Remove the remainder of the skia source code from the Chromium repo....

skia/sgl/SkGeometry.h

-/* libs/graphics/sgl/SkGeometry.h
-**
-** Copyright 2006, The Android Open Source Project
-**
-** Licensed under the Apache License, Version 2.0 (the "License"); 
-** you may not use this file except in compliance with the License. 
-** You may obtain a copy of the License at 
-**
-**     http://www.apache.org/licenses/LICENSE-2.0 
-**
-** Unless required by applicable law or agreed to in writing, software 
-** distributed under the License is distributed on an "AS IS" BASIS, 
-** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
-** See the License for the specific language governing permissions and 
-** limitations under the License.
-*/
-
-#ifndef SkGeometry_DEFINED
-#define SkGeometry_DEFINED
-
-#include "SkMatrix.h"
-
-/** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
-    equation.
-*/
-int SkFindUnitQuadRoots(SkScalar A, SkScalar B, SkScalar C, SkScalar roots[2]);
-
-///////////////////////////////////////////////////////////////////////////////
-
-/** Set pt to the point on the src quadratic specified by t. t must be
-    0 <= t <= 1.0
-*/
-void SkEvalQuadAt(const SkPoint src[3], SkScalar t, SkPoint* pt, SkVector* tangent = NULL);
-void SkEvalQuadAtHalf(const SkPoint src[3], SkPoint* pt, SkVector* tangent = NULL);
-
-/** Given a src quadratic bezier, chop it at the specified t value,
-    where 0 < t < 1, and return the two new quadratics in dst:
-    dst[0..2] and dst[2..4]
-*/
-void SkChopQuadAt(const SkPoint src[3], SkPoint dst[5], SkScalar t);
-
-/** Given a src quadratic bezier, chop it at the specified t == 1/2,
-    The new quads are returned in dst[0..2] and dst[2..4]
-*/
-void SkChopQuadAtHalf(const SkPoint src[3], SkPoint dst[5]);
-
-/** Given the 3 coefficients for a quadratic bezier (either X or Y values), look
-    for extrema, and return the number of t-values that are found that represent
-    these extrema. If the quadratic has no extrema betwee (0..1) exclusive, the
-    function returns 0.
-    Returned count      tValues[]
-    0                   ignored
-    1                   0 < tValues[0] < 1
-*/
-int SkFindQuadExtrema(SkScalar a, SkScalar b, SkScalar c, SkScalar tValues[1]);
-
-/** Given 3 points on a quadratic bezier, chop it into 1, 2 beziers such that
-    the resulting beziers are monotonic in Y. This is called by the scan converter.
-    Depending on what is returned, dst[] is treated as follows
-    1   dst[0..2] is the original quad
-    2   dst[0..2] and dst[2..4] are the two new quads
-    If dst == null, it is ignored and only the count is returned.
-*/
-int SkChopQuadAtYExtrema(const SkPoint src[3], SkPoint dst[5]);
-
-/** Given 3 points on a quadratic bezier, divide it into 2 quadratics
-    if the point of maximum curvature exists on the quad segment.
-    Depending on what is returned, dst[] is treated as follows
-    1   dst[0..2] is the original quad
-    2   dst[0..2] and dst[2..4] are the two new quads
-    If dst == null, it is ignored and only the count is returned.
-*/
-int SkChopQuadAtMaxCurvature(const SkPoint src[3], SkPoint dst[5]);
-
-////////////////////////////////////////////////////////////////////////////////////////
-
-/** Convert from parametric from (pts) to polynomial coefficients
-    coeff[0]*T^3 + coeff[1]*T^2 + coeff[2]*T + coeff[3]
-*/
-void SkGetCubicCoeff(const SkPoint pts[4], SkScalar cx[4], SkScalar cy[4]);
-
-/** Set pt to the point on the src cubic specified by t. t must be
-    0 <= t <= 1.0
-*/
-void SkEvalCubicAt(const SkPoint src[4], SkScalar t, SkPoint* locOrNull, SkVector* tangentOrNull, SkVector* curvatureOrNull);
-
-/** Given a src cubic bezier, chop it at the specified t value,
-    where 0 < t < 1, and return the two new cubics in dst:
-    dst[0..3] and dst[3..6]
-*/
-void SkChopCubicAt(const SkPoint src[4], SkPoint dst[7], SkScalar t);
-void SkChopCubicAt(const SkPoint src[4], SkPoint dst[7], const SkScalar t[], int t_count);
-
-/** Given a src cubic bezier, chop it at the specified t == 1/2,
-    The new cubics are returned in dst[0..3] and dst[3..6]
-*/
-void SkChopCubicAtHalf(const SkPoint src[4], SkPoint dst[7]);
-
-/** Given the 4 coefficients for a cubic bezier (either X or Y values), look
-    for extrema, and return the number of t-values that are found that represent
-    these extrema. If the cubic has no extrema betwee (0..1) exclusive, the
-    function returns 0.
-    Returned count      tValues[]
-    0                   ignored
-    1                   0 < tValues[0] < 1
-    2                   0 < tValues[0] < tValues[1] < 1
-*/
-int SkFindCubicExtrema(SkScalar a, SkScalar b, SkScalar c, SkScalar d, SkScalar tValues[2]);
-
-/** Given 4 points on a cubic bezier, chop it into 1, 2, 3 beziers such that
-    the resulting beziers are monotonic in Y. This is called by the scan converter.
-    Depending on what is returned, dst[] is treated as follows
-    1   dst[0..3] is the original cubic
-    2   dst[0..3] and dst[3..6] are the two new cubics
-    3   dst[0..3], dst[3..6], dst[6..9] are the three new cubics
-    If dst == null, it is ignored and only the count is returned.
-*/
-int SkChopCubicAtYExtrema(const SkPoint src[4], SkPoint dst[10]);
-
-/** Given a cubic bezier, return 0, 1, or 2 t-values that represent the
-    inflection points.
-*/
-int SkFindCubicInflections(const SkPoint src[4], SkScalar tValues[2]);
-
-/** Return 1 for no chop, or 2 for having chopped the cubic at its
-    inflection point.
-*/
-int SkChopCubicAtInflections(const SkPoint src[4], SkPoint dst[10]);
-
-int SkFindCubicMaxCurvature(const SkPoint src[4], SkScalar tValues[3]);
-int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13], SkScalar tValues[3] = NULL);
-
-///////////////////////////////////////////////////////////////////////////////////////////
-
-enum SkRotationDirection {
-    kCW_SkRotationDirection,
-    kCCW_SkRotationDirection
-};
-
-/** Maximum number of points needed in the quadPoints[] parameter for
-    SkBuildQuadArc()
-*/
-#define kSkBuildQuadArcStorage  17
-
-/** Given 2 unit vectors and a rotation direction, fill out the specified
-    array of points with quadratic segments. Return is the number of points
-    written to, which will be { 0, 3, 5, 7, ... kSkBuildQuadArcStorage }
-
-    matrix, if not null, is appled to the points before they are returned.
-*/
-int SkBuildQuadArc(const SkVector& unitStart, const SkVector& unitStop, SkRotationDirection,
-                   const SkMatrix* matrix, SkPoint quadPoints[]);
-
-//////////////////////////////////////////////////////////////////////////////
-
-#ifdef SK_DEBUG
-    class SkGeometry {
-    public:
-        static void UnitTest();
-    };
-#endif
-
-#endif