How to properly do line spacing with multi line text using vsg::Text?

[Mikalai]

Hello,

I've got next case while precisely placing multi line text on the scene. Besides the text there is also some icons in the line. Icons are a bit bigger then text, thus to make the whole group look good a need to increase line spacing appeared.

As an example the default spacing looks like this:

I didn't find find a way to increase line spacing and modified vsg code like in the attached patch. This allowed me to increase line spacing to 1.5 and this made appearance more appealing, I guess)

I'm wondering is this a proper way to achieve such result?

diff --git a/include/vsg/text/StandardLayout.h b/include/vsg/text/StandardLayout.h
index 0b6df523..0f29f8ed 100644
--- a/include/vsg/text/StandardLayout.h
+++ b/include/vsg/text/StandardLayout.h
@@ -52,6 +52,7 @@ namespace vsg
         float outlineWidth = 0.0f;
         bool billboard = false;
         float billboardAutoScaleDistance = 0.0f;
+        float lineSpacing = 1.0f;
 
         bool requiresBillboard() const override { return billboard; }
         void layout(const Data* text, const Font& font, TextQuads& texQuads) override;
diff --git a/src/vsg/text/StandardLayout.cpp b/src/vsg/text/StandardLayout.cpp
index bfded57e..d21960e0 100644
--- a/src/vsg/text/StandardLayout.cpp
+++ b/src/vsg/text/StandardLayout.cpp
@@ -86,10 +86,10 @@ namespace
                 {
                 case (StandardLayout::LEFT_TO_RIGHT_LAYOUT):
                 case (StandardLayout::RIGHT_TO_LEFT_LAYOUT):
-                    row_position.y -= 1.0f;
+                    row_position.y -= layout.lineSpacing;
                     break;
                 case (StandardLayout::VERTICAL_LAYOUT):
-                    row_position.x += 1.0f;
+                    row_position.x += layout.lineSpacing;
                     break;
                 }
                 pen_position = row_position;
@@ -220,6 +220,11 @@ void StandardLayout::read(Input& input)
         input.read("billboard", billboard);
         input.read("billboardAutoScaleDistance", billboardAutoScaleDistance);
     }
+
+    if (input.version_greater_equal(1, 1, 0))
+    {
+        input.read("lineSpacing", lineSpacing);
+    }
 }
 
 void StandardLayout::write(Output& output) const
@@ -241,6 +246,11 @@ void StandardLayout::write(Output& output) const
         output.write("billboard", billboard);
         output.write("billboardAutoScaleDistance", billboardAutoScaleDistance);
     }
+
+    if (output.version_greater_equal(1, 1, 0))
+    {
+        output.write("lineSpacing", lineSpacing);
+    }
 }
 
 void StandardLayout::layout(const Data* text, const Font& font, TextQuads& quads)
@@ -462,10 +472,10 @@ void StandardLayout::layout(const Data* text, const Font& font, TextQuads& quads
                 {
                 case (LEFT_TO_RIGHT_LAYOUT):
                 case (RIGHT_TO_LEFT_LAYOUT):
-                    row_position.y -= 1.0f;
+                    row_position.y -= layout.lineSpacing;
                     break;
                 case (VERTICAL_LAYOUT):
-                    row_position.x += 1.0f;
+                    row_position.x += layout.lineSpacing;
                     break;
                 }
                 pen_position = row_position;

line-spacing.txt

[robertosfield]

The vsg::TextLayout base class exist to facilitate user defined layouts.

The vsg::StandardLayout subclass provides standard way of laying out text glyphs, while not flexibile for your usage case should help provide an example of how one implements layout.