SkPdf: smaller color serialization

src/pdf/SkPDFUtils.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFUtils_DEFINED
 #define SkPDFUtils_DEFINED
@@ skipping 39 matching lines @@
     SkPDFUtils::EmitPath(path, paintStyle, true, content);
 }
 void ClosePath(SkWStream* content);
 void PaintPath(SkPaint::Style style, SkPath::FillType fill,
                       SkWStream* content);
 void StrokePath(SkWStream* content);
 void DrawFormXObject(int objectIndex, SkWStream* content);
 void ApplyGraphicState(int objectIndex, SkWStream* content);
 void ApplyPattern(int objectIndex, SkWStream* content);
 
+// Converts (value / 255.0) with three significant digits of accuracy.
+// Writes value as string into result.  Returns strlen() of result.
+size_t ColorToDecimal(uint8_t value, char result[5]);
+inline void AppendColorComponent(uint8_t value, SkWStream* wStream) {
+    char buffer[5];
+    size_t len = SkPDFUtils::ColorToDecimal(value, buffer);
+    wStream->write(buffer, len);
+}
+
 // 3 = '-', '.', and '\0' characters.
 // 9 = number of significant digits
 // abs(FLT_MIN_10_EXP) = number of zeros in FLT_MIN
 const size_t kMaximumFloatDecimalLength = 3 + 9 - FLT_MIN_10_EXP;
 // FloatToDecimal is exposed for unit tests.
 size_t FloatToDecimal(float value,
                       char output[kMaximumFloatDecimalLength]);
 void AppendScalar(SkScalar value, SkWStream* stream);
 void WriteString(SkWStream* wStream, const char* input, size_t len);
 
 inline void WriteUInt16BE(SkDynamicMemoryWStream* wStream, uint16_t value) {
     static const char gHex[] = "0123456789ABCDEF";
     char result[4];
     result[0] = gHex[       value >> 12 ];
     result[1] = gHex[0xF & (value >> 8 )];
     result[2] = gHex[0xF & (value >> 4 )];
     result[3] = gHex[0xF & (value      )];
     wStream->write(result, 4);
 }
 
 }  // namespace SkPDFUtils
 
 #endif