mirror of
https://github.com/unidoc/unipdf.git
synced 2025-04-29 13:48:54 +08:00
Fixed text position tracking.
This commit is contained in:
Peter Williams
parent
ee3e2a45a0
commit
b0c440dd00
@ -49,5 +49,5 @@ func (p *Point) transformByMatrix(m contentstream.Matrix) {
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// String returns a string describing `p`.
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func (p *Point) String() string {
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return fmt.Sprintf("(%.1f,%.1f)", p.X, p.Y)
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return fmt.Sprintf("(%.2f,%.2f)", p.X, p.Y)
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}
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@ -9,6 +9,8 @@ import (
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"errors"
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"fmt"
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"math"
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"path/filepath"
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"runtime"
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"sort"
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"strings"
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@ -585,8 +587,10 @@ func newTextObject(e *Extractor, gs contentstream.GraphicsState, state *textStat
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func (to *textObject) renderText(data []byte) error {
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font := to.getCurrentFont()
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text, numChars, numMisses := font.CharcodeBytesToUnicode(data)
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runes := []rune(text)
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charcodes := font.BytesToCharcodes(data)
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runes, numChars, numMisses := font.CharcodesToUnicode(charcodes)
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to.State.numChars += numChars
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to.State.numMisses += numMisses
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@ -598,7 +602,7 @@ func (to *textObject) renderText(data []byte) error {
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spaceMetrics, _ = model.DefaultFont().GetRuneCharMetrics(' ')
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}
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spaceWidth := spaceMetrics.Wx * glyphTextRatio
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common.Log.Debug("spaceWidth=%.2f text=%q font=%s fontSize=%.1f", spaceWidth, text,
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common.Log.Debug("spaceWidth=%.2f text=%q font=%s fontSize=%.1f", spaceWidth, runes,
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font, tfs)
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stateMatrix := contentstream.NewMatrix(
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@ -606,7 +610,8 @@ func (to *textObject) renderText(data []byte) error {
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0, tfs,
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0, state.Trise)
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for _, r := range runes {
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for i, r := range runes {
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code := charcodes[i]
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// The location of the text on the page in device coordinates is given by trm, the text
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// rendering matrix.
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trm := stateMatrix.Mult(to.Tm).Mult(to.gs.CTM)
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@ -616,40 +621,33 @@ func (to *textObject) renderText(data []byte) error {
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// w is the unscaled movement at the end of a word.
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w := 0.0
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if r == ' ' {
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if r == " " {
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w = state.Tw
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}
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m, err := font.GetRuneCharMetrics(r)
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if err != nil {
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common.Log.Debug("ERROR: No metric for 0x%04x=%c %s", r, r, font)
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return err
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m, ok := font.GetCharMetrics(code)
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if !ok {
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common.Log.Debug("ERROR: No metric for code=%d r=0x%04x=%c %s", code, r, r, font)
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return errors.New("no char metrics")
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}
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// c is the character size in unscaled text units.
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c := Point{X: m.Wx * glyphTextRatio, Y: m.Wy * glyphTextRatio}
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// cScaled is the character size
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cScaled := Point{X: c.X * tfs * th}
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// t is the displacement of the text cursor when the character is rendered.
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t := Point{X: (c.X*tfs + state.Tc + w) * th}
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common.Log.Debug("t=%s cScaled=%s c=%s tfs=%.2f state.Tc=%.2f w=%.2f th=%.2f",
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t.String(), cScaled.String(), c.String(), tfs, state.Tc, w, th)
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// td is t in matrix from
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// td is t in matrix form.
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td := translationMatrix(t)
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common.Log.Debug("displacement=%s t=%s td=%s m=%s",
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c.String(), t.String(), td.String(), m.String())
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nextTm := to.Tm.Mult(td)
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common.Log.Debug(" next: td=%s %s->%s", td, to.Tm, nextTm)
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xyt := XYText{Text: string(r),
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Point: translation(trm),
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End: translation(trm).Displace(cScaled),
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End: translation(to.Tm.Mult(td).Mult(to.gs.CTM)),
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SpaceWidth: spaceWidth * trm.ScalingFactorX(),
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}
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to.Texts = append(to.Texts, xyt)
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common.Log.Debug(" xyt=%s", xyt.String())
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// update the text matrix by the displacement of the text location.
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to.Tm = nextTm
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@ -738,6 +736,7 @@ func (tl *TextList) AppendText(gs contentstream.GraphicsState, p, e Point, text
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// ToText returns the contents of `tl` as a single string.
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func (tl *TextList) ToText() string {
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tl.printTexts("ToText: before sorting")
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tl.SortPosition()
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lines := tl.toLines()
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@ -770,7 +769,7 @@ type Line struct {
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// toLines return the text and positions in `tl` as a slice of Line.
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// NOTE: Caller must sort the text list top-to-bottom, left-to-write before calling this function.
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func (tl *TextList) toLines() []Line {
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tl.printTexts()
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tl.printTexts("toLines: before")
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if len(*tl) == 0 {
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return []Line{}
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}
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@ -870,13 +869,28 @@ func (exp *ExponAve) update(x float64) float64 {
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}
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// printTexts is a debugging function. XXX Remove this.
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func (tl *TextList) printTexts() {
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func (tl *TextList) printTexts(message string) {
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return
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common.Log.Error("=====================================")
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common.Log.Error("%d texts", len(*tl))
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for i, t := range (*tl)[1:] {
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fmt.Printf("%5d: %s\n", i, t.String())
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_, file, line, ok := runtime.Caller(1)
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if !ok {
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file = "???"
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line = 0
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} else {
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file = filepath.Base(file)
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}
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prefix := fmt.Sprintf("[%s:%d]", file, line)
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common.Log.Error("=====================================")
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common.Log.Error("printTexts %s %s", prefix, message)
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common.Log.Error("%d texts", len(*tl))
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parts := []string{}
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for i, t := range *tl {
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fmt.Printf("%5d: %s\n", i, t.String())
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parts = append(parts, t.Text)
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}
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common.Log.Error("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
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fmt.Printf("%s\n", strings.Join(parts, ""))
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common.Log.Error("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^")
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}
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// newLine returns the Line representation of strings `words` with y coordinate `y` and x
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@ -3,3 +3,5 @@ Font Metrics
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1 Leave char->unicode until end
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2 Build metrics tables for charcodes
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3 Remove double Font interface definition
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4 Express CharcodeBytesToUnicode2 in terms of
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@ -18,13 +18,26 @@ import (
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"github.com/unidoc/unidoc/pdf/model/textencoding"
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)
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// Font represents a font which is a series of glyphs. Character codes from PDF strings can be
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// mapped to and from glyphs. Each glyph has metrics.
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// XXX: FIXME (peterwilliams97) HACK to add GetCharMetrics() for fonts other than standard 14
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// Remove this hack.
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type Font interface {
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Encoder() textencoding.TextEncoder
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SetEncoder(encoder textencoding.TextEncoder)
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GetGlyphCharMetrics(glyph string) (fonts.CharMetrics, bool)
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GetCharMetrics(code uint16) (fonts.CharMetrics, bool)
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GetAverageCharWidth() float64
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ToPdfObject() core.PdfObject
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}
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// PdfFont represents an underlying font structure which can be of type:
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// - Type0
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// - Type1
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// - TrueType
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// etc.
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type PdfFont struct {
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context fonts.Font // The underlying font: Type0, Type1, Truetype, etc..
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context Font // The underlying font: Type0, Type1, Truetype, etc..
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}
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// String returns a string that describes `font`.
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@ -303,12 +316,7 @@ func newPdfFontFromPdfObject(fontObj core.PdfObject, allowType0 bool) (*PdfFont,
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// conforming writers, instead of using a simple font, shall use a Type 0 font with an Identity-H
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// encoding and use the glyph indices as character codes, as described following Table 118.
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func (font PdfFont) CharcodeBytesToUnicode(data []byte) (string, int, int) {
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_, out, numChars, numMisses := font.CharcodeBytesToUnicode2(data)
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return out, numChars, numMisses
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}
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func (font PdfFont) CharcodeBytesToUnicode2(data []byte) ([]uint16, string, int, int) {
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common.Log.Trace("showText: data=[% 02x]=%#q", data, data)
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common.Log.Trace("CharcodeBytesToUnicode: data=[% 02x]=%#q", data, data)
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charcodes := make([]uint16, 0, len(data)+len(data)%2)
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if font.baseFields().isCIDFont() {
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@ -363,7 +371,74 @@ func (font PdfFont) CharcodeBytesToUnicode2(data []byte) ([]uint16, string, int,
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}
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out := strings.Join(charstrings, "")
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return charcodes, out, len([]rune(out)), numMisses
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return out, len([]rune(out)), numMisses
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}
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// BytesToCharcodes converts the bytes in a PDF string to character codes.
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func (font PdfFont) BytesToCharcodes(data []byte) []uint16 {
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common.Log.Trace("BytesToCharcodes: data=[% 02x]=%#q", data, data)
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charcodes := make([]uint16, 0, len(data)+len(data)%2)
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if font.baseFields().isCIDFont() {
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if len(data) == 1 {
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data = []byte{0, data[0]}
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}
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if len(data)%2 != 0 {
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common.Log.Debug("ERROR: Padding data=%+v to even length", data)
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data = append(data, 0)
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}
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for i := 0; i < len(data); i += 2 {
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b := uint16(data[i])<<8 | uint16(data[i+1])
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charcodes = append(charcodes, b)
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}
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} else {
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for _, b := range data {
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charcodes = append(charcodes, uint16(b))
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}
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}
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return charcodes
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}
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// CharcodesToUnicode converts the character codes `charcodes` to a slice of unicode strings.
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func (font PdfFont) CharcodesToUnicode(charcodes []uint16) ([]string, int, int) {
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charstrings := make([]string, 0, len(charcodes))
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numMisses := 0
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for _, code := range charcodes {
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if font.baseFields().toUnicodeCmap != nil {
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r, ok := font.baseFields().toUnicodeCmap.CharcodeToUnicode(cmap.CharCode(code))
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if ok {
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charstrings = append(charstrings, r)
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continue
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}
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}
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// Fall back to encoding
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encoder := font.Encoder()
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if encoder != nil {
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r, ok := encoder.CharcodeToRune(code)
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if ok {
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charstrings = append(charstrings, textencoding.RuneToString(r))
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continue
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}
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}
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common.Log.Debug("ERROR: No rune. code=0x%04x charcodes=[% 04x] CID=%t\n"+
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"\tfont=%s\n\tencoding=%s",
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code, charcodes, font.baseFields().isCIDFont(), font, encoder)
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numMisses++
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charstrings = append(charstrings, cmap.MissingCodeString)
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}
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if numMisses != 0 {
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common.Log.Debug("ERROR: Couldn't convert to unicode. Using input.\n"+
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"\tnumChars=%d numMisses=%d\n"+
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"\tfont=%s",
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len(charcodes), numMisses, font)
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}
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if len(charcodes) != len(charstrings) {
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panic(fmt.Errorf("charcodes=%d charstrings=%d", len(charcodes), len(charstrings)))
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}
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return charstrings, len(charstrings), numMisses
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}
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// ToPdfObject converts the PdfFont object to its PDF representation.
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@ -402,9 +477,21 @@ func (font PdfFont) GetGlyphCharMetrics(glyph string) (fonts.CharMetrics, bool)
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t := font.actualFont()
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if t == nil {
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common.Log.Debug("ERROR: GetGlyphCharMetrics Not implemented for font type=%#T", font.context)
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return fonts.CharMetrics{GlyphName: glyph}, false
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}
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metrics, ok := t.GetGlyphCharMetrics(glyph)
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return metrics, ok
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}
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// GetCharMetrics returns the char metrics for character code `code`.
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func (font PdfFont) GetCharMetrics(code uint16) (fonts.CharMetrics, bool) {
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t := font.actualFont()
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if t == nil {
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common.Log.Debug("ERROR: GetCharMetrics Not implemented for font type=%#T", font.context)
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return fonts.CharMetrics{}, false
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}
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return t.GetGlyphCharMetrics(glyph)
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m, ok := t.GetCharMetrics(code)
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return m, ok
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}
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// GetRuneCharMetrics returns the char metrics for rune `r`.
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@ -438,7 +525,7 @@ func (font PdfFont) GetAverageCharWidth() float64 {
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}
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// actualFont returns the Font in font.context
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func (font PdfFont) actualFont() fonts.Font {
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func (font PdfFont) actualFont() Font {
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if font.context == nil {
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common.Log.Debug("ERROR: actualFont. context is nil. font=%s", font)
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}
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@ -121,6 +121,15 @@ func (font pdfFontType0) GetGlyphCharMetrics(glyph string) (fonts.CharMetrics, b
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return font.DescendantFont.GetGlyphCharMetrics(glyph)
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}
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// !@#$ stub
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func (font pdfFontType0) GetCharMetrics(code uint16) (fonts.CharMetrics, bool) {
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if font.DescendantFont == nil {
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common.Log.Debug("ERROR: No descendant. font=%s", font)
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return fonts.CharMetrics{}, false
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}
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return font.DescendantFont.GetCharMetrics(code)
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}
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// GetAverageCharWidth returns the average width of all the characters in `font`.
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func (font pdfFontType0) GetAverageCharWidth() float64 {
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if font.DescendantFont == nil {
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@ -238,6 +247,11 @@ func (font pdfCIDFontType0) GetGlyphCharMetrics(glyph string) (fonts.CharMetrics
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return fonts.CharMetrics{}, true
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}
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// !@#$ stub
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func (font pdfCIDFontType0) GetCharMetrics(code uint16) (fonts.CharMetrics, bool) {
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return fonts.CharMetrics{}, true
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}
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// GetAverageCharWidth returns the average width of all the characters in `font`.
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func (font pdfCIDFontType0) GetAverageCharWidth() float64 {
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return 0.0
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@ -347,6 +361,12 @@ func (font pdfCIDFontType2) GetGlyphCharMetrics(glyph string) (fonts.CharMetrics
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return metrics, true
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}
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// !@#$ stub
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func (font pdfCIDFontType2) GetCharMetrics(code uint16) (fonts.CharMetrics, bool) {
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metrics := fonts.CharMetrics{}
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return metrics, true
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}
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// GetAverageCharWidth returns the average width of all the characters in `font`.
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func (font pdfCIDFontType2) GetAverageCharWidth() float64 {
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if len(font.runeToWidthMap) == 0 {
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@ -93,13 +93,20 @@ func (font pdfFontSimple) GetGlyphCharMetrics(glyph string) (fonts.CharMetrics,
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return metrics, ok
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}
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metrics := fonts.CharMetrics{}
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code, found := font.encoder.GlyphToCharcode(glyph)
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if !found {
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return metrics, false
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return fonts.CharMetrics{GlyphName: glyph}, false
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}
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// !@#$ Shouldn't we fall back from GetCharMetrics to GetGlyphCharMetrics?
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metrics, ok := font.GetCharMetrics(code)
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metrics.GlyphName = glyph
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return metrics, ok
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}
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// GetCharMetrics returns the character metrics for the specified character code. A bool flag is
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// returned to indicate whether or not the entry was found in the glyph to charcode mapping.
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func (font pdfFontSimple) GetCharMetrics(code uint16) (fonts.CharMetrics, bool) {
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metrics := fonts.CharMetrics{}
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if int(code) < font.firstChar {
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common.Log.Debug("Code lower than firstchar (%d < %d)", code, font.firstChar)
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