SkAnalyticCubicEdge Struct Reference

#include <SkAnalyticEdge.h>

Inheritance diagram for SkAnalyticCubicEdge:

Public Member Functions
bool	setCubic (const SkPoint pts[4], bool sortY=true)
bool	updateCubic (bool sortY=true)
void	keepContinuous ()
Public Member Functions inherited from SkAnalyticEdge
void	goY (SkFixed y)
void	goY (SkFixed y, int yShift)
bool	setLine (const SkPoint &p0, const SkPoint &p1)
bool	updateLine (SkFixed ax, SkFixed ay, SkFixed bx, SkFixed by, SkFixed slope)
bool	update (SkFixed last_y, bool sortY=true)

Public Attributes
SkCubicEdge	fCEdge
SkFixed	fSnappedY
Public Attributes inherited from SkAnalyticEdge
SkAnalyticEdge *	fNext
SkAnalyticEdge *	fPrev
SkFixed	fX
SkFixed	fDX
SkFixed	fUpperX
SkFixed	fY
SkFixed	fUpperY
SkFixed	fLowerY
SkFixed	fDY
Type	fEdgeType
int8_t	fCurveCount
uint8_t	fCurveShift
uint8_t	fCubicDShift
int8_t	fWinding

Additional Inherited Members
Public Types inherited from SkAnalyticEdge
enum	Type { kLine_Type , kQuad_Type , kCubic_Type }
Static Public Member Functions inherited from SkAnalyticEdge
static SkFixed	SnapY (SkFixed y)
Static Public Attributes inherited from SkAnalyticEdge
static const int	kDefaultAccuracy = 2

Detailed Description

Definition at line 118 of file SkAnalyticEdge.h.

Member Function Documentation

keepContinuous()

void SkAnalyticCubicEdge::keepContinuous ( )

inline

Definition at line 125 of file SkAnalyticEdge.h.

                                 {
        SkASSERT(SkAbs32(fX - SkFixedMul(fDX, fY - SnapY(fCEdge.fCy)) - fCEdge.fCx) < SK_Fixed1);
        fCEdge.fCx = fX;
        fSnappedY = fY;
    }

setCubic()

bool SkAnalyticCubicEdge::setCubic	(	const SkPoint	pts[4],
		bool	sortY = true
	)

Definition at line 352 of file SkAnalyticEdge.cpp.

                                                                   {
    if (!fCEdge.setCubicWithoutUpdate(pts, kDefaultAccuracy, sortY)) {
        return false;
    }
 
    fCEdge.fCx >>= kDefaultAccuracy;
    fCEdge.fCy >>= kDefaultAccuracy;
    fCEdge.fCDx >>= kDefaultAccuracy;
    fCEdge.fCDy >>= kDefaultAccuracy;
    fCEdge.fCDDx >>= kDefaultAccuracy;
    fCEdge.fCDDy >>= kDefaultAccuracy;
    fCEdge.fCDDDx >>= kDefaultAccuracy;
    fCEdge.fCDDDy >>= kDefaultAccuracy;
    fCEdge.fCLastX >>= kDefaultAccuracy;
    fCEdge.fCLastY >>= kDefaultAccuracy;
    fCEdge.fCy = SnapY(fCEdge.fCy);
    fCEdge.fCLastY = SnapY(fCEdge.fCLastY);
 
    fWinding = fCEdge.fWinding;
    fEdgeType = kCubic_Type;
    fCurveCount = fCEdge.fCurveCount;
    fCurveShift = fCEdge.fCurveShift;
    fCubicDShift = fCEdge.fCubicDShift;
 
    fSnappedY = fCEdge.fCy;
 
    return this->updateCubic(sortY);
}

updateCubic()

bool SkAnalyticCubicEdge::updateCubic

(

bool

sortY = true

)

Definition at line 381 of file SkAnalyticEdge.cpp.

                                                {
    int     success;
    int     count = fCurveCount;
    SkFixed oldx = fCEdge.fCx;
    SkFixed oldy = fCEdge.fCy;
    SkFixed newx, newy;
    const int ddshift = fCurveShift;
    const int dshift = fCubicDShift;
 
    SkASSERT(count < 0);
 
    do {
        if (++count < 0) {
            newx    = oldx + (fCEdge.fCDx >> dshift);
            fCEdge.fCDx    += fCEdge.fCDDx >> ddshift;
            fCEdge.fCDDx   += fCEdge.fCDDDx;
 
            newy    = oldy + (fCEdge.fCDy >> dshift);
            fCEdge.fCDy    += fCEdge.fCDDy >> ddshift;
            fCEdge.fCDDy   += fCEdge.fCDDDy;
        }
        else {    // last segment
            newx    = fCEdge.fCLastX;
            newy    = fCEdge.fCLastY;
        }
 
        // we want to say SkASSERT(oldy <= newy), but our finite fixedpoint
        // doesn't always achieve that, so we have to explicitly pin it here.
        if (sortY && newy < oldy) {
            newy = oldy;
        }
 
        SkFixed newSnappedY = SnapY(newy);
        // we want to SkASSERT(snappedNewY <= fCEdge.fCLastY), but our finite fixedpoint
        // doesn't always achieve that, so we have to explicitly pin it here.
        if (sortY && fCEdge.fCLastY < newSnappedY) {
            newSnappedY = fCEdge.fCLastY;
            count = 0;
        }
 
        SkFixed slope = SkFixedToFDot6(newSnappedY - fSnappedY) == 0
                        ? SK_MaxS32
                        : SkFDot6Div(SkFixedToFDot6(newx - oldx),
                                     SkFixedToFDot6(newSnappedY - fSnappedY));
 
        success = this->updateLine(oldx, fSnappedY, newx, newSnappedY, slope);
 
        oldx = newx;
        oldy = newy;
        fSnappedY = newSnappedY;
    } while (count < 0 && !success);
 
    fCEdge.fCx  = newx;
    fCEdge.fCy  = newy;
    fCurveCount = SkToS8(count);
    return success;
}

Member Data Documentation

fCEdge

SkCubicEdge SkAnalyticCubicEdge::fCEdge

Definition at line 119 of file SkAnalyticEdge.h.

fSnappedY

SkFixed SkAnalyticCubicEdge::fSnappedY

Definition at line 121 of file SkAnalyticEdge.h.

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The documentation for this struct was generated from the following files:

• third_party/skia/src/core/SkAnalyticEdge.h
• third_party/skia/src/core/SkAnalyticEdge.cpp