1 /*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkPDFUtils.h"
9
10 #include "SkData.h"
11 #include "SkFixed.h"
12 #include "SkGeometry.h"
13 #include "SkImage_Base.h"
14 #include "SkPDFResourceDict.h"
15 #include "SkPDFTypes.h"
16 #include "SkStream.h"
17 #include "SkString.h"
18
19 #include <cmath>
20
BlendModeName(SkBlendMode mode)21 const char* SkPDFUtils::BlendModeName(SkBlendMode mode) {
22 // PDF32000.book section 11.3.5 "Blend Mode"
23 switch (mode) {
24 case SkBlendMode::kSrcOver: return "Normal";
25 case SkBlendMode::kXor: return "Normal"; // (unsupported mode)
26 case SkBlendMode::kPlus: return "Normal"; // (unsupported mode)
27 case SkBlendMode::kScreen: return "Screen";
28 case SkBlendMode::kOverlay: return "Overlay";
29 case SkBlendMode::kDarken: return "Darken";
30 case SkBlendMode::kLighten: return "Lighten";
31 case SkBlendMode::kColorDodge: return "ColorDodge";
32 case SkBlendMode::kColorBurn: return "ColorBurn";
33 case SkBlendMode::kHardLight: return "HardLight";
34 case SkBlendMode::kSoftLight: return "SoftLight";
35 case SkBlendMode::kDifference: return "Difference";
36 case SkBlendMode::kExclusion: return "Exclusion";
37 case SkBlendMode::kMultiply: return "Multiply";
38 case SkBlendMode::kHue: return "Hue";
39 case SkBlendMode::kSaturation: return "Saturation";
40 case SkBlendMode::kColor: return "Color";
41 case SkBlendMode::kLuminosity: return "Luminosity";
42 // Other blendmodes are handled in SkPDFDevice::setUpContentEntry.
43 default: return nullptr;
44 }
45 }
46
RectToArray(const SkRect & r)47 std::unique_ptr<SkPDFArray> SkPDFUtils::RectToArray(const SkRect& r) {
48 return SkPDFMakeArray(r.left(), r.top(), r.right(), r.bottom());
49 }
50
MatrixToArray(const SkMatrix & matrix)51 std::unique_ptr<SkPDFArray> SkPDFUtils::MatrixToArray(const SkMatrix& matrix) {
52 SkScalar a[6];
53 if (!matrix.asAffine(a)) {
54 SkMatrix::SetAffineIdentity(a);
55 }
56 return SkPDFMakeArray(a[0], a[1], a[2], a[3], a[4], a[5]);
57 }
58
MoveTo(SkScalar x,SkScalar y,SkWStream * content)59 void SkPDFUtils::MoveTo(SkScalar x, SkScalar y, SkWStream* content) {
60 SkPDFUtils::AppendScalar(x, content);
61 content->writeText(" ");
62 SkPDFUtils::AppendScalar(y, content);
63 content->writeText(" m\n");
64 }
65
AppendLine(SkScalar x,SkScalar y,SkWStream * content)66 void SkPDFUtils::AppendLine(SkScalar x, SkScalar y, SkWStream* content) {
67 SkPDFUtils::AppendScalar(x, content);
68 content->writeText(" ");
69 SkPDFUtils::AppendScalar(y, content);
70 content->writeText(" l\n");
71 }
72
append_cubic(SkScalar ctl1X,SkScalar ctl1Y,SkScalar ctl2X,SkScalar ctl2Y,SkScalar dstX,SkScalar dstY,SkWStream * content)73 static void append_cubic(SkScalar ctl1X, SkScalar ctl1Y,
74 SkScalar ctl2X, SkScalar ctl2Y,
75 SkScalar dstX, SkScalar dstY, SkWStream* content) {
76 SkString cmd("y\n");
77 SkPDFUtils::AppendScalar(ctl1X, content);
78 content->writeText(" ");
79 SkPDFUtils::AppendScalar(ctl1Y, content);
80 content->writeText(" ");
81 if (ctl2X != dstX || ctl2Y != dstY) {
82 cmd.set("c\n");
83 SkPDFUtils::AppendScalar(ctl2X, content);
84 content->writeText(" ");
85 SkPDFUtils::AppendScalar(ctl2Y, content);
86 content->writeText(" ");
87 }
88 SkPDFUtils::AppendScalar(dstX, content);
89 content->writeText(" ");
90 SkPDFUtils::AppendScalar(dstY, content);
91 content->writeText(" ");
92 content->writeText(cmd.c_str());
93 }
94
append_quad(const SkPoint quad[],SkWStream * content)95 static void append_quad(const SkPoint quad[], SkWStream* content) {
96 SkPoint cubic[4];
97 SkConvertQuadToCubic(quad, cubic);
98 append_cubic(cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY,
99 cubic[3].fX, cubic[3].fY, content);
100 }
101
AppendRectangle(const SkRect & rect,SkWStream * content)102 void SkPDFUtils::AppendRectangle(const SkRect& rect, SkWStream* content) {
103 // Skia has 0,0 at top left, pdf at bottom left. Do the right thing.
104 SkScalar bottom = SkMinScalar(rect.fBottom, rect.fTop);
105
106 SkPDFUtils::AppendScalar(rect.fLeft, content);
107 content->writeText(" ");
108 SkPDFUtils::AppendScalar(bottom, content);
109 content->writeText(" ");
110 SkPDFUtils::AppendScalar(rect.width(), content);
111 content->writeText(" ");
112 SkPDFUtils::AppendScalar(rect.height(), content);
113 content->writeText(" re\n");
114 }
115
EmitPath(const SkPath & path,SkPaint::Style paintStyle,bool doConsumeDegerates,SkWStream * content,SkScalar tolerance)116 void SkPDFUtils::EmitPath(const SkPath& path, SkPaint::Style paintStyle,
117 bool doConsumeDegerates, SkWStream* content,
118 SkScalar tolerance) {
119 if (path.isEmpty() && SkPaint::kFill_Style == paintStyle) {
120 SkPDFUtils::AppendRectangle({0, 0, 0, 0}, content);
121 return;
122 }
123 // Filling a path with no area results in a drawing in PDF renderers but
124 // Chrome expects to be able to draw some such entities with no visible
125 // result, so we detect those cases and discard the drawing for them.
126 // Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y).
127
128 SkRect rect;
129 bool isClosed; // Both closure and direction need to be checked.
130 SkPath::Direction direction;
131 if (path.isRect(&rect, &isClosed, &direction) &&
132 isClosed &&
133 (SkPath::kCW_Direction == direction ||
134 SkPath::kEvenOdd_FillType == path.getFillType()))
135 {
136 SkPDFUtils::AppendRectangle(rect, content);
137 return;
138 }
139
140 enum SkipFillState {
141 kEmpty_SkipFillState,
142 kSingleLine_SkipFillState,
143 kNonSingleLine_SkipFillState,
144 };
145 SkipFillState fillState = kEmpty_SkipFillState;
146 //if (paintStyle != SkPaint::kFill_Style) {
147 // fillState = kNonSingleLine_SkipFillState;
148 //}
149 SkPoint lastMovePt = SkPoint::Make(0,0);
150 SkDynamicMemoryWStream currentSegment;
151 SkPoint args[4];
152 SkPath::Iter iter(path, false);
153 for (SkPath::Verb verb = iter.next(args, doConsumeDegerates);
154 verb != SkPath::kDone_Verb;
155 verb = iter.next(args, doConsumeDegerates)) {
156 // args gets all the points, even the implicit first point.
157 switch (verb) {
158 case SkPath::kMove_Verb:
159 MoveTo(args[0].fX, args[0].fY, ¤tSegment);
160 lastMovePt = args[0];
161 fillState = kEmpty_SkipFillState;
162 break;
163 case SkPath::kLine_Verb:
164 AppendLine(args[1].fX, args[1].fY, ¤tSegment);
165 if ((fillState == kEmpty_SkipFillState) && (args[0] != lastMovePt)) {
166 fillState = kSingleLine_SkipFillState;
167 break;
168 }
169 fillState = kNonSingleLine_SkipFillState;
170 break;
171 case SkPath::kQuad_Verb:
172 append_quad(args, ¤tSegment);
173 fillState = kNonSingleLine_SkipFillState;
174 break;
175 case SkPath::kConic_Verb: {
176 SkAutoConicToQuads converter;
177 const SkPoint* quads = converter.computeQuads(args, iter.conicWeight(), tolerance);
178 for (int i = 0; i < converter.countQuads(); ++i) {
179 append_quad(&quads[i * 2], ¤tSegment);
180 }
181 fillState = kNonSingleLine_SkipFillState;
182 } break;
183 case SkPath::kCubic_Verb:
184 append_cubic(args[1].fX, args[1].fY, args[2].fX, args[2].fY,
185 args[3].fX, args[3].fY, ¤tSegment);
186 fillState = kNonSingleLine_SkipFillState;
187 break;
188 case SkPath::kClose_Verb:
189 ClosePath(¤tSegment);
190 currentSegment.writeToStream(content);
191 currentSegment.reset();
192 break;
193 default:
194 SkASSERT(false);
195 break;
196 }
197 }
198 if (currentSegment.bytesWritten() > 0) {
199 currentSegment.writeToStream(content);
200 }
201 }
202
ClosePath(SkWStream * content)203 void SkPDFUtils::ClosePath(SkWStream* content) {
204 content->writeText("h\n");
205 }
206
PaintPath(SkPaint::Style style,SkPath::FillType fill,SkWStream * content)207 void SkPDFUtils::PaintPath(SkPaint::Style style, SkPath::FillType fill,
208 SkWStream* content) {
209 if (style == SkPaint::kFill_Style) {
210 content->writeText("f");
211 } else if (style == SkPaint::kStrokeAndFill_Style) {
212 content->writeText("B");
213 } else if (style == SkPaint::kStroke_Style) {
214 content->writeText("S");
215 }
216
217 if (style != SkPaint::kStroke_Style) {
218 NOT_IMPLEMENTED(fill == SkPath::kInverseEvenOdd_FillType, false);
219 NOT_IMPLEMENTED(fill == SkPath::kInverseWinding_FillType, false);
220 if (fill == SkPath::kEvenOdd_FillType) {
221 content->writeText("*");
222 }
223 }
224 content->writeText("\n");
225 }
226
StrokePath(SkWStream * content)227 void SkPDFUtils::StrokePath(SkWStream* content) {
228 SkPDFUtils::PaintPath(
229 SkPaint::kStroke_Style, SkPath::kWinding_FillType, content);
230 }
231
ApplyGraphicState(int objectIndex,SkWStream * content)232 void SkPDFUtils::ApplyGraphicState(int objectIndex, SkWStream* content) {
233 SkPDFWriteResourceName(content, SkPDFResourceType::kExtGState, objectIndex);
234 content->writeText(" gs\n");
235 }
236
ApplyPattern(int objectIndex,SkWStream * content)237 void SkPDFUtils::ApplyPattern(int objectIndex, SkWStream* content) {
238 // Select Pattern color space (CS, cs) and set pattern object as current
239 // color (SCN, scn)
240 content->writeText("/Pattern CS/Pattern cs");
241 SkPDFWriteResourceName(content, SkPDFResourceType::kPattern, objectIndex);
242 content->writeText(" SCN");
243 SkPDFWriteResourceName(content, SkPDFResourceType::kPattern, objectIndex);
244 content->writeText(" scn\n");
245 }
246
247 // return "x/pow(10, places)", given 0<x<pow(10, places)
248 // result points to places+2 chars.
print_permil_as_decimal(int x,char * result,unsigned places)249 static size_t print_permil_as_decimal(int x, char* result, unsigned places) {
250 result[0] = '.';
251 for (int i = places; i > 0; --i) {
252 result[i] = '0' + x % 10;
253 x /= 10;
254 }
255 int j;
256 for (j = places; j > 1; --j) {
257 if (result[j] != '0') {
258 break;
259 }
260 }
261 result[j + 1] = '\0';
262 return j + 1;
263 }
264
265
int_pow(int base,unsigned exp,int acc=1)266 static constexpr int int_pow(int base, unsigned exp, int acc = 1) {
267 return exp < 1 ? acc
268 : int_pow(base * base,
269 exp / 2,
270 (exp % 2) ? acc * base : acc);
271 }
272
273
ColorToDecimalF(float value,char result[kFloatColorDecimalCount+2])274 size_t SkPDFUtils::ColorToDecimalF(float value, char result[kFloatColorDecimalCount + 2]) {
275 static constexpr int kFactor = int_pow(10, kFloatColorDecimalCount);
276 int x = sk_float_round2int(value * kFactor);
277 if (x >= kFactor || x <= 0) { // clamp to 0-1
278 result[0] = x > 0 ? '1' : '0';
279 result[1] = '\0';
280 return 1;
281 }
282 return print_permil_as_decimal(x, result, kFloatColorDecimalCount);
283 }
284
ColorToDecimal(uint8_t value,char result[5])285 size_t SkPDFUtils::ColorToDecimal(uint8_t value, char result[5]) {
286 if (value == 255 || value == 0) {
287 result[0] = value ? '1' : '0';
288 result[1] = '\0';
289 return 1;
290 }
291 // int x = 0.5 + (1000.0 / 255.0) * value;
292 int x = SkFixedRoundToInt((SK_Fixed1 * 1000 / 255) * value);
293 return print_permil_as_decimal(x, result, 3);
294 }
295
InverseTransformBBox(const SkMatrix & matrix,SkRect * bbox)296 bool SkPDFUtils::InverseTransformBBox(const SkMatrix& matrix, SkRect* bbox) {
297 SkMatrix inverse;
298 if (!matrix.invert(&inverse)) {
299 return false;
300 }
301 inverse.mapRect(bbox);
302 return true;
303 }
304
PopulateTilingPatternDict(SkPDFDict * pattern,SkRect & bbox,std::unique_ptr<SkPDFDict> resources,const SkMatrix & matrix)305 void SkPDFUtils::PopulateTilingPatternDict(SkPDFDict* pattern,
306 SkRect& bbox,
307 std::unique_ptr<SkPDFDict> resources,
308 const SkMatrix& matrix) {
309 const int kTiling_PatternType = 1;
310 const int kColoredTilingPattern_PaintType = 1;
311 const int kConstantSpacing_TilingType = 1;
312
313 pattern->insertName("Type", "Pattern");
314 pattern->insertInt("PatternType", kTiling_PatternType);
315 pattern->insertInt("PaintType", kColoredTilingPattern_PaintType);
316 pattern->insertInt("TilingType", kConstantSpacing_TilingType);
317 pattern->insertObject("BBox", SkPDFUtils::RectToArray(bbox));
318 pattern->insertScalar("XStep", bbox.width());
319 pattern->insertScalar("YStep", bbox.height());
320 pattern->insertObject("Resources", std::move(resources));
321 if (!matrix.isIdentity()) {
322 pattern->insertObject("Matrix", SkPDFUtils::MatrixToArray(matrix));
323 }
324 }
325
ToBitmap(const SkImage * img,SkBitmap * dst)326 bool SkPDFUtils::ToBitmap(const SkImage* img, SkBitmap* dst) {
327 SkASSERT(img);
328 SkASSERT(dst);
329 SkBitmap bitmap;
330 if(as_IB(img)->getROPixels(&bitmap)) {
331 SkASSERT(bitmap.dimensions() == img->dimensions());
332 SkASSERT(!bitmap.drawsNothing());
333 *dst = std::move(bitmap);
334 return true;
335 }
336 return false;
337 }
338
339 #ifdef SK_PDF_BASE85_BINARY
Base85Encode(std::unique_ptr<SkStreamAsset> stream,SkDynamicMemoryWStream * dst)340 void SkPDFUtils::Base85Encode(std::unique_ptr<SkStreamAsset> stream, SkDynamicMemoryWStream* dst) {
341 SkASSERT(dst);
342 SkASSERT(stream);
343 dst->writeText("\n");
344 int column = 0;
345 while (true) {
346 uint8_t src[4] = {0, 0, 0, 0};
347 size_t count = stream->read(src, 4);
348 SkASSERT(count < 5);
349 if (0 == count) {
350 dst->writeText("~>\n");
351 return;
352 }
353 uint32_t v = ((uint32_t)src[0] << 24) | ((uint32_t)src[1] << 16) |
354 ((uint32_t)src[2] << 8) | src[3];
355 if (v == 0 && count == 4) {
356 dst->writeText("z");
357 column += 1;
358 } else {
359 char buffer[5];
360 for (int n = 4; n > 0; --n) {
361 buffer[n] = (v % 85) + '!';
362 v /= 85;
363 }
364 buffer[0] = v + '!';
365 dst->write(buffer, count + 1);
366 column += count + 1;
367 }
368 if (column > 74) {
369 dst->writeText("\n");
370 column = 0;
371 }
372 }
373 }
374 #endif // SK_PDF_BASE85_BINARY
375