////////////////////////////////////////////////////////////////////////////////
// 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;
}
void GrDefaultPathRenderer::onDrawPath(GrDrawTarget::StageBitfield stages,
                                       bool stencilOnly) {

    GrMatrix viewM = fTarget->getViewMatrix();
    GrScalar tol = GR_Scalar1;
    tol = GrPathUtils::scaleToleranceToSrc(tol, viewM, fPath->getBounds());

    // FIXME: It's really dumb that we recreate the verts for a new vertex
    // layout. We only do that because the GrDrawTarget API doesn't allow
    // us to change the vertex layout after reserveVertexSpace(). We won't
    // actually change the vertex data when the layout changes since all the
    // stages reference the positions (rather than having separate tex coords)
    // and we don't ever have per-vert colors. In practice our call sites
    // won't change the stages in use inside a setPath / removePath pair. But
    // it is a silly limitation of the GrDrawTarget design that should be fixed.
    if (tol != fPreviousSrcTol ||
        stages != fPreviousStages) {
        if (!this->createGeom(tol, stages)) {
            return;
        }
    }

    GrAssert(NULL != fTarget);
    GrDrawTarget::AutoStateRestore asr(fTarget);
    bool colorWritesWereDisabled = fTarget->isColorWriteDisabled();
    // face culling doesn't make sense here
    GrAssert(GrDrawTarget::kBoth_DrawFace == fTarget->getDrawFace());

    int                         passCount = 0;
    const GrStencilSettings*    passes[3];
    GrDrawTarget::DrawFace      drawFace[3];
    bool                        reverse = false;
    bool                        lastPassIsBounds;

    if (kHairLine_PathFill == fFill) {
        passCount = 1;
        if (stencilOnly) {
            passes[0] = &gDirectToStencil;
        } else {
            passes[0] = NULL;
        }
        lastPassIsBounds = false;
        drawFace[0] = GrDrawTarget::kBoth_DrawFace;
    } else {
        if (single_pass_path(*fTarget, *fPath, fFill)) {
            passCount = 1;
            if (stencilOnly) {
                passes[0] = &gDirectToStencil;
            } else {
                passes[0] = NULL;
            }
            drawFace[0] = GrDrawTarget::kBoth_DrawFace;
            lastPassIsBounds = false;
        } else {
            switch (fFill) {
                case kInverseEvenOdd_PathFill:
                    reverse = true;
                    // fallthrough
                case kEvenOdd_PathFill:
                    passes[0] = &gEOStencilPass;
                    if (stencilOnly) {
                        passCount = 1;
                        lastPassIsBounds = false;
                    } else {
                        passCount = 2;
                        lastPassIsBounds = true;
                        if (reverse) {
                            passes[1] = &gInvEOColorPass;
                        } else {
                            passes[1] = &gEOColorPass;
                        }
                    }
                    drawFace[0] = drawFace[1] = GrDrawTarget::kBoth_DrawFace;
                    break;

                case kInverseWinding_PathFill:
                    reverse = true;
                    // fallthrough
                case kWinding_PathFill:
                    if (fSeparateStencil) {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindStencilSeparateWithWrap;
                        } else {
                            passes[0] = &gWindStencilSeparateNoWrap;
                        }
                        passCount = 2;
                        drawFace[0] = GrDrawTarget::kBoth_DrawFace;
                    } else {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindSingleStencilWithWrapInc;
                            passes[1] = &gWindSingleStencilWithWrapDec;
                        } else {
                            passes[0] = &gWindSingleStencilNoWrapInc;
                            passes[1] = &gWindSingleStencilNoWrapDec;
                        }
                        // which is cw and which is ccw is arbitrary.
                        drawFace[0] = GrDrawTarget::kCW_DrawFace;
                        drawFace[1] = GrDrawTarget::kCCW_DrawFace;
                        passCount = 3;
                    }
                    if (stencilOnly) {
                        lastPassIsBounds = false;
                        --passCount;
                    } else {
                        lastPassIsBounds = true;
                        drawFace[passCount-1] = GrDrawTarget::kBoth_DrawFace;
                        if (reverse) {
                            passes[passCount-1] = &gInvWindColorPass;
                        } else {
                            passes[passCount-1] = &gWindColorPass;
                        }
                    }
                    break;
                default:
                    GrAssert(!"Unknown path fFill!");
                    return;
            }
        }
    }

    {
    for (int p = 0; p < passCount; ++p) {
        fTarget->setDrawFace(drawFace[p]);
        if (NULL != passes[p]) {
            fTarget->setStencil(*passes[p]);
        }

        if (lastPassIsBounds && (p == passCount-1)) {
            if (!colorWritesWereDisabled) {
                fTarget->disableState(GrDrawTarget::kNoColorWrites_StateBit);
            }
            GrRect bounds;
            if (reverse) {
                GrAssert(NULL != fTarget->getRenderTarget());
                // draw over the whole world.
                bounds.setLTRB(0, 0,
                               GrIntToScalar(fTarget->getRenderTarget()->width()),
                               GrIntToScalar(fTarget->getRenderTarget()->height()));
                GrMatrix vmi;
                // mapRect through persp matrix may not be correct
                if (!fTarget->getViewMatrix().hasPerspective() &&
                    fTarget->getViewInverse(&vmi)) {
                    vmi.mapRect(&bounds);
                } else {
                    if (stages) {
                        if (!fTarget->getViewInverse(&vmi)) {
                            GrPrintf("Could not invert matrix.");
                            return;
                        }
                        fTarget->preConcatSamplerMatrices(stages, vmi);
                    }
                    fTarget->setViewMatrix(GrMatrix::I());
                }
            } else {
                bounds = fPath->getBounds();
                bounds.offset(fTranslate);
            }
            GrDrawTarget::AutoGeometryPush agp(fTarget);
            fTarget->drawSimpleRect(bounds, NULL, stages);
        } else {
            if (passCount > 1) {
                fTarget->enableState(GrDrawTarget::kNoColorWrites_StateBit);
            }
            if (fUseIndexedDraw) {
                fTarget->drawIndexed(fPrimitiveType, 0, 0, 
                                     fVertexCnt, fIndexCnt);
            } else {
                int baseVertex = 0;
                for (int sp = 0; sp < fSubpathCount; ++sp) {
                    fTarget->drawNonIndexed(fPrimitiveType, baseVertex,
                                            fSubpathVertCount[sp]);
                    baseVertex += fSubpathVertCount[sp];
                }
            }
        }
    }
    }
}
Beispiel #3
0
////////////////////////////////////////////////////////////////////////////////
// Create a 8-bit clip mask in alpha
bool GrClipMaskManager::createAlphaClipMask(const GrClipData& clipDataIn,
                                            GrTexture** result,
                                            GrIRect *devResultBounds) {
    GrAssert(NULL != devResultBounds);
    GrAssert(kNone_ClipMaskType == fCurrClipMaskType);

    if (this->clipMaskPreamble(clipDataIn, result, devResultBounds)) {
        fCurrClipMaskType = kAlpha_ClipMaskType;
        return true;
    }

    // Note: 'resultBounds' is in device (as opposed to canvas) coordinates

    GrTexture* accum = fAACache.getLastMask();
    if (NULL == accum) {
        fAACache.reset();
        return false;
    }

    GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
    GrDrawState* drawState = fGpu->drawState();

    GrDrawTarget::AutoGeometryPush agp(fGpu);

    // The mask we generate is translated so that its upper-left corner is at devResultBounds
    // upper-left corner in device space.
    GrIRect maskResultBounds = GrIRect::MakeWH(devResultBounds->width(), devResultBounds->height());

    // Set the matrix so that rendered clip elements are transformed from the space of the clip
    // stack to the alpha-mask. This accounts for both translation due to the clip-origin and the
    // placement of the mask within the device.
    SkVector clipToMaskOffset = {
        SkIntToScalar(-devResultBounds->fLeft - clipDataIn.fOrigin.fX),
        SkIntToScalar(-devResultBounds->fTop - clipDataIn.fOrigin.fY)
    };
    drawState->viewMatrix()->setTranslate(clipToMaskOffset);

    bool clearToInside;
    SkRegion::Op firstOp = SkRegion::kReplace_Op; // suppress warning

    SkClipStack::Iter iter(*clipDataIn.fClipStack,
                           SkClipStack::Iter::kBottom_IterStart);
    const SkClipStack::Iter::Clip* clip = process_initial_clip_elements(&iter,
                                                              *devResultBounds,
                                                              &clearToInside,
                                                              &firstOp,
                                                              clipDataIn);
    // 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(&maskResultBounds,
                clearToInside ? 0xffffffff : 0x00000000,
                accum->asRenderTarget());
    bool accumClearedToZero = !clearToInside;

    GrAutoScratchTexture temp;
    bool first = true;
    // walk through each clip element and perform its set op
    for ( ; NULL != clip; clip = iter.nextCombined()) {

        SkRegion::Op op = clip->fOp;
        if (first) {
            first = false;
            op = firstOp;
        }

        if (SkRegion::kReplace_Op == op) {
            // clear the accumulator and draw the new object directly into it
            if (!accumClearedToZero) {
                fGpu->clear(&maskResultBounds, 0x00000000, accum->asRenderTarget());
            }

            setup_boolean_blendcoeffs(drawState, op);
            this->drawClipShape(accum, clip, *devResultBounds);

        } else if (SkRegion::kReverseDifference_Op == op ||
                   SkRegion::kIntersect_Op == op) {
            // there is no point in intersecting a screen filling rectangle.
            if (SkRegion::kIntersect_Op == op && NULL != clip->fRect &&
                contains(*clip->fRect, *devResultBounds, clipDataIn.fOrigin)) {
                continue;
            }

            getTemp(*devResultBounds, &temp);
            if (NULL == temp.texture()) {
                fAACache.reset();
                return false;
            }

            // 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
            GrRect elementMaskBounds = clip->getBounds();
            elementMaskBounds.offset(clipToMaskOffset);
            GrIRect elementMaskIBounds;
            elementMaskBounds.roundOut(&elementMaskIBounds);

            // clear the temp target & draw into it
            fGpu->clear(&elementMaskIBounds, 0x00000000, temp.texture()->asRenderTarget());

            setup_boolean_blendcoeffs(drawState, SkRegion::kReplace_Op);
            this->drawClipShape(temp.texture(), clip, elementMaskIBounds);

            // Now draw into the accumulator using the real operation
            // and the temp buffer as a texture
            this->mergeMask(accum, temp.texture(), op, maskResultBounds, elementMaskIBounds);
        } else {
            // all the remaining ops can just be directly draw into
            // the accumulation buffer
            setup_boolean_blendcoeffs(drawState, op);
            this->drawClipShape(accum, clip, *devResultBounds);
        }
        accumClearedToZero = false;
    }

    *result = accum;
    fCurrClipMaskType = kAlpha_ClipMaskType;
    return true;
}