SkPdf: smaller color serialization

tests/PDFPrimitivesTest.cpp

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Resources.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 473 matching lines @@
     float alwaysCheck[] = {
         0.0f, -0.0f, 1.0f, -1.0f, SK_ScalarPI, 0.1f, FLT_MIN, FLT_MAX,
         -FLT_MIN, -FLT_MAX, FLT_MIN / 16.0f, -FLT_MIN / 16.0f,
         SK_FloatNaN, SK_FloatInfinity, SK_FloatNegativeInfinity,
         -FLT_MIN / 8388608.0
     };
     for (float inputFloat: alwaysCheck) {
         check_pdf_scalar_serialization(reporter, inputFloat);
     }
 }
+
+// Test SkPDFUtils:: for accuracy.
+DEF_TEST(PDFPrimitives_Color, reporter) {
+    char buffer[5];
+    for (int i = 0; i < 256; ++i) {
+        size_t len = SkPDFUtils::ColorToDecimal(i, buffer);
+        REPORTER_ASSERT(reporter, len == strlen(buffer));
+        float f;
+        REPORTER_ASSERT(reporter, 1 == sscanf(buffer, "%f", &f));
+        int roundTrip = (int)(0.5 + f * 255);
+        REPORTER_ASSERT(reporter, roundTrip == i);
+    }
+}