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/*
Copyright 2023 The pdfcpu Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package pdfcpu
import (
"bytes"
"fmt"
"io"
"math"
"strings"
"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/color"
"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/draw"
"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/matrix"
"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/model"
"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/types"
"github.com/pkg/errors"
)
// ParseCutConfigForPoster parses a Cut command string into an internal structure.
// formsize(=papersize) or dimensions, optionally: scalefactor, border, margin, bgcolor
func ParseCutConfigForPoster(s string, u types.DisplayUnit) (*model.Cut, error) {
if s == "" {
return nil, errors.New("pdfcpu: missing poster configuration string")
}
cut := &model.Cut{Unit: u, Scale: 1.0}
ss := strings.Split(s, ",")
for _, s := range ss {
ss1 := strings.Split(s, ":")
if len(ss1) != 2 {
return nil, errors.New("pdfcpu: Invalid poster configuration string. Please consult pdfcpu help poster")
}
paramPrefix := strings.TrimSpace(ss1[0])
paramValueStr := strings.TrimSpace(ss1[1])
if err := model.CutParamMap.Handle(paramPrefix, paramValueStr, cut); err != nil {
return nil, err
}
}
return cut, nil
}
// ParseCutConfigForN parses a NDown command string into an internal structure.
// n, Optionally: border, margin, bgcolor
func ParseCutConfigForN(n int, s string, u types.DisplayUnit) (*model.Cut, error) {
cut := &model.Cut{Unit: u}
if !types.IntMemberOf(n, []int{2, 3, 4, 6, 8, 9, 12, 16}) {
return nil, errors.New("pdfcpu: invalid n: Please choose one of 2, 3, 4, 6, 8, 9, 12, 16")
}
if s == "" {
return cut, nil
}
ss := strings.Split(s, ",")
for _, s := range ss {
ss1 := strings.Split(s, ":")
if len(ss1) != 2 {
return nil, errors.New("pdfcpu: Invalid ndown configuration string. Please consult pdfcpu help ndown")
}
paramPrefix := strings.TrimSpace(ss1[0])
paramValueStr := strings.TrimSpace(ss1[1])
if err := model.CutParamMap.Handle(paramPrefix, paramValueStr, cut); err != nil {
return nil, err
}
}
return cut, nil
}
// ParseCutConfig parses a Cut command string into an internal structure.
// optionally: horizontalCut, verticalCut, bgcolor, border, margin, origin
func ParseCutConfig(s string, u types.DisplayUnit) (*model.Cut, error) {
if s == "" {
return nil, errors.New("pdfcpu: missing cut configuration string")
}
cut := &model.Cut{Unit: u}
ss := strings.Split(s, ",")
for _, s := range ss {
ss1 := strings.Split(s, ":")
if len(ss1) != 2 {
return nil, errors.New("pdfcpu: Invalid cut configuration string. Please consult pdfcpu help cut")
}
paramPrefix := strings.TrimSpace(ss1[0])
paramValueStr := strings.TrimSpace(ss1[1])
if err := model.CutParamMap.Handle(paramPrefix, paramValueStr, cut); err != nil {
return nil, err
}
}
return cut, nil
}
func drawOutlineCuts(w io.Writer, cropBox, cb *types.Rectangle, cut *model.Cut) {
for i, f := range cut.Hor {
if i == 0 {
continue
}
y := cropBox.UR.Y - f*cropBox.Height()
draw.DrawLineSimple(w, cb.LL.X, y, cb.UR.X, y)
}
for i, f := range cut.Vert {
if i == 0 {
continue
}
x := cropBox.LL.X + f*cropBox.Width()
draw.DrawLineSimple(w, x, cb.LL.Y, x, cb.UR.Y)
}
}
func createOutline(
ctxSrc, ctxDest *model.Context,
pagesIndRef types.IndirectRef,
pagesDict, d types.Dict,
cropBox *types.Rectangle,
migrated map[int]int,
cut *model.Cut) error {
cb := cropBox.Clone()
var expCropBox bool
if len(cut.Hor) > 0 && cut.Hor[len(cut.Hor)-1] > 1 {
h := cut.Hor[len(cut.Hor)-1] * cropBox.Height()
cb.LL.Y = cb.UR.Y - h
expCropBox = true
}
if len(cut.Vert) > 0 && cut.Vert[len(cut.Vert)-1] > 1 {
w := cut.Vert[len(cut.Vert)-1] * cropBox.Width()
cb.UR.X = cb.LL.X + w
expCropBox = true
}
d1 := d.Clone().(types.Dict)
var buf bytes.Buffer
fmt.Fprint(&buf, "[3] 0 d ")
draw.SetStrokeColor(&buf, color.Red)
// Assumption: origin = top left corner
drawOutlineCuts(&buf, cropBox, cb, cut)
bb, err := ctxSrc.PageContent(d1)
if err != nil {
return err
}
bb = append([]byte("q "), bb...)
bb = append(bb, []byte("Q ")...)
bb = append(bb, buf.Bytes()...)
sd, _ := ctxSrc.NewStreamDictForBuf(bb)
if err := sd.Encode(); err != nil {
return err
}
indRef, err := ctxSrc.IndRefForNewObject(*sd)
if err != nil {
return err
}
d1["Contents"] = *indRef
d1["Parent"] = pagesIndRef
if expCropBox {
d1["MediaBox"] = cb.Array()
d1["CropBox"] = cb.Array()
}
pageIndRef, err := ctxDest.IndRefForNewObject(d1)
if err != nil {
return err
}
if err := ctxDest.SetValid(*pageIndRef); err != nil {
return err
}
if err := migratePageDict(d1, *pageIndRef, ctxSrc, ctxDest, migrated); err != nil {
return err
}
if err := model.AppendPageTree(pageIndRef, 1, pagesDict); err != nil {
return err
}
return nil
}
func prepForCut(ctxSrc *model.Context, i int) (
*model.Context,
*types.Rectangle,
*types.IndirectRef,
types.Dict,
types.Dict,
*model.InheritedPageAttrs,
error) {
ctxDest, err := CreateContextWithXRefTable(nil, types.PaperSize["A4"])
if err != nil {
return nil, nil, nil, nil, nil, nil, err
}
pagesIndRef, err := ctxDest.Pages()
if err != nil {
return nil, nil, nil, nil, nil, nil, err
}
pagesDict, err := ctxDest.DereferenceDict(*pagesIndRef)
if err != nil {
return nil, nil, nil, nil, nil, nil, err
}
d, _, inhPAttrs, err := ctxSrc.PageDict(i, false)
if err != nil {
return nil, nil, nil, nil, nil, nil, err
}
if d == nil {
return nil, nil, nil, nil, nil, nil, errors.Errorf("pdfcpu: unknown page number: %d\n", i)
}
d.Delete("Annots")
cropBox := inhPAttrs.MediaBox
if inhPAttrs.CropBox != nil {
cropBox = inhPAttrs.CropBox
}
return ctxDest, cropBox, pagesIndRef, pagesDict, d, inhPAttrs, nil
}
func internPageRot(ctxSrc *model.Context, rotate int, cropBox *types.Rectangle, d types.Dict, trans []byte) error {
bb, err := ctxSrc.PageContent(d)
if err != nil {
return err
}
if rotate != 0 {
bbInvRot := append([]byte(" q "), model.ContentBytesForPageRotation(rotate, cropBox.Width(), cropBox.Height())...)
bb = append(bbInvRot, bb...)
bb = append(bb, []byte(" Q ")...)
}
if len(trans) == 0 {
trans = []byte("q ")
}
bb = append(trans, bb...)
bb = append(bb, []byte("Q ")...)
sd, _ := ctxSrc.NewStreamDictForBuf(bb)
if err := sd.Encode(); err != nil {
return err
}
indRef, err := ctxSrc.IndRefForNewObject(*sd)
if err != nil {
return err
}
d["Contents"] = *indRef
return nil
}
func handleCutMargin(ctxSrc *model.Context, d, d1 types.Dict, cropBox, cb *types.Rectangle, i, j int, w, h float64, sc *float64, cut *model.Cut) error {
ar := cb.AspectRatio()
mv := cut.Margin / ar
// Scale & translate content.
if *sc == 0 {
*sc = (cb.Width() - 2*cut.Margin) / cb.Width()
}
cbsc := cropBox.Clone()
cbsc.UR.X = cbsc.LL.X + cbsc.Width()**sc
cbsc.UR.Y = cbsc.LL.Y + cbsc.Height()**sc
llx := cbsc.LL.X + cut.Vert[j]*cbsc.Width()
lly := cbsc.LL.Y
if i+1 < len(cut.Hor) {
lly = cbsc.UR.Y - cut.Hor[i+1]*cbsc.Height()
}
cbb := types.RectForWidthAndHeight(llx, lly, w, h)
d1["MediaBox"] = cbb.Array()
d1["CropBox"] = cbb.Array()
cb1 := cbb.Clone()
cb1.LL.X += cut.Margin
cb1.LL.Y += mv
cb1.UR.X -= cut.Margin
cb1.UR.Y -= mv
var buf bytes.Buffer
c := color.White
if cut.BgColor != nil {
c = *cut.BgColor
}
w, h = cb1.Width(), mv
r := types.RectForWidthAndHeight(cb1.LL.X, cb1.UR.Y, w, h)
draw.FillRectNoBorder(&buf, r, c)
r = types.RectForWidthAndHeight(cb1.LL.X, cb1.LL.Y-mv, w, h)
draw.FillRectNoBorder(&buf, r, c)
w, h = cut.Margin, cbb.Height()
r = types.RectForWidthAndHeight(cb1.UR.X, cb1.LL.Y-mv, w, h)
draw.FillRectNoBorder(&buf, r, c)
r = types.RectForWidthAndHeight(cb1.LL.X-cut.Margin, cb1.LL.Y-mv, w, h)
draw.FillRectNoBorder(&buf, r, c)
if cut.Border {
draw.DrawRect(&buf, cb1, 1, &color.Black, nil)
}
m := matrix.CalcTransformMatrix(*sc, *sc, 0, 1, cut.Margin, mv)
var trans bytes.Buffer
fmt.Fprintf(&trans, "q %.5f %.5f %.5f %.5f %.5f %.5f cm ", m[0][0], m[0][1], m[1][0], m[1][1], m[2][0], m[2][1])
bbOrig, err := ctxSrc.PageContent(d)
if err != nil {
return err
}
bb := append(trans.Bytes(), bbOrig...)
bb = append(bb, []byte(" Q ")...)
bb = append(bb, buf.Bytes()...)
sd, _ := ctxSrc.NewStreamDictForBuf(bb)
if err := sd.Encode(); err != nil {
return err
}
indRef, err := ctxSrc.IndRefForNewObject(*sd)
if err != nil {
return err
}
d1["Contents"] = *indRef
return nil
}
func createTiles(
ctxSrc, ctxDest *model.Context,
pagesIndRef types.IndirectRef,
pagesDict, d types.Dict,
cropBox *types.Rectangle,
inhPAttrs *model.InheritedPageAttrs,
migrated map[int]int,
cut *model.Cut) error {
var sc float64
for i := 0; i < len(cut.Hor); i++ {
ury := cropBox.UR.Y - cut.Hor[i]*cropBox.Height()
if ury < cropBox.LL.Y {
continue
}
lly := cropBox.LL.Y
if i+1 < len(cut.Hor) {
lly = cropBox.UR.Y - cut.Hor[i+1]*cropBox.Height()
}
h := ury - lly
for j := 0; j < len(cut.Vert); j++ {
llx := cropBox.LL.X + cut.Vert[j]*cropBox.Width()
if llx > cropBox.UR.X {
continue
}
urx := cropBox.UR.X
if j+1 < len(cut.Vert) {
urx = cropBox.LL.X + cut.Vert[j+1]*cropBox.Width()
}
w := urx - llx
cb := types.NewRectangle(llx, lly, urx, ury)
d1 := d.Clone().(types.Dict)
d1["Resources"] = inhPAttrs.Resources.Clone()
d1["Parent"] = pagesIndRef
d1["MediaBox"] = cb.Array()
d1["CropBox"] = cb.Array()
if cut.Margin > 0 {
if err := handleCutMargin(ctxSrc, d, d1, cropBox, cb, i, j, w, h, &sc, cut); err != nil {
return err
}
}
pageIndRef, err := ctxDest.IndRefForNewObject(d1)
if err != nil {
return err
}
if err := ctxDest.SetValid(*pageIndRef); err != nil {
return err
}
if err := migratePageDict(d1, *pageIndRef, ctxSrc, ctxDest, migrated); err != nil {
return err
}
if err := model.AppendPageTree(pageIndRef, 1, pagesDict); err != nil {
return err
}
}
}
return nil
}
func CutPage(ctxSrc *model.Context, i int, cut *model.Cut) (*model.Context, error) {
// required: at least one of horizontalCut, verticalCut
// optionally: border, margin, bgcolor
ctxDest, cropBox, pagesIndRef, pagesDict, d, inhPAttrs, err := prepForCut(ctxSrc, i)
if err != nil {
return nil, err
}
rotate := inhPAttrs.Rotate
if types.IntMemberOf(rotate, []int{+90, -90, +270, -270}) {
w := cropBox.Width()
cropBox.UR.X = cropBox.LL.X + cropBox.Height()
cropBox.UR.Y = cropBox.LL.Y + w
d["MediaBox"] = cropBox.Array()
d["CropBox"] = cropBox.Array()
d.Delete("Rotate")
}
if err := internPageRot(ctxSrc, rotate, cropBox, d, nil); err != nil {
return nil, err
}
migrated := map[int]int{}
if err := createOutline(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, migrated, cut); err != nil {
return nil, err
}
if err := createTiles(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, inhPAttrs, migrated, cut); err != nil {
return nil, err
}
return ctxDest, nil
}
func createNDownCuts(n int, cropBox *types.Rectangle, cut *model.Cut) {
var s1, s2 []float64
switch n {
case 2:
s1 = append(s1, 0, .5)
s2 = append(s2, 0)
case 3:
s1 = append(s1, 0, .33333, .66666)
s2 = append(s2, 0)
case 4:
s1 = append(s1, 0, .5)
s2 = append(s2, 0, .5)
case 6:
s1 = append(s1, 0, .33333, .66666)
s2 = append(s2, 0, .5)
case 8:
s1 = append(s1, 0, .25, .5, .75)
s2 = append(s2, 0, .5)
case 9:
s1 = append(s1, 0, .33333, .66666)
s2 = append(s2, 0, .33333, .66666)
case 12:
s1 = append(s1, 0, .25, .5, .75)
s2 = append(s2, 0, .33333, .66666)
case 16:
s1 = append(s1, 0, .25, .5, .75)
s2 = append(s2, 0, .25, .5, .75)
}
if cropBox.Portrait() {
cut.Hor, cut.Vert = s1, s2
} else {
cut.Hor, cut.Vert = s2, s1
}
}
func NDownPage(ctxSrc *model.Context, i, n int, cut *model.Cut) (*model.Context, error) {
// Optionally: border, margin, bgcolor
ctxDest, cropBox, pagesIndRef, pagesDict, d, inhPAttrs, err := prepForCut(ctxSrc, i)
if err != nil {
return nil, err
}
rotate := inhPAttrs.Rotate
if types.IntMemberOf(rotate, []int{+90, -90, +270, -270}) {
w := cropBox.Width()
cropBox.UR.X = cropBox.LL.X + cropBox.Height()
cropBox.UR.Y = cropBox.LL.Y + w
d["MediaBox"] = cropBox.Array()
d["CropBox"] = cropBox.Array()
d.Delete("Rotate")
}
if err := internPageRot(ctxSrc, rotate, cropBox, d, nil); err != nil {
return nil, err
}
createNDownCuts(n, cropBox, cut)
migrated := map[int]int{}
if err := createOutline(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, migrated, cut); err != nil {
return nil, err
}
if err := createTiles(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, inhPAttrs, migrated, cut); err != nil {
return nil, err
}
return ctxDest, nil
}
func createPosterCuts(cropBox *types.Rectangle, cut *model.Cut) {
dim := cut.PageDim
cut.Vert = []float64{0.}
for x := 0.; ; x += dim.Width {
f := (x + dim.Width) / cropBox.Width()
fr := math.Round(f*100) / 100
if fr != 1 {
cut.Vert = append(cut.Vert, f)
}
if fr >= 1 {
break
}
}
cut.Hor = []float64{0.}
for y := 0.; ; y += dim.Height {
f := (y + dim.Height) / cropBox.Height()
fr := math.Round(f*100) / 100
if fr != 1 {
cut.Hor = append(cut.Hor, f)
}
if fr >= 1 {
break
}
}
}
func PosterPage(ctxSrc *model.Context, i int, cut *model.Cut) (*model.Context, error) {
// required: formsize(=papersize) or dimensions
// optionally: scalefactor, border, margin, bgcolor
ctxDest, cropBox, pagesIndRef, pagesDict, d, inhPAttrs, err := prepForCut(ctxSrc, i)
if err != nil {
return nil, err
}
cropBox.UR.X = cropBox.LL.X + cropBox.Width()*cut.Scale
cropBox.UR.Y = cropBox.LL.Y + cropBox.Height()*cut.Scale
// Ensure cut.PageDim fits into scaled cropBox.
dim := cut.PageDim
if dim.Width > cropBox.Width() || dim.Height > cropBox.Height() {
return nil, errors.New("pdfcpu: selected poster tile dimensions too big")
}
rotate := inhPAttrs.Rotate
if types.IntMemberOf(rotate, []int{+90, -90, +270, -270}) {
w := cropBox.Width()
cropBox.UR.X = cropBox.LL.X + cropBox.Height()
cropBox.UR.Y = cropBox.LL.Y + w
}
d["MediaBox"] = cropBox.Array()
d["CropBox"] = cropBox.Array()
d.Delete("Rotate")
// Scale transform
m := matrix.IdentMatrix
m[0][0] = cut.Scale
m[1][1] = cut.Scale
var trans bytes.Buffer
fmt.Fprintf(&trans, "q %.5f %.5f %.5f %.5f %.5f %.5f cm ", m[0][0], m[0][1], m[1][0], m[1][1], m[2][0], m[2][1])
if err := internPageRot(ctxSrc, rotate, cropBox, d, trans.Bytes()); err != nil {
return nil, err
}
createPosterCuts(cropBox, cut)
migrated := map[int]int{}
if err := createOutline(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, migrated, cut); err != nil {
return nil, err
}
if err := createTiles(ctxSrc, ctxDest, *pagesIndRef, pagesDict, d, cropBox, inhPAttrs, migrated, cut); err != nil {
return nil, err
}
return ctxDest, nil
}
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