SkDrawProcs.h File Reference

#include "include/core/SkPaint.h"
#include "include/core/SkScalar.h"

Go to the source code of this file.

Functions
bool	SkDrawTreatAAStrokeAsHairline (SkScalar strokeWidth, const SkMatrix &, SkScalar *coverage)
bool	SkDrawTreatAsHairline (const SkPaint &paint, const SkMatrix &matrix, SkScalar *coverage)

Function Documentation

SkDrawTreatAAStrokeAsHairline()

bool SkDrawTreatAAStrokeAsHairline	(	SkScalar	strokeWidth,
		const SkMatrix &	matrix,
		SkScalar *	coverage
	)

Definition at line 262 of file SkDrawBase.cpp.

                                                       {
    SkASSERT(strokeWidth > 0);
    // We need to try to fake a thick-stroke with a modulated hairline.
 
    if (matrix.hasPerspective()) {
        return false;
    }
 
    SkVector src[2], dst[2];
    src[0].set(strokeWidth, 0);
    src[1].set(0, strokeWidth);
    matrix.mapVectors(dst, src, 2);
    SkScalar len0 = fast_len(dst[0]);
    SkScalar len1 = fast_len(dst[1]);
    if (len0 <= SK_Scalar1 && len1 <= SK_Scalar1) {
        if (coverage) {
            *coverage = SkScalarAve(len0, len1);
        }
        return true;
    }
    return false;
}

SkDrawTreatAsHairline()

bool SkDrawTreatAsHairline ( const SkPaint &  paint, const SkMatrix &  matrix, SkScalar *  coverage  )

inline

If the current paint is set to stroke and the stroke-width when applied to the matrix is <= 1.0, then this returns true, and sets coverage (simulating a stroke by drawing a hairline with partial coverage). If any of these conditions are false, then this returns false and coverage is ignored.

Definition at line 24 of file SkDrawProcs.h.

                                                      {
    if (SkPaint::kStroke_Style != paint.getStyle()) {
        return false;
    }
 
    SkScalar strokeWidth = paint.getStrokeWidth();
    if (0 == strokeWidth) {
        *coverage = SK_Scalar1;
        return true;
    }
 
    if (!paint.isAntiAlias()) {
        return false;
    }
 
    return SkDrawTreatAAStrokeAsHairline(strokeWidth, matrix, coverage);
}