////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::setupClipping(const GrPipelineBuilder& pipelineBuilder,
GrPipelineBuilder::AutoRestoreStencil* ars,
const SkRect* devBounds,
GrAppliedClip* out) {
if (kRespectClip_StencilClipMode == fClipMode) {
fClipMode = kIgnoreClip_StencilClipMode;
}
GrReducedClip::ElementList elements;
int32_t genID = 0;
GrReducedClip::InitialState initialState = GrReducedClip::kAllIn_InitialState;
SkIRect clipSpaceIBounds;
bool requiresAA = false;
GrRenderTarget* rt = pipelineBuilder.getRenderTarget();
// GrDrawTarget should have filtered this for us
SkASSERT(rt);
SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
GrClip devBoundsClip;
bool doDevBoundsClip = fDebugClipBatchToBounds && devBounds;
if (doDevBoundsClip) {
add_rect_to_clip(pipelineBuilder.clip(), *devBounds, &devBoundsClip);
}
const GrClip& clip = doDevBoundsClip ? devBoundsClip : pipelineBuilder.clip();
if (clip.isWideOpen(clipSpaceRTIBounds)) {
this->setPipelineBuilderStencil(pipelineBuilder, ars);
return true;
}
// The clip mask manager always draws with a single IRect so we special case that logic here
// Image filters just use a rect, so we also special case that logic
switch (clip.clipType()) {
case GrClip::kWideOpen_ClipType:
SkFAIL("Should have caught this with clip.isWideOpen()");
return true;
case GrClip::kIRect_ClipType: {
SkIRect scissor = clip.irect();
if (scissor.intersect(clipSpaceRTIBounds)) {
out->fScissorState.set(scissor);
this->setPipelineBuilderStencil(pipelineBuilder, ars);
return true;
}
return false;
}
case GrClip::kClipStack_ClipType: {
clipSpaceRTIBounds.offset(clip.origin());
SkIRect clipSpaceReduceQueryBounds;
#define DISABLE_DEV_BOUNDS_FOR_CLIP_REDUCTION 0
if (devBounds && !DISABLE_DEV_BOUNDS_FOR_CLIP_REDUCTION) {
SkIRect devIBounds = devBounds->roundOut();
devIBounds.offset(clip.origin());
if (!clipSpaceReduceQueryBounds.intersect(clipSpaceRTIBounds, devIBounds)) {
return false;
}
} else {
clipSpaceReduceQueryBounds = clipSpaceRTIBounds;
}
GrReducedClip::ReduceClipStack(*clip.clipStack(),
clipSpaceReduceQueryBounds,
&elements,
&genID,
&initialState,
&clipSpaceIBounds,
&requiresAA);
if (elements.isEmpty()) {
if (GrReducedClip::kAllIn_InitialState == initialState) {
if (clipSpaceIBounds == clipSpaceRTIBounds) {
this->setPipelineBuilderStencil(pipelineBuilder, ars);
return true;
}
} else {
return false;
}
}
} break;
}
// 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 (elements.count() <= kMaxAnalyticElements) {
SkVector clipToRTOffset = { SkIntToScalar(-clip.origin().fX),
SkIntToScalar(-clip.origin().fY) };
// When there are multiple samples we want to do per-sample clipping, not compute a
// fractional pixel coverage.
bool disallowAnalyticAA = rt->isUnifiedMultisampled() || pipelineBuilder.hasMixedSamples();
const GrFragmentProcessor* clipFP = nullptr;
if (elements.isEmpty() ||
(requiresAA &&
this->getAnalyticClipProcessor(elements, disallowAnalyticAA, clipToRTOffset, devBounds,
&clipFP))) {
SkIRect scissorSpaceIBounds(clipSpaceIBounds);
scissorSpaceIBounds.offset(-clip.origin());
if (nullptr == devBounds ||
!SkRect::Make(scissorSpaceIBounds).contains(*devBounds)) {
out->fScissorState.set(scissorSpaceIBounds);
}
this->setPipelineBuilderStencil(pipelineBuilder, ars);
out->fClipCoverageFP.reset(clipFP);
return true;
}
}
// If the stencil buffer is multisampled we can use it to do everything.
if (!rt->isStencilBufferMultisampled() && requiresAA) {
SkAutoTUnref<GrTexture> result;
// The top-left of the mask corresponds to the top-left corner of the bounds.
SkVector clipToMaskOffset = {
SkIntToScalar(-clipSpaceIBounds.fLeft),
SkIntToScalar(-clipSpaceIBounds.fTop)
};
if (UseSWOnlyPath(this->getContext(), pipelineBuilder, rt, clipToMaskOffset, elements)) {
// The clip geometry is complex enough that it will be more efficient to create it
// entirely in software
result.reset(CreateSoftwareClipMask(this->getContext(),
genID,
initialState,
elements,
clipToMaskOffset,
clipSpaceIBounds));
} else {
result.reset(CreateAlphaClipMask(this->getContext(),
genID,
initialState,
elements,
clipToMaskOffset,
clipSpaceIBounds));
// If createAlphaClipMask fails it means UseSWOnlyPath has a bug
SkASSERT(result);
}
if (result) {
// The mask's top left coord should be pinned to the rounded-out top left corner of
// clipSpace bounds. We determine the mask's position WRT to the render target here.
SkIRect rtSpaceMaskBounds = clipSpaceIBounds;
rtSpaceMaskBounds.offset(-clip.origin());
out->fClipCoverageFP.reset(create_fp_for_mask(result, rtSpaceMaskBounds));
this->setPipelineBuilderStencil(pipelineBuilder, ars);
return true;
}
// if alpha clip mask creation fails fall through to the non-AA code paths
}
// use the stencil clip if we can't represent the clip as a rectangle.
SkIPoint clipSpaceToStencilSpaceOffset = -clip.origin();
this->createStencilClipMask(rt,
genID,
initialState,
elements,
clipSpaceIBounds,
clipSpaceToStencilSpaceOffset);
// This must occur after createStencilClipMask. That function may change the scissor. Also, it
// only guarantees that the stencil mask is correct within the bounds it was passed, so we must
// use both stencil and scissor test to the bounds for the final draw.
SkIRect scissorSpaceIBounds(clipSpaceIBounds);
scissorSpaceIBounds.offset(clipSpaceToStencilSpaceOffset);
out->fScissorState.set(scissorSpaceIBounds);
this->setPipelineBuilderStencil(pipelineBuilder, ars);
return true;
}
