C++ GrDrawState::viewMatrix方法代码示例

////////////////////////////////////////////////////////////////////////////////
// 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);

    if (0 != devResultBounds->fTop || 0 != devResultBounds->fLeft ||
        0 != clipDataIn.fOrigin.fX || 0 != clipDataIn.fOrigin.fY) {
        // if we were able to trim down the size of the mask we need to
        // offset the paths & rects that will be used to compute it
        drawState->viewMatrix()->setTranslate(
                SkIntToScalar(-devResultBounds->fLeft-clipDataIn.fOrigin.fX),
                SkIntToScalar(-devResultBounds->fTop-clipDataIn.fOrigin.fY));
    }

    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);

    fGpu->clear(NULL,
                clearToInside ? 0xffffffff : 0x00000000,
                accum->asRenderTarget());

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

        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
            fGpu->clear(NULL, 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;
            }

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

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

            // TODO: rather than adding these two translations here
            // compute the bounding box needed to render the texture
            // into temp
            if (0 != devResultBounds->fTop || 0 != devResultBounds->fLeft ||
                0 != clipDataIn.fOrigin.fX || 0 != clipDataIn.fOrigin.fY) {
                // In order for the merge of the temp clip into the accumulator
                // to work we need to disable the translation
                drawState->viewMatrix()->reset();
            }

            // Now draw into the accumulator using the real operation
            // and the temp buffer as a texture
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(const GrClipData& clipDataIn,
                                              const GrIRect& devClipBounds) {

    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;
    }

    if (stencilBuffer->mustRenderClip(clipDataIn, rt->width(), rt->height())) {

        stencilBuffer->setLastClip(clipDataIn, rt->width(), rt->height());

        // we set the current clip to the bounds so that our recursive
        // draws are scissored to them. We use the copy of the complex clip
        // we just stashed on the SB to render from. We set it back after
        // we finish drawing it into the stencil.
        const GrClipData* oldClipData = fGpu->getClip();

        // The origin of 'newClipData' is (0, 0) so it is okay to place
        // a device-coordinate bound in 'newClipStack'
        SkClipStack newClipStack(devClipBounds);
        GrClipData newClipData;
        newClipData.fClipStack = &newClipStack;

        fGpu->setClip(&newClipData);

        GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
        drawState = fGpu->drawState();
        drawState->setRenderTarget(rt);
        GrDrawTarget::AutoGeometryPush agp(fGpu);

        if (0 != clipDataIn.fOrigin.fX || 0 != clipDataIn.fOrigin.fY) {
            // Add the saveLayer's offset to the view matrix rather than
            // offset each individual draw
            drawState->viewMatrix()->setTranslate(
                           SkIntToScalar(-clipDataIn.fOrigin.fX),
                           SkIntToScalar(-clipDataIn.fOrigin.fY));
        }

#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));

        GrIRect devRTRect = GrIRect::MakeWH(rt->width(), rt->height());

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

        SkClipStack::Iter iter(*oldClipData->fClipStack,
                               SkClipStack::Iter::kBottom_IterStart);
        const SkClipStack::Iter::Clip* clip = process_initial_clip_elements(&iter,
                                                  devRTRect,
                                                  &clearToInside,
                                                  &firstOp,
                                                  clipDataIn);

        fGpu->clearStencilClip(devClipBounds, clearToInside);
        bool first = true;

        // walk through each clip element and perform its set op
        // with the existing clip.
        for ( ; NULL != clip; clip = iter.next()) {
            GrPathFill fill;
            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()) {
                if (clip->fDoAA) {
                    drawState->enableState(GrDrawState::kHWAntialias_StateBit);
                } else {
                    drawState->disableState(GrDrawState::kHWAntialias_StateBit);
                }
            }

            // Can the clip element be drawn directly to the stencil buffer
            // with a non-inverted fill rule without extra passes to
            // resolve in/out status?
            bool canRenderDirectToStencil = false;

            SkRegion::Op op = clip->fOp;
            if (first) {
                first = false;
//.........这里部分代码省略.........

bool GrAAHairLinePathRenderer::onDrawPath(const SkPath& path,
                                          GrPathFill fill,
                                          const GrVec* translate,
                                          GrDrawTarget* target,
                                          GrDrawState::StageMask stageMask,
                                          bool antiAlias) {

    int lineCnt;
    int quadCnt;
    GrDrawTarget::AutoReleaseGeometry arg;
    if (!this->createGeom(path,
                          translate,
                          target,
                          stageMask,
                          &lineCnt,
                          &quadCnt,
                          &arg)) {
        return false;
    }

    GrDrawTarget::AutoStateRestore asr;
    GrDrawState* drawState = target->drawState();
    if (!drawState->getViewMatrix().hasPerspective()) {
        // we are going to whack the view matrix to identity to remove
        // perspective.
        asr.set(target,
                GrDrawTarget::kPreserve_ASRInit);
        drawState = target->drawState();
        GrMatrix ivm;
        if (drawState->getViewInverse(&ivm)) {
            drawState->preConcatSamplerMatrices(stageMask, ivm);
        }
        drawState->viewMatrix()->reset();
    }
    

    // TODO: See whether rendering lines as degenerate quads improves perf
    // when we have a mix
    target->setIndexSourceToBuffer(fLinesIndexBuffer);
    int lines = 0;
    int nBufLines = fLinesIndexBuffer->maxQuads();
    while (lines < lineCnt) {
        int n = GrMin(lineCnt - lines, nBufLines);
        drawState->setVertexEdgeType(GrDrawState::kHairLine_EdgeType);
        target->drawIndexed(kTriangles_GrPrimitiveType,
                            kVertsPerLineSeg*lines,    // startV
                            0,                         // startI
                            kVertsPerLineSeg*n,        // vCount
                            kIdxsPerLineSeg*n);        // iCount
        lines += n;
    }

    target->setIndexSourceToBuffer(fQuadsIndexBuffer);
    int quads = 0;
    while (quads < quadCnt) {
        int n = GrMin(quadCnt - quads, kNumQuadsInIdxBuffer);
        drawState->setVertexEdgeType(GrDrawState::kHairQuad_EdgeType);
        target->drawIndexed(kTriangles_GrPrimitiveType,
                            4 * lineCnt + kVertsPerQuad*quads, // startV
                            0,                                 // startI
                            kVertsPerQuad*n,                   // vCount
                            kIdxsPerQuad*n);                   // iCount
        quads += n;
    }
    return true;
}