Added the stylesheet option to the C API

crates/c-api/lib.rs

@@ -158,6 +158,20 @@ pub extern "C" fn resvg_options_set_dpi(opt: *mut resvg_options, dpi: f32) {
     cast_opt(opt).dpi = dpi as f32;
 }
 
+/// @brief Sets a stylesheet path that will be used when resolving CSS attributes.
+///
+/// Must be UTF-8. Can be set to NULL.
+///
+/// Default: NULL
+#[no_mangle]
+pub extern "C" fn resvg_options_set_stylesheet(opt: *mut resvg_options, path: *const c_char) {
+    if path.is_null() {
+        cast_opt(opt).style_sheet = None;
+    } else {
+        cast_opt(opt).style_sheet = Some(cstr_to_str(path).unwrap().into());
+    }
+}
+
 /// @brief Sets the default font family.
 ///
 /// Will be used when no `font-family` attribute is set in the SVG.

crates/c-api/resvg.h

@@ -173,6 +173,15 @@ void resvg_options_set_resources_dir(resvg_options *opt, const char *path);
  */
 void resvg_options_set_dpi(resvg_options *opt, float dpi);
 
+/**
+ * @brief Sets a stylesheet path that will be used when resolving CSS attributes.
+ *
+ * Must be UTF-8. Can be set to NULL.
+ *
+ * Default: NULL
+ */
+void resvg_options_set_stylesheet(resvg_options *opt, const char *path);
+
 /**
  * @brief Sets the default font family.
  *