fix wrong git ignore

internal/pdf/annotator/line.go

@@ -0,0 +1,133 @@
+package annotator
+
+import (
+	"gitea.tecamino.com/paadi/pdfmerge/internal/pdf/common"
+	"gitea.tecamino.com/paadi/pdfmerge/internal/pdf/contentstream/draw"
+	pdfcore "gitea.tecamino.com/paadi/pdfmerge/internal/pdf/core"
+	pdf "gitea.tecamino.com/paadi/pdfmerge/internal/pdf/model"
+)
+
+// Defines a line between point 1 (X1,Y1) and point 2 (X2,Y2).  The line ending styles can be none (regular line),
+// or arrows at either end.  The line also has a specified width, color and opacity.
+type LineAnnotationDef struct {
+	X1               float64
+	Y1               float64
+	X2               float64
+	Y2               float64
+	LineColor        *pdf.PdfColorDeviceRGB
+	Opacity          float64 // Alpha value (0-1).
+	LineWidth        float64
+	LineEndingStyle1 draw.LineEndingStyle // Line ending style of point 1.
+	LineEndingStyle2 draw.LineEndingStyle // Line ending style of point 2.
+}
+
+// Creates a line annotation object that can be added to page PDF annotations.
+func CreateLineAnnotation(lineDef LineAnnotationDef) (*pdf.PdfAnnotation, error) {
+	// Line annotation.
+	lineAnnotation := pdf.NewPdfAnnotationLine()
+
+	// Line endpoint locations.
+	lineAnnotation.L = pdfcore.MakeArrayFromFloats([]float64{lineDef.X1, lineDef.Y1, lineDef.X2, lineDef.Y2})
+
+	// Line endings.
+	le1 := pdfcore.MakeName("None")
+	if lineDef.LineEndingStyle1 == draw.LineEndingStyleArrow {
+		le1 = pdfcore.MakeName("ClosedArrow")
+	}
+	le2 := pdfcore.MakeName("None")
+	if lineDef.LineEndingStyle2 == draw.LineEndingStyleArrow {
+		le2 = pdfcore.MakeName("ClosedArrow")
+	}
+	lineAnnotation.LE = pdfcore.MakeArray(le1, le2)
+
+	// Opacity.
+	if lineDef.Opacity < 1.0 {
+		lineAnnotation.CA = pdfcore.MakeFloat(lineDef.Opacity)
+	}
+
+	r, g, b := lineDef.LineColor.R(), lineDef.LineColor.G(), lineDef.LineColor.B()
+	lineAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b}) // fill color of line endings, rgb 0-1.
+	lineAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})  // line color, rgb 0-1.
+	bs := pdf.NewBorderStyle()
+	bs.SetBorderWidth(lineDef.LineWidth) // Line width: 3 points.
+	lineAnnotation.BS = bs.ToPdfObject()
+
+	// Make the appearance stream (for uniform appearance).
+	apDict, bbox, err := makeLineAnnotationAppearanceStream(lineDef)
+	if err != nil {
+		return nil, err
+	}
+	lineAnnotation.AP = apDict
+
+	// The rect specifies the location and dimensions of the annotation.  Technically if the annotation could not
+	// be displayed if it goes outside these bounds, although rarely enforced.
+	lineAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
+
+	return lineAnnotation.PdfAnnotation, nil
+}
+
+func makeLineAnnotationAppearanceStream(lineDef LineAnnotationDef) (*pdfcore.PdfObjectDictionary, *pdf.PdfRectangle, error) {
+	form := pdf.NewXObjectForm()
+	form.Resources = pdf.NewPdfPageResources()
+
+	gsName := ""
+	if lineDef.Opacity < 1.0 {
+		// Create graphics state with right opacity.
+		gsState := pdfcore.MakeDict()
+		gsState.Set("ca", pdfcore.MakeFloat(lineDef.Opacity))
+		err := form.Resources.AddExtGState("gs1", gsState)
+		if err != nil {
+			common.Log.Debug("Unable to add extgstate gs1")
+			return nil, nil, err
+		}
+
+		gsName = "gs1"
+	}
+
+	content, localBbox, globalBbox, err := drawPdfLine(lineDef, gsName)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = form.SetContentStream(content, nil)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Local bounding box for the XObject Form.
+	form.BBox = localBbox.ToPdfObject()
+
+	apDict := pdfcore.MakeDict()
+	apDict.Set("N", form.ToPdfObject())
+
+	return apDict, globalBbox, nil
+}
+
+func drawPdfLine(lineDef LineAnnotationDef, gsName string) ([]byte, *pdf.PdfRectangle, *pdf.PdfRectangle, error) {
+	// The annotation is drawn locally in a relative coordinate system with 0,0 as the origin rather than an offset.
+	line := draw.Line{
+		X1:               0,
+		Y1:               0,
+		X2:               lineDef.X2 - lineDef.X1,
+		Y2:               lineDef.Y2 - lineDef.Y1,
+		LineColor:        lineDef.LineColor,
+		Opacity:          lineDef.Opacity,
+		LineWidth:        lineDef.LineWidth,
+		LineEndingStyle1: lineDef.LineEndingStyle1,
+		LineEndingStyle2: lineDef.LineEndingStyle2,
+	}
+
+	content, localBbox, err := line.Draw(gsName)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	// Bounding box - global page coordinate system (with offset).
+	globalBbox := &pdf.PdfRectangle{}
+	globalBbox.Llx = lineDef.X1 + localBbox.Llx
+	globalBbox.Lly = lineDef.Y1 + localBbox.Lly
+	globalBbox.Urx = lineDef.X1 + localBbox.Urx
+	globalBbox.Ury = lineDef.Y1 + localBbox.Ury
+
+	return content, localBbox, globalBbox, nil
+}