GrAAConvexTessellator.cpp File Reference

#include "src/gpu/ganesh/geometry/GrAAConvexTessellator.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPath.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/private/base/SkAssert.h"
#include "include/private/base/SkFloatingPoint.h"
#include "include/private/base/SkTPin.h"
#include "src/core/SkPathPriv.h"
#include "src/gpu/ganesh/geometry/GrPathUtils.h"
#include <algorithm>
#include "src/core/SkGeometry.h"

Go to the source code of this file.

Functions
static bool	intersect (const SkPoint &p0, const SkPoint &n0, const SkPoint &p1, const SkPoint &n1, SkScalar *t)
static bool	perp_intersect (const SkPoint &p0, const SkPoint &n0, const SkPoint &p1, const SkPoint &perp, SkScalar *t)
static bool	duplicate_pt (const SkPoint &p0, const SkPoint &p1)
static bool	points_are_colinear_and_b_is_middle (const SkPoint &a, const SkPoint &b, const SkPoint &c, float *accumError)
static SkScalar	compute_coverage (SkScalar depth, SkScalar initialDepth, SkScalar initialCoverage, SkScalar targetDepth, SkScalar targetCoverage)

Variables
static constexpr SkScalar	kClose = (SK_Scalar1 / 16)
static constexpr SkScalar	kCloseSqd = kClose * kClose
static constexpr SkScalar	kQuadTolerance = 0.2f
static constexpr SkScalar	kCubicTolerance = 0.2f
static constexpr SkScalar	kQuadToleranceSqd = kQuadTolerance * kQuadTolerance
static constexpr SkScalar	kCubicToleranceSqd = kCubicTolerance * kCubicTolerance
static constexpr SkScalar	kConicTolerance = 0.25f
static constexpr SkScalar	kRoundCapThreshold = 0.8f
static constexpr SkScalar	kCurveConnectionThreshold = 0.8f

Function Documentation

compute_coverage()

static SkScalar compute_coverage ( SkScalar  depth, SkScalar  initialDepth, SkScalar  initialCoverage, SkScalar  targetDepth, SkScalar  targetCoverage  )

static

Definition at line 683 of file GrAAConvexTessellator.cpp.

                                                                               {
    if (SkScalarNearlyEqual(initialDepth, targetDepth)) {
        return targetCoverage;
    }
    SkScalar result = (depth - initialDepth) / (targetDepth - initialDepth) *
            (targetCoverage - initialCoverage) + initialCoverage;
    return SkTPin(result, 0.0f, 1.0f);
}

duplicate_pt()

static bool duplicate_pt ( const SkPoint &  p0, const SkPoint &  p1  )

static

Definition at line 70 of file GrAAConvexTessellator.cpp.

                                                               {
    SkScalar distSq = SkPointPriv::DistanceToSqd(p0, p1);
    return distSq < kCloseSqd;
}

intersect()

static bool intersect ( const SkPoint &  p0, const SkPoint &  n0, const SkPoint &  p1, const SkPoint &  n1, SkScalar *  t  )

static

Definition at line 44 of file GrAAConvexTessellator.cpp.

                                   {
    const SkPoint v = p1 - p0;
    SkScalar perpDot = n0.fX * n1.fY - n0.fY * n1.fX;
    if (SkScalarNearlyZero(perpDot)) {
        return false;
    }
    *t = (v.fX * n1.fY - v.fY * n1.fX) / perpDot;
    return SkIsFinite(*t);
}

perp_intersect()

static bool perp_intersect ( const SkPoint &  p0, const SkPoint &  n0, const SkPoint &  p1, const SkPoint &  perp, SkScalar *  t  )

static

Definition at line 58 of file GrAAConvexTessellator.cpp.

                                        {
    const SkPoint v = p1 - p0;
    SkScalar perpDot = n0.dot(perp);
    if (SkScalarNearlyZero(perpDot)) {
        return false;
    }
    *t = v.dot(perp) / perpDot;
    return SkIsFinite(*t);
}

points_are_colinear_and_b_is_middle()

static bool points_are_colinear_and_b_is_middle ( const SkPoint &  a, const SkPoint &  b, const SkPoint &  c, float *  accumError  )

static

Definition at line 75 of file GrAAConvexTessellator.cpp.

                                                                                     {
    // First check distance from b to the infinite line through a, c
    SkVector aToC = c - a;
    SkVector n = {aToC.fY, -aToC.fX};
    n.normalize();
 
    SkScalar distBToLineAC = SkScalarAbs(n.dot(b) - n.dot(a));
    if (*accumError + distBToLineAC >= kClose || aToC.dot(b - a) <= 0.f || aToC.dot(c - b) <= 0.f) {
        // Too far from the line or not between the line segment from a to c
        return false;
    } else {
        // Accumulate the distance from b to |ac| that goes "away" when this near-colinear point
        // is removed to simplify the path.
        *accumError += distBToLineAC;
        return true;
    }
}

Variable Documentation

kClose

constexpr SkScalar kClose = (SK_Scalar1 / 16)

staticconstexpr

Definition at line 28 of file GrAAConvexTessellator.cpp.

kCloseSqd

constexpr SkScalar kCloseSqd = kClose * kClose

staticconstexpr

Definition at line 29 of file GrAAConvexTessellator.cpp.

kConicTolerance

constexpr SkScalar kConicTolerance = 0.25f

staticconstexpr

Definition at line 36 of file GrAAConvexTessellator.cpp.

kCubicTolerance

constexpr SkScalar kCubicTolerance = 0.2f

staticconstexpr

Definition at line 33 of file GrAAConvexTessellator.cpp.

kCubicToleranceSqd

constexpr SkScalar kCubicToleranceSqd = kCubicTolerance * kCubicTolerance

staticconstexpr

Definition at line 35 of file GrAAConvexTessellator.cpp.

kCurveConnectionThreshold

constexpr SkScalar kCurveConnectionThreshold = 0.8f

staticconstexpr

Definition at line 42 of file GrAAConvexTessellator.cpp.

kQuadTolerance

constexpr SkScalar kQuadTolerance = 0.2f

staticconstexpr

Definition at line 32 of file GrAAConvexTessellator.cpp.

kQuadToleranceSqd

constexpr SkScalar kQuadToleranceSqd = kQuadTolerance * kQuadTolerance

staticconstexpr

Definition at line 34 of file GrAAConvexTessellator.cpp.

kRoundCapThreshold

constexpr SkScalar kRoundCapThreshold = 0.8f

staticconstexpr

Definition at line 39 of file GrAAConvexTessellator.cpp.