feat: calculate size of rasterized png using content area

src/raster.rs

@@ -1,3 +1,5 @@
+use std::default;
+
 use resvg::usvg::{fontdb, TreeParsing, TreeTextToPath};
 use resvg::{tiny_skia, usvg};
 
@@ -45,8 +47,13 @@ impl Rasterizer {
             resvg::Tree::from_usvg(&tree)
         };
 
-        let pixmap_size = tree.size.to_int_size();
-        let mut pixmap = tiny_skia::Pixmap::new(pixmap_size.width(), pixmap_size.height()).unwrap();
+        let content_area = tree.content_area.unwrap();
+
+        let mut pixmap = tiny_skia::Pixmap::new(
+            (content_area.width() + content_area.left() * 2f32).ceil() as u32,
+            (content_area.height() + content_area.top() * 2f32).ceil() as u32,
+        )
+        .unwrap();
         tree.render(tiny_skia::Transform::default(), &mut pixmap.as_mut());
 
         pixmap.encode_png().map_err(|_| RenderError {

src/templates/basic.svg

@@ -1,6 +1,6 @@
-<svg width="512" height="34" xmlns="http://www.w3.org/2000/svg" font-family="Roboto Mono" font-size="27">
-    <text x="8" y="27">{{ text }}</text>
-    <style>
-        text
-    </style>
+<svg xmlns="http://www.w3.org/2000/svg" font-family="Roboto Mono"
+    font-size="27">
+    <text x="8" y="27" text-anchor="start">
+        {{ text }}
+    </text>
 </svg>