Add base types for path ops

src/pathops/SkPathOpsCurve.h

+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkPathOpsCurve_DEFINE
+#define SkPathOpsCurve_DEFINE
+
+#include "SkPathOpsCubic.h"
+#include "SkPathOpsLine.h"
+#include "SkPathOpsQuad.h"
+
+static SkDPoint dline_xy_at_t(const SkPoint a[2], double t) {
+    SkDLine line;
+    line.set(a);
+    return line.xyAtT(t);
+}
+
+static SkDPoint dquad_xy_at_t(const SkPoint a[3], double t) {
+    SkDQuad quad;
+    quad.set(a);
+    return quad.xyAtT(t);
+}
+
+static SkDPoint dcubic_xy_at_t(const SkPoint a[4], double t) {
+    SkDCubic cubic;
+    cubic.set(a);
+    return cubic.xyAtT(t);
+}
+
+static SkDPoint (* const CurveDPointAtT[])(const SkPoint[], double ) = {
+    NULL,
+    dline_xy_at_t,
+    dquad_xy_at_t,
+    dcubic_xy_at_t
+};
+
+static SkPoint fline_xy_at_t(const SkPoint a[2], double t) {
+    return dline_xy_at_t(a, t).asSkPoint();
+}
+
+static SkPoint fquad_xy_at_t(const SkPoint a[3], double t) {
+    return dquad_xy_at_t(a, t).asSkPoint();
+}
+
+static SkPoint fcubic_xy_at_t(const SkPoint a[4], double t) {
+    return dcubic_xy_at_t(a, t).asSkPoint();
+}
+
+static SkPoint (* const CurvePointAtT[])(const SkPoint[], double ) = {
+    NULL,
+    fline_xy_at_t,
+    fquad_xy_at_t,
+    fcubic_xy_at_t
+};
+
+static SkDVector dline_dxdy_at_t(const SkPoint a[2], double ) {
+    SkDLine line;
+    line.set(a);
+    return line[1] - line[0];
+}
+
+static SkDVector dquad_dxdy_at_t(const SkPoint a[3], double t) {
+    SkDQuad quad;
+    quad.set(a);
+    return quad.dxdyAtT(t);
+}
+
+static SkDVector dcubic_dxdy_at_t(const SkPoint a[4], double t) {
+    SkDCubic cubic;
+    cubic.set(a);
+    return cubic.dxdyAtT(t);
+}
+
+static SkDVector (* const CurveDSlopeAtT[])(const SkPoint[], double ) = {
+    NULL,
+    dline_dxdy_at_t,
+    dquad_dxdy_at_t,
+    dcubic_dxdy_at_t
+};
+
+static SkVector fline_dxdy_at_t(const SkPoint a[2], double ) {
+    return a[1] - a[0];
+}
+
+static SkVector fquad_dxdy_at_t(const SkPoint a[3], double t) {
+    return dquad_dxdy_at_t(a, t).asSkVector();
+}
+
+static SkVector fcubic_dxdy_at_t(const SkPoint a[4], double t) {
+    return dcubic_dxdy_at_t(a, t).asSkVector();
+}
+
+static SkVector (* const CurveSlopeAtT[])(const SkPoint[], double ) = {
+    NULL,
+    fline_dxdy_at_t,
+    fquad_dxdy_at_t,
+    fcubic_dxdy_at_t
+};
+
+static SkPoint quad_top(const SkPoint a[3], double startT, double endT) {
+    SkDQuad quad;
+    quad.set(a);
+    SkDPoint topPt = quad.top(startT, endT);
+    return topPt.asSkPoint();
+}
+
+static SkPoint cubic_top(const SkPoint a[4], double startT, double endT) {
+    SkDCubic cubic;
+    cubic.set(a);
+    SkDPoint topPt = cubic.top(startT, endT);
+    return topPt.asSkPoint();
+}
+
+static SkPoint (* const CurveTop[])(const SkPoint[], double , double ) = {
+    NULL,
+    NULL,
+    quad_top,
+    cubic_top
+};
+
+static bool line_is_vertical(const SkPoint a[2], double startT, double endT) {
+    SkDLine line;
+    line.set(a);
+    SkDPoint dst[2] = { line.xyAtT(startT), line.xyAtT(endT) };
+    return AlmostEqualUlps(dst[0].fX, dst[1].fX);
+}
+
+static bool quad_is_vertical(const SkPoint a[3], double startT, double endT) {
+    SkDQuad quad;
+    quad.set(a);
+    SkDQuad dst = quad.subDivide(startT, endT);
+    return AlmostEqualUlps(dst[0].fX, dst[1].fX) && AlmostEqualUlps(dst[1].fX, dst[2].fX);
+}
+
+static bool cubic_is_vertical(const SkPoint a[4], double startT, double endT) {
+    SkDCubic cubic;
+    cubic.set(a);
+    SkDCubic dst = cubic.subDivide(startT, endT);
+    return AlmostEqualUlps(dst[0].fX, dst[1].fX) && AlmostEqualUlps(dst[1].fX, dst[2].fX)
+            && AlmostEqualUlps(dst[2].fX, dst[3].fX);
+}
+
+static bool (* const CurveIsVertical[])(const SkPoint[], double , double) = {
+    NULL,
+    line_is_vertical,
+    quad_is_vertical,
+    cubic_is_vertical
+};
+
+#endif