/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrClipMaskManager.h"
#include "effects/GrTextureDomainEffect.h"
#include "GrGpu.h"
#include "GrRenderTarget.h"
#include "GrStencilBuffer.h"
#include "GrPathRenderer.h"
#include "GrPaint.h"
#include "SkRasterClip.h"
#include "SkStrokeRec.h"
#include "GrAAConvexPathRenderer.h"
#include "GrAAHairLinePathRenderer.h"
#include "GrSWMaskHelper.h"
#include "SkTLazy.h"
#define GR_AA_CLIP 1
typedef SkClipStack::Element Element;
using namespace GrReducedClip;
////////////////////////////////////////////////////////////////////////////////
namespace {
// set up the draw state to enable the aa clipping mask. Besides setting up the
// stage matrix this also alters the vertex layout
void setup_drawstate_aaclip(GrGpu* gpu,
GrTexture* result,
const GrIRect &devBound) {
GrDrawState* drawState = gpu->drawState();
GrAssert(drawState);
static const int kMaskStage = GrPaint::kTotalStages+1;
SkMatrix mat;
mat.setIDiv(result->width(), result->height());
mat.preTranslate(SkIntToScalar(-devBound.fLeft),
SkIntToScalar(-devBound.fTop));
mat.preConcat(drawState->getViewMatrix());
SkIRect domainTexels = SkIRect::MakeWH(devBound.width(), devBound.height());
// This could be a long-lived effect that is cached with the alpha-mask.
drawState->setEffect(kMaskStage,
GrTextureDomainEffect::Create(result,
mat,
GrTextureDomainEffect::MakeTexelDomain(result, domainTexels),
GrTextureDomainEffect::kDecal_WrapMode))->unref();
}
bool path_needs_SW_renderer(GrContext* context,
GrGpu* gpu,
const SkPath& origPath,
const SkStrokeRec& stroke,
bool doAA) {
// the gpu alpha mask will draw the inverse paths as non-inverse to a temp buffer
SkTCopyOnFirstWrite<SkPath> path(origPath);
if (path->isInverseFillType()) {
path.writable()->toggleInverseFillType();
}
// last (false) parameter disallows use of the SW path renderer
GrPathRendererChain::DrawType type = doAA ?
GrPathRendererChain::kColorAntiAlias_DrawType :
GrPathRendererChain::kColor_DrawType;
return NULL == context->getPathRenderer(*path, stroke, gpu, false, type);
}
}
/*
* 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 GrClipMaskManager::useSWOnlyPath(const ElementList& elements) {
// 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.
SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
for (ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
const Element* element = iter.get();
// rects can always be drawn directly w/o using the software path
// so only paths need to be checked
if (Element::kPath_Type == element->getType() &&
path_needs_SW_renderer(this->getContext(), fGpu,
element->getPath(),
stroke,
element->isAA())) {
return true;
}
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn) {
fCurrClipMaskType = kNone_ClipMaskType;
ElementList elements(16);
InitialState initialState;
SkIRect clipSpaceIBounds;
bool requiresAA;
bool isRect = false;
GrDrawState* drawState = fGpu->drawState();
const GrRenderTarget* rt = drawState->getRenderTarget();
// GrDrawTarget should have filtered this for us
GrAssert(NULL != rt);
bool ignoreClip = !drawState->isClipState() || clipDataIn->fClipStack->isWideOpen();
if (!ignoreClip) {
SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
clipSpaceRTIBounds.offset(clipDataIn->fOrigin);
ReduceClipStack(*clipDataIn->fClipStack,
clipSpaceRTIBounds,
&elements,
&initialState,
&clipSpaceIBounds,
&requiresAA);
if (elements.isEmpty()) {
if (kAllIn_InitialState == initialState) {
ignoreClip = clipSpaceIBounds == clipSpaceRTIBounds;
isRect = true;
} else {
return false;
}
}
}
if (ignoreClip) {
fGpu->disableScissor();
this->setGpuStencil();
return true;
}
#if GR_AA_CLIP
// TODO: catch isRect && requiresAA and use clip planes if available rather than a mask.
// If MSAA is enabled we can do everything in the stencil buffer.
if (0 == rt->numSamples() && requiresAA) {
int32_t genID = clipDataIn->fClipStack->getTopmostGenID();
GrTexture* result = NULL;
if (this->useSWOnlyPath(elements)) {
// The clip geometry is complex enough that it will be more efficient to create it
// entirely in software
result = this->createSoftwareClipMask(genID,
initialState,
elements,
clipSpaceIBounds);
} else {
result = this->createAlphaClipMask(genID,
initialState,
elements,
clipSpaceIBounds);
}
if (NULL != 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(-clipDataIn->fOrigin);
setup_drawstate_aaclip(fGpu, result, rtSpaceMaskBounds);
fGpu->disableScissor();
this->setGpuStencil();
return true;
}
// if alpha clip mask creation fails fall through to the non-AA code paths
}
#endif // GR_AA_CLIP
// Either a hard (stencil buffer) clip was explicitly requested or an anti-aliased clip couldn't
// be created. In either case, free up the texture in the anti-aliased mask cache.
// TODO: this may require more investigation. Ganesh performs a lot of utility draws (e.g.,
// clears, InOrderDrawBuffer playbacks) that hit the stencil buffer path. These may be
// "incorrectly" clearing the AA cache.
fAACache.reset();
// If the clip is a rectangle then just set the scissor. Otherwise, create
// a stencil mask.
if (isRect) {
SkIRect clipRect = clipSpaceIBounds;
clipRect.offset(-clipDataIn->fOrigin);
fGpu->enableScissor(clipRect);
this->setGpuStencil();
return true;
}
// use the stencil clip if we can't represent the clip as a rectangle.
SkIPoint clipSpaceToStencilSpaceOffset = -clipDataIn->fOrigin;
this->createStencilClipMask(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);
fGpu->enableScissor(scissorSpaceIBounds);
this->setGpuStencil();
return true;
}
#define VISUALIZE_COMPLEX_CLIP 0
#if VISUALIZE_COMPLEX_CLIP
#include "SkRandom.h"
SkRandom gRandom;
#define SET_RANDOM_COLOR drawState->setColor(0xff000000 | gRandom.nextU());
#else
#define SET_RANDOM_COLOR
#endif
namespace {
////////////////////////////////////////////////////////////////////////////////
// set up the OpenGL blend function to perform the specified
// boolean operation for alpha clip mask creation
void setup_boolean_blendcoeffs(GrDrawState* drawState, SkRegion::Op op) {
switch (op) {
case SkRegion::kReplace_Op:
drawState->setBlendFunc(kOne_GrBlendCoeff, kZero_GrBlendCoeff);
break;
case SkRegion::kIntersect_Op:
drawState->setBlendFunc(kDC_GrBlendCoeff, kZero_GrBlendCoeff);
break;
case SkRegion::kUnion_Op:
drawState->setBlendFunc(kOne_GrBlendCoeff, kISC_GrBlendCoeff);
break;
case SkRegion::kXOR_Op:
drawState->setBlendFunc(kIDC_GrBlendCoeff, kISC_GrBlendCoeff);
break;
case SkRegion::kDifference_Op:
drawState->setBlendFunc(kZero_GrBlendCoeff, kISC_GrBlendCoeff);
break;
case SkRegion::kReverseDifference_Op:
drawState->setBlendFunc(kIDC_GrBlendCoeff, kZero_GrBlendCoeff);
break;
default:
GrAssert(false);
break;
}
}
}
////////////////////////////////////////////////////////////////////////////////
bool GrClipMaskManager::drawElement(GrTexture* target,
const SkClipStack::Element* element,
GrPathRenderer* pr) {
GrDrawState* drawState = fGpu->drawState();
drawState->setRenderTarget(target->asRenderTarget());
switch (element->getType()) {
case Element::kRect_Type:
// TODO: Do rects directly to the accumulator using a aa-rect GrEffect that covers the
// entire mask bounds and writes 0 outside the rect.
if (element->isAA()) {
getContext()->getAARectRenderer()->fillAARect(fGpu,
fGpu,
element->getRect(),
false);
} else {
fGpu->drawSimpleRect(element->getRect(), NULL);
}
return true;
case Element::kPath_Type: {
SkTCopyOnFirstWrite<SkPath> path(element->getPath());
if (path->isInverseFillType()) {
path.writable()->toggleInverseFillType();
}
SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
if (NULL == pr) {
GrPathRendererChain::DrawType type;
type = element->isAA() ? GrPathRendererChain::kColorAntiAlias_DrawType :
GrPathRendererChain::kColor_DrawType;
pr = this->getContext()->getPathRenderer(*path, stroke, fGpu, false, type);
}
if (NULL == pr) {
return false;
}
pr->drawPath(element->getPath(), stroke, fGpu, element->isAA());
break;
}
default:
// something is wrong if we're trying to draw an empty element.
GrCrash("Unexpected element type");
return false;
}
return true;
}
bool GrClipMaskManager::canStencilAndDrawElement(GrTexture* target,
const SkClipStack::Element* element,
GrPathRenderer** pr) {
GrDrawState* drawState = fGpu->drawState();
drawState->setRenderTarget(target->asRenderTarget());
switch (element->getType()) {
case Element::kRect_Type:
return true;
case Element::kPath_Type: {
SkTCopyOnFirstWrite<SkPath> path(element->getPath());
if (path->isInverseFillType()) {
path.writable()->toggleInverseFillType();
}
SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
GrPathRendererChain::DrawType type = element->isAA() ?
GrPathRendererChain::kStencilAndColorAntiAlias_DrawType :
GrPathRendererChain::kStencilAndColor_DrawType;
*pr = this->getContext()->getPathRenderer(*path, stroke, fGpu, false, type);
return NULL != *pr;
}
default:
// something is wrong if we're trying to draw an empty element.
GrCrash("Unexpected element type");
return false;
}
}
void GrClipMaskManager::mergeMask(GrTexture* dstMask,
GrTexture* srcMask,
SkRegion::Op op,
const GrIRect& dstBound,
const GrIRect& srcBound) {
GrDrawState* drawState = fGpu->drawState();
SkMatrix oldMatrix = drawState->getViewMatrix();
drawState->viewMatrix()->reset();
drawState->setRenderTarget(dstMask->asRenderTarget());
setup_boolean_blendcoeffs(drawState, op);
SkMatrix sampleM;
sampleM.setIDiv(srcMask->width(), srcMask->height());
drawState->setEffect(0,
GrTextureDomainEffect::Create(srcMask,
sampleM,
GrTextureDomainEffect::MakeTexelDomain(srcMask, srcBound),
GrTextureDomainEffect::kDecal_WrapMode))->unref();
fGpu->drawSimpleRect(SkRect::MakeFromIRect(dstBound), NULL);
drawState->disableStage(0);
drawState->setViewMatrix(oldMatrix);
}
// get a texture to act as a temporary buffer for AA clip boolean operations
// TODO: given the expense of createTexture we may want to just cache this too
void GrClipMaskManager::getTemp(int width, int height, GrAutoScratchTexture* temp) {
if (NULL != temp->texture()) {
// we've already allocated the temp texture
return;
}
GrTextureDesc desc;
desc.fFlags = kRenderTarget_GrTextureFlagBit|kNoStencil_GrTextureFlagBit;
desc.fWidth = width;
desc.fHeight = height;
desc.fConfig = kAlpha_8_GrPixelConfig;
temp->set(this->getContext(), desc);
}
////////////////////////////////////////////////////////////////////////////////
// Handles caching & allocation (if needed) of a clip alpha-mask texture for both the sw-upload
// or gpu-rendered cases. Returns true if there is no more work to be done (i.e., we got a cache
// hit)
bool GrClipMaskManager::getMaskTexture(int32_t clipStackGenID,
const SkIRect& clipSpaceIBounds,
GrTexture** result) {
bool cached = fAACache.canReuse(clipStackGenID, clipSpaceIBounds);
if (!cached) {
// There isn't a suitable entry in the cache so we create a new texture to store the mask.
// Since we are setting up the cache we know the last lookup was a miss. Free up the
// currently cached mask so it can be reused.
fAACache.reset();
GrTextureDesc desc;
desc.fFlags = kRenderTarget_GrTextureFlagBit;
desc.fWidth = clipSpaceIBounds.width();
desc.fHeight = clipSpaceIBounds.height();
desc.fConfig = kAlpha_8_GrPixelConfig;
fAACache.acquireMask(clipStackGenID, desc, clipSpaceIBounds);
}
*result = fAACache.getLastMask();
return cached;
}
////////////////////////////////////////////////////////////////////////////////
// Create a 8-bit clip mask in alpha
GrTexture* GrClipMaskManager::createAlphaClipMask(int32_t clipStackGenID,
InitialState initialState,
const ElementList& elements,
const SkIRect& clipSpaceIBounds) {
GrAssert(kNone_ClipMaskType == fCurrClipMaskType);
GrTexture* result;
if (this->getMaskTexture(clipStackGenID, clipSpaceIBounds, &result)) {
fCurrClipMaskType = kAlpha_ClipMaskType;
return result;
}
if (NULL == result) {
fAACache.reset();
return NULL;
}
GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
GrDrawState* drawState = fGpu->drawState();
GrDrawTarget::AutoGeometryPush agp(fGpu);
// The top-left of the mask corresponds to the top-left corner of the bounds.
SkVector clipToMaskOffset = {
SkIntToScalar(-clipSpaceIBounds.fLeft),
SkIntToScalar(-clipSpaceIBounds.fTop)
};
// The texture may be larger than necessary, this rect represents the part of the texture
// we populate with a rasterization of the clip.
SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
// We're drawing a coverage mask and want coverage to be run through the blend function.
drawState->enableState(GrDrawState::kCoverageDrawing_StateBit);
// Set the matrix so that rendered clip elements are transformed to mask space from clip space.
drawState->viewMatrix()->setTranslate(clipToMaskOffset);
// The scratch texture that we are drawing into can be substantially larger than the mask. Only
// clear the part that we care about.
fGpu->clear(&maskSpaceIBounds,
kAllIn_InitialState == initialState ? 0xffffffff : 0x00000000,
result->asRenderTarget());
// When we use the stencil in the below loop it is important to have this clip installed.
// The second pass that zeros the stencil buffer renders the rect maskSpaceIBounds so the first
// pass must not set values outside of this bounds or stencil values outside the rect won't be
// cleared.
GrDrawTarget::AutoClipRestore acr(fGpu, maskSpaceIBounds);
drawState->enableState(GrDrawState::kClip_StateBit);
GrAutoScratchTexture temp;
// walk through each clip element and perform its set op
for (ElementList::Iter iter = elements.headIter(); iter.get(); iter.next()) {
const Element* element = iter.get();
SkRegion::Op op = element->getOp();
bool invert = element->isInverseFilled();
if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
GrPathRenderer* pr = NULL;
bool useTemp = !this->canStencilAndDrawElement(result, element, &pr);
GrTexture* dst;
// This is the bounds of the clip element in the space of the alpha-mask. The temporary
// mask buffer can be substantially larger than the actually clip stack element. We
// touch the minimum number of pixels necessary and use decal mode to combine it with
// the accumulator.
GrIRect maskSpaceElementIBounds;
if (useTemp) {
if (invert) {
maskSpaceElementIBounds = maskSpaceIBounds;
} else {
GrRect elementBounds = element->getBounds();
elementBounds.offset(clipToMaskOffset);
elementBounds.roundOut(&maskSpaceElementIBounds);
}
this->getTemp(maskSpaceIBounds.fRight, maskSpaceIBounds.fBottom, &temp);
if (NULL == temp.texture()) {
fAACache.reset();
return NULL;
}
dst = temp.texture();
// clear the temp target and set blend to replace
fGpu->clear(&maskSpaceElementIBounds,
invert ? 0xffffffff : 0x00000000,
dst->asRenderTarget());
setup_boolean_blendcoeffs(drawState, SkRegion::kReplace_Op);
} else {
// draw directly into the result with the stencil set to make the pixels affected
// by the clip shape be non-zero.
dst = result;
GR_STATIC_CONST_SAME_STENCIL(kStencilInElement,
kReplace_StencilOp,
kReplace_StencilOp,
kAlways_StencilFunc,
0xffff,
0xffff,
0xffff);
drawState->setStencil(kStencilInElement);
setup_boolean_blendcoeffs(drawState, op);
}
drawState->setAlpha(invert ? 0x00 : 0xff);
if (!this->drawElement(dst, element, pr)) {
fAACache.reset();
return NULL;
}
if (useTemp) {
// Now draw into the accumulator using the real operation and the temp buffer as a
// texture
this->mergeMask(result,
temp.texture(),
op,
maskSpaceIBounds,
maskSpaceElementIBounds);
} else {
// Draw to the exterior pixels (those with a zero stencil value).
drawState->setAlpha(invert ? 0xff : 0x00);
GR_STATIC_CONST_SAME_STENCIL(kDrawOutsideElement,
kZero_StencilOp,
kZero_StencilOp,
kEqual_StencilFunc,
0xffff,
0x0000,
0xffff);
drawState->setStencil(kDrawOutsideElement);
fGpu->drawSimpleRect(clipSpaceIBounds);
drawState->disableStencil();
}
} else {
// all the remaining ops can just be directly draw into the accumulation buffer
drawState->setAlpha(0xff);
setup_boolean_blendcoeffs(drawState, op);
this->drawElement(result, element);
}
}
fCurrClipMaskType = kAlpha_ClipMaskType;
return result;
}
////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(InitialState initialState,
const ElementList& elements,
const SkIRect& clipSpaceIBounds,
const SkIPoint& clipSpaceToStencilOffset) {
GrAssert(kNone_ClipMaskType == fCurrClipMaskType);
GrDrawState* drawState = fGpu->drawState();
GrAssert(drawState->isClipState());
GrRenderTarget* rt = drawState->getRenderTarget();
GrAssert(NULL != rt);
// TODO: dynamically attach a SB when needed.
GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
if (NULL == stencilBuffer) {
return false;
}
int32_t genID = elements.tail()->getGenID();
if (stencilBuffer->mustRenderClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset)) {
stencilBuffer->setLastClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset);
GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
drawState = fGpu->drawState();
drawState->setRenderTarget(rt);
GrDrawTarget::AutoGeometryPush agp(fGpu);
// We set the current clip to the bounds so that our recursive draws are scissored to them.
SkIRect stencilSpaceIBounds(clipSpaceIBounds);
stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
GrDrawTarget::AutoClipRestore acr(fGpu, stencilSpaceIBounds);
drawState->enableState(GrDrawState::kClip_StateBit);
// Set the matrix so that rendered clip elements are transformed from clip to stencil space.
SkVector translate = {
SkIntToScalar(clipSpaceToStencilOffset.fX),
SkIntToScalar(clipSpaceToStencilOffset.fY)
};
drawState->viewMatrix()->setTranslate(translate);
#if !VISUALIZE_COMPLEX_CLIP
drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#endif
int clipBit = stencilBuffer->bits();
SkASSERT((clipBit <= 16) && "Ganesh only handles 16b or smaller stencil buffers");
clipBit = (1 << (clipBit-1));
fGpu->clearStencilClip(stencilSpaceIBounds, kAllIn_InitialState == initialState);
// walk through each clip element and perform its set op
// with the existing clip.
for (ElementList::Iter iter(elements.headIter()); NULL != iter.get(); iter.next()) {
const Element* element = iter.get();
bool fillInverted = false;
// enabled at bottom of loop
drawState->disableState(GrGpu::kModifyStencilClip_StateBit);
// if the target is MSAA then we want MSAA enabled when the clip is soft
if (rt->isMultisampled()) {
drawState->setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
}
// This will be used to determine whether the clip shape can be rendered into the
// stencil with arbitrary stencil settings.
GrPathRenderer::StencilSupport stencilSupport;
SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
SkRegion::Op op = element->getOp();
GrPathRenderer* pr = NULL;
SkTCopyOnFirstWrite<SkPath> clipPath;
if (Element::kRect_Type == element->getType()) {
stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
fillInverted = false;
} else {
GrAssert(Element::kPath_Type == element->getType());
clipPath.init(element->getPath());
fillInverted = clipPath->isInverseFillType();
if (fillInverted) {
clipPath.writable()->toggleInverseFillType();
}
pr = this->getContext()->getPathRenderer(*clipPath,
stroke,
fGpu,
false,
GrPathRendererChain::kStencilOnly_DrawType,
&stencilSupport);
if (NULL == pr) {
return false;
}
}
int passes;
GrStencilSettings stencilSettings[GrStencilSettings::kMaxStencilClipPasses];
bool canRenderDirectToStencil =
GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport;
bool canDrawDirectToClip; // Given the renderer, the element,
// fill rule, and set operation can
// we render the element directly to
// stencil bit used for clipping.
canDrawDirectToClip = GrStencilSettings::GetClipPasses(op,
canRenderDirectToStencil,
clipBit,
fillInverted,
&passes,
stencilSettings);
// draw the element to the client stencil bits if necessary
if (!canDrawDirectToClip) {
GR_STATIC_CONST_SAME_STENCIL(gDrawToStencil,
kIncClamp_StencilOp,
kIncClamp_StencilOp,
kAlways_StencilFunc,
0xffff,
0x0000,
0xffff);
SET_RANDOM_COLOR
if (Element::kRect_Type == element->getType()) {
*drawState->stencil() = gDrawToStencil;
fGpu->drawSimpleRect(element->getRect(), NULL);
} else {
GrAssert(Element::kPath_Type == element->getType());
if (canRenderDirectToStencil) {
*drawState->stencil() = gDrawToStencil;
pr->drawPath(*clipPath, stroke, fGpu, false);
} else {
pr->stencilPath(*clipPath, stroke, fGpu);
}
}
}
// now we modify the clip bit by rendering either the clip
// element directly or a bounding rect of the entire clip.
drawState->enableState(GrGpu::kModifyStencilClip_StateBit);
for (int p = 0; p < passes; ++p) {
*drawState->stencil() = stencilSettings[p];
if (canDrawDirectToClip) {
if (Element::kRect_Type == element->getType()) {
SET_RANDOM_COLOR
fGpu->drawSimpleRect(element->getRect(), NULL);
} else {
GrAssert(Element::kPath_Type == element->getType());
SET_RANDOM_COLOR
pr->drawPath(*clipPath, stroke, fGpu, false);
}
} else {
SET_RANDOM_COLOR
// The view matrix is setup to do clip space -> stencil space translation, so
// draw rect in clip space.
fGpu->drawSimpleRect(SkRect::MakeFromIRect(clipSpaceIBounds), NULL);
}
}
}
}
// set this last because recursive draws may overwrite it back to kNone.
GrAssert(kNone_ClipMaskType == fCurrClipMaskType);
fCurrClipMaskType = kStencil_ClipMaskType;
return true;
}
// mapping of clip-respecting stencil funcs to normal stencil funcs
// mapping depends on whether stencil-clipping is in effect.
static const GrStencilFunc
gSpecialToBasicStencilFunc[2][kClipStencilFuncCount] = {
{// Stencil-Clipping is DISABLED, we are effectively always inside the clip
// In the Clip Funcs
kAlways_StencilFunc, // kAlwaysIfInClip_StencilFunc
kEqual_StencilFunc, // kEqualIfInClip_StencilFunc
kLess_StencilFunc, // kLessIfInClip_StencilFunc
kLEqual_StencilFunc, // kLEqualIfInClip_StencilFunc
// Special in the clip func that forces user's ref to be 0.
kNotEqual_StencilFunc, // kNonZeroIfInClip_StencilFunc
// make ref 0 and do normal nequal.
},
{// Stencil-Clipping is ENABLED
// In the Clip Funcs
kEqual_StencilFunc, // kAlwaysIfInClip_StencilFunc
// eq stencil clip bit, mask
// out user bits.
kEqual_StencilFunc, // kEqualIfInClip_StencilFunc
// add stencil bit to mask and ref
kLess_StencilFunc, // kLessIfInClip_StencilFunc
kLEqual_StencilFunc, // kLEqualIfInClip_StencilFunc
// for both of these we can add
// the clip bit to the mask and
// ref and compare as normal
// Special in the clip func that forces user's ref to be 0.
kLess_StencilFunc, // kNonZeroIfInClip_StencilFunc
// make ref have only the clip bit set
// and make comparison be less
// 10..0 < 1..user_bits..
}
};
namespace {
// Sets the settings to clip against the stencil buffer clip while ignoring the
// client bits.
const GrStencilSettings& basic_apply_stencil_clip_settings() {
// stencil settings to use when clip is in stencil
GR_STATIC_CONST_SAME_STENCIL_STRUCT(gSettings,
kKeep_StencilOp,
kKeep_StencilOp,
kAlwaysIfInClip_StencilFunc,
0x0000,
0x0000,
0x0000);
return *GR_CONST_STENCIL_SETTINGS_PTR_FROM_STRUCT_PTR(&gSettings);
}
}
void GrClipMaskManager::setGpuStencil() {
// We make two copies of the StencilSettings here (except in the early
// exit scenario. One copy from draw state to the stack var. Then another
// from the stack var to the gpu. We could make this class hold a ptr to
// GrGpu's fStencilSettings and eliminate the stack copy here.
const GrDrawState& drawState = fGpu->getDrawState();
// use stencil for clipping if clipping is enabled and the clip
// has been written into the stencil.
GrClipMaskManager::StencilClipMode clipMode;
if (this->isClipInStencil() && drawState.isClipState()) {
clipMode = GrClipMaskManager::kRespectClip_StencilClipMode;
// We can't be modifying the clip and respecting it at the same time.
GrAssert(!drawState.isStateFlagEnabled(
GrGpu::kModifyStencilClip_StateBit));
} else if (drawState.isStateFlagEnabled(
GrGpu::kModifyStencilClip_StateBit)) {
clipMode = GrClipMaskManager::kModifyClip_StencilClipMode;
} else {
clipMode = GrClipMaskManager::kIgnoreClip_StencilClipMode;
}
GrStencilSettings settings;
// The GrGpu client may not be using the stencil buffer but we may need to
// enable it in order to respect a stencil clip.
if (drawState.getStencil().isDisabled()) {
if (GrClipMaskManager::kRespectClip_StencilClipMode == clipMode) {
settings = basic_apply_stencil_clip_settings();
} else {
fGpu->disableStencil();
return;
}
} else {
settings = drawState.getStencil();
}
// TODO: dynamically attach a stencil buffer
int stencilBits = 0;
GrStencilBuffer* stencilBuffer =
drawState.getRenderTarget()->getStencilBuffer();
if (NULL != stencilBuffer) {
stencilBits = stencilBuffer->bits();
}
GrAssert(fGpu->getCaps().stencilWrapOpsSupport() || !settings.usesWrapOp());
GrAssert(fGpu->getCaps().twoSidedStencilSupport() || !settings.isTwoSided());
this->adjustStencilParams(&settings, clipMode, stencilBits);
fGpu->setStencilSettings(settings);
}
void GrClipMaskManager::adjustStencilParams(GrStencilSettings* settings,
StencilClipMode mode,
int stencilBitCnt) {
GrAssert(stencilBitCnt > 0);
if (kModifyClip_StencilClipMode == mode) {
// We assume that this clip manager itself is drawing to the GrGpu and
// has already setup the correct values.
return;
}
unsigned int clipBit = (1 << (stencilBitCnt - 1));
unsigned int userBits = clipBit - 1;
GrStencilSettings::Face face = GrStencilSettings::kFront_Face;
bool twoSided = fGpu->getCaps().twoSidedStencilSupport();
bool finished = false;
while (!finished) {
GrStencilFunc func = settings->func(face);
uint16_t writeMask = settings->writeMask(face);
uint16_t funcMask = settings->funcMask(face);
uint16_t funcRef = settings->funcRef(face);
GrAssert((unsigned) func < kStencilFuncCount);
writeMask &= userBits;
if (func >= kBasicStencilFuncCount) {
int respectClip = kRespectClip_StencilClipMode == mode;
if (respectClip) {
// The GrGpu class should have checked this
GrAssert(this->isClipInStencil());
switch (func) {
case kAlwaysIfInClip_StencilFunc:
funcMask = clipBit;
funcRef = clipBit;
break;
case kEqualIfInClip_StencilFunc:
case kLessIfInClip_StencilFunc:
case kLEqualIfInClip_StencilFunc:
funcMask = (funcMask & userBits) | clipBit;
funcRef = (funcRef & userBits) | clipBit;
break;
case kNonZeroIfInClip_StencilFunc:
funcMask = (funcMask & userBits) | clipBit;
funcRef = clipBit;
break;
default:
GrCrash("Unknown stencil func");
}
} else {
funcMask &= userBits;
funcRef &= userBits;
}
const GrStencilFunc* table =
gSpecialToBasicStencilFunc[respectClip];
func = table[func - kBasicStencilFuncCount];
GrAssert(func >= 0 && func < kBasicStencilFuncCount);
} else {
funcMask &= userBits;
funcRef &= userBits;
}
settings->setFunc(face, func);
settings->setWriteMask(face, writeMask);
settings->setFuncMask(face, funcMask);
settings->setFuncRef(face, funcRef);
if (GrStencilSettings::kFront_Face == face) {
face = GrStencilSettings::kBack_Face;
finished = !twoSided;
} else {
finished = true;
}
}
if (!twoSided) {
settings->copyFrontSettingsToBack();
}
}
////////////////////////////////////////////////////////////////////////////////
GrTexture* GrClipMaskManager::createSoftwareClipMask(int32_t clipStackGenID,
GrReducedClip::InitialState initialState,
const GrReducedClip::ElementList& elements,
const SkIRect& clipSpaceIBounds) {
GrAssert(kNone_ClipMaskType == fCurrClipMaskType);
GrTexture* result;
if (this->getMaskTexture(clipStackGenID, clipSpaceIBounds, &result)) {
return result;
}
if (NULL == result) {
fAACache.reset();
return NULL;
}
// The mask texture may be larger than necessary. We round out the clip space bounds and pin
// the top left corner of the resulting rect to the top left of the texture.
SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
GrSWMaskHelper helper(this->getContext());
SkMatrix matrix;
matrix.setTranslate(SkIntToScalar(-clipSpaceIBounds.fLeft),
SkIntToScalar(-clipSpaceIBounds.fTop));
helper.init(maskSpaceIBounds, &matrix);
helper.clear(kAllIn_InitialState == initialState ? 0xFF : 0x00);
SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
for (ElementList::Iter iter(elements.headIter()) ; NULL != iter.get(); iter.next()) {
const Element* element = iter.get();
SkRegion::Op op = element->getOp();
if (SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == 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 (SkRegion::kReverseDifference_Op == op) {
SkRect temp = SkRect::MakeFromIRect(clipSpaceIBounds);
// invert the entire scene
helper.draw(temp, SkRegion::kXOR_Op, false, 0xFF);
}
if (Element::kRect_Type == element->getType()) {
// convert the rect to a path so we can invert the fill
SkPath temp;
temp.addRect(element->getRect());
temp.setFillType(SkPath::kInverseEvenOdd_FillType);
helper.draw(temp, stroke, SkRegion::kReplace_Op,
element->isAA(),
0x00);
} else {
GrAssert(Element::kPath_Type == element->getType());
SkPath clipPath = element->getPath();
clipPath.toggleInverseFillType();
helper.draw(clipPath, stroke,
SkRegion::kReplace_Op,
element->isAA(),
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.draw(element->getRect(), op, element->isAA(), 0xFF);
} else {
GrAssert(Element::kPath_Type == element->getType());
helper.draw(element->getPath(), stroke, op, element->isAA(), 0xFF);
}
}
helper.toTexture(result, kAllIn_InitialState == initialState ? 0xFF : 0x00);
fCurrClipMaskType = kAlpha_ClipMaskType;
return result;
}
////////////////////////////////////////////////////////////////////////////////
void GrClipMaskManager::releaseResources() {
fAACache.releaseResources();
}