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Add core support for creating PDF content via content streams
This commit is contained in:
Gunnsteinn Hall
parent
b0479f6914
commit
a1d15f3838
399
pdf/contentstream/creator.go
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399
pdf/contentstream/creator.go
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package contentstream
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import . "github.com/unidoc/unidoc/pdf/core"
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type ContentCreator struct {
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operands ContentStreamOperations
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}
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func NewContentCreator() *ContentCreator {
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creator := &ContentCreator{}
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creator.operands = ContentStreamOperations{}
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return creator
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}
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// Convert a set of content stream operations to a content stream byte presentation, i.e. the kind that can be
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// stored as a PDF stream or string format.
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func (this *ContentCreator) Bytes() []byte {
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return this.operands.Bytes()
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}
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/* Graphics state operators. */
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// Save the current graphics state on the stack - push.
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func (this *ContentCreator) Add_q() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "q"
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this.operands = append(this.operands, &op)
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return this
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}
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// Restore the most recently stored state from the stack - pop.
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func (this *ContentCreator) Add_Q() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "Q"
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this.operands = append(this.operands, &op)
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return this
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}
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// Modify the current transformation matrix (ctm).
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func (this *ContentCreator) Add_cm(a, b, c, d, e, f float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "cm"
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op.Params = makeParamsFromFloats([]float64{a, b, c, d, e, f})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the line width.
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func (this *ContentCreator) Add_w(lineWidth float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "w"
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op.Params = makeParamsFromFloats([]float64{lineWidth})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the line cap style.
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func (this *ContentCreator) Add_J(lineCapStyle string) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "J"
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op.Params = makeParamsFromNames([]PdfObjectName{PdfObjectName(lineCapStyle)})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the line join style.
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func (this *ContentCreator) Add_j(lineJoinStyle string) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "j"
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op.Params = makeParamsFromNames([]PdfObjectName{PdfObjectName(lineJoinStyle)})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the miter limit.
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func (this *ContentCreator) Add_M(miterlimit float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "M"
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op.Params = makeParamsFromFloats([]float64{miterlimit})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the line dash pattern.
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func (this *ContentCreator) Add_d(dashArray []int64, dashPhase int64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "d"
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op.Params = makeParamsFromInts(dashArray)
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op.Params = append(op.Params, MakeInteger(dashPhase))
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the color rendering intent.
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func (this *ContentCreator) Add_ri(intent PdfObjectName) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "ri"
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op.Params = makeParamsFromNames([]PdfObjectName{intent})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the flatness tolerance.
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func (this *ContentCreator) Add_i(flatness float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "i"
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op.Params = makeParamsFromFloats([]float64{flatness})
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this.operands = append(this.operands, &op)
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return this
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}
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// Set the graphics state.
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func (this *ContentCreator) Add_gs(dictName PdfObjectName) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "gs"
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op.Params = makeParamsFromNames([]PdfObjectName{dictName})
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this.operands = append(this.operands, &op)
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return this
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}
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/* Path construction operators. */
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// m: Move the current point to (x,y).
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func (this *ContentCreator) Add_m(x, y float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "m"
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op.Params = makeParamsFromFloats([]float64{x, y})
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this.operands = append(this.operands, &op)
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return this
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}
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// l: Append a straight line segment from the current point to (x,y).
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func (this *ContentCreator) Add_l(x, y float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "l"
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op.Params = makeParamsFromFloats([]float64{x, y})
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this.operands = append(this.operands, &op)
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return this
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}
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// c: Append a Bezier curve to the current path from the current point to (x3,y3) with (x1,x1) and (x2,y2) as control
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// points.
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func (this *ContentCreator) Add_c(x1, y1, x2, y2, x3, y3 float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "c"
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op.Params = makeParamsFromFloats([]float64{x1, y1, x2, y2, x3, y3})
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this.operands = append(this.operands, &op)
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return this
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}
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// v: Append a Bezier curve to the current path from the current point to (x3,y3) with the current point and (x2,y2) as
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// control points.
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func (this *ContentCreator) Add_v(x2, y2, x3, y3 float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "v"
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op.Params = makeParamsFromFloats([]float64{x2, y2, x3, y3})
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this.operands = append(this.operands, &op)
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return this
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}
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// y: Append a Bezier curve to the current path from the current point to (x3,y3) with (x1, y1) and (x3,y3) as
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// control points.
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func (this *ContentCreator) Add_y(x1, y1, x3, y3 float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "y"
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op.Params = makeParamsFromFloats([]float64{x1, y1, x3, y3})
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this.operands = append(this.operands, &op)
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return this
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}
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// h: Close the current subpath by adding a line between the current position and the starting position.
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func (this *ContentCreator) Add_h() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "h"
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this.operands = append(this.operands, &op)
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return this
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}
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// re: Append a rectangle to the current path as a complete subpath, with lower left corner (x,y).
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func (this *ContentCreator) Add_re(x, y, width, height float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "re"
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op.Params = makeParamsFromFloats([]float64{x, y, width, height})
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this.operands = append(this.operands, &op)
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return this
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}
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/* Path painting operators. */
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// S: stroke the path.
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func (this *ContentCreator) Add_S() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "S"
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this.operands = append(this.operands, &op)
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return this
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}
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// s: Close and stroke the path.
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func (this *ContentCreator) Add_s() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "s"
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this.operands = append(this.operands, &op)
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return this
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}
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// f: Fill the path using the nonzero winding number rule to determine fill region.
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func (this *ContentCreator) Add_f() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "f"
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this.operands = append(this.operands, &op)
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return this
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}
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// f*: Fill the path using the even-odd rule to determine fill region.
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func (this *ContentCreator) Add_f_starred() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "f*"
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this.operands = append(this.operands, &op)
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return this
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}
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// B: Fill and then stroke the path (nonzero winding number rule).
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func (this *ContentCreator) Add_B() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "B"
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this.operands = append(this.operands, &op)
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return this
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}
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// B*: Fill and then stroke the path (even-odd rule).
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func (this *ContentCreator) Add_B_starred() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "B*"
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this.operands = append(this.operands, &op)
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return this
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}
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// b: Close, fill and then stroke the path (nonzero winding number rule).
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func (this *ContentCreator) Add_b() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "b"
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this.operands = append(this.operands, &op)
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return this
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}
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// b*: Close, fill and then stroke the path (even-odd winding number rule).
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func (this *ContentCreator) Add_b_starred() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "b*"
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this.operands = append(this.operands, &op)
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return this
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}
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// n: End the path without filling or stroking.
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func (this *ContentCreator) Add_n() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "n"
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this.operands = append(this.operands, &op)
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return this
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}
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/* Clipping path operators. */
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// W: Modify the current clipping path by intersecting with the current path (nonzero winding rule).
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func (this *ContentCreator) Add_W() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "W"
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this.operands = append(this.operands, &op)
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return this
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}
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// W*: Modify the current clipping path by intersecting with the current path (even odd rule).
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func (this *ContentCreator) Add_W_starred() *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "W*"
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this.operands = append(this.operands, &op)
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return this
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}
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/* Color operators. */
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// CS: Set the current colorspace for stroking operations.
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func (this *ContentCreator) Add_CS(name PdfObjectName) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "CS"
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op.Params = makeParamsFromNames([]PdfObjectName{name})
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this.operands = append(this.operands, &op)
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return this
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}
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// cs: Same as CS but for non-stroking operations.
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func (this *ContentCreator) Add_cs(name PdfObjectName) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "cs"
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op.Params = makeParamsFromNames([]PdfObjectName{name})
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this.operands = append(this.operands, &op)
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return this
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}
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// SC: Set color for stroking operations. Input: c1, ..., cn.
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func (this *ContentCreator) Add_SC(c ...float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "SC"
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op.Params = makeParamsFromFloats(c)
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this.operands = append(this.operands, &op)
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return this
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}
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// SCN: Same as SC but supports more colorspaces.
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func (this *ContentCreator) Add_SCN(c ...float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "SCN"
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op.Params = makeParamsFromFloats(c)
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this.operands = append(this.operands, &op)
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return this
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}
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// SCN with name attribute (for pattern). Syntax: c1 ... cn name SCN.
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func (this *ContentCreator) Add_SCN_pattern(name PdfObjectName, c ...float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "SCN"
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op.Params = makeParamsFromFloats(c)
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op.Params = append(op.Params, MakeName(string(name)))
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this.operands = append(this.operands, &op)
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return this
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}
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// scn: Same as SC but for nonstroking operations.
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func (this *ContentCreator) Add_scn(c ...float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "scn"
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op.Params = makeParamsFromFloats(c)
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this.operands = append(this.operands, &op)
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return this
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}
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// scn with name attribute (for pattern). Syntax: c1 ... cn name scn.
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func (this *ContentCreator) Add_scn_pattern(name PdfObjectName, c ...float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "scn"
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op.Params = makeParamsFromFloats(c)
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op.Params = append(op.Params, MakeName(string(name)))
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this.operands = append(this.operands, &op)
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return this
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}
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// G: Set the stroking colorspace to DeviceGray and sets the gray level (0-1).
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func (this *ContentCreator) Add_G(gray float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "G"
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op.Params = makeParamsFromFloats([]float64{gray})
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this.operands = append(this.operands, &op)
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return this
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}
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// g: Same as G but used for nonstroking operations.
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func (this *ContentCreator) Add_g(gray float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "g"
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op.Params = makeParamsFromFloats([]float64{gray})
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this.operands = append(this.operands, &op)
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return this
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}
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// RG: Set the stroking colorspace to DeviceRGB and sets the r,g,b colors (0-1 each).
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func (this *ContentCreator) Add_RG(r, g, b float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "RG"
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op.Params = makeParamsFromFloats([]float64{r, g, b})
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this.operands = append(this.operands, &op)
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return this
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}
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// rg: Same as RG but used for nonstroking operations.
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func (this *ContentCreator) Add_rg(r, g, b float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "rg"
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op.Params = makeParamsFromFloats([]float64{r, g, b})
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this.operands = append(this.operands, &op)
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return this
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}
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// K: Set the stroking colorspace to DeviceCMYK and sets the c,m,y,k color (0-1 each component).
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func (this *ContentCreator) Add_K(c, m, y, k float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "K"
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op.Params = makeParamsFromFloats([]float64{c, m, y, k})
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this.operands = append(this.operands, &op)
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return this
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}
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// k: Same as K but used for nonstroking operations.
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func (this *ContentCreator) Add_k(c, m, y, k float64) *ContentCreator {
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op := ContentStreamOperation{}
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op.Operand = "k"
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op.Params = makeParamsFromFloats([]float64{c, m, y, k})
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this.operands = append(this.operands, &op)
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return this
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}
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27
pdf/contentstream/utils.go
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27
pdf/contentstream/utils.go
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@ -0,0 +1,27 @@
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package contentstream
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import . "github.com/unidoc/unidoc/pdf/core"
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func makeParamsFromFloats(vals []float64) []PdfObject {
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params := []PdfObject{}
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for _, val := range vals {
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params = append(params, MakeFloat(val))
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}
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return params
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}
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func makeParamsFromNames(vals []PdfObjectName) []PdfObject {
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params := []PdfObject{}
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for _, val := range vals {
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params = append(params, MakeName(string(val)))
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}
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return params
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}
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func makeParamsFromInts(vals []int64) []PdfObject {
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params := []PdfObject{}
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for _, val := range vals {
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params = append(params, MakeInteger(val))
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}
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return params
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}
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