calculate viewport

metamodel/image/svg_test.go

@@ -13,9 +13,7 @@ func TestNewSvg(t *testing.T) {
 	// Load a model from a URL
 	mm := metamodel.New("test")
 	mm.UnzipUrl(sampleUrl)
-	x1, y1, x2, y2 := mm.GetViewPort()
-	width := x2 - x1
-	height := y2 - y1
+	x1, y1, width, height := mm.GetViewPort()
 	i := image.NewSvgFile("/tmp/test.svg", width, height, x1, y1, width, height)
 	i.Rect(x1, y1, width, height, "fill: #fff; stroke: #000; stroke-width: 1px;")
 	i.Render(mm)

metamodel/metamodel.go

@@ -398,7 +398,7 @@ type Model struct {
 	*PetriNet
 }
 
-func (m *Model) GetViewPort() (x1 int, x2 int, y1 int, y2 int) {
+func (m *Model) GetViewPort() (x1 int, y1 int, width int, height int) {
 	var minX int64 = 0
 	var minY int64 = 0
 	var limitX int64 = 0
@@ -433,7 +433,12 @@ func (m *Model) GetViewPort() (x1 int, x2 int, y1 int, y2 int) {
 		}
 	}
 	const margin = 60
-	return int(minX) - margin, int(minY) - margin, int(limitX) + margin, int(limitY) + margin
+	x1 = int(minX) - margin
+	y1 = int(minY) - margin
+	x2 := int(limitX) + margin
+	y2 := int(limitY) + margin
+
+	return x1, y1, x2 - x1, y2 - y1
 }
 
 func (m *Model) exportObjectJsonDefinition() (obj []byte, ok bool) {