Add TextStyle text rendering mode property

pdf/creator/const.go

@@ -41,6 +41,39 @@ const (
 	TextAlignmentJustify
 )
 
+// TextRenderingMode determines whether showing text shall cause glyph
+// outlines to be stroked, filled, used as a clipping boundary, or some
+// combination of the three.
+// See section 9.3 "Text State Parameters and Operators" and
+// Table 106 (pp. 254-255 PDF32000_2008).
+type TextRenderingMode int
+
+const (
+	// TextRenderingModeFill (default) - Fill text.
+	TextRenderingModeFill TextRenderingMode = iota
+
+	// TextRenderingModeStroke - Stroke text.
+	TextRenderingModeStroke
+
+	// TextRenderingModeFillStroke - Fill, then stroke text.
+	TextRenderingModeFillStroke
+
+	// TextRenderingModeInvisible - Neither fill nor stroke text (invisible).
+	TextRenderingModeInvisible
+
+	// TextRenderingModeFillClip - Fill text and add to path for clipping.
+	TextRenderingModeFillClip
+
+	// TextRenderingModeStrokeClip - Stroke text and add to path for clipping.
+	TextRenderingModeStrokeClip
+
+	// TextRenderingModeFillStrokeClip - Fill, then stroke text and add to path for clipping.
+	TextRenderingModeFillStrokeClip
+
+	// TextRenderingModeClip - Add text to path for clipping.
+	TextRenderingModeClip
+)
+
 // Relative and absolute positioning types.
 type positioning int
 

pdf/creator/styled_paragraph.go

@@ -656,6 +656,9 @@ func drawStyledParagraphOnBlock(blk *Block, p *StyledParagraph, ctx DrawContext)
 			fontName := defaultFontName
 			fontSize := defaultFontSize
 
+			// Set chunk rendering mode.
+			cc.Add_Tr(int64(style.RenderingMode))
+
 			if p.alignment != TextAlignmentJustify || isLastLine {
 				spaceMetrics, found := style.Font.GetRuneMetrics(' ')
 				if !found {
@@ -744,6 +747,9 @@ func drawStyledParagraphOnBlock(blk *Block, p *StyledParagraph, ctx DrawContext)
 			}
 
 			currX += chunkWidth
+
+			// Reset rendering mode.
+			cc.Add_Tr(int64(TextRenderingModeFill))
 		}
 
 		currY -= height

pdf/creator/text_style.go

@@ -19,6 +19,9 @@ type TextStyle struct {
 
 	// The size of the font.
 	FontSize float64
+
+	// The rendering mode.
+	RenderingMode TextRenderingMode
 }
 
 // newTextStyle creates a new text style object using the specified font.