2 * Copyright 2011 Google Inc.
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
8 #include "include/core/SkPath.h"
9 #include "include/core/SkPathTypes.h"
10 #include "include/core/SkPoint.h"
11 #include "include/core/SkScalar.h"
12 #include "include/core/SkStream.h"
13 #include "include/core/SkString.h"
14 #include "include/core/SkTypes.h"
15 #include "include/utils/SkParse.h"
16 #include "include/utils/SkParsePath.h"
17 #include "src/core/SkGeometry.h"
21 static inline bool is_between(int c, int min, int max) {
22 return (unsigned)(c - min) <= (unsigned)(max - min);
25 static inline bool is_ws(int c) {
26 return is_between(c, 1, 32);
29 static inline bool is_digit(int c) {
30 return is_between(c, '0', '9');
33 static inline bool is_sep(int c) {
34 return is_ws(c) || c == ',';
37 static inline bool is_lower(int c) {
38 return is_between(c, 'a', 'z');
41 static inline int to_upper(int c) {
45 static const char* skip_ws(const char str[]) {
52 static const char* skip_sep(const char str[]) {
61 static const char* find_points(const char str[], SkPoint value[], int count,
62 bool isRelative, SkPoint* relative) {
63 str = SkParse::FindScalars(str, &value[0].fX, count * 2);
65 for (int index = 0; index < count; index++) {
66 value[index].fX += relative->fX;
67 value[index].fY += relative->fY;
73 static const char* find_scalar(const char str[], SkScalar* value,
74 bool isRelative, SkScalar relative) {
75 str = SkParse::FindScalar(str, value);
86 // https://www.w3.org/TR/SVG11/paths.html#PathDataBNF
90 static const char* find_flag(const char str[], bool* value) {
94 if (str[0] != '1' && str[0] != '0') {
97 *value = str[0] != '0';
98 str = skip_sep(str + 1);
102 bool SkParsePath::FromSVGString(const char data[], SkPath* result) {
104 SkPoint first = {0, 0};
106 SkPoint lastc = {0, 0};
109 char previousOp = '\0';
110 bool relative = false;
116 data = skip_ws(data);
117 if (data[0] == '\0') {
121 if (is_digit(ch) || ch == '-' || ch == '+' || ch == '.') {
122 if (op == '\0' || op == 'Z') {
125 } else if (is_sep(ch)) {
126 data = skip_sep(data);
131 op = (char) to_upper(op);
135 data = skip_sep(data);
139 data = find_points(data, points, 1, relative, &c);
140 path.moveTo(points[0]);
146 data = find_points(data, points, 1, relative, &c);
147 path.lineTo(points[0]);
152 data = find_scalar(data, &x, relative, c.fX);
153 path.lineTo(x, c.fY);
158 data = find_scalar(data, &y, relative, c.fY);
159 path.lineTo(c.fX, y);
163 data = find_points(data, points, 3, relative, &c);
166 data = find_points(data, &points[1], 2, relative, &c);
168 if (previousOp == 'C' || previousOp == 'S') {
169 points[0].fX -= lastc.fX - c.fX;
170 points[0].fY -= lastc.fY - c.fY;
173 path.cubicTo(points[0], points[1], points[2]);
177 case 'Q': // Quadratic Bezier Curve
178 data = find_points(data, points, 2, relative, &c);
179 goto quadraticCommon;
181 data = find_points(data, &points[1], 1, relative, &c);
183 if (previousOp == 'Q' || previousOp == 'T') {
184 points[0].fX -= lastc.fX - c.fX;
185 points[0].fY -= lastc.fY - c.fY;
188 path.quadTo(points[0], points[1]);
195 bool largeArc, sweep;
196 if ((data = find_points(data, &radii, 1, false, nullptr))
197 && (data = skip_sep(data))
198 && (data = find_scalar(data, &angle, false, 0))
199 && (data = skip_sep(data))
200 && (data = find_flag(data, &largeArc))
201 && (data = skip_sep(data))
202 && (data = find_flag(data, &sweep))
203 && (data = skip_sep(data))
204 && (data = find_points(data, &points[0], 1, relative, &c))) {
205 path.arcTo(radii, angle, (SkPath::ArcSize) largeArc,
206 (SkPathDirection) !sweep, points[0]);
216 data = find_points(data, args, 2, false, nullptr);
217 path.moveTo(args[0].fX, args[0].fY);
218 path.lineTo(args[1].fX, args[1].fY);
223 if (previousOp == 0) {
228 // we're good, go ahead and swap in the result
233 ///////////////////////////////////////////////////////////////////////////////
235 static void write_scalar(SkWStream* stream, SkScalar value) {
237 #ifdef SK_BUILD_FOR_WIN
238 int len = _snprintf(buffer, sizeof(buffer), "%g", value);
240 int len = snprintf(buffer, sizeof(buffer), "%g", value);
242 char* stop = buffer + len;
243 stream->write(buffer, stop - buffer);
246 void SkParsePath::ToSVGString(const SkPath& path, SkString* str, PathEncoding encoding) {
247 SkDynamicMemoryWStream stream;
249 SkPoint current_point{0,0};
250 const auto rel_selector = encoding == PathEncoding::Relative;
252 const auto append_command = [&](char cmd, const SkPoint pts[], size_t count) {
253 // Use lower case cmds for relative encoding.
254 cmd += 32 * rel_selector;
255 stream.write(&cmd, 1);
257 for (size_t i = 0; i < count; ++i) {
258 const auto pt = pts[i] - current_point;
260 stream.write(" ", 1);
262 write_scalar(&stream, pt.fX);
263 stream.write(" ", 1);
264 write_scalar(&stream, pt.fY);
268 // For relative encoding, track the current point (otherwise == origin).
269 current_point = pts[count - 1] * rel_selector;
272 SkPath::Iter iter(path, false);
276 switch (iter.next(pts)) {
277 case SkPath::kConic_Verb: {
278 const SkScalar tol = SK_Scalar1 / 1024; // how close to a quad
279 SkAutoConicToQuads quadder;
280 const SkPoint* quadPts = quadder.computeQuads(pts, iter.conicWeight(), tol);
281 for (int i = 0; i < quadder.countQuads(); ++i) {
282 append_command('Q', &quadPts[i*2 + 1], 2);
285 case SkPath::kMove_Verb:
286 append_command('M', &pts[0], 1);
288 case SkPath::kLine_Verb:
289 append_command('L', &pts[1], 1);
291 case SkPath::kQuad_Verb:
292 append_command('Q', &pts[1], 2);
294 case SkPath::kCubic_Verb:
295 append_command('C', &pts[1], 3);
297 case SkPath::kClose_Verb:
298 stream.write("Z", 1);
300 case SkPath::kDone_Verb:
301 str->resize(stream.bytesWritten());
302 stream.copyTo(str->writable_str());