////////////////////////////////////////////////////////////////////////////////
// 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::AutoGeometryAndStatePush agasp(fGpu, GrDrawTarget::kReset_ASRInit);
GrDrawState* drawState = fGpu->drawState();
// 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;
}
bool GrStencilAndCoverPathRenderer::onDrawPath(const SkPath& path,
const SkStrokeRec& stroke,
GrDrawTarget* target,
bool antiAlias) {
SkASSERT(!antiAlias);
SkASSERT(!stroke.isHairlineStyle());
GrDrawState* drawState = target->drawState();
SkASSERT(drawState->getStencil().isDisabled());
SkAutoTUnref<GrPath> p(get_gr_path(fGpu, path, stroke));
if (path.isInverseFillType()) {
GR_STATIC_CONST_SAME_STENCIL(kInvertedStencilPass,
kZero_StencilOp,
kZero_StencilOp,
// We know our rect will hit pixels outside the clip and the user bits will be 0
// outside the clip. So we can't just fill where the user bits are 0. We also need to
// check that the clip bit is set.
kEqualIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
drawState->setStencil(kInvertedStencilPass);
// fake inverse with a stencil and cover
target->stencilPath(p, convert_skpath_filltype(path.getFillType()));
GrDrawState::AutoViewMatrixRestore avmr;
SkRect bounds = SkRect::MakeLTRB(0, 0,
SkIntToScalar(drawState->getRenderTarget()->width()),
SkIntToScalar(drawState->getRenderTarget()->height()));
SkMatrix vmi;
// mapRect through persp matrix may not be correct
if (!drawState->getViewMatrix().hasPerspective() && drawState->getViewInverse(&vmi)) {
vmi.mapRect(&bounds);
// theoretically could set bloat = 0, instead leave it because of matrix inversion
// precision.
SkScalar bloat = drawState->getViewMatrix().getMaxScale() * SK_ScalarHalf;
bounds.outset(bloat, bloat);
} else {
avmr.setIdentity(drawState);
}
target->drawSimpleRect(bounds);
} else {
GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
kZero_StencilOp,
kZero_StencilOp,
kNotEqual_StencilFunc,
0xffff,
0x0000,
0xffff);
drawState->setStencil(kStencilPass);
target->drawPath(p, convert_skpath_filltype(path.getFillType()));
}
target->drawState()->stencil()->setDisabled();
return true;
}
