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/*
* 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 "SkGeometry.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkPDFResourceDict.h"
#include "SkPDFUtils.h"
#include "SkStream.h"
#include "SkString.h"
#include "SkPDFTypes.h"
//static
SkPDFArray* SkPDFUtils::RectToArray(const SkRect& rect) {
SkPDFArray* result = new SkPDFArray();
result->reserve(4);
result->appendScalar(rect.fLeft);
result->appendScalar(rect.fTop);
result->appendScalar(rect.fRight);
result->appendScalar(rect.fBottom);
return result;
}
// static
SkPDFArray* SkPDFUtils::MatrixToArray(const SkMatrix& matrix) {
SkScalar values[6];
if (!matrix.asAffine(values)) {
SkMatrix::SetAffineIdentity(values);
}
SkPDFArray* result = new 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,
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 = 0,
kSingleLine_SkipFillState = 1,
kNonSingleLine_SkipFillState = 2,
};
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); verb != SkPath::kDone_Verb; verb = iter.next(args)) {
// 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) {
if (args[0] != lastMovePt) {
fillState = kSingleLine_SkipFillState;
}
} else if (fillState == kSingleLine_SkipFillState) {
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);
}
} 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:
if (fillState != kSingleLine_SkipFillState) {
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");
}
void SkPDFUtils::AppendScalar(SkScalar value, SkWStream* stream) {
// 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_ALLOW_LARGE_PDF_SCALARS)
if (value > 32767 || value < -32767) {
stream->writeDecAsText(SkScalarRoundToInt(value));
return;
}
char buffer[SkStrAppendScalar_MaxSize];
char* end = SkStrAppendFixed(buffer, SkScalarToFixed(value));
stream->write(buffer, end - buffer);
return;
#endif // !SK_ALLOW_LARGE_PDF_SCALARS
#if 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)) {
stream->writeDecAsText(value);
return;
}
// Continue to enforce the PDF limits for small floats.
if (value < 1.0f/65536 && value > -1.0f/65536) {
stream->writeDecAsText(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';
}
stream->writeText(buffer);
return;
#endif // SK_ALLOW_LARGE_PDF_SCALARS
}
SkString SkPDFUtils::FormatString(const char* cin, size_t len) {
SkDEBUGCODE(static const size_t kMaxLen = 65535;)
SkASSERT(len <= kMaxLen);
// 7-bit clean is a heuristic to decide what string format to use;
// a 7-bit clean string should require little escaping.
bool sevenBitClean = true;
size_t characterCount = 2 + len;
for (size_t i = 0; i < len; i++) {
if (cin[i] > '~' || cin[i] < ' ') {
sevenBitClean = false;
break;
}
if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') {
++characterCount;
}
}
SkString result;
if (sevenBitClean) {
result.resize(characterCount);
char* str = result.writable_str();
*str++ = '(';
for (size_t i = 0; i < len; i++) {
if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') {
*str++ = '\\';
}
*str++ = cin[i];
}
*str++ = ')';
} else {
result.resize(2 * len + 2);
char* str = result.writable_str();
*str++ = '<';
for (size_t i = 0; i < len; i++) {
uint8_t c = static_cast<uint8_t>(cin[i]);
static const char gHex[] = "0123456789ABCDEF";
*str++ = gHex[(c >> 4) & 0xF];
*str++ = gHex[(c ) & 0xF];
}
*str++ = '>';
}
return result;
}