->filterMaskGPU(dContext,
	maskRTC->readSurfaceView(),
	maskRTC->colorInfo().colorType(),
	maskRTC->colorInfo().alphaType(),
	viewMatrix,
	*maskRect);
	if (!filteredMaskView) {
	if (key->isValid()) {
	// Remove the lazy-view from the cache and fallback to a SW-created mask. Note that
	// any recording threads that glommed onto the lazy-view will have to, later, drop
	// those draws.
	threadSafeCache->remove(*key);
	}
	return {};
	}

	if (key->isValid()) {
	SkASSERT(filteredMaskView.dimensions() == lazyView.dimensions());
	SkASSERT(filteredMaskView.swizzle() == lazyView.swizzle());
	SkASSERT(filteredMaskView.origin() == lazyView.origin());

	trampoline->fProxy = filteredMaskView.asTextureProxyRef();
	return lazyView;
	}

	return filteredMaskView;
	}

	static void draw_shape_with_mask_filter(GrRecordingContext* rContext,
	GrSurfaceDrawContext* surfaceDrawContext,
	const GrClip* clip,
	GrPaint&& paint,
	const SkMatrix& viewMatrix,
	const SkMaskFilterBase* maskFilter,
	const GrStyledShape& origShape) {
	SkASSERT(maskFilter);

	const GrStyledShape* shape = &origShape;
	SkTLazy<GrStyledShape> tmpShape;

	if (origShape.style().applies()) {
	SkScalar styleScale = GrStyle::MatrixToScaleFactor(viewMatrix);
	if (styleScale == 0) {
	return;
	}

	tmpShape.init(origShape.applyStyle(GrStyle::Apply::kPathEffectAndStrokeRec, styleScale));
	if (tmpShape->isEmpty()) {
	return;
	}

	shape = tmpShape.get();
	}

	if (maskFilter->directFilterMaskGPU(rContext, surfaceDrawContext, std::move(paint), clip,
	viewMatrix, *shape)) {
	// the mask filter was able to draw itself directly, so there's nothing
	// left to do.
	return;
	}
	assert_alive(paint);

	// If the path is hairline, ignore inverse fill.
	bool inverseFilled = shape->inverseFilled() &&
	!GrPathRenderer::IsStrokeHairlineOrEquivalent(shape->style(),
	viewMatrix, nullptr);

	SkIRect unclippedDevShapeBounds, devClipBounds;
	if (!get_shape_and_clip_bounds(surfaceDrawContext, clip, *shape, viewMatrix,
	&unclippedDevShapeBounds, &devClipBounds)) {
	// TODO: just cons up an opaque mask here
	if (!inverseFilled) {
	return;
	}
	}

	GrUniqueKey maskKey;
	SkIRect boundsForClip;
	if (!compute_key_and_clip_bounds(&maskKey, &boundsForClip,
	surfaceDrawContext->caps(),
	viewMatrix, inverseFilled,
	maskFilter, *shape,
	unclippedDevShapeBounds,
	devClipBounds)) {
	return; // 'shape' was entirely clipped out
	}

	GrSurfaceProxyView filteredMaskView;
	SkIRect maskRect;

	if (auto dContext = rContext->asDirectContext()) {
	filteredMaskView = hw_create_filtered_mask(dContext, surfaceDrawContext,
	viewMatrix, *shape, maskFilter,
	unclippedDevShapeBounds, boundsForClip,
	&maskRect, &maskKey);
	if (filteredMaskView) {
	if (draw_mask(surfaceDrawContext, clip, viewMatrix, maskRect, std::move(paint),
	std::move(filteredMaskView))) {
	// This path is completely drawn
	return;
	}
	assert_alive(paint);
	}
	}

	// Either HW mask rendering failed or we're in a DDL recording thread
	filteredMaskView = sw_create_filtered_mask(rContext,
	viewMatrix, *shape, maskFilter,
	unclippedDevShapeBounds, boundsForClip,
	&maskRect, &maskKey);
	if (filteredMaskView) {
	if (draw_mask(surfaceDrawContext, clip, viewMatrix, maskRect, std::move(paint),
	std::move(filteredMaskView))) {
	return;
	}
	assert_alive(paint);
	}
	}

	void GrBlurUtils::drawShapeWithMaskFilter(GrRecordingContext* context,
	GrSurfaceDrawContext* surfaceDrawContext,
	const GrClip* clip,
	const GrStyledShape& shape,
	GrPaint&& paint,
	const SkMatrix& viewMatrix,
	const SkMaskFilter* mf) {
	draw_shape_with_mask_filter(context, surfaceDrawContext, clip, std::move(paint),
	viewMatrix, as_MFB(mf), shape);
	}

	void GrBlurUtils::drawShapeWithMaskFilter(GrRecordingContext* context,
	GrSurfaceDrawContext* surfaceDrawContext,
	const GrClip* clip,
	const SkPaint& paint,
	const SkMatrixProvider& matrixProvider,
	const GrStyledShape& shape) {
	if (context->abandoned()) {
	return;
	}

	GrPaint grPaint;
	if (!SkPaintToGrPaint(context, surfaceDrawContext->colorInfo(), paint, matrixProvider,
	&grPaint)) {
	return;
	}

	const SkMatrix& viewMatrix(matrixProvider.localToDevice());
	SkMaskFilterBase* mf = as_MFB(paint.getMaskFilter());
	if (mf && !mf->hasFragmentProcessor()) {
	// The MaskFilter wasn't already handled in SkPaintToGrPaint
	draw_shape_with_mask_filter(context, surfaceDrawContext, clip, std::move(grPaint),
	viewMatrix, mf, shape);
	} else {
	surfaceDrawContext->drawShape(clip, std::move(grPaint), context->priv().chooseAA(paint),
	viewMatrix, GrStyledShape(shape));
	}
	}