• feat(fonts): add variable font instancing for PDF embedding Phase_1

Cargo.toml

@@ -99,6 +99,10 @@ required-features = []
 name = "customfont"
 required-features = []
 
+[[example]]
+name = "variable_font"
+required-features = ["text_layout"]
+
 [[example]]
 name = "graphics"
 required-features = []

examples/variable_font.rs

@@ -0,0 +1,67 @@
+use std::{env, error::Error, fs};
+
+use printpdf::{
+    FontVariationSettings, FontVariationTag, Mm, Op, PdfDocument, PdfFontHandle, PdfPage,
+    PdfSaveOptions, Point, Pt, TextItem,
+};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let font_path = env::args()
+        .nth(1)
+        .ok_or("usage: cargo run --example variable_font -- path/to/variable-font.ttf")?;
+    let font_bytes = fs::read(font_path)?;
+    let mut warnings = Vec::new();
+    let mut document = PdfDocument::new("Variable font instances");
+
+    let light = document.add_variable_font(
+        &font_bytes,
+        0,
+        &FontVariationSettings::new().with(FontVariationTag::WGHT, 300.0),
+        &mut warnings,
+    )?;
+    let bold = document.add_variable_font(
+        &font_bytes,
+        0,
+        &FontVariationSettings::new().with(FontVariationTag::WGHT, 800.0),
+        &mut warnings,
+    )?;
+
+    let page = PdfPage::new(
+        Mm(210.0),
+        Mm(297.0),
+        vec![
+            Op::StartTextSection,
+            Op::SetTextCursor {
+                pos: Point::new(Mm(20.0), Mm(260.0)),
+            },
+            Op::SetFont {
+                font: PdfFontHandle::External(light),
+                size: Pt(24.0),
+            },
+            Op::ShowText {
+                items: vec![TextItem::Text("Weight 300".into())],
+            },
+            Op::SetTextCursor {
+                pos: Point::new(Mm(20.0), Mm(240.0)),
+            },
+            Op::SetFont {
+                font: PdfFontHandle::External(bold),
+                size: Pt(24.0),
+            },
+            Op::ShowText {
+                items: vec![TextItem::Text("Weight 800".into())],
+            },
+            Op::EndTextSection,
+        ],
+    );
+
+    let pdf = document
+        .with_pages(vec![page])
+        .save(&PdfSaveOptions::default(), &mut warnings);
+    fs::write("variable_font.pdf", pdf)?;
+
+    for warning in warnings {
+        eprintln!("{}", warning.msg);
+    }
+    Ok(())
+}