def.go

Documentation: github.com/jung-kurt/gofpdf

     1  /*
     2   * Copyright (c) 2013-2014 Kurt Jung (Gmail: kurt.w.jung)
     3   *
     4   * Permission to use, copy, modify, and distribute this software for any
     5   * purpose with or without fee is hereby granted, provided that the above
     6   * copyright notice and this permission notice appear in all copies.
     7   *
     8   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     9   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
    10   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    11   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    12   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
    13   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    14   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
    15   */
    16  
    17  package gofpdf
    18  
    19  import (
    20  	"bytes"
    21  	"crypto/sha1"
    22  	"encoding/gob"
    23  	"encoding/json"
    24  	"fmt"
    25  	"io"
    26  	"time"
    27  )
    28  
    29  // Version of FPDF from which this package is derived
    30  const (
    31  	cnFpdfVersion = "1.7"
    32  )
    33  
    34  type blendModeType struct {
    35  	strokeStr, fillStr, modeStr string
    36  	objNum                      int
    37  }
    38  
    39  type gradientType struct {
    40  	tp                int // 2: linear, 3: radial
    41  	clr1Str, clr2Str  string
    42  	x1, y1, x2, y2, r float64
    43  	objNum            int
    44  }
    45  
    46  const (
    47  	// OrientationPortrait represents the portrait orientation.
    48  	OrientationPortrait = "portrait"
    49  
    50  	// OrientationLandscape represents the landscape orientation.
    51  	OrientationLandscape = "landscape"
    52  )
    53  
    54  const (
    55  	// UnitPoint represents the size unit point
    56  	UnitPoint = "pt"
    57  	// UnitMillimeter represents the size unit millimeter
    58  	UnitMillimeter = "mm"
    59  	// UnitCentimeter represents the size unit centimeter
    60  	UnitCentimeter = "cm"
    61  	// UnitInch represents the size unit inch
    62  	UnitInch = "inch"
    63  )
    64  
    65  const (
    66  	// PageSizeA3 represents DIN/ISO A3 page size
    67  	PageSizeA3 = "A3"
    68  	// PageSizeA4 represents DIN/ISO A4 page size
    69  	PageSizeA4 = "A4"
    70  	// PageSizeA5 represents DIN/ISO A5 page size
    71  	PageSizeA5 = "A5"
    72  	// PageSizeLetter represents US Letter page size
    73  	PageSizeLetter = "Letter"
    74  	// PageSizeLegal represents US Legal page size
    75  	PageSizeLegal = "Legal"
    76  )
    77  
    78  const (
    79  	// BorderNone set no border
    80  	BorderNone = ""
    81  	// BorderFull sets a full border
    82  	BorderFull = "1"
    83  	// BorderLeft sets the border on the left side
    84  	BorderLeft = "L"
    85  	// BorderTop sets the border at the top
    86  	BorderTop = "T"
    87  	// BorderRight sets the border on the right side
    88  	BorderRight = "R"
    89  	// BorderBottom sets the border on the bottom
    90  	BorderBottom = "B"
    91  )
    92  
    93  const (
    94  	// LineBreakNone disables linebreak
    95  	LineBreakNone = 0
    96  	// LineBreakNormal enables normal linebreak
    97  	LineBreakNormal = 1
    98  	// LineBreakBelow enables linebreak below
    99  	LineBreakBelow = 2
   100  )
   101  
   102  const (
   103  	// AlignLeft left aligns the cell
   104  	AlignLeft = "L"
   105  	// AlignRight right aligns the cell
   106  	AlignRight = "R"
   107  	// AlignCenter centers the cell
   108  	AlignCenter = "C"
   109  	// AlignTop aligns the cell to the top
   110  	AlignTop = "T"
   111  	// AlignBottom aligns the cell to the bottom
   112  	AlignBottom = "B"
   113  	// AlignMiddle aligns the cell to the middle
   114  	AlignMiddle = "M"
   115  	// AlignBaseline aligns the cell to the baseline
   116  	AlignBaseline = "B"
   117  )
   118  
   119  type colorMode int
   120  
   121  const (
   122  	colorModeRGB colorMode = iota
   123  	colorModeSpot
   124  	colorModeCMYK
   125  )
   126  
   127  type colorType struct {
   128  	r, g, b    float64
   129  	ir, ig, ib int
   130  	mode       colorMode
   131  	spotStr    string // name of current spot color
   132  	gray       bool
   133  	str        string
   134  }
   135  
   136  // SpotColorType specifies a named spot color value
   137  type spotColorType struct {
   138  	id, objID int
   139  	val       cmykColorType
   140  }
   141  
   142  // CMYKColorType specifies an ink-based CMYK color value
   143  type cmykColorType struct {
   144  	c, m, y, k byte // 0% to 100%
   145  }
   146  
   147  // SizeType fields Wd and Ht specify the horizontal and vertical extents of a
   148  // document element such as a page.
   149  type SizeType struct {
   150  	Wd, Ht float64
   151  }
   152  
   153  // PointType fields X and Y specify the horizontal and vertical coordinates of
   154  // a point, typically used in drawing.
   155  type PointType struct {
   156  	X, Y float64
   157  }
   158  
   159  // XY returns the X and Y components of the receiver point.
   160  func (p PointType) XY() (float64, float64) {
   161  	return p.X, p.Y
   162  }
   163  
   164  // ImageInfoType contains size, color and other information about an image.
   165  // Changes to this structure should be reflected in its GobEncode and GobDecode
   166  // methods.
   167  type ImageInfoType struct {
   168  	data  []byte  // Raw image data
   169  	smask []byte  // Soft Mask, an 8bit per-pixel transparency mask
   170  	n     int     // Image object number
   171  	w     float64 // Width
   172  	h     float64 // Height
   173  	cs    string  // Color space
   174  	pal   []byte  // Image color palette
   175  	bpc   int     // Bits Per Component
   176  	f     string  // Image filter
   177  	dp    string  // DecodeParms
   178  	trns  []int   // Transparency mask
   179  	scale float64 // Document scale factor
   180  	dpi   float64 // Dots-per-inch found from image file (png only)
   181  	i     string  // SHA-1 checksum of the above values.
   182  }
   183  
   184  func generateImageID(info *ImageInfoType) (string, error) {
   185  	b, err := info.GobEncode()
   186  	return fmt.Sprintf("%x", sha1.Sum(b)), err
   187  }
   188  
   189  // GobEncode encodes the receiving image to a byte slice.
   190  func (info *ImageInfoType) GobEncode() (buf []byte, err error) {
   191  	fields := []interface{}{info.data, info.smask, info.n, info.w, info.h, info.cs,
   192  		info.pal, info.bpc, info.f, info.dp, info.trns, info.scale, info.dpi}
   193  	w := new(bytes.Buffer)
   194  	encoder := gob.NewEncoder(w)
   195  	for j := 0; j < len(fields) && err == nil; j++ {
   196  		err = encoder.Encode(fields[j])
   197  	}
   198  	if err == nil {
   199  		buf = w.Bytes()
   200  	}
   201  	return
   202  }
   203  
   204  // GobDecode decodes the specified byte buffer (generated by GobEncode) into
   205  // the receiving image.
   206  func (info *ImageInfoType) GobDecode(buf []byte) (err error) {
   207  	fields := []interface{}{&info.data, &info.smask, &info.n, &info.w, &info.h,
   208  		&info.cs, &info.pal, &info.bpc, &info.f, &info.dp, &info.trns, &info.scale, &info.dpi}
   209  	r := bytes.NewBuffer(buf)
   210  	decoder := gob.NewDecoder(r)
   211  	for j := 0; j < len(fields) && err == nil; j++ {
   212  		err = decoder.Decode(fields[j])
   213  	}
   214  
   215  	info.i, err = generateImageID(info)
   216  	return
   217  }
   218  
   219  // PointConvert returns the value of pt, expressed in points (1/72 inch), as a
   220  // value expressed in the unit of measure specified in New(). Since font
   221  // management in Fpdf uses points, this method can help with line height
   222  // calculations and other methods that require user units.
   223  func (f *Fpdf) PointConvert(pt float64) (u float64) {
   224  	return pt / f.k
   225  }
   226  
   227  // PointToUnitConvert is an alias for PointConvert.
   228  func (f *Fpdf) PointToUnitConvert(pt float64) (u float64) {
   229  	return pt / f.k
   230  }
   231  
   232  // UnitToPointConvert returns the value of u, expressed in the unit of measure
   233  // specified in New(), as a value expressed in points (1/72 inch). Since font
   234  // management in Fpdf uses points, this method can help with setting font sizes
   235  // based on the sizes of other non-font page elements.
   236  func (f *Fpdf) UnitToPointConvert(u float64) (pt float64) {
   237  	return u * f.k
   238  }
   239  
   240  // Extent returns the width and height of the image in the units of the Fpdf
   241  // object.
   242  func (info *ImageInfoType) Extent() (wd, ht float64) {
   243  	return info.Width(), info.Height()
   244  }
   245  
   246  // Width returns the width of the image in the units of the Fpdf object.
   247  func (info *ImageInfoType) Width() float64 {
   248  	return info.w / (info.scale * info.dpi / 72)
   249  }
   250  
   251  // Height returns the height of the image in the units of the Fpdf object.
   252  func (info *ImageInfoType) Height() float64 {
   253  	return info.h / (info.scale * info.dpi / 72)
   254  }
   255  
   256  // SetDpi sets the dots per inch for an image. PNG images MAY have their dpi
   257  // set automatically, if the image specifies it. DPI information is not
   258  // currently available automatically for JPG and GIF images, so if it's
   259  // important to you, you can set it here. It defaults to 72 dpi.
   260  func (info *ImageInfoType) SetDpi(dpi float64) {
   261  	info.dpi = dpi
   262  }
   263  
   264  type fontFileType struct {
   265  	length1, length2 int64
   266  	n                int
   267  	embedded         bool
   268  	content          []byte
   269  	fontType         string
   270  }
   271  
   272  type linkType struct {
   273  	x, y, wd, ht float64
   274  	link         int    // Auto-generated internal link ID or...
   275  	linkStr      string // ...application-provided external link string
   276  }
   277  
   278  type intLinkType struct {
   279  	page int
   280  	y    float64
   281  }
   282  
   283  // outlineType is used for a sidebar outline of bookmarks
   284  type outlineType struct {
   285  	text                                   string
   286  	level, parent, first, last, next, prev int
   287  	y                                      float64
   288  	p                                      int
   289  }
   290  
   291  // InitType is used with NewCustom() to customize an Fpdf instance.
   292  // OrientationStr, UnitStr, SizeStr and FontDirStr correspond to the arguments
   293  // accepted by New(). If the Wd and Ht fields of Size are each greater than
   294  // zero, Size will be used to set the default page size rather than SizeStr. Wd
   295  // and Ht are specified in the units of measure indicated by UnitStr.
   296  type InitType struct {
   297  	OrientationStr string
   298  	UnitStr        string
   299  	SizeStr        string
   300  	Size           SizeType
   301  	FontDirStr     string
   302  }
   303  
   304  // FontLoader is used to read fonts (JSON font specification and zlib compressed font binaries)
   305  // from arbitrary locations (e.g. files, zip files, embedded font resources).
   306  //
   307  // Open provides an io.Reader for the specified font file (.json or .z). The file name
   308  // never includes a path. Open returns an error if the specified file cannot be opened.
   309  type FontLoader interface {
   310  	Open(name string) (io.Reader, error)
   311  }
   312  
   313  // Pdf defines the interface used for various methods. It is implemented by the
   314  // main FPDF instance as well as templates.
   315  type Pdf interface {
   316  	AddFont(familyStr, styleStr, fileStr string)
   317  	AddFontFromBytes(familyStr, styleStr string, jsonFileBytes, zFileBytes []byte)
   318  	AddFontFromReader(familyStr, styleStr string, r io.Reader)
   319  	AddLayer(name string, visible bool) (layerID int)
   320  	AddLink() int
   321  	AddPage()
   322  	AddPageFormat(orientationStr string, size SizeType)
   323  	AddSpotColor(nameStr string, c, m, y, k byte)
   324  	AliasNbPages(aliasStr string)
   325  	ArcTo(x, y, rx, ry, degRotate, degStart, degEnd float64)
   326  	Arc(x, y, rx, ry, degRotate, degStart, degEnd float64, styleStr string)
   327  	BeginLayer(id int)
   328  	Beziergon(points []PointType, styleStr string)
   329  	Bookmark(txtStr string, level int, y float64)
   330  	CellFormat(w, h float64, txtStr, borderStr string, ln int, alignStr string, fill bool, link int, linkStr string)
   331  	Cellf(w, h float64, fmtStr string, args ...interface{})
   332  	Cell(w, h float64, txtStr string)
   333  	Circle(x, y, r float64, styleStr string)
   334  	ClearError()
   335  	ClipCircle(x, y, r float64, outline bool)
   336  	ClipEllipse(x, y, rx, ry float64, outline bool)
   337  	ClipEnd()
   338  	ClipPolygon(points []PointType, outline bool)
   339  	ClipRect(x, y, w, h float64, outline bool)
   340  	ClipRoundedRect(x, y, w, h, r float64, outline bool)
   341  	ClipText(x, y float64, txtStr string, outline bool)
   342  	Close()
   343  	ClosePath()
   344  	CreateTemplateCustom(corner PointType, size SizeType, fn func(*Tpl)) Template
   345  	CreateTemplate(fn func(*Tpl)) Template
   346  	CurveBezierCubicTo(cx0, cy0, cx1, cy1, x, y float64)
   347  	CurveBezierCubic(x0, y0, cx0, cy0, cx1, cy1, x1, y1 float64, styleStr string)
   348  	CurveCubic(x0, y0, cx0, cy0, x1, y1, cx1, cy1 float64, styleStr string)
   349  	CurveTo(cx, cy, x, y float64)
   350  	Curve(x0, y0, cx, cy, x1, y1 float64, styleStr string)
   351  	DrawPath(styleStr string)
   352  	Ellipse(x, y, rx, ry, degRotate float64, styleStr string)
   353  	EndLayer()
   354  	Err() bool
   355  	Error() error
   356  	GetAlpha() (alpha float64, blendModeStr string)
   357  	GetAutoPageBreak() (auto bool, margin float64)
   358  	GetCellMargin() float64
   359  	GetConversionRatio() float64
   360  	GetDrawColor() (int, int, int)
   361  	GetDrawSpotColor() (name string, c, m, y, k byte)
   362  	GetFillColor() (int, int, int)
   363  	GetFillSpotColor() (name string, c, m, y, k byte)
   364  	GetFontDesc(familyStr, styleStr string) FontDescType
   365  	GetFontSize() (ptSize, unitSize float64)
   366  	GetImageInfo(imageStr string) (info *ImageInfoType)
   367  	GetLineWidth() float64
   368  	GetMargins() (left, top, right, bottom float64)
   369  	GetPageSizeStr(sizeStr string) (size SizeType)
   370  	GetPageSize() (width, height float64)
   371  	GetStringWidth(s string) float64
   372  	GetTextColor() (int, int, int)
   373  	GetTextSpotColor() (name string, c, m, y, k byte)
   374  	GetX() float64
   375  	GetXY() (float64, float64)
   376  	GetY() float64
   377  	HTMLBasicNew() (html HTMLBasicType)
   378  	Image(imageNameStr string, x, y, w, h float64, flow bool, tp string, link int, linkStr string)
   379  	ImageOptions(imageNameStr string, x, y, w, h float64, flow bool, options ImageOptions, link int, linkStr string)
   380  	ImageTypeFromMime(mimeStr string) (tp string)
   381  	LinearGradient(x, y, w, h float64, r1, g1, b1, r2, g2, b2 int, x1, y1, x2, y2 float64)
   382  	LineTo(x, y float64)
   383  	Line(x1, y1, x2, y2 float64)
   384  	LinkString(x, y, w, h float64, linkStr string)
   385  	Link(x, y, w, h float64, link int)
   386  	Ln(h float64)
   387  	MoveTo(x, y float64)
   388  	MultiCell(w, h float64, txtStr, borderStr, alignStr string, fill bool)
   389  	Ok() bool
   390  	OpenLayerPane()
   391  	OutputAndClose(w io.WriteCloser) error
   392  	OutputFileAndClose(fileStr string) error
   393  	Output(w io.Writer) error
   394  	PageCount() int
   395  	PageNo() int
   396  	PageSize(pageNum int) (wd, ht float64, unitStr string)
   397  	PointConvert(pt float64) (u float64)
   398  	PointToUnitConvert(pt float64) (u float64)
   399  	Polygon(points []PointType, styleStr string)
   400  	RadialGradient(x, y, w, h float64, r1, g1, b1, r2, g2, b2 int, x1, y1, x2, y2, r float64)
   401  	RawWriteBuf(r io.Reader)
   402  	RawWriteStr(str string)
   403  	Rect(x, y, w, h float64, styleStr string)
   404  	RegisterAlias(alias, replacement string)
   405  	RegisterImage(fileStr, tp string) (info *ImageInfoType)
   406  	RegisterImageOptions(fileStr string, options ImageOptions) (info *ImageInfoType)
   407  	RegisterImageOptionsReader(imgName string, options ImageOptions, r io.Reader) (info *ImageInfoType)
   408  	RegisterImageReader(imgName, tp string, r io.Reader) (info *ImageInfoType)
   409  	SetAcceptPageBreakFunc(fnc func() bool)
   410  	SetAlpha(alpha float64, blendModeStr string)
   411  	SetAuthor(authorStr string, isUTF8 bool)
   412  	SetAutoPageBreak(auto bool, margin float64)
   413  	SetCatalogSort(flag bool)
   414  	SetCellMargin(margin float64)
   415  	SetCompression(compress bool)
   416  	SetCreationDate(tm time.Time)
   417  	SetCreator(creatorStr string, isUTF8 bool)
   418  	SetDashPattern(dashArray []float64, dashPhase float64)
   419  	SetDisplayMode(zoomStr, layoutStr string)
   420  	SetDrawColor(r, g, b int)
   421  	SetDrawSpotColor(nameStr string, tint byte)
   422  	SetError(err error)
   423  	SetErrorf(fmtStr string, args ...interface{})
   424  	SetFillColor(r, g, b int)
   425  	SetFillSpotColor(nameStr string, tint byte)
   426  	SetFont(familyStr, styleStr string, size float64)
   427  	SetFontLoader(loader FontLoader)
   428  	SetFontLocation(fontDirStr string)
   429  	SetFontSize(size float64)
   430  	SetFontStyle(styleStr string)
   431  	SetFontUnitSize(size float64)
   432  	SetFooterFunc(fnc func())
   433  	SetFooterFuncLpi(fnc func(lastPage bool))
   434  	SetHeaderFunc(fnc func())
   435  	SetHeaderFuncMode(fnc func(), homeMode bool)
   436  	SetHomeXY()
   437  	SetJavascript(script string)
   438  	SetKeywords(keywordsStr string, isUTF8 bool)
   439  	SetLeftMargin(margin float64)
   440  	SetLineCapStyle(styleStr string)
   441  	SetLineJoinStyle(styleStr string)
   442  	SetLineWidth(width float64)
   443  	SetLink(link int, y float64, page int)
   444  	SetMargins(left, top, right float64)
   445  	SetPageBoxRec(t string, pb PageBox)
   446  	SetPageBox(t string, x, y, wd, ht float64)
   447  	SetPage(pageNum int)
   448  	SetProtection(actionFlag byte, userPassStr, ownerPassStr string)
   449  	SetRightMargin(margin float64)
   450  	SetSubject(subjectStr string, isUTF8 bool)
   451  	SetTextColor(r, g, b int)
   452  	SetTextSpotColor(nameStr string, tint byte)
   453  	SetTitle(titleStr string, isUTF8 bool)
   454  	SetTopMargin(margin float64)
   455  	SetUnderlineThickness(thickness float64)
   456  	SetXmpMetadata(xmpStream []byte)
   457  	SetX(x float64)
   458  	SetXY(x, y float64)
   459  	SetY(y float64)
   460  	SplitLines(txt []byte, w float64) [][]byte
   461  	String() string
   462  	SVGBasicWrite(sb *SVGBasicType, scale float64)
   463  	Text(x, y float64, txtStr string)
   464  	TransformBegin()
   465  	TransformEnd()
   466  	TransformMirrorHorizontal(x float64)
   467  	TransformMirrorLine(angle, x, y float64)
   468  	TransformMirrorPoint(x, y float64)
   469  	TransformMirrorVertical(y float64)
   470  	TransformRotate(angle, x, y float64)
   471  	TransformScale(scaleWd, scaleHt, x, y float64)
   472  	TransformScaleX(scaleWd, x, y float64)
   473  	TransformScaleXY(s, x, y float64)
   474  	TransformScaleY(scaleHt, x, y float64)
   475  	TransformSkew(angleX, angleY, x, y float64)
   476  	TransformSkewX(angleX, x, y float64)
   477  	TransformSkewY(angleY, x, y float64)
   478  	Transform(tm TransformMatrix)
   479  	TransformTranslate(tx, ty float64)
   480  	TransformTranslateX(tx float64)
   481  	TransformTranslateY(ty float64)
   482  	UnicodeTranslatorFromDescriptor(cpStr string) (rep func(string) string)
   483  	UnitToPointConvert(u float64) (pt float64)
   484  	UseTemplateScaled(t Template, corner PointType, size SizeType)
   485  	UseTemplate(t Template)
   486  	WriteAligned(width, lineHeight float64, textStr, alignStr string)
   487  	Writef(h float64, fmtStr string, args ...interface{})
   488  	Write(h float64, txtStr string)
   489  	WriteLinkID(h float64, displayStr string, linkID int)
   490  	WriteLinkString(h float64, displayStr, targetStr string)
   491  }
   492  
   493  // PageBox defines the coordinates and extent of the various page box types
   494  type PageBox struct {
   495  	SizeType
   496  	PointType
   497  }
   498  
   499  // Fpdf is the principal structure for creating a single PDF document
   500  type Fpdf struct {
   501  	isCurrentUTF8    bool                       // is current font used in utf-8 mode
   502  	isRTL            bool                       // is is right to left mode enabled
   503  	page             int                        // current page number
   504  	n                int                        // current object number
   505  	offsets          []int                      // array of object offsets
   506  	templates        map[string]Template        // templates used in this document
   507  	templateObjects  map[string]int             // template object IDs within this document
   508  	importedObjs     map[string][]byte          // imported template objects (gofpdi)
   509  	importedObjPos   map[string]map[int]string  // imported template objects hashes and their positions (gofpdi)
   510  	importedTplObjs  map[string]string          // imported template names and IDs (hashed) (gofpdi)
   511  	importedTplIDs   map[string]int             // imported template ids hash to object id int (gofpdi)
   512  	buffer           fmtBuffer                  // buffer holding in-memory PDF
   513  	pages            []*bytes.Buffer            // slice[page] of page content; 1-based
   514  	state            int                        // current document state
   515  	compress         bool                       // compression flag
   516  	k                float64                    // scale factor (number of points in user unit)
   517  	defOrientation   string                     // default orientation
   518  	curOrientation   string                     // current orientation
   519  	stdPageSizes     map[string]SizeType        // standard page sizes
   520  	defPageSize      SizeType                   // default page size
   521  	defPageBoxes     map[string]PageBox         // default page size
   522  	curPageSize      SizeType                   // current page size
   523  	pageSizes        map[int]SizeType           // used for pages with non default sizes or orientations
   524  	pageBoxes        map[int]map[string]PageBox // used to define the crop, trim, bleed and art boxes
   525  	unitStr          string                     // unit of measure for all rendered objects except fonts
   526  	wPt, hPt         float64                    // dimensions of current page in points
   527  	w, h             float64                    // dimensions of current page in user unit
   528  	lMargin          float64                    // left margin
   529  	tMargin          float64                    // top margin
   530  	rMargin          float64                    // right margin
   531  	bMargin          float64                    // page break margin
   532  	cMargin          float64                    // cell margin
   533  	x, y             float64                    // current position in user unit
   534  	lasth            float64                    // height of last printed cell
   535  	lineWidth        float64                    // line width in user unit
   536  	fontpath         string                     // path containing fonts
   537  	fontLoader       FontLoader                 // used to load font files from arbitrary locations
   538  	coreFonts        map[string]bool            // array of core font names
   539  	fonts            map[string]fontDefType     // array of used fonts
   540  	fontFiles        map[string]fontFileType    // array of font files
   541  	diffs            []string                   // array of encoding differences
   542  	fontFamily       string                     // current font family
   543  	fontStyle        string                     // current font style
   544  	underline        bool                       // underlining flag
   545  	strikeout        bool                       // strike out flag
   546  	currentFont      fontDefType                // current font info
   547  	fontSizePt       float64                    // current font size in points
   548  	fontSize         float64                    // current font size in user unit
   549  	ws               float64                    // word spacing
   550  	images           map[string]*ImageInfoType  // array of used images
   551  	aliasMap         map[string]string          // map of alias->replacement
   552  	pageLinks        [][]linkType               // pageLinks[page][link], both 1-based
   553  	links            []intLinkType              // array of internal links
   554  	attachments      []Attachment               // slice of content to embed globally
   555  	pageAttachments  [][]annotationAttach       // 1-based array of annotation for file attachments (per page)
   556  	outlines         []outlineType              // array of outlines
   557  	outlineRoot      int                        // root of outlines
   558  	autoPageBreak    bool                       // automatic page breaking
   559  	acceptPageBreak  func() bool                // returns true to accept page break
   560  	pageBreakTrigger float64                    // threshold used to trigger page breaks
   561  	inHeader         bool                       // flag set when processing header
   562  	headerFnc        func()                     // function provided by app and called to write header
   563  	headerHomeMode   bool                       // set position to home after headerFnc is called
   564  	inFooter         bool                       // flag set when processing footer
   565  	footerFnc        func()                     // function provided by app and called to write footer
   566  	footerFncLpi     func(bool)                 // function provided by app and called to write footer with last page flag
   567  	zoomMode         string                     // zoom display mode
   568  	layoutMode       string                     // layout display mode
   569  	xmp              []byte                     // XMP metadata
   570  	producer         string                     // producer
   571  	title            string                     // title
   572  	subject          string                     // subject
   573  	author           string                     // author
   574  	keywords         string                     // keywords
   575  	creator          string                     // creator
   576  	creationDate     time.Time                  // override for document CreationDate value
   577  	modDate          time.Time                  // override for document ModDate value
   578  	aliasNbPagesStr  string                     // alias for total number of pages
   579  	pdfVersion       string                     // PDF version number
   580  	fontDirStr       string                     // location of font definition files
   581  	capStyle         int                        // line cap style: butt 0, round 1, square 2
   582  	joinStyle        int                        // line segment join style: miter 0, round 1, bevel 2
   583  	dashArray        []float64                  // dash array
   584  	dashPhase        float64                    // dash phase
   585  	blendList        []blendModeType            // slice[idx] of alpha transparency modes, 1-based
   586  	blendMap         map[string]int             // map into blendList
   587  	blendMode        string                     // current blend mode
   588  	alpha            float64                    // current transpacency
   589  	gradientList     []gradientType             // slice[idx] of gradient records
   590  	clipNest         int                        // Number of active clipping contexts
   591  	transformNest    int                        // Number of active transformation contexts
   592  	err              error                      // Set if error occurs during life cycle of instance
   593  	protect          protectType                // document protection structure
   594  	layer            layerRecType               // manages optional layers in document
   595  	catalogSort      bool                       // sort resource catalogs in document
   596  	nJs              int                        // JavaScript object number
   597  	javascript       *string                    // JavaScript code to include in the PDF
   598  	colorFlag        bool                       // indicates whether fill and text colors are different
   599  	color            struct {
   600  		// Composite values of colors
   601  		draw, fill, text colorType
   602  	}
   603  	spotColorMap           map[string]spotColorType // Map of named ink-based colors
   604  	userUnderlineThickness float64                  // A custom user underline thickness multiplier.
   605  }
   606  
   607  type encType struct {
   608  	uv   int
   609  	name string
   610  }
   611  
   612  type encListType [256]encType
   613  
   614  type fontBoxType struct {
   615  	Xmin, Ymin, Xmax, Ymax int
   616  }
   617  
   618  // Font flags for FontDescType.Flags as defined in the pdf specification.
   619  const (
   620  	// FontFlagFixedPitch is set if all glyphs have the same width (as
   621  	// opposed to proportional or variable-pitch fonts, which have
   622  	// different widths).
   623  	FontFlagFixedPitch = 1 << 0
   624  	// FontFlagSerif is set if glyphs have serifs, which are short
   625  	// strokes drawn at an angle on the top and bottom of glyph stems.
   626  	// (Sans serif fonts do not have serifs.)
   627  	FontFlagSerif = 1 << 1
   628  	// FontFlagSymbolic is set if font contains glyphs outside the
   629  	// Adobe standard Latin character set. This flag and the
   630  	// Nonsymbolic flag shall not both be set or both be clear.
   631  	FontFlagSymbolic = 1 << 2
   632  	// FontFlagScript is set if glyphs resemble cursive handwriting.
   633  	FontFlagScript = 1 << 3
   634  	// FontFlagNonsymbolic is set if font uses the Adobe standard
   635  	// Latin character set or a subset of it.
   636  	FontFlagNonsymbolic = 1 << 5
   637  	// FontFlagItalic is set if glyphs have dominant vertical strokes
   638  	// that are slanted.
   639  	FontFlagItalic = 1 << 6
   640  	// FontFlagAllCap is set if font contains no lowercase letters;
   641  	// typically used for display purposes, such as for titles or
   642  	// headlines.
   643  	FontFlagAllCap = 1 << 16
   644  	// SmallCap is set if font contains both uppercase and lowercase
   645  	// letters. The uppercase letters are similar to those in the
   646  	// regular version of the same typeface family. The glyphs for the
   647  	// lowercase letters have the same shapes as the corresponding
   648  	// uppercase letters, but they are sized and their proportions
   649  	// adjusted so that they have the same size and stroke weight as
   650  	// lowercase glyphs in the same typeface family.
   651  	SmallCap = 1 << 18
   652  	// ForceBold determines whether bold glyphs shall be painted with
   653  	// extra pixels even at very small text sizes by a conforming
   654  	// reader. If the ForceBold flag is set, features of bold glyphs
   655  	// may be thickened at small text sizes.
   656  	ForceBold = 1 << 18
   657  )
   658  
   659  // FontDescType (font descriptor) specifies metrics and other
   660  // attributes of a font, as distinct from the metrics of individual
   661  // glyphs (as defined in the pdf specification).
   662  type FontDescType struct {
   663  	// The maximum height above the baseline reached by glyphs in this
   664  	// font (for example for "S"). The height of glyphs for accented
   665  	// characters shall be excluded.
   666  	Ascent int
   667  	// The maximum depth below the baseline reached by glyphs in this
   668  	// font. The value shall be a negative number.
   669  	Descent int
   670  	// The vertical coordinate of the top of flat capital letters,
   671  	// measured from the baseline (for example "H").
   672  	CapHeight int
   673  	// A collection of flags defining various characteristics of the
   674  	// font. (See the FontFlag* constants.)
   675  	Flags int
   676  	// A rectangle, expressed in the glyph coordinate system, that
   677  	// shall specify the font bounding box. This should be the smallest
   678  	// rectangle enclosing the shape that would result if all of the
   679  	// glyphs of the font were placed with their origins coincident
   680  	// and then filled.
   681  	FontBBox fontBoxType
   682  	// The angle, expressed in degrees counterclockwise from the
   683  	// vertical, of the dominant vertical strokes of the font. (The
   684  	// 9-o’clock position is 90 degrees, and the 3-o’clock position
   685  	// is –90 degrees.) The value shall be negative for fonts that
   686  	// slope to the right, as almost all italic fonts do.
   687  	ItalicAngle int
   688  	// The thickness, measured horizontally, of the dominant vertical
   689  	// stems of glyphs in the font.
   690  	StemV int
   691  	// The width to use for character codes whose widths are not
   692  	// specified in a font dictionary’s Widths array. This shall have
   693  	// a predictable effect only if all such codes map to glyphs whose
   694  	// actual widths are the same as the value of the MissingWidth
   695  	// entry. (Default value: 0.)
   696  	MissingWidth int
   697  }
   698  
   699  type fontDefType struct {
   700  	Tp           string        // "Core", "TrueType", ...
   701  	Name         string        // "Courier-Bold", ...
   702  	Desc         FontDescType  // Font descriptor
   703  	Up           int           // Underline position
   704  	Ut           int           // Underline thickness
   705  	Cw           []int         // Character width by ordinal
   706  	Enc          string        // "cp1252", ...
   707  	Diff         string        // Differences from reference encoding
   708  	File         string        // "Redressed.z"
   709  	Size1, Size2 int           // Type1 values
   710  	OriginalSize int           // Size of uncompressed font file
   711  	N            int           // Set by font loader
   712  	DiffN        int           // Position of diff in app array, set by font loader
   713  	i            string        // 1-based position in font list, set by font loader, not this program
   714  	utf8File     *utf8FontFile // UTF-8 font
   715  	usedRunes    map[int]int   // Array of used runes
   716  }
   717  
   718  // generateFontID generates a font Id from the font definition
   719  func generateFontID(fdt fontDefType) (string, error) {
   720  	// file can be different if generated in different instance
   721  	fdt.File = ""
   722  	b, err := json.Marshal(&fdt)
   723  	return fmt.Sprintf("%x", sha1.Sum(b)), err
   724  }
   725  
   726  type fontInfoType struct {
   727  	Data               []byte
   728  	File               string
   729  	OriginalSize       int
   730  	FontName           string
   731  	Bold               bool
   732  	IsFixedPitch       bool
   733  	UnderlineThickness int
   734  	UnderlinePosition  int
   735  	Widths             []int
   736  	Size1, Size2       uint32
   737  	Desc               FontDescType
   738  }
   739
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