[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/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index d0f32ac..ff9e4db 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -48,14 +48,14 @@
SkASSERT(SkColorGetA(color) == 0xFF); // We handle alpha elsewhere.
SkScalar colorMax = SkIntToScalar(0xFF);
SkString result;
- result.appendScalar(SkScalarDiv(SkIntToScalar(SkColorGetR(color)),
- colorMax));
+ SkPDFScalar::Append(
+ SkScalarDiv(SkIntToScalar(SkColorGetR(color)), colorMax), &result);
result.append(" ");
- result.appendScalar(SkScalarDiv(SkIntToScalar(SkColorGetG(color)),
- colorMax));
+ SkPDFScalar::Append(
+ SkScalarDiv(SkIntToScalar(SkColorGetG(color)), colorMax), &result);
result.append(" ");
- result.appendScalar(SkScalarDiv(SkIntToScalar(SkColorGetB(color)),
- colorMax));
+ SkPDFScalar::Append(
+ SkScalarDiv(SkIntToScalar(SkColorGetB(color)), colorMax), &result);
result.append(" ");
return result;
}
@@ -610,7 +610,7 @@
newPaint.getTextScaleX()) {
SkScalar scale = newPaint.getTextScaleX();
SkScalar pdfScale = SkScalarMul(scale, SkIntToScalar(100));
- fContent.appendScalar(pdfScale);
+ SkPDFScalar::Append(pdfScale, &fContent);
fContent.append(" Tz\n");
fGraphicStack[fGraphicStackIndex].fTextScaleX = scale;
}
@@ -639,7 +639,7 @@
fContent.append("/F");
fContent.appendS32(fontIndex);
fContent.append(" ");
- fContent.appendScalar(paint.getTextSize());
+ SkPDFScalar::Append(paint.getTextSize(), &fContent);
fContent.append(" Tf\n");
fGraphicStack[fGraphicStackIndex].fTextSize = paint.getTextSize();
fGraphicStack[fGraphicStackIndex].fFont = fFontResources[fontIndex];
@@ -660,16 +660,16 @@
}
void SkPDFDevice::moveTo(SkScalar x, SkScalar y) {
- fContent.appendScalar(x);
+ SkPDFScalar::Append(x, &fContent);
fContent.append(" ");
- fContent.appendScalar(y);
+ SkPDFScalar::Append(y, &fContent);
fContent.append(" m\n");
}
void SkPDFDevice::appendLine(SkScalar x, SkScalar y) {
- fContent.appendScalar(x);
+ SkPDFScalar::Append(x, &fContent);
fContent.append(" ");
- fContent.appendScalar(y);
+ SkPDFScalar::Append(y, &fContent);
fContent.append(" l\n");
}
@@ -677,33 +677,33 @@
SkScalar ctl2X, SkScalar ctl2Y,
SkScalar dstX, SkScalar dstY) {
SkString cmd("y\n");
- fContent.appendScalar(ctl1X);
+ SkPDFScalar::Append(ctl1X, &fContent);
fContent.append(" ");
- fContent.appendScalar(ctl1Y);
+ SkPDFScalar::Append(ctl1Y, &fContent);
fContent.append(" ");
if (ctl2X != dstX || ctl2Y != dstY) {
cmd.set("c\n");
- fContent.appendScalar(ctl2X);
+ SkPDFScalar::Append(ctl2X, &fContent);
fContent.append(" ");
- fContent.appendScalar(ctl2Y);
+ SkPDFScalar::Append(ctl2Y, &fContent);
fContent.append(" ");
}
- fContent.appendScalar(dstX);
+ SkPDFScalar::Append(dstX, &fContent);
fContent.append(" ");
- fContent.appendScalar(dstY);
+ SkPDFScalar::Append(dstY, &fContent);
fContent.append(" ");
fContent.append(cmd);
}
void SkPDFDevice::appendRectangle(SkScalar x, SkScalar y,
SkScalar w, SkScalar h) {
- fContent.appendScalar(x);
+ SkPDFScalar::Append(x, &fContent);
fContent.append(" ");
- fContent.appendScalar(y);
+ SkPDFScalar::Append(y, &fContent);
fContent.append(" ");
- fContent.appendScalar(w);
+ SkPDFScalar::Append(w, &fContent);
fContent.append(" ");
- fContent.appendScalar(h);
+ SkPDFScalar::Append(h, &fContent);
fContent.append(" re\n");
}
@@ -791,11 +791,11 @@
// Flip the text about the x-axis to account for origin swap and include
// the passed parameters.
fContent.append("1 0 ");
- fContent.appendScalar(0 - textSkewX);
+ SkPDFScalar::Append(0 - textSkewX, &fContent);
fContent.append(" -1 ");
- fContent.appendScalar(x);
+ SkPDFScalar::Append(x, &fContent);
fContent.append(" ");
- fContent.appendScalar(y);
+ SkPDFScalar::Append(y, &fContent);
fContent.append(" Tm\n");
}
@@ -851,7 +851,7 @@
SkScalar transform[6];
SkAssertResult(m.pdfTransform(transform));
for (size_t i = 0; i < SK_ARRAY_COUNT(transform); i++) {
- fContent.appendScalar(transform[i]);
+ SkPDFScalar::Append(transform[i], &fContent);
fContent.append(" ");
}
fContent.append("cm\n");
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[])