Class: Emfsvg::Translation::EmfRenderer

Inherits:
Object
  • Object
show all
Defined in:
lib/emfsvg/translation/emf_renderer.rb

Overview

Top-level orchestrator: takes an Svg::Document, walks its element tree via a HandlerRegistry, and produces an Emf::Model::Metafile whose serialized bytes can be re-parsed by Emf.parse and re-rendered by Emfsvg.from_bytes.

The default registry maps the supported SVG element vocabulary (rect, ellipse, circle, line, polyline, polygon, path, group, text, image, defs, clipPath) to handler classes.

If the SVG contains any decimal coordinates, the renderer installs Scaler::Fixed (multiplies coords by 10_000 to preserve 4 decimal places in EMF int32 fields) and emits SetMapMode + SetWindowExtEx + SetViewportExtEx so emfsvg's renderer computes the matching sf_x = 1/10_000.

Constant Summary collapse

DEFAULT_REGISTRY = 
HandlerRegistry.new

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document, registry: DEFAULT_REGISTRY) ⇒ EmfRenderer

Returns a new instance of EmfRenderer.



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# File 'lib/emfsvg/translation/emf_renderer.rb', line 43

def initialize(document, registry: DEFAULT_REGISTRY)
  @document = document
  @registry = registry
  @scaler = pick_scaler
  @context = Context.new(
    handler_registry: registry,
    clip_path_registry: Svg::ClipPathRegistry.from_document(document),
    scaler: @scaler
  )
end

Class Method Details

.call(document, registry: DEFAULT_REGISTRY) ⇒ Object 



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# File 'lib/emfsvg/translation/emf_renderer.rb', line 24

def self.call(document, registry: DEFAULT_REGISTRY)
  new(document, registry: registry).call
end

.register_default_handlers! ⇒ Object 



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# File 'lib/emfsvg/translation/emf_renderer.rb', line 28

def self.register_default_handlers!
  DEFAULT_REGISTRY.register(Svg::Elements::Rect, Handlers::RectHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Ellipse, Handlers::EllipseHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Circle, Handlers::CircleHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Line, Handlers::LineHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Polyline, Handlers::PolylineHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Polygon, Handlers::PolygonHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Path, Handlers::PathHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Group, Handlers::GroupHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Text, Handlers::TextHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Image, Handlers::ImageHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::Defs, Handlers::DefsHandler)
  DEFAULT_REGISTRY.register(Svg::Elements::ClipPath, Handlers::ClipPathHandler)
end

Instance Method Details

#call ⇒ Object 



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# File 'lib/emfsvg/translation/emf_renderer.rb', line 54

def call
  emit_scaling_prelude if @scaler.scaled?
  dispatch_root(@document.root_element)
  emit_eof
  header = HeaderBuilder.build(@document,
                               n_records: @context.records.size + 1,
                               n_handles: @context.object_table.size + 1)
  Emf::Model::Metafile.new(
    format: :emf,
    header: header,
    records: @context.records.freeze
  )
end