Transformation functionality adapted from Moritz Wagner and Andreas Würmser.

1 files changed, 119 insertions, 0 deletions

diff --git a/fpdf_test.go b/fpdf_test.go
index fad67bc..ccdf1bf 100644
--- a/fpdf_test.go
+++ b/fpdf_test.go
@@ -964,3 +964,122 @@ func ExampleFpdf_tutorial16() {
 	// Output:
 	// Successfully generated pdf/tutorial16.pdf
 }
+
+// Transformation test adapted from an example script by Moritz Wagner and
+// Andreas Würmser.
+func ExampleFpdf_tutorial17() {
+	const (
+		light = 200
+		dark  = 0
+	)
+	var refX, refY float64
+	var refStr string
+	pdf := gofpdf.New("P", "mm", "A4", FONT_DIR)
+	pdf.AddPage()
+	color := func(val int) {
+		pdf.SetDrawColor(val, val, val)
+		pdf.SetTextColor(val, val, val)
+	}
+	reference := func(str string, x, y float64, val int) {
+		color(val)
+		pdf.Rect(x, y, 40, 10, "D")
+		pdf.Text(x, y-1, str)
+	}
+	refDraw := func(str string, x, y float64) {
+		refStr = str
+		refX = x
+		refY = y
+		reference(str, x, y, light)
+	}
+	refDupe := func() {
+		reference(refStr, refX, refY, dark)
+	}
+
+	titleStr := "Transformations"
+	titlePt := 36.0
+	titleHt := titlePt * 25.4 / 72.0
+	pdf.SetFont("Helvetica", "", titlePt)
+	titleWd := pdf.GetStringWidth(titleStr)
+	titleX := (210 - titleWd) / 2
+	pdf.Text(titleX, 10+titleHt, titleStr)
+	pdf.TransformBegin()
+	pdf.TransformMirrorVertical(10 + titleHt + 0.5)
+	pdf.ClipText(titleX, 10+titleHt, titleStr, false)
+	// Remember that the transform will mirror the gradient box too
+	pdf.LinearGradient(titleX, 10, titleWd, titleHt+4, 120, 120, 120, 255, 255, 255, 0, 0, 0, 0.6)
+	pdf.ClipEnd()
+	pdf.TransformEnd()
+
+	pdf.SetFont("Helvetica", "", 12)
+
+	// Scale by 150% centered by lower left corner of the rectangle
+	refDraw("Scale", 50, 60)
+	pdf.TransformBegin()
+	pdf.TransformScaleXY(150, 50, 70)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Translate 7 to the right, 5 to the bottom
+	refDraw("Translate", 125, 60)
+	pdf.TransformBegin()
+	pdf.TransformTranslate(7, 5)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Rotate 20 degrees counter-clockwise centered by the lower left corner of
+	// the rectangle
+	refDraw("Rotate", 50, 110)
+	pdf.TransformBegin()
+	pdf.TransformRotate(20, 50, 120)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Skew 30 degrees along the x-axis centered by the lower left corner of the
+	// rectangle
+	refDraw("Skew", 125, 110)
+	pdf.TransformBegin()
+	pdf.TransformSkewX(30, 125, 110)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Mirror horizontally with axis of reflection at left side of the rectangle
+	refDraw("Mirror horizontal", 50, 160)
+	pdf.TransformBegin()
+	pdf.TransformMirrorHorizontal(50)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Mirror vertically with axis of reflection at bottom side of the rectangle
+	refDraw("Mirror vertical", 125, 160)
+	pdf.TransformBegin()
+	pdf.TransformMirrorVertical(170)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Reflect against a point at the lower left point of rectangle
+	refDraw("Mirror point", 50, 210)
+	pdf.TransformBegin()
+	pdf.TransformMirrorPoint(50, 220)
+	refDupe()
+	pdf.TransformEnd()
+
+	// Mirror against a straight line described by a point and an angle
+	angle := -20.0
+	px := 120.0
+	py := 220.0
+	refDraw("Mirror line", 125, 210)
+	pdf.TransformBegin()
+	pdf.TransformRotate(angle, px, py)
+	pdf.Line(px-1, py-1, px+1, py+1)
+	pdf.Line(px-1, py+1, px+1, py-1)
+	pdf.Line(px-5, py, px+60, py)
+	pdf.TransformEnd()
+	pdf.TransformBegin()
+	pdf.TransformMirrorLine(angle, px, py)
+	refDupe()
+	pdf.TransformEnd()
+
+	pdf.OutputAndClose(docWriter(pdf, 17))
+	// Output:
+	// Successfully generated pdf/tutorial17.pdf
+}