/src/poppler/splash/SplashClip.cc
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1 | | //======================================================================== |
2 | | // |
3 | | // SplashClip.cc |
4 | | // |
5 | | //======================================================================== |
6 | | |
7 | | //======================================================================== |
8 | | // |
9 | | // Modified under the Poppler project - http://poppler.freedesktop.org |
10 | | // |
11 | | // All changes made under the Poppler project to this file are licensed |
12 | | // under GPL version 2 or later |
13 | | // |
14 | | // Copyright (C) 2010, 2021, 2025, 2026 Albert Astals Cid <aacid@kde.org> |
15 | | // Copyright (C) 2013, 2021 Thomas Freitag <Thomas.Freitag@alfa.de> |
16 | | // Copyright (C) 2019, 2025 Stefan Brüns <stefan.bruens@rwth-aachen.de> |
17 | | // |
18 | | // To see a description of the changes please see the Changelog file that |
19 | | // came with your tarball or type make ChangeLog if you are building from git |
20 | | // |
21 | | //======================================================================== |
22 | | |
23 | | #include <config.h> |
24 | | |
25 | | #include <algorithm> |
26 | | #include "SplashErrorCodes.h" |
27 | | #include "SplashMath.h" |
28 | | #include "SplashPath.h" |
29 | | #include "SplashXPath.h" |
30 | | #include "SplashXPathScanner.h" |
31 | | #include "SplashBitmap.h" |
32 | | #include "SplashClip.h" |
33 | | |
34 | | //------------------------------------------------------------------------ |
35 | | // SplashClip |
36 | | //------------------------------------------------------------------------ |
37 | | |
38 | | SplashClip::SplashClip(double x0, double y0, double x1, double y1, bool antialiasA) |
39 | 0 | { |
40 | 0 | antialias = antialiasA; |
41 | 0 | if (x0 < x1) { |
42 | 0 | xMin = x0; |
43 | 0 | xMax = x1; |
44 | 0 | } else { |
45 | 0 | xMin = x1; |
46 | 0 | xMax = x0; |
47 | 0 | } |
48 | 0 | if (y0 < y1) { |
49 | 0 | yMin = y0; |
50 | 0 | yMax = y1; |
51 | 0 | } else { |
52 | 0 | yMin = y1; |
53 | 0 | yMax = y0; |
54 | 0 | } |
55 | 0 | xMinI = splashFloor(xMin); |
56 | 0 | yMinI = splashFloor(yMin); |
57 | 0 | xMaxI = splashCeil(xMax) - 1; |
58 | 0 | yMaxI = splashCeil(yMax) - 1; |
59 | 0 | } |
60 | | |
61 | | SplashClip::SplashClip(const SplashClip *clip, PrivateTag /*unused*/) |
62 | 0 | { |
63 | 0 | antialias = clip->antialias; |
64 | 0 | xMin = clip->xMin; |
65 | 0 | yMin = clip->yMin; |
66 | 0 | xMax = clip->xMax; |
67 | 0 | yMax = clip->yMax; |
68 | 0 | xMinI = clip->xMinI; |
69 | 0 | yMinI = clip->yMinI; |
70 | 0 | xMaxI = clip->xMaxI; |
71 | 0 | yMaxI = clip->yMaxI; |
72 | 0 | scanners = clip->scanners; |
73 | 0 | } |
74 | | |
75 | | void SplashClip::resetToRect(double x0, double y0, double x1, double y1) |
76 | 0 | { |
77 | 0 | scanners = {}; |
78 | |
|
79 | 0 | if (x0 < x1) { |
80 | 0 | xMin = x0; |
81 | 0 | xMax = x1; |
82 | 0 | } else { |
83 | 0 | xMin = x1; |
84 | 0 | xMax = x0; |
85 | 0 | } |
86 | 0 | if (y0 < y1) { |
87 | 0 | yMin = y0; |
88 | 0 | yMax = y1; |
89 | 0 | } else { |
90 | 0 | yMin = y1; |
91 | 0 | yMax = y0; |
92 | 0 | } |
93 | 0 | xMinI = splashFloor(xMin); |
94 | 0 | yMinI = splashFloor(yMin); |
95 | 0 | xMaxI = splashCeil(xMax) - 1; |
96 | 0 | yMaxI = splashCeil(yMax) - 1; |
97 | 0 | } |
98 | | |
99 | | SplashError SplashClip::clipToRect(double x0, double y0, double x1, double y1) |
100 | 0 | { |
101 | 0 | if (x0 < x1) { |
102 | 0 | if (x0 > xMin) { |
103 | 0 | xMin = x0; |
104 | 0 | xMinI = splashFloor(xMin); |
105 | 0 | } |
106 | 0 | if (x1 < xMax) { |
107 | 0 | xMax = x1; |
108 | 0 | xMaxI = splashCeil(xMax) - 1; |
109 | 0 | } |
110 | 0 | } else { |
111 | 0 | if (x1 > xMin) { |
112 | 0 | xMin = x1; |
113 | 0 | xMinI = splashFloor(xMin); |
114 | 0 | } |
115 | 0 | if (x0 < xMax) { |
116 | 0 | xMax = x0; |
117 | 0 | xMaxI = splashCeil(xMax) - 1; |
118 | 0 | } |
119 | 0 | } |
120 | 0 | if (y0 < y1) { |
121 | 0 | if (y0 > yMin) { |
122 | 0 | yMin = y0; |
123 | 0 | yMinI = splashFloor(yMin); |
124 | 0 | } |
125 | 0 | if (y1 < yMax) { |
126 | 0 | yMax = y1; |
127 | 0 | yMaxI = splashCeil(yMax) - 1; |
128 | 0 | } |
129 | 0 | } else { |
130 | 0 | if (y1 > yMin) { |
131 | 0 | yMin = y1; |
132 | 0 | yMinI = splashFloor(yMin); |
133 | 0 | } |
134 | 0 | if (y0 < yMax) { |
135 | 0 | yMax = y0; |
136 | 0 | yMaxI = splashCeil(yMax) - 1; |
137 | 0 | } |
138 | 0 | } |
139 | 0 | return SplashError::NoError; |
140 | 0 | } |
141 | | |
142 | | namespace { |
143 | | // returns true if the 4 consecutive segments form a axis aligned rectangle |
144 | | // first and third segment must be the vertical segments |
145 | | constexpr bool isRect(const SplashXPathSeg &a, const SplashXPathSeg &b, const SplashXPathSeg &c, const SplashXPathSeg &d) |
146 | 0 | { |
147 | | // Check if segment a and c are vertical, and b and d are horizontal |
148 | 0 | if ((a.x0 != a.x1) || (b.y0 != b.y1) || (c.x0 != c.x1) || (d.y0 != d.y1)) { |
149 | 0 | return false; |
150 | 0 | } |
151 | | // Check if x coordinates match |
152 | 0 | if ((a.x1 != b.x0) || (b.x1 != c.x0) || (c.x1 != d.x0) || (d.x1 != a.x0)) { |
153 | 0 | return false; |
154 | 0 | } |
155 | 0 | if ((a.y0 != c.y0) || (a.y1 != c.y1)) { |
156 | 0 | return false; |
157 | 0 | } |
158 | 0 | if ((a.y0 == b.y0) && (a.y1 == d.y0)) { |
159 | 0 | return true; |
160 | 0 | } |
161 | 0 | if ((a.y0 == d.y0) && (a.y1 == b.y0)) { |
162 | 0 | return true; |
163 | 0 | } |
164 | 0 | return false; |
165 | 0 | } |
166 | | // 4 valid cases - two orientations, start on left or right |
167 | | static_assert(isRect({ .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 1.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
168 | | { .x0 = 2.0, .y0 = 0.0, .x1 = 0.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
169 | | static_assert(isRect({ .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
170 | | { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 })); |
171 | | static_assert(isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 0.0, .x1 = 0.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
172 | | { .x0 = 0.0, .y0 = 1.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 })); |
173 | | static_assert(isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
174 | | { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
175 | | // 4 invalid cases, one segment point not closing |
176 | | static_assert(!isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 3.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
177 | | { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
178 | | static_assert(!isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 3.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
179 | | { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
180 | | static_assert(!isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 3.0, .dxdy = 0.0, .flags = 0 }, |
181 | | { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
182 | | static_assert(!isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
183 | | { .x0 = 0.0, .y0 = 0.0, .x1 = 3.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
184 | | // invalid case, closed, but left segment not vertical |
185 | | static_assert(!isRect({ .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 1.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 1.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
186 | | { .x0 = 1.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
187 | | // invalid case, all horizontal/vertical, but horizontal segments coincident |
188 | | static_assert(!isRect({ .x0 = 0.0, .y0 = 0.0, .x1 = 0.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 0.0, .y0 = 0.0, .x1 = 2.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 }, { .x0 = 2.0, .y0 = 0.0, .x1 = 2.0, .y1 = 1.0, .dxdy = 0.0, .flags = 0 }, |
189 | | { .x0 = 2.0, .y0 = 0.0, .x1 = 0.0, .y1 = 0.0, .dxdy = 0.0, .flags = 0 })); |
190 | | } |
191 | | |
192 | | SplashError SplashClip::clipToPath(const SplashPath &path, const std::array<double, 6> &matrix, double flatness, bool eo) |
193 | 0 | { |
194 | 0 | int yMinAA, yMaxAA; |
195 | |
|
196 | 0 | SplashXPath xPath(path, matrix, flatness, true); |
197 | | |
198 | | // check for an empty path |
199 | 0 | if (xPath.length == 0) { |
200 | 0 | xMax = xMin - 1; |
201 | 0 | yMax = yMin - 1; |
202 | 0 | xMaxI = splashCeil(xMax) - 1; |
203 | 0 | yMaxI = splashCeil(yMax) - 1; |
204 | | |
205 | | // check for an axis aligned rectangle |
206 | 0 | } else if (xPath.length == 4 && isRect(xPath.segs[0], xPath.segs[1], xPath.segs[2], xPath.segs[3])) { |
207 | 0 | clipToRect(xPath.segs[0].x0, xPath.segs[0].y0, xPath.segs[2].x0, xPath.segs[2].y1); |
208 | 0 | } else if (xPath.length == 4 && isRect(xPath.segs[1], xPath.segs[2], xPath.segs[3], xPath.segs[0])) { |
209 | 0 | clipToRect(xPath.segs[1].x0, xPath.segs[1].y0, xPath.segs[3].x0, xPath.segs[3].y1); |
210 | |
|
211 | 0 | } else { |
212 | 0 | if (antialias) { |
213 | 0 | xPath.aaScale(); |
214 | 0 | yMinAA = yMinI * splashAASize; |
215 | 0 | yMaxAA = (yMaxI + 1) * splashAASize - 1; |
216 | 0 | } else { |
217 | 0 | yMinAA = yMinI; |
218 | 0 | yMaxAA = yMaxI; |
219 | 0 | } |
220 | 0 | scanners.emplace_back(std::make_shared<SplashXPathScanner>(xPath, eo, yMinAA, yMaxAA)); |
221 | 0 | } |
222 | |
|
223 | 0 | return SplashError::NoError; |
224 | 0 | } |
225 | | |
226 | | SplashClipResult SplashClip::testRect(int rectXMin, int rectYMin, int rectXMax, int rectYMax) const |
227 | 0 | { |
228 | | // This tests the rectangle: |
229 | | // x = [rectXMin, rectXMax + 1) (note: rect coords are ints) |
230 | | // y = [rectYMin, rectYMax + 1) |
231 | | // against the clipping region: |
232 | | // x = [xMin, xMax) (note: clipping coords are fp) |
233 | | // y = [yMin, yMax) |
234 | 0 | if (static_cast<double>(rectXMax + 1) <= xMin || static_cast<double>(rectXMin) >= xMax || static_cast<double>(rectYMax + 1) <= yMin || static_cast<double>(rectYMin) >= yMax) { |
235 | 0 | return splashClipAllOutside; |
236 | 0 | } |
237 | 0 | if (static_cast<double>(rectXMin) >= xMin && static_cast<double>(rectXMax + 1) <= xMax && static_cast<double>(rectYMin) >= yMin && static_cast<double>(rectYMax + 1) <= yMax && scanners.empty()) { |
238 | 0 | return splashClipAllInside; |
239 | 0 | } |
240 | 0 | return splashClipPartial; |
241 | 0 | } |
242 | | |
243 | | SplashClipResult SplashClip::testSpan(int spanXMin, int spanXMax, int spanY) |
244 | 0 | { |
245 | | // This tests the rectangle: |
246 | | // x = [spanXMin, spanXMax + 1) (note: span coords are ints) |
247 | | // y = [spanY, spanY + 1) |
248 | | // against the clipping region: |
249 | | // x = [xMin, xMax) (note: clipping coords are fp) |
250 | | // y = [yMin, yMax) |
251 | 0 | if (static_cast<double>(spanXMax + 1) <= xMin || static_cast<double>(spanXMin) >= xMax || static_cast<double>(spanY + 1) <= yMin || static_cast<double>(spanY) >= yMax) { |
252 | 0 | return splashClipAllOutside; |
253 | 0 | } |
254 | 0 | if (static_cast<double>(spanXMin) < xMin || static_cast<double>(spanXMax + 1) > xMax || static_cast<double>(spanY) < yMin || static_cast<double>(spanY + 1) > yMax) { |
255 | 0 | return splashClipPartial; |
256 | 0 | } |
257 | 0 | if (antialias) { |
258 | 0 | for (const auto &scanner : scanners) { |
259 | 0 | if (!scanner->testSpan(spanXMin * splashAASize, spanXMax * splashAASize + (splashAASize - 1), spanY * splashAASize)) { |
260 | 0 | return splashClipPartial; |
261 | 0 | } |
262 | 0 | } |
263 | 0 | } else { |
264 | 0 | for (const auto &scanner : scanners) { |
265 | 0 | if (!scanner->testSpan(spanXMin, spanXMax, spanY)) { |
266 | 0 | return splashClipPartial; |
267 | 0 | } |
268 | 0 | } |
269 | 0 | } |
270 | 0 | return splashClipAllInside; |
271 | 0 | } |
272 | | |
273 | | void SplashClip::clipAALine(SplashBitmap *aaBuf, int *x0, int *x1, int y, bool adjustVertLine) |
274 | 0 | { |
275 | 0 | int xx0, xx1, xx, yy; |
276 | 0 | SplashColorPtr p; |
277 | | |
278 | | // zero out pixels with x < xMin |
279 | 0 | xx0 = *x0 * splashAASize; |
280 | 0 | xx1 = splashFloor(xMin * splashAASize); |
281 | 0 | if (xx1 > aaBuf->getWidth()) { |
282 | 0 | xx1 = aaBuf->getWidth(); |
283 | 0 | } |
284 | 0 | if (xx0 < xx1) { |
285 | 0 | xx0 &= ~7; |
286 | 0 | for (yy = 0; yy < splashAASize; ++yy) { |
287 | 0 | p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx0 >> 3); |
288 | 0 | for (xx = xx0; xx + 7 < xx1; xx += 8) { |
289 | 0 | *p++ = 0; |
290 | 0 | } |
291 | 0 | if (xx < xx1 && !adjustVertLine) { |
292 | 0 | *p &= 0xff >> (xx1 & 7); |
293 | 0 | } |
294 | 0 | } |
295 | 0 | *x0 = splashFloor(xMin); |
296 | 0 | } |
297 | | |
298 | | // zero out pixels with x > xMax |
299 | 0 | xx0 = splashFloor(xMax * splashAASize) + 1; |
300 | 0 | if (xx0 < 0) { |
301 | 0 | xx0 = 0; |
302 | 0 | } |
303 | 0 | xx1 = (*x1 + 1) * splashAASize; |
304 | 0 | if (xx0 < xx1 && !adjustVertLine) { |
305 | 0 | for (yy = 0; yy < splashAASize; ++yy) { |
306 | 0 | p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx0 >> 3); |
307 | 0 | xx = xx0; |
308 | 0 | if (xx & 7) { |
309 | 0 | *p &= 0xff00 >> (xx & 7); |
310 | 0 | xx = (xx & ~7) + 8; |
311 | 0 | ++p; |
312 | 0 | } |
313 | 0 | for (; xx < xx1; xx += 8) { |
314 | 0 | *p++ = 0; |
315 | 0 | } |
316 | 0 | } |
317 | 0 | *x1 = splashFloor(xMax); |
318 | 0 | } |
319 | | |
320 | | // check the paths |
321 | 0 | for (const auto &scanner : scanners) { |
322 | 0 | scanner->clipAALine(aaBuf, x0, x1, y); |
323 | 0 | } |
324 | 0 | if (*x0 > *x1) { |
325 | 0 | *x0 = *x1; |
326 | 0 | } |
327 | 0 | if (*x0 < 0) { |
328 | 0 | *x0 = 0; |
329 | 0 | } |
330 | 0 | if ((*x0 >> 1) >= aaBuf->getRowSize()) { |
331 | 0 | xx0 = *x0; |
332 | 0 | *x0 = (aaBuf->getRowSize() - 1) << 1; |
333 | 0 | if (xx0 & 1) { |
334 | 0 | *x0 = *x0 + 1; |
335 | 0 | } |
336 | 0 | } |
337 | 0 | if (*x1 < *x0) { |
338 | 0 | *x1 = *x0; |
339 | 0 | } |
340 | 0 | if ((*x1 >> 1) >= aaBuf->getRowSize()) { |
341 | 0 | xx0 = *x1; |
342 | 0 | *x1 = (aaBuf->getRowSize() - 1) << 1; |
343 | 0 | if (xx0 & 1) { |
344 | 0 | *x1 = *x1 + 1; |
345 | 0 | } |
346 | 0 | } |
347 | 0 | } |
348 | | |
349 | | bool SplashClip::testClipPaths(int x, int y) const |
350 | 0 | { |
351 | 0 | if (antialias) { |
352 | 0 | x *= splashAASize; |
353 | 0 | y *= splashAASize; |
354 | 0 | } |
355 | |
|
356 | 0 | auto testXY = [x, y](const auto &scanner) -> bool { // |
357 | 0 | return scanner->test(x, y); |
358 | 0 | }; |
359 | |
|
360 | 0 | return std::ranges::all_of(scanners, testXY); |
361 | 0 | } |