src/pdf/SkPDFUtils.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */


 #include "SkData.h"
 #include "SkFixed.h"
 #include "SkGeometry.h"
 #include "SkPDFResourceDict.h"
 #include "SkPDFUtils.h"
 #include "SkStream.h"
 #include "SkString.h"
 #include "SkPDFTypes.h"

 #include <cmath>

 sk_sp<SkPDFArray> SkPDFUtils::RectToArray(const SkRect& rect) {
     auto result = sk_make_sp<SkPDFArray>();
     result->reserve(4);
     result->appendScalar(rect.fLeft);
     result->appendScalar(rect.fTop);
     result->appendScalar(rect.fRight);
     result->appendScalar(rect.fBottom);
     return result;
 }

 sk_sp<SkPDFArray> SkPDFUtils::MatrixToArray(const SkMatrix& matrix) {
     SkScalar values[6];
     if (!matrix.asAffine(values)) {
         SkMatrix::SetAffineIdentity(values);
     }

     auto result = sk_make_sp<SkPDFArray>();
     result->reserve(6);
     for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) {
         result->appendScalar(values[i]);
     }
     return result;
 }

 // static
 void SkPDFUtils::AppendTransform(const SkMatrix& matrix, SkWStream* content) {
     SkScalar values[6];
     if (!matrix.asAffine(values)) {
         SkMatrix::SetAffineIdentity(values);
     }
     for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) {
         SkPDFUtils::AppendScalar(values[i], content);
         content->writeText(" ");
     }
     content->writeText("cm\n");
 }

 // static
 void SkPDFUtils::MoveTo(SkScalar x, SkScalar y, SkWStream* content) {
     SkPDFUtils::AppendScalar(x, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(y, content);
     content->writeText(" m\n");
 }

 // static
 void SkPDFUtils::AppendLine(SkScalar x, SkScalar y, SkWStream* content) {
     SkPDFUtils::AppendScalar(x, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(y, content);
     content->writeText(" l\n");
 }

 // static
 void SkPDFUtils::AppendCubic(SkScalar ctl1X, SkScalar ctl1Y,
                              SkScalar ctl2X, SkScalar ctl2Y,
                              SkScalar dstX, SkScalar dstY, SkWStream* content) {
     SkString cmd("y\n");
     SkPDFUtils::AppendScalar(ctl1X, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(ctl1Y, content);
     content->writeText(" ");
     if (ctl2X != dstX || ctl2Y != dstY) {
         cmd.set("c\n");
         SkPDFUtils::AppendScalar(ctl2X, content);
         content->writeText(" ");
         SkPDFUtils::AppendScalar(ctl2Y, content);
         content->writeText(" ");
     }
     SkPDFUtils::AppendScalar(dstX, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(dstY, content);
     content->writeText(" ");
     content->writeText(cmd.c_str());
 }

 static void append_quad(const SkPoint quad[], SkWStream* content) {
     SkPoint cubic[4];
     SkConvertQuadToCubic(quad, cubic);
     SkPDFUtils::AppendCubic(cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY,
                             cubic[3].fX, cubic[3].fY, content);
 }

 // static
 void SkPDFUtils::AppendRectangle(const SkRect& rect, SkWStream* content) {
     // Skia has 0,0 at top left, pdf at bottom left.  Do the right thing.
     SkScalar bottom = SkMinScalar(rect.fBottom, rect.fTop);

     SkPDFUtils::AppendScalar(rect.fLeft, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(bottom, content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(rect.width(), content);
     content->writeText(" ");
     SkPDFUtils::AppendScalar(rect.height(), content);
     content->writeText(" re\n");
 }

 // static
 void SkPDFUtils::EmitPath(const SkPath& path, SkPaint::Style paintStyle,
                           bool doConsumeDegerates, SkWStream* content) {
     // Filling a path with no area results in a drawing in PDF renderers but
     // Chrome expects to be able to draw some such entities with no visible
     // result, so we detect those cases and discard the drawing for them.
     // Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y).
     enum SkipFillState {
         kEmpty_SkipFillState,
         kSingleLine_SkipFillState,
         kNonSingleLine_SkipFillState,
     };
     SkipFillState fillState = kEmpty_SkipFillState;
     //if (paintStyle != SkPaint::kFill_Style) {
     //    fillState = kNonSingleLine_SkipFillState;
     //}
     SkPoint lastMovePt = SkPoint::Make(0,0);
     SkDynamicMemoryWStream currentSegment;
     SkPoint args[4];
     SkPath::Iter iter(path, false);
     for (SkPath::Verb verb = iter.next(args, doConsumeDegerates);
          verb != SkPath::kDone_Verb;
          verb = iter.next(args, doConsumeDegerates)) {
         // args gets all the points, even the implicit first point.
         switch (verb) {
             case SkPath::kMove_Verb:
                 MoveTo(args[0].fX, args[0].fY, &currentSegment);
                 lastMovePt = args[0];
                 fillState = kEmpty_SkipFillState;
                 break;
             case SkPath::kLine_Verb:
                 AppendLine(args[1].fX, args[1].fY, &currentSegment);
                 if ((fillState == kEmpty_SkipFillState) && (args[0] != lastMovePt)) {
                     fillState = kSingleLine_SkipFillState;
                     break;
                 }
                 fillState = kNonSingleLine_SkipFillState;
                 break;
             case SkPath::kQuad_Verb:
                 append_quad(args, &currentSegment);
                 fillState = kNonSingleLine_SkipFillState;
                 break;
             case SkPath::kConic_Verb: {
                 const SkScalar tol = SK_Scalar1 / 4;
                 SkAutoConicToQuads converter;
                 const SkPoint* quads = converter.computeQuads(args, iter.conicWeight(), tol);
                 for (int i = 0; i < converter.countQuads(); ++i) {
                     append_quad(&quads[i * 2], &currentSegment);
                 }
                 fillState = kNonSingleLine_SkipFillState;
             } break;
             case SkPath::kCubic_Verb:
                 AppendCubic(args[1].fX, args[1].fY, args[2].fX, args[2].fY,
                             args[3].fX, args[3].fY, &currentSegment);
                 fillState = kNonSingleLine_SkipFillState;
                 break;
             case SkPath::kClose_Verb:

                     ClosePath(&currentSegment);

                 currentSegment.writeToStream(content);
                 currentSegment.reset();
                 break;
             default:
                 SkASSERT(false);
                 break;
         }
     }
     if (currentSegment.bytesWritten() > 0) {
         currentSegment.writeToStream(content);
     }
 }

 // static
 void SkPDFUtils::ClosePath(SkWStream* content) {
     content->writeText("h\n");
 }

 // static
 void SkPDFUtils::PaintPath(SkPaint::Style style, SkPath::FillType fill,
                            SkWStream* content) {
     if (style == SkPaint::kFill_Style) {
         content->writeText("f");
     } else if (style == SkPaint::kStrokeAndFill_Style) {
         content->writeText("B");
     } else if (style == SkPaint::kStroke_Style) {
         content->writeText("S");
     }

     if (style != SkPaint::kStroke_Style) {
         NOT_IMPLEMENTED(fill == SkPath::kInverseEvenOdd_FillType, false);
         NOT_IMPLEMENTED(fill == SkPath::kInverseWinding_FillType, false);
         if (fill == SkPath::kEvenOdd_FillType) {
             content->writeText("*");
         }
     }
     content->writeText("\n");
 }

 // static
 void SkPDFUtils::StrokePath(SkWStream* content) {
     SkPDFUtils::PaintPath(
         SkPaint::kStroke_Style, SkPath::kWinding_FillType, content);
 }

 // static
 void SkPDFUtils::DrawFormXObject(int objectIndex, SkWStream* content) {
     content->writeText("/");
     content->writeText(SkPDFResourceDict::getResourceName(
             SkPDFResourceDict::kXObject_ResourceType,
             objectIndex).c_str());
     content->writeText(" Do\n");
 }

 // static
 void SkPDFUtils::ApplyGraphicState(int objectIndex, SkWStream* content) {
     content->writeText("/");
     content->writeText(SkPDFResourceDict::getResourceName(
             SkPDFResourceDict::kExtGState_ResourceType,
             objectIndex).c_str());
     content->writeText(" gs\n");
 }

 // static
 void SkPDFUtils::ApplyPattern(int objectIndex, SkWStream* content) {
     // Select Pattern color space (CS, cs) and set pattern object as current
     // color (SCN, scn)
     SkString resourceName = SkPDFResourceDict::getResourceName(
             SkPDFResourceDict::kPattern_ResourceType,
             objectIndex);
     content->writeText("/Pattern CS/Pattern cs/");
     content->writeText(resourceName.c_str());
     content->writeText(" SCN/");
     content->writeText(resourceName.c_str());
     content->writeText(" scn\n");
 }

 size_t SkPDFUtils::ColorToDecimal(uint8_t value, char result[5]) {
     if (value == 255 || value == 0) {
         result[0] = value ? '1' : '0';
         result[1] = '\0';
         return 1;
     }
     // int x = 0.5 + (1000.0 / 255.0) * value;
     int x = SkFixedRoundToInt((SK_Fixed1 * 1000 / 255) * value);
     result[0] = '.';
     for (int i = 3; i > 0; --i) {
         result[i] = '0' + x % 10;
         x /= 10;
     }
     int j;
     for (j = 3; j > 1; --j) {
         if (result[j] != '0') {
             break;
         }
     }
     result[j + 1] = '\0';
     return j + 1;
 }

 void SkPDFUtils::AppendScalar(SkScalar value, SkWStream* stream) {
     char result[kMaximumFloatDecimalLength];
     size_t len = SkPDFUtils::FloatToDecimal(SkScalarToFloat(value), result);
     SkASSERT(len < kMaximumFloatDecimalLength);
     stream->write(result, len);
 }

 // Return pow(10.0, e), optimized for common cases.
 inline double pow10(int e) {
     switch (e) {
         case 0:  return 1.0;  // common cases
         case 1:  return 10.0;
         case 2:  return 100.0;
         case 3:  return 1e+03;
         case 4:  return 1e+04;
         case 5:  return 1e+05;
         case 6:  return 1e+06;
         case 7:  return 1e+07;
         case 8:  return 1e+08;
         case 9:  return 1e+09;
         case 10: return 1e+10;
         case 11: return 1e+11;
         case 12: return 1e+12;
         case 13: return 1e+13;
         case 14: return 1e+14;
         case 15: return 1e+15;
         default:
             if (e > 15) {
                 double value = 1e+15;
                 while (e-- > 15) { value *= 10.0; }
                 return value;
             } else {
                 SkASSERT(e < 0);
                 double value = 1.0;
                 while (e++ < 0) { value /= 10.0; }
                 return value;
             }
     }
 }

 /** Write a string into result, includeing a terminating '\0' (for
     unit testing).  Return strlen(result) (for SkWStream::write) The
     resulting string will be in the form /[-]?([0-9]*.)?[0-9]+/ and
     sscanf(result, "%f", &x) will return the original value iff the
     value is finite. This function accepts all possible input values.

     Motivation: "PDF does not support [numbers] in exponential format
     (such as 6.02e23)."  Otherwise, this function would rely on a
     sprintf-type function from the standard library. */
 size_t SkPDFUtils::FloatToDecimal(float value,
                                   char result[kMaximumFloatDecimalLength]) {
     /* The longest result is -FLT_MIN.
        We serialize it as "-.0000000000000000000000000000000000000117549435"
        which has 48 characters plus a terminating '\0'. */

     /* section C.1 of the PDF1.4 spec (http://goo.gl/0SCswJ) says that
        most PDF rasterizers will use fixed-point scalars that lack the
        dynamic range of floats.  Even if this is the case, I want to
        serialize these (uncommon) very small and very large scalar
        values with enough precision to allow a floating-point
        rasterizer to read them in with perfect accuracy.
        Experimentally, rasterizers such as pdfium do seem to benefit
        from this.  Rasterizers that rely on fixed-point scalars should
        gracefully ignore these values that they can not parse. */
     char* output = &result[0];
     const char* const end = &result[kMaximumFloatDecimalLength - 1];
     // subtract one to leave space for '\0'.

     /* This function is written to accept any possible input value,
        including non-finite values such as INF and NAN.  In that case,
        we ignore value-correctness and and output a syntacticly-valid
        number. */
     if (value == SK_FloatInfinity) {
         value = FLT_MAX;  // nearest finite float.
     }
     if (value == SK_FloatNegativeInfinity) {
         value = -FLT_MAX;  // nearest finite float.
     }
     if (!std::isfinite(value) || value == 0.0f) {
         // NAN is unsupported in PDF.  Always output a valid number.
         // Also catch zero here, as a special case.
         *output++ = '0';
         *output = '\0';
         return output - result;
     }
     if (value < 0.0) {
         *output++ = '-';
         value = -value;
     }
     SkASSERT(value >= 0.0f);

     int binaryExponent;
     (void)std::frexp(value, &binaryExponent);
     static const double kLog2 = 0.3010299956639812;  // log10(2.0);
     int decimalExponent = static_cast<int>(std::floor(kLog2 * binaryExponent));
     int decimalShift = decimalExponent - 8;
     double power = pow10(-decimalShift);
     int32_t d = static_cast<int32_t>(value * power + 0.5);
     // SkASSERT(value == (float)(d * pow(10.0, decimalShift)));
     SkASSERT(d <= 999999999);
     if (d > 167772159) {  // floor(pow(10,1+log10(1<<24)))
        // need one fewer decimal digits for 24-bit precision.
        decimalShift = decimalExponent - 7;
        // SkASSERT(power * 0.1 = pow10(-decimalShift));
        // recalculate to get rounding right.
        d = static_cast<int32_t>(value * (power * 0.1) + 0.5);
        SkASSERT(d <= 99999999);
     }
     while (d % 10 == 0) {
         d /= 10;
         ++decimalShift;
     }
     SkASSERT(d > 0);
     // SkASSERT(value == (float)(d * pow(10.0, decimalShift)));
     uint8_t buffer[9]; // decimal value buffer.
     int bufferIndex = 0;
     do {
         buffer[bufferIndex++] = d % 10;
         d /= 10;
     } while (d != 0);
     SkASSERT(bufferIndex <= (int)sizeof(buffer) && bufferIndex > 0);
     if (decimalShift >= 0) {
         do {
             --bufferIndex;
             *output++ = '0' + buffer[bufferIndex];
         } while (bufferIndex);
         for (int i = 0; i < decimalShift; ++i) {
             *output++ = '0';
         }
     } else {
         int placesBeforeDecimal = bufferIndex + decimalShift;
         if (placesBeforeDecimal > 0) {
             while (placesBeforeDecimal-- > 0) {
                 --bufferIndex;
                 *output++ = '0' + buffer[bufferIndex];
             }
             *output++ = '.';
         } else {
             *output++ = '.';
             int placesAfterDecimal = -placesBeforeDecimal;
             while (placesAfterDecimal-- > 0) {
                 *output++ = '0';
             }
         }
         while (bufferIndex > 0) {
             --bufferIndex;
             *output++ = '0' + buffer[bufferIndex];
             if (output == end) {
                 break;  // denormalized: don't need extra precision.
                 // Note: denormalized numbers will not have the same number of
                 // significantDigits, but do not need them to round-trip.
             }
         }
     }
     SkASSERT(output <= end);
     *output = '\0';
     return output - result;
 }

 void SkPDFUtils::WriteString(SkWStream* wStream, const char* cin, size_t len) {
     SkDEBUGCODE(static const size_t kMaxLen = 65535;)
     SkASSERT(len <= kMaxLen);

     size_t extraCharacterCount = 0;
     for (size_t i = 0; i < len; i++) {
         if (cin[i] > '~' || cin[i] < ' ') {
             extraCharacterCount += 3;
         }
         if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') {
             ++extraCharacterCount;
         }
     }
     if (extraCharacterCount <= len) {
         wStream->writeText("(");
         for (size_t i = 0; i < len; i++) {
             if (cin[i] > '~' || cin[i] < ' ') {
                 uint8_t c = static_cast<uint8_t>(cin[i]);
                 uint8_t octal[4];
                 octal[0] = '\\';
                 octal[1] = '0' + ( c >> 6        );
                 octal[2] = '0' + ((c >> 3) & 0x07);
                 octal[3] = '0' + ( c       & 0x07);
                 wStream->write(octal, 4);
             } else {
                 if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') {
                     wStream->writeText("\\");
                 }
                 wStream->write(&cin[i], 1);
             }
         }
         wStream->writeText(")");
     } else {
         wStream->writeText("<");
         for (size_t i = 0; i < len; i++) {
             uint8_t c = static_cast<uint8_t>(cin[i]);
             static const char gHex[] = "0123456789ABCDEF";
             char hexValue[2];
             hexValue[0] = gHex[(c >> 4) & 0xF];
             hexValue[1] = gHex[ c       & 0xF];
             wStream->write(hexValue, 2);
         }
         wStream->writeText(">");
     }
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/


	#include "SkData.h"
	#include "SkFixed.h"
	#include "SkGeometry.h"
	#include "SkPDFResourceDict.h"
	#include "SkPDFUtils.h"
	#include "SkStream.h"
	#include "SkString.h"
	#include "SkPDFTypes.h"

	#include <cmath>

	sk_sp<SkPDFArray> SkPDFUtils::RectToArray(const SkRect& rect) {
	auto result = sk_make_sp<SkPDFArray>();
	result->reserve(4);
	result->appendScalar(rect.fLeft);
	result->appendScalar(rect.fTop);
	result->appendScalar(rect.fRight);
	result->appendScalar(rect.fBottom);
	return result;
	}

	sk_sp<SkPDFArray> SkPDFUtils::MatrixToArray(const SkMatrix& matrix) {
	SkScalar values[6];
	if (!matrix.asAffine(values)) {
	SkMatrix::SetAffineIdentity(values);
	}

	auto result = sk_make_sp<SkPDFArray>();
	result->reserve(6);
	for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) {
	result->appendScalar(values[i]);
	}
	return result;
	}

	// static
	void SkPDFUtils::AppendTransform(const SkMatrix& matrix, SkWStream* content) {
	SkScalar values[6];
	if (!matrix.asAffine(values)) {
	SkMatrix::SetAffineIdentity(values);
	}
	for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) {
	SkPDFUtils::AppendScalar(values[i], content);
	content->writeText(" ");
	}
	content->writeText("cm\n");
	}

	// static
	void SkPDFUtils::MoveTo(SkScalar x, SkScalar y, SkWStream* content) {
	SkPDFUtils::AppendScalar(x, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(y, content);
	content->writeText(" m\n");
	}

	// static
	void SkPDFUtils::AppendLine(SkScalar x, SkScalar y, SkWStream* content) {
	SkPDFUtils::AppendScalar(x, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(y, content);
	content->writeText(" l\n");
	}

	// static
	void SkPDFUtils::AppendCubic(SkScalar ctl1X, SkScalar ctl1Y,
	SkScalar ctl2X, SkScalar ctl2Y,
	SkScalar dstX, SkScalar dstY, SkWStream* content) {
	SkString cmd("y\n");
	SkPDFUtils::AppendScalar(ctl1X, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(ctl1Y, content);
	content->writeText(" ");
	if (ctl2X != dstX \|\| ctl2Y != dstY) {
	cmd.set("c\n");
	SkPDFUtils::AppendScalar(ctl2X, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(ctl2Y, content);
	content->writeText(" ");
	}
	SkPDFUtils::AppendScalar(dstX, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(dstY, content);
	content->writeText(" ");
	content->writeText(cmd.c_str());
	}

	static void append_quad(const SkPoint quad[], SkWStream* content) {
	SkPoint cubic[4];
	SkConvertQuadToCubic(quad, cubic);
	SkPDFUtils::AppendCubic(cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY,
	cubic[3].fX, cubic[3].fY, content);
	}

	// static
	void SkPDFUtils::AppendRectangle(const SkRect& rect, SkWStream* content) {
	// Skia has 0,0 at top left, pdf at bottom left. Do the right thing.
	SkScalar bottom = SkMinScalar(rect.fBottom, rect.fTop);

	SkPDFUtils::AppendScalar(rect.fLeft, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(bottom, content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(rect.width(), content);
	content->writeText(" ");
	SkPDFUtils::AppendScalar(rect.height(), content);
	content->writeText(" re\n");
	}

	// static
	void SkPDFUtils::EmitPath(const SkPath& path, SkPaint::Style paintStyle,
	bool doConsumeDegerates, SkWStream* content) {
	// Filling a path with no area results in a drawing in PDF renderers but
	// Chrome expects to be able to draw some such entities with no visible
	// result, so we detect those cases and discard the drawing for them.
	// Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y).
	enum SkipFillState {
	kEmpty_SkipFillState,
	kSingleLine_SkipFillState,
	kNonSingleLine_SkipFillState,
	};
	SkipFillState fillState = kEmpty_SkipFillState;
	//if (paintStyle != SkPaint::kFill_Style) {
	// fillState = kNonSingleLine_SkipFillState;
	//}
	SkPoint lastMovePt = SkPoint::Make(0,0);
	SkDynamicMemoryWStream currentSegment;
	SkPoint args[4];
	SkPath::Iter iter(path, false);
	for (SkPath::Verb verb = iter.next(args, doConsumeDegerates);
	verb != SkPath::kDone_Verb;
	verb = iter.next(args, doConsumeDegerates)) {
	// args gets all the points, even the implicit first point.
	switch (verb) {
	case SkPath::kMove_Verb:
	MoveTo(args[0].fX, args[0].fY, &currentSegment);
	lastMovePt = args[0];
	fillState = kEmpty_SkipFillState;
	break;
	case SkPath::kLine_Verb:
	AppendLine(args[1].fX, args[1].fY, &currentSegment);
	if ((fillState == kEmpty_SkipFillState) && (args[0] != lastMovePt)) {
	fillState = kSingleLine_SkipFillState;
	break;
	}
	fillState = kNonSingleLine_SkipFillState;
	break;
	case SkPath::kQuad_Verb:
	append_quad(args, &currentSegment);
	fillState = kNonSingleLine_SkipFillState;
	break;
	case SkPath::kConic_Verb: {
	const SkScalar tol = SK_Scalar1 / 4;
	SkAutoConicToQuads converter;
	const SkPoint* quads = converter.computeQuads(args, iter.conicWeight(), tol);
	for (int i = 0; i < converter.countQuads(); ++i) {
	append_quad(&quads[i * 2], &currentSegment);
	}
	fillState = kNonSingleLine_SkipFillState;
	} break;
	case SkPath::kCubic_Verb:
	AppendCubic(args[1].fX, args[1].fY, args[2].fX, args[2].fY,
	args[3].fX, args[3].fY, &currentSegment);
	fillState = kNonSingleLine_SkipFillState;
	break;
	case SkPath::kClose_Verb:

	ClosePath(&currentSegment);

	currentSegment.writeToStream(content);
	currentSegment.reset();
	break;
	default:
	SkASSERT(false);
	break;
	}
	}
	if (currentSegment.bytesWritten() > 0) {
	currentSegment.writeToStream(content);
	}
	}

	// static
	void SkPDFUtils::ClosePath(SkWStream* content) {
	content->writeText("h\n");
	}

	// static
	void SkPDFUtils::PaintPath(SkPaint::Style style, SkPath::FillType fill,
	SkWStream* content) {
	if (style == SkPaint::kFill_Style) {
	content->writeText("f");
	} else if (style == SkPaint::kStrokeAndFill_Style) {
	content->writeText("B");
	} else if (style == SkPaint::kStroke_Style) {
	content->writeText("S");
	}

	if (style != SkPaint::kStroke_Style) {
	NOT_IMPLEMENTED(fill == SkPath::kInverseEvenOdd_FillType, false);
	NOT_IMPLEMENTED(fill == SkPath::kInverseWinding_FillType, false);
	if (fill == SkPath::kEvenOdd_FillType) {
	content->writeText("*");
	}
	}
	content->writeText("\n");
	}

	// static
	void SkPDFUtils::StrokePath(SkWStream* content) {
	SkPDFUtils::PaintPath(
	SkPaint::kStroke_Style, SkPath::kWinding_FillType, content);
	}

	// static
	void SkPDFUtils::DrawFormXObject(int objectIndex, SkWStream* content) {
	content->writeText("/");
	content->writeText(SkPDFResourceDict::getResourceName(
	SkPDFResourceDict::kXObject_ResourceType,
	objectIndex).c_str());
	content->writeText(" Do\n");
	}

	// static
	void SkPDFUtils::ApplyGraphicState(int objectIndex, SkWStream* content) {
	content->writeText("/");
	content->writeText(SkPDFResourceDict::getResourceName(
	SkPDFResourceDict::kExtGState_ResourceType,
	objectIndex).c_str());
	content->writeText(" gs\n");
	}

	// static
	void SkPDFUtils::ApplyPattern(int objectIndex, SkWStream* content) {
	// Select Pattern color space (CS, cs) and set pattern object as current
	// color (SCN, scn)
	SkString resourceName = SkPDFResourceDict::getResourceName(
	SkPDFResourceDict::kPattern_ResourceType,
	objectIndex);
	content->writeText("/Pattern CS/Pattern cs/");
	content->writeText(resourceName.c_str());
	content->writeText(" SCN/");
	content->writeText(resourceName.c_str());
	content->writeText(" scn\n");
	}

	size_t SkPDFUtils::ColorToDecimal(uint8_t value, char result[5]) {
	if (value == 255 \|\| value == 0) {
	result[0] = value ? '1' : '0';
	result[1] = '\0';
	return 1;
	}
	// int x = 0.5 + (1000.0 / 255.0) * value;
	int x = SkFixedRoundToInt((SK_Fixed1 * 1000 / 255) * value);
	result[0] = '.';
	for (int i = 3; i > 0; --i) {
	result[i] = '0' + x % 10;
	x /= 10;
	}
	int j;
	for (j = 3; j > 1; --j) {
	if (result[j] != '0') {
	break;
	}
	}
	result[j + 1] = '\0';
	return j + 1;
	}

	void SkPDFUtils::AppendScalar(SkScalar value, SkWStream* stream) {
	char result[kMaximumFloatDecimalLength];
	size_t len = SkPDFUtils::FloatToDecimal(SkScalarToFloat(value), result);
	SkASSERT(len < kMaximumFloatDecimalLength);
	stream->write(result, len);
	}

	// Return pow(10.0, e), optimized for common cases.
	inline double pow10(int e) {
	switch (e) {
	case 0: return 1.0; // common cases
	case 1: return 10.0;
	case 2: return 100.0;
	case 3: return 1e+03;
	case 4: return 1e+04;
	case 5: return 1e+05;
	case 6: return 1e+06;
	case 7: return 1e+07;
	case 8: return 1e+08;
	case 9: return 1e+09;
	case 10: return 1e+10;
	case 11: return 1e+11;
	case 12: return 1e+12;
	case 13: return 1e+13;
	case 14: return 1e+14;
	case 15: return 1e+15;
	default:
	if (e > 15) {
	double value = 1e+15;
	while (e-- > 15) { value *= 10.0; }
	return value;
	} else {
	SkASSERT(e < 0);
	double value = 1.0;
	while (e++ < 0) { value /= 10.0; }
	return value;
	}
	}
	}

	/** Write a string into result, includeing a terminating '\0' (for
	unit testing). Return strlen(result) (for SkWStream::write) The
	resulting string will be in the form /[-]?([0-9]*.)?[0-9]+/ and
	sscanf(result, "%f", &x) will return the original value iff the
	value is finite. This function accepts all possible input values.

	Motivation: "PDF does not support [numbers] in exponential format
	(such as 6.02e23)." Otherwise, this function would rely on a
	sprintf-type function from the standard library. */
	size_t SkPDFUtils::FloatToDecimal(float value,
	char result[kMaximumFloatDecimalLength]) {
	/* The longest result is -FLT_MIN.
	We serialize it as "-.0000000000000000000000000000000000000117549435"
	which has 48 characters plus a terminating '\0'. */

	/* section C.1 of the PDF1.4 spec (http://goo.gl/0SCswJ) says that
	most PDF rasterizers will use fixed-point scalars that lack the
	dynamic range of floats. Even if this is the case, I want to
	serialize these (uncommon) very small and very large scalar
	values with enough precision to allow a floating-point
	rasterizer to read them in with perfect accuracy.
	Experimentally, rasterizers such as pdfium do seem to benefit
	from this. Rasterizers that rely on fixed-point scalars should
	gracefully ignore these values that they can not parse. */
	char* output = &result[0];
	const char* const end = &result[kMaximumFloatDecimalLength - 1];
	// subtract one to leave space for '\0'.

	/* This function is written to accept any possible input value,
	including non-finite values such as INF and NAN. In that case,
	we ignore value-correctness and and output a syntacticly-valid
	number. */
	if (value == SK_FloatInfinity) {
	value = FLT_MAX; // nearest finite float.
	}
	if (value == SK_FloatNegativeInfinity) {
	value = -FLT_MAX; // nearest finite float.
	}
	if (!std::isfinite(value) \|\| value == 0.0f) {
	// NAN is unsupported in PDF. Always output a valid number.
	// Also catch zero here, as a special case.
	*output++ = '0';
	*output = '\0';
	return output - result;
	}
	if (value < 0.0) {
	*output++ = '-';
	value = -value;
	}
	SkASSERT(value >= 0.0f);

	int binaryExponent;
	(void)std::frexp(value, &binaryExponent);
	static const double kLog2 = 0.3010299956639812; // log10(2.0);
	int decimalExponent = static_cast<int>(std::floor(kLog2 * binaryExponent));
	int decimalShift = decimalExponent - 8;
	double power = pow10(-decimalShift);
	int32_t d = static_cast<int32_t>(value * power + 0.5);
	// SkASSERT(value == (float)(d * pow(10.0, decimalShift)));
	SkASSERT(d <= 999999999);
	if (d > 167772159) { // floor(pow(10,1+log10(1<<24)))
	// need one fewer decimal digits for 24-bit precision.
	decimalShift = decimalExponent - 7;
	// SkASSERT(power * 0.1 = pow10(-decimalShift));
	// recalculate to get rounding right.
	d = static_cast<int32_t>(value * (power * 0.1) + 0.5);
	SkASSERT(d <= 99999999);
	}
	while (d % 10 == 0) {
	d /= 10;
	++decimalShift;
	}
	SkASSERT(d > 0);
	// SkASSERT(value == (float)(d * pow(10.0, decimalShift)));
	uint8_t buffer[9]; // decimal value buffer.
	int bufferIndex = 0;
	do {
	buffer[bufferIndex++] = d % 10;
	d /= 10;
	} while (d != 0);
	SkASSERT(bufferIndex <= (int)sizeof(buffer) && bufferIndex > 0);
	if (decimalShift >= 0) {
	do {
	--bufferIndex;
	*output++ = '0' + buffer[bufferIndex];
	} while (bufferIndex);
	for (int i = 0; i < decimalShift; ++i) {
	*output++ = '0';
	}
	} else {
	int placesBeforeDecimal = bufferIndex + decimalShift;
	if (placesBeforeDecimal > 0) {
	while (placesBeforeDecimal-- > 0) {
	--bufferIndex;
	*output++ = '0' + buffer[bufferIndex];
	}
	*output++ = '.';
	} else {
	*output++ = '.';
	int placesAfterDecimal = -placesBeforeDecimal;
	while (placesAfterDecimal-- > 0) {
	*output++ = '0';
	}
	}
	while (bufferIndex > 0) {
	--bufferIndex;
	*output++ = '0' + buffer[bufferIndex];
	if (output == end) {
	break; // denormalized: don't need extra precision.
	// Note: denormalized numbers will not have the same number of
	// significantDigits, but do not need them to round-trip.
	}
	}
	}
	SkASSERT(output <= end);
	*output = '\0';
	return output - result;
	}

	void SkPDFUtils::WriteString(SkWStream* wStream, const char* cin, size_t len) {
	SkDEBUGCODE(static const size_t kMaxLen = 65535;)
	SkASSERT(len <= kMaxLen);

	size_t extraCharacterCount = 0;
	for (size_t i = 0; i < len; i++) {
	if (cin[i] > '~' \|\| cin[i] < ' ') {
	extraCharacterCount += 3;
	}
	if (cin[i] == '\\' \|\| cin[i] == '(' \|\| cin[i] == ')') {
	++extraCharacterCount;
	}
	}
	if (extraCharacterCount <= len) {
	wStream->writeText("(");
	for (size_t i = 0; i < len; i++) {
	if (cin[i] > '~' \|\| cin[i] < ' ') {
	uint8_t c = static_cast<uint8_t>(cin[i]);
	uint8_t octal[4];
	octal[0] = '\\';
	octal[1] = '0' + ( c >> 6 );
	octal[2] = '0' + ((c >> 3) & 0x07);
	octal[3] = '0' + ( c & 0x07);
	wStream->write(octal, 4);
	} else {
	if (cin[i] == '\\' \|\| cin[i] == '(' \|\| cin[i] == ')') {
	wStream->writeText("\\");
	}
	wStream->write(&cin[i], 1);
	}
	}
	wStream->writeText(")");
	} else {
	wStream->writeText("<");
	for (size_t i = 0; i < len; i++) {
	uint8_t c = static_cast<uint8_t>(cin[i]);
	static const char gHex[] = "0123456789ABCDEF";
	char hexValue[2];
	hexValue[0] = gHex[(c >> 4) & 0xF];
	hexValue[1] = gHex[ c & 0xF];
	wStream->write(hexValue, 2);
	}
	wStream->writeText(">");
	}
	}