C++ SkStrokeRec::getCap方法代码示例

/**
 * Draw a single path element of the clip stack into the accumulation bitmap
 */
void GrSWMaskHelper::draw(const SkPath& path, const SkStrokeRec& stroke, SkRegion::Op op,
                          bool antiAlias, uint8_t alpha) {

    SkPaint paint;
    if (stroke.isHairlineStyle()) {
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setStrokeWidth(SK_Scalar1);
    } else {
        if (stroke.isFillStyle()) {
            paint.setStyle(SkPaint::kFill_Style);
        } else {
            paint.setStyle(SkPaint::kStroke_Style);
            paint.setStrokeJoin(stroke.getJoin());
            paint.setStrokeCap(stroke.getCap());
            paint.setStrokeWidth(stroke.getWidth());
        }
    }
    paint.setAntiAlias(antiAlias);

    if (SkRegion::kReplace_Op == op && 0xFF == alpha) {
        SkASSERT(0xFF == paint.getAlpha());
        fDraw.drawPathCoverage(path, paint);
    } else {
        paint.setXfermodeMode(op_to_mode(op));
        paint.setColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
        fDraw.drawPath(path, paint);
    }
}

uint64_t GrPath::ComputeStrokeKey(const SkStrokeRec& stroke) {
    enum {
        kStyleBits = 2,
        kJoinBits = 2,
        kCapBits = 2,
        kWidthBits = 29,
        kMiterBits = 29,

        kJoinShift = kStyleBits,
        kCapShift = kJoinShift + kJoinBits,
        kWidthShift = kCapShift + kCapBits,
        kMiterShift = kWidthShift + kWidthBits,

        kBitCount = kMiterShift + kMiterBits
    };

    SK_COMPILE_ASSERT(SkStrokeRec::kStyleCount <= (1 << kStyleBits), style_shift_will_be_wrong);
    SK_COMPILE_ASSERT(SkPaint::kJoinCount <= (1 << kJoinBits), cap_shift_will_be_wrong);
    SK_COMPILE_ASSERT(SkPaint::kCapCount <= (1 << kCapBits), miter_shift_will_be_wrong);
    SK_COMPILE_ASSERT(kBitCount == 64, wrong_stroke_key_size);

    if (!stroke.needToApply()) {
        return SkStrokeRec::kFill_Style;
    }

    uint64_t key = stroke.getStyle();
    key |= stroke.getJoin() << kJoinShift;
    key |= stroke.getCap() << kCapShift;
    key |= get_top_n_float_bits<kWidthBits>(stroke.getWidth()) << kWidthShift;
    key |= get_top_n_float_bits<kMiterBits>(stroke.getMiter()) << kMiterShift;

    return key;
}

bool GrStrokePathRenderer::canDrawPath(const SkPath& path,
                                       const SkStrokeRec& stroke,
                                       const GrDrawTarget* target,
                                       bool antiAlias) const {
    // FIXME : put the proper condition once GrDrawTarget::isOpaque is implemented
    const bool isOpaque = true; // target->isOpaque();

    // FIXME : remove this requirement once we have AA circles and implement the
    //         circle joins/caps appropriately in the ::onDrawPath() function.
    const bool requiresAACircle = (stroke.getCap()  == SkPaint::kRound_Cap) ||
                                  (stroke.getJoin() == SkPaint::kRound_Join);

    // Indices being stored in uint16, we don't want to overflow the indices capacity
    static const int maxVBSize = 1 << 16;
    const int maxNbVerts = (path.countPoints() + 1) * 5;

    // Check that the path contains no curved lines, only straight lines
    static const uint32_t unsupportedMask = SkPath::kQuad_SegmentMask | SkPath::kCubic_SegmentMask;

    // Must not be filled nor hairline nor semi-transparent
    // Note : May require a check to path.isConvex() if AA is supported
    return ((stroke.getStyle() == SkStrokeRec::kStroke_Style) && (maxNbVerts < maxVBSize) &&
            !path.isInverseFillType() && isOpaque && !requiresAACircle && !antiAlias &&
            ((path.getSegmentMasks() & unsupportedMask) == 0));
}

/**
 * Draw a single path element of the clip stack into the accumulation bitmap
 */
void GrSWMaskHelper::draw(const SkPath& path, const SkStrokeRec& stroke, SkRegion::Op op,
                          bool antiAlias, uint8_t alpha) {

    SkPaint paint;
    if (stroke.isHairlineStyle()) {
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setStrokeWidth(SK_Scalar1);
    } else {
        if (stroke.isFillStyle()) {
            paint.setStyle(SkPaint::kFill_Style);
        } else {
            paint.setStyle(SkPaint::kStroke_Style);
            paint.setStrokeJoin(stroke.getJoin());
            paint.setStrokeCap(stroke.getCap());
            paint.setStrokeWidth(stroke.getWidth());
        }
    }
    paint.setAntiAlias(antiAlias);

    SkTBlitterAllocator allocator;
    SkBlitter* blitter = nullptr;
    if (kBlitter_CompressionMode == fCompressionMode) {
        SkASSERT(fCompressedBuffer.get());
        blitter = SkTextureCompressor::CreateBlitterForFormat(
            fPixels.width(), fPixels.height(), fCompressedBuffer.get(), &allocator,
                                                              fCompressedFormat);
    }

    if (SkRegion::kReplace_Op == op && 0xFF == alpha) {
        SkASSERT(0xFF == paint.getAlpha());
        fDraw.drawPathCoverage(path, paint, blitter);
    } else {
        paint.setXfermodeMode(op_to_mode(op));
        paint.setColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
        fDraw.drawPath(path, paint, blitter);
    }
}

// Currently asPoints is more restrictive then it needs to be. In the future
// we need to:
//      allow kRound_Cap capping (could allow rotations in the matrix with this)
//      allow paths to be returned
bool SkDashPathEffect::asPoints(PointData* results,
                                const SkPath& src,
                                const SkStrokeRec& rec,
                                const SkMatrix& matrix,
                                const SkRect* cullRect) const {
    // width < 0 -> fill && width == 0 -> hairline so requiring width > 0 rules both out
    if (fInitialDashLength < 0 || 0 >= rec.getWidth()) {
        return false;
    }

    // TODO: this next test could be eased up. We could allow any number of
    // intervals as long as all the ons match and all the offs match.
    // Additionally, they do not necessarily need to be integers.
    // We cannot allow arbitrary intervals since we want the returned points
    // to be uniformly sized.
    if (fCount != 2 ||
        !SkScalarNearlyEqual(fIntervals[0], fIntervals[1]) ||
        !SkScalarIsInt(fIntervals[0]) ||
        !SkScalarIsInt(fIntervals[1])) {
        return false;
    }

    SkPoint pts[2];

    if (!src.isLine(pts)) {
        return false;
    }

    // TODO: this test could be eased up to allow circles
    if (SkPaint::kButt_Cap != rec.getCap()) {
        return false;
    }

    // TODO: this test could be eased up for circles. Rotations could be allowed.
    if (!matrix.rectStaysRect()) {
        return false;
    }

    // See if the line can be limited to something plausible.
    if (!cull_line(pts, rec, matrix, cullRect, fIntervalLength)) {
        return false;
    }

    SkScalar length = SkPoint::Distance(pts[1], pts[0]);

    SkVector tangent = pts[1] - pts[0];
    if (tangent.isZero()) {
        return false;
    }

    tangent.scale(SkScalarInvert(length));

    // TODO: make this test for horizontal & vertical lines more robust
    bool isXAxis = true;
    if (SkScalarNearlyEqual(SK_Scalar1, tangent.fX) ||
        SkScalarNearlyEqual(-SK_Scalar1, tangent.fX)) {
        results->fSize.set(SkScalarHalf(fIntervals[0]), SkScalarHalf(rec.getWidth()));
    } else if (SkScalarNearlyEqual(SK_Scalar1, tangent.fY) ||
               SkScalarNearlyEqual(-SK_Scalar1, tangent.fY)) {
        results->fSize.set(SkScalarHalf(rec.getWidth()), SkScalarHalf(fIntervals[0]));
        isXAxis = false;
    } else if (SkPaint::kRound_Cap != rec.getCap()) {
        // Angled lines don't have axis-aligned boxes.
        return false;
    }

    if (results) {
        results->fFlags = 0;
        SkScalar clampedInitialDashLength = SkMinScalar(length, fInitialDashLength);

        if (SkPaint::kRound_Cap == rec.getCap()) {
            results->fFlags |= PointData::kCircles_PointFlag;
        }

        results->fNumPoints = 0;
        SkScalar len2 = length;
        if (clampedInitialDashLength > 0 || 0 == fInitialDashIndex) {
            SkASSERT(len2 >= clampedInitialDashLength);
            if (0 == fInitialDashIndex) {
                if (clampedInitialDashLength > 0) {
                    if (clampedInitialDashLength >= fIntervals[0]) {
                        ++results->fNumPoints;  // partial first dash
                    }
                    len2 -= clampedInitialDashLength;
                }
                len2 -= fIntervals[1];  // also skip first space
                if (len2 < 0) {
                    len2 = 0;
                }
            } else {
                len2 -= clampedInitialDashLength; // skip initial partial empty
            }
        }
        int numMidPoints = SkScalarFloorToInt(len2 / fIntervalLength);
        results->fNumPoints += numMidPoints;
        len2 -= numMidPoints * fIntervalLength;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                                                        miterPt[0] = *pt0+v0;
                                                    }
                                                } else {
                                                    miterPt[1] = miterPt[0];
                                                }
                                                useMiterPoint = true;
                                            }
                                        }
                                        if (useMiterPoint && (miterPt[1] == miterPt[0])) {
                                            break;
                                        }
                                    }
                                    default:
                                    case SkPaint::kBevel_Join:
                                    {
                                        // Note : This currently causes some overdraw where both
                                        //        lines initially intersect. We'd need to add
                                        //        another line intersection check here if the
                                        //        overdraw becomes an issue instead of using the
                                        //        current point directly.

                                        // Add center point
                                        *verts++ = pts[0]; // Use current point directly
                                        // This idx is passed the current point so increment it
                                        ++idx1;
                                        // Add center triangle
                                        *idxs++ = idx0;
                                        *idxs++ = vCount;
                                        *idxs++ = idx1;
                                        vCount++;
                                        iCount += 3;
                                    }
                                    break;
                                }
                            }
                        }
                    }
                    *verts++ = l1a;
                    *verts++ = l2a;
                    lastPt   = verts;
                    *verts++ = l1b;
                    *verts++ = l2b;

                    if (useMiterPoint && (idx0 >= 0) && (idx1 >= 0)) {
                        firstPt[idx0] = miterPt[0];
                        firstPt[idx1] = miterPt[1];
                    }

                    // 1st triangle
                    *idxs++  = vCount+0;
                    *idxs++  = vCount+2;
                    *idxs++  = vCount+1;
                    // 2nd triangle
                    *idxs++  = vCount+1;
                    *idxs++  = vCount+2;
                    *idxs++  = vCount+3;

                    vCount += 4;
                    iCount += 6;
                }
            }
                break;
            case SkPath::kQuad_Verb:
            case SkPath::kCubic_Verb:
                SkDEBUGFAIL("Curves not supported!");
            default:
                // Unhandled cases
                SkASSERT(false);
        }
    }

    if (isOpen) {
        // Add caps
        switch (stroke.getCap()) {
            case SkPaint::kSquare_Cap:
                firstPt[0] -= firstDir;
                firstPt[1] -= firstDir;
                lastPt [0] += dir;
                lastPt [1] += dir;
                break;
            case SkPaint::kRound_Cap:
                SkDEBUGFAIL("Round caps not supported!");
            default: // No cap
                break;
        }
    }

    SkASSERT(vCount <= maxVertexCount);
    SkASSERT(iCount <= maxIndexCount);

    if (vCount > 0) {
        target->drawIndexed(kTriangles_GrPrimitiveType,
                            0,        // start vertex
                            0,        // start index
                            vCount,
                            iCount);
    }

    return true;
}