/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrClipStackClip.h"
#include "GrAppliedClip.h"
#include "GrContextPriv.h"
#include "GrDrawingManager.h"
#include "GrRenderTargetContextPriv.h"
#include "GrFixedClip.h"
#include "GrGpuResourcePriv.h"
#include "GrRenderTargetPriv.h"
#include "GrStencilAttachment.h"
#include "GrSWMaskHelper.h"
#include "GrTextureProxy.h"
#include "effects/GrConvexPolyEffect.h"
#include "effects/GrRRectEffect.h"
#include "effects/GrTextureDomain.h"
#include "SkClipOpPriv.h"
typedef SkClipStack::Element Element;
typedef GrReducedClip::InitialState InitialState;
typedef GrReducedClip::ElementList ElementList;
static const int kMaxAnalyticElements = 4;
const char GrClipStackClip::kMaskTestTag[] = "clip_mask";
bool GrClipStackClip::quickContains(const SkRect& rect) const {
if (!fStack || fStack->isWideOpen()) {
return true;
}
return fStack->quickContains(rect);
}
bool GrClipStackClip::quickContains(const SkRRect& rrect) const {
if (!fStack || fStack->isWideOpen()) {
return true;
}
return fStack->quickContains(rrect);
}
bool GrClipStackClip::isRRect(const SkRect& origRTBounds, SkRRect* rr, GrAA* aa) const {
if (!fStack) {
return false;
}
const SkRect* rtBounds = &origRTBounds;
bool isAA;
if (fStack->isRRect(*rtBounds, rr, &isAA)) {
*aa = GrBoolToAA(isAA);
return true;
}
return false;
}
void GrClipStackClip::getConservativeBounds(int width, int height, SkIRect* devResult,
bool* isIntersectionOfRects) const {
if (!fStack) {
devResult->setXYWH(0, 0, width, height);
if (isIntersectionOfRects) {
*isIntersectionOfRects = true;
}
return;
}
SkRect devBounds;
fStack->getConservativeBounds(0, 0, width, height, &devBounds, isIntersectionOfRects);
devBounds.roundOut(devResult);
}
////////////////////////////////////////////////////////////////////////////////
// set up the draw state to enable the aa clipping mask.
static sk_sp<GrFragmentProcessor> create_fp_for_mask(GrResourceProvider* resourceProvider,
sk_sp<GrTextureProxy> mask,
const SkIRect &devBound) {
SkIRect domainTexels = SkIRect::MakeWH(devBound.width(), devBound.height());
return GrDeviceSpaceTextureDecalFragmentProcessor::Make(resourceProvider,
std::move(mask), domainTexels,
{devBound.fLeft, devBound.fTop});
}
// Does the path in 'element' require SW rendering? If so, return true (and,
// optionally, set 'prOut' to NULL. If not, return false (and, optionally, set
// 'prOut' to the non-SW path renderer that will do the job).
bool GrClipStackClip::PathNeedsSWRenderer(GrContext* context,
bool hasUserStencilSettings,
const GrRenderTargetContext* renderTargetContext,
const SkMatrix& viewMatrix,
const Element* element,
GrPathRenderer** prOut,
bool needsStencil) {
if (Element::kRect_Type == element->getType()) {
// rects can always be drawn directly w/o using the software path
// TODO: skip rrects once we're drawing them directly.
if (prOut) {
*prOut = nullptr;
}
return false;
} else {
// We shouldn't get here with an empty clip element.
SkASSERT(Element::kEmpty_Type != element->getType());
// the gpu alpha mask will draw the inverse paths as non-inverse to a temp buffer
SkPath path;
element->asPath(&path);
if (path.isInverseFillType()) {
path.toggleInverseFillType();
}
GrPathRendererChain::DrawType type =
needsStencil ? GrPathRendererChain::DrawType::kStencilAndColor
: GrPathRendererChain::DrawType::kColor;
GrShape shape(path, GrStyle::SimpleFill());
GrPathRenderer::CanDrawPathArgs canDrawArgs;
canDrawArgs.fShaderCaps = context->caps()->shaderCaps();
canDrawArgs.fViewMatrix = &viewMatrix;
canDrawArgs.fShape = &shape;
if (!element->isAA()) {
canDrawArgs.fAAType = GrAAType::kNone;
} else if (renderTargetContext->isUnifiedMultisampled()) {
canDrawArgs.fAAType = GrAAType::kMSAA;
} else if (renderTargetContext->isStencilBufferMultisampled()){
canDrawArgs.fAAType = GrAAType::kMixedSamples;
} else {
canDrawArgs.fAAType = GrAAType::kCoverage;
}
canDrawArgs.fHasUserStencilSettings = hasUserStencilSettings;
// the 'false' parameter disallows use of the SW path renderer
GrPathRenderer* pr =
context->contextPriv().drawingManager()->getPathRenderer(canDrawArgs, false, type);
if (prOut) {
*prOut = pr;
}
return SkToBool(!pr);
}
}
/*
* This method traverses the clip stack to see if the GrSoftwarePathRenderer
* will be used on any element. If so, it returns true to indicate that the
* entire clip should be rendered in SW and then uploaded en masse to the gpu.
*/
bool GrClipStackClip::UseSWOnlyPath(GrContext* context,
bool hasUserStencilSettings,
const GrRenderTargetContext* renderTargetContext,
const GrReducedClip& reducedClip) {
// TODO: generalize this function so that when
// a clip gets complex enough it can just be done in SW regardless
// of whether it would invoke the GrSoftwarePathRenderer.
// Set the matrix so that rendered clip elements are transformed to mask space from clip
// space.
SkMatrix translate;
translate.setTranslate(SkIntToScalar(-reducedClip.left()), SkIntToScalar(-reducedClip.top()));
for (ElementList::Iter iter(reducedClip.elements()); iter.get(); iter.next()) {
const Element* element = iter.get();
SkClipOp op = element->getOp();
bool invert = element->isInverseFilled();
bool needsStencil = invert ||
kIntersect_SkClipOp == op || kReverseDifference_SkClipOp == op;
if (PathNeedsSWRenderer(context, hasUserStencilSettings,
renderTargetContext, translate, element, nullptr, needsStencil)) {
return true;
}
}
return false;
}
static bool get_analytic_clip_processor(const ElementList& elements,
bool abortIfAA,
const SkRect& drawDevBounds,
sk_sp<GrFragmentProcessor>* resultFP) {
SkASSERT(elements.count() <= kMaxAnalyticElements);
SkSTArray<kMaxAnalyticElements, sk_sp<GrFragmentProcessor>> fps;
ElementList::Iter iter(elements);
while (iter.get()) {
SkClipOp op = iter.get()->getOp();
bool invert;
bool skip = false;
switch (op) {
case kReplace_SkClipOp:
SkASSERT(iter.get() == elements.head());
// Fallthrough, handled same as intersect.
case kIntersect_SkClipOp:
invert = false;
if (iter.get()->contains(drawDevBounds)) {
skip = true;
}
break;
case kDifference_SkClipOp:
invert = true;
// We don't currently have a cheap test for whether a rect is fully outside an
// element's primitive, so don't attempt to set skip.
break;
default:
return false;
}
if (!skip) {
GrPrimitiveEdgeType edgeType;
if (iter.get()->isAA()) {
if (abortIfAA) {
return false;
}
edgeType =
invert ? kInverseFillAA_GrProcessorEdgeType : kFillAA_GrProcessorEdgeType;
} else {
edgeType =
invert ? kInverseFillBW_GrProcessorEdgeType : kFillBW_GrProcessorEdgeType;
}
switch (iter.get()->getType()) {
case SkClipStack::Element::kPath_Type:
fps.emplace_back(GrConvexPolyEffect::Make(edgeType, iter.get()->getPath()));
break;
case SkClipStack::Element::kRRect_Type: {
fps.emplace_back(GrRRectEffect::Make(edgeType, iter.get()->getRRect()));
break;
}
case SkClipStack::Element::kRect_Type: {
fps.emplace_back(GrConvexPolyEffect::Make(edgeType, iter.get()->getRect()));
break;
}
default:
break;
}
if (!fps.back()) {
return false;
}
}
iter.next();
}
*resultFP = nullptr;
if (fps.count()) {
*resultFP = GrFragmentProcessor::RunInSeries(fps.begin(), fps.count());
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipStackClip::apply(GrContext* context, GrRenderTargetContext* renderTargetContext,
bool useHWAA, bool hasUserStencilSettings, GrAppliedClip* out,
SkRect* bounds) const {
SkRect devBounds = SkRect::MakeIWH(renderTargetContext->width(), renderTargetContext->height());
if (!devBounds.intersect(*bounds)) {
return false;
}
if (!fStack || fStack->isWideOpen()) {
return true;
}
const GrReducedClip reducedClip(*fStack, devBounds,
renderTargetContext->priv().maxWindowRectangles());
if (reducedClip.hasIBounds() && !GrClip::IsInsideClip(reducedClip.ibounds(), devBounds)) {
out->addScissor(reducedClip.ibounds(), bounds);
}
if (!reducedClip.windowRectangles().empty()) {
out->addWindowRectangles(reducedClip.windowRectangles(),
GrWindowRectsState::Mode::kExclusive);
}
if (reducedClip.elements().isEmpty()) {
return InitialState::kAllIn == reducedClip.initialState();
}
#ifdef SK_DEBUG
SkASSERT(reducedClip.hasIBounds());
SkIRect rtIBounds = SkIRect::MakeWH(renderTargetContext->width(),
renderTargetContext->height());
const SkIRect& clipIBounds = reducedClip.ibounds();
SkASSERT(rtIBounds.contains(clipIBounds)); // Mask shouldn't be larger than the RT.
#endif
// An element count of 4 was chosen because of the common pattern in Blink of:
// isect RR
// diff RR
// isect convex_poly
// isect convex_poly
// when drawing rounded div borders. This could probably be tuned based on a
// configuration's relative costs of switching RTs to generate a mask vs
// longer shaders.
if (reducedClip.elements().count() <= kMaxAnalyticElements) {
// When there are multiple samples we want to do per-sample clipping, not compute a
// fractional pixel coverage.
bool disallowAnalyticAA = renderTargetContext->isStencilBufferMultisampled();
if (disallowAnalyticAA && !renderTargetContext->numColorSamples()) {
// With a single color sample, any coverage info is lost from color once it hits the
// color buffer anyway, so we may as well use coverage AA if nothing else in the pipe
// is multisampled.
disallowAnalyticAA = useHWAA || hasUserStencilSettings;
}
sk_sp<GrFragmentProcessor> clipFP;
if (reducedClip.requiresAA() &&
get_analytic_clip_processor(reducedClip.elements(), disallowAnalyticAA, devBounds,
&clipFP)) {
out->addCoverageFP(std::move(clipFP));
return true;
}
}
// If the stencil buffer is multisampled we can use it to do everything.
if (!renderTargetContext->isStencilBufferMultisampled() && reducedClip.requiresAA()) {
sk_sp<GrTextureProxy> result;
if (UseSWOnlyPath(context, hasUserStencilSettings, renderTargetContext, reducedClip)) {
// The clip geometry is complex enough that it will be more efficient to create it
// entirely in software
result = this->createSoftwareClipMask(context, reducedClip);
} else {
result = this->createAlphaClipMask(context, reducedClip);
}
if (result) {
// The mask's top left coord should be pinned to the rounded-out top left corner of
// the clip's device space bounds.
out->addCoverageFP(create_fp_for_mask(context->resourceProvider(), std::move(result),
reducedClip.ibounds()));
return true;
}
// if alpha clip mask creation fails fall through to the non-AA code paths
}
GrRenderTarget* rt = renderTargetContext->accessRenderTarget();
if (!rt) {
return true;
}
// use the stencil clip if we can't represent the clip as a rectangle.
if (!context->resourceProvider()->attachStencilAttachment(rt)) {
SkDebugf("WARNING: failed to attach stencil buffer for clip mask. Clip will be ignored.\n");
return true;
}
// This relies on the property that a reduced sub-rect of the last clip will contain all the
// relevant window rectangles that were in the last clip. This subtle requirement will go away
// after clipping is overhauled.
if (renderTargetContext->priv().mustRenderClip(reducedClip.elementsGenID(),
reducedClip.ibounds())) {
reducedClip.drawStencilClipMask(context, renderTargetContext);
renderTargetContext->priv().setLastClip(reducedClip.elementsGenID(), reducedClip.ibounds());
}
out->addStencilClip();
return true;
}
////////////////////////////////////////////////////////////////////////////////
// Create a 8-bit clip mask in alpha
static void create_clip_mask_key(int32_t clipGenID, const SkIRect& bounds, GrUniqueKey* key) {
static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
GrUniqueKey::Builder builder(key, kDomain, 3, GrClipStackClip::kMaskTestTag);
builder[0] = clipGenID;
// SkToS16 because image filters outset layers to a size indicated by the filter, which can
// sometimes result in negative coordinates from device space.
builder[1] = SkToS16(bounds.fLeft) | (SkToS16(bounds.fRight) << 16);
builder[2] = SkToS16(bounds.fTop) | (SkToS16(bounds.fBottom) << 16);
}
static void add_invalidate_on_pop_message(const SkClipStack& stack, int32_t clipGenID,
const GrUniqueKey& clipMaskKey) {
SkClipStack::Iter iter(stack, SkClipStack::Iter::kTop_IterStart);
while (const Element* element = iter.prev()) {
if (element->getGenID() == clipGenID) {
std::unique_ptr<GrUniqueKeyInvalidatedMessage> msg(
new GrUniqueKeyInvalidatedMessage(clipMaskKey));
element->addResourceInvalidationMessage(std::move(msg));
return;
}
}
SkDEBUGFAIL("Gen ID was not found in stack.");
}
sk_sp<GrTextureProxy> GrClipStackClip::createAlphaClipMask(GrContext* context,
const GrReducedClip& reducedClip) const {
GrResourceProvider* resourceProvider = context->resourceProvider();
GrUniqueKey key;
create_clip_mask_key(reducedClip.elementsGenID(), reducedClip.ibounds(), &key);
sk_sp<GrTextureProxy> proxy(resourceProvider->findProxyByUniqueKey(key));
if (proxy) {
return proxy;
}
sk_sp<GrRenderTargetContext> rtc(context->makeRenderTargetContextWithFallback(
SkBackingFit::kApprox,
reducedClip.width(),
reducedClip.height(),
kAlpha_8_GrPixelConfig,
nullptr));
if (!rtc) {
return nullptr;
}
if (!reducedClip.drawAlphaClipMask(rtc.get())) {
return nullptr;
}
sk_sp<GrTextureProxy> result(rtc->asTextureProxyRef());
if (!result) {
return nullptr;
}
resourceProvider->assignUniqueKeyToProxy(key, result.get());
// MDB TODO (caching): this has to play nice with the GrSurfaceProxy's caching
add_invalidate_on_pop_message(*fStack, reducedClip.elementsGenID(), key);
return result;
}
sk_sp<GrTextureProxy> GrClipStackClip::createSoftwareClipMask(
GrContext* context,
const GrReducedClip& reducedClip) const {
GrUniqueKey key;
create_clip_mask_key(reducedClip.elementsGenID(), reducedClip.ibounds(), &key);
sk_sp<GrTextureProxy> proxy(context->resourceProvider()->findProxyByUniqueKey(key));
if (proxy) {
return proxy;
}
// The mask texture may be larger than necessary. We round out the clip bounds and pin the top
// left corner of the resulting rect to the top left of the texture.
SkIRect maskSpaceIBounds = SkIRect::MakeWH(reducedClip.width(), reducedClip.height());
GrSWMaskHelper helper;
// Set the matrix so that rendered clip elements are transformed to mask space from clip
// space.
SkMatrix translate;
translate.setTranslate(SkIntToScalar(-reducedClip.left()), SkIntToScalar(-reducedClip.top()));
if (!helper.init(maskSpaceIBounds, &translate)) {
return nullptr;
}
helper.clear(InitialState::kAllIn == reducedClip.initialState() ? 0xFF : 0x00);
for (ElementList::Iter iter(reducedClip.elements()); iter.get(); iter.next()) {
const Element* element = iter.get();
SkClipOp op = element->getOp();
GrAA aa = GrBoolToAA(element->isAA());
if (kIntersect_SkClipOp == op || kReverseDifference_SkClipOp == op) {
// Intersect and reverse difference require modifying pixels outside of the geometry
// that is being "drawn". In both cases we erase all the pixels outside of the geometry
// but leave the pixels inside the geometry alone. For reverse difference we invert all
// the pixels before clearing the ones outside the geometry.
if (kReverseDifference_SkClipOp == op) {
SkRect temp = SkRect::Make(reducedClip.ibounds());
// invert the entire scene
helper.drawRect(temp, SkRegion::kXOR_Op, GrAA::kNo, 0xFF);
}
SkPath clipPath;
element->asPath(&clipPath);
clipPath.toggleInverseFillType();
GrShape shape(clipPath, GrStyle::SimpleFill());
helper.drawShape(shape, SkRegion::kReplace_Op, aa, 0x00);
continue;
}
// The other ops (union, xor, diff) only affect pixels inside
// the geometry so they can just be drawn normally
if (Element::kRect_Type == element->getType()) {
helper.drawRect(element->getRect(), (SkRegion::Op)op, aa, 0xFF);
} else {
SkPath path;
element->asPath(&path);
GrShape shape(path, GrStyle::SimpleFill());
helper.drawShape(shape, (SkRegion::Op)op, aa, 0xFF);
}
}
sk_sp<GrTextureProxy> result(helper.toTextureProxy(context, SkBackingFit::kApprox));
context->resourceProvider()->assignUniqueKeyToProxy(key, result.get());
// MDB TODO (caching): this has to play nice with the GrSurfaceProxy's caching
add_invalidate_on_pop_message(*fStack, reducedClip.elementsGenID(), key);
return result;
}