[PDF] Restrict scalars to the range that PDF understands.
* Add a config flag to ignore the restrictions
* Apply restriction to both SkPDFScalar and scalars used in content streams.
* +/- 32,767 for the integer part.
* +/1 1/65536 for the fraction part.
Review URL: http://codereview.appspot.com/4240050
git-svn-id: http://skia.googlecode.com/svn/trunk@882 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pdf/SkPDFTypes.cpp b/src/pdf/SkPDFTypes.cpp
index 209a2cf..bbeeeeb 100644
--- a/src/pdf/SkPDFTypes.cpp
+++ b/src/pdf/SkPDFTypes.cpp
@@ -18,6 +18,12 @@
#include "SkPDFTypes.h"
#include "SkStream.h"
+#ifdef SK_BUILD_FOR_WIN
+ #define SNPRINTF _snprintf
+#else
+ #define SNPRINTF snprintf
+#endif
+
SkPDFObject::SkPDFObject() {}
SkPDFObject::~SkPDFObject() {}
@@ -93,7 +99,64 @@
bool indirect) {
if (indirect)
return emitIndirectObject(stream, catalog);
- stream->writeScalarAsText(fValue);
+
+ SkString tmp;
+ Append(fValue, &tmp);
+ stream->write(tmp.c_str(), tmp.size());
+}
+
+// static
+void SkPDFScalar::Append(SkScalar value, SkString* string) {
+ // The range of reals in PDF/A is the same as SkFixed: +/- 32,767 and
+ // +/- 1/65,536 (though integers can range from 2^31 - 1 to -2^31).
+ // When using floats that are outside the whole value range, we can use
+ // integers instead.
+
+#if defined(SK_SCALAR_IS_FIXED)
+ string->appendScalar(value);
+ return;
+#endif // SK_SCALAR_IS_FIXED
+
+#if !defined(SK_ALLOW_LARGE_PDF_SCALARS)
+ if (value > 32767 || value < -32767) {
+ string->appendS32(SkScalarRound(value));
+ return;
+ }
+
+ char buffer[SkStrAppendScalar_MaxSize];
+ char* end = SkStrAppendFixed(buffer, SkScalarToFixed(value));
+ string->append(buffer, end - buffer);
+ return;
+#endif // !SK_ALLOW_LARGE_PDF_SCALARS
+
+#if defined(SK_SCALAR_IS_FLOAT) && defined(SK_ALLOW_LARGE_PDF_SCALARS)
+ // Floats have 24bits of significance, so anything outside that range is
+ // no more precise than an int. (Plus PDF doesn't support scientific
+ // notation, so this clamps to SK_Max/MinS32).
+ if (value > (1 << 24) || value < -(1 << 24)) {
+ string->appendS32(value);
+ return;
+ }
+ // Continue to enforce the PDF limits for small floats.
+ if (value < 1.0f/65536 && value > -1.0f/65536) {
+ string->appendS32(0);
+ return;
+ }
+ // SkStrAppendFloat might still use scientific notation, so use snprintf
+ // directly..
+ static const int kFloat_MaxSize = 19;
+ char buffer[kFloat_MaxSize];
+ int len = SNPRINTF(buffer, kFloat_MaxSize, "%#.8f", value);
+ // %f always prints trailing 0s, so strip them.
+ for (; buffer[len - 1] == '0' && len > 0; len--) {
+ buffer[len - 1] = '\0';
+ }
+ if (buffer[len - 1] == '.') {
+ buffer[len - 1] = '\0';
+ }
+ string->append(buffer);
+ return;
+#endif // SK_SCALAR_IS_FLOAT && SK_ALLOW_LARGE_PDF_SCALARS
}
SkPDFString::SkPDFString(const char value[])