Add generate_svg function (closes #40)

README.md

@@ -9,7 +9,7 @@
 - [Developer docs: Testing](#developer-docs-testing)
 
 `draw_tree` is a game tree drawing tool for publication-ready extensive form games in Game Theory.
-It can generate TikZ code, LaTeX documents, PDFs, and PNGs from game specifications.
+It can generate TikZ code, LaTeX documents, PDFs, PNGs, and SVGs from game specifications.
 
 Games can be specified via `.ef` format files which include layout formatting.
 These can be created via [Game Theory Explorer](https://gametheoryexplorer-a68c7.web.app/), or by hand, see [specs.pdf](specs.pdf) for details.
@@ -35,10 +35,11 @@ pip install -e .
 - Python 3.10+ (tested on 3.13)
 - LaTeX with TikZ (for PDF/PNG generation)
 - (optional) ImageMagick or Ghostscript or Poppler (for PNG generation)
+- (optional) pdf2svg (for SVG generation)
 
 ### Installing LaTeX
 
-Note: PDF and PNG generation require `pdflatex` to be installed and available in PATH. Tested methods have a ✅ next to them. Methods include:
+Note: PDF, PNG and SVG generation require `pdflatex` to be installed and available in PATH. Tested methods have a ✅ next to them. Methods include:
 
 - macOS:
     - Install [MacTEX](https://www.tug.org/mactex/mactex-download.html) ✅
@@ -60,6 +61,14 @@ PNG generation will default to using any of ImageMagick or Ghostscript or Popple
     - `sudo apt-get install poppler-utils`
 - Windows: Install ImageMagick or Ghostscript from their websites
 
+### SVG generation
+
+SVG generation requires `pdflatex` and `pdf2svg`. To install `pdf2svg`:
+
+- macOS: `brew install pdf2svg`
+- Ubuntu: `sudo apt install pdf2svg`
+- Windows: see [pdf2svg releases](https://github.com/dawbarton/pdf2svg)
+
 ## CLI
 
 By default, `draw_tree` generates TikZ code and prints it to standard output.
@@ -73,20 +82,24 @@ draw_tree games/example.ef --pdf                           # Creates example.pdf
 draw_tree games/example.ef --png                           # Creates example.png
 draw_tree games/example.ef --png --dpi=600                 # Creates high-res example.png (72-2400, default: 300)
 draw_tree games/example.ef --output=mygame.png scale=0.8   # Creates mygame.png with 0.8 scaling (0.01 to 100)
+draw_tree games/example.ef --svg                           # Creates example.svg
 ```
 
 ## Python API
 
 You can also use `draw_tree` as a Python library:
 
 ```python
-from draw_tree import generate_tex, generate_pdf, generate_png
+from draw_tree import generate_tex, generate_pdf, generate_png, generate_svg
 generate_tex('games/example.ef')                                    # Creates example.tex
 generate_tex('games/example.ef', save_to='custom')                  # Creates custom.tex
 generate_pdf('games/example.ef')                                    # Creates example.pdf
 generate_png('games/example.ef')                                    # Creates example.png
 generate_png('games/example.ef', dpi=600)                           # Creates high-res example.png (72-2400, default: 300)
 generate_png('games/example.ef', save_to='mygame', scale_factor=0.8)    # Creates mygame.png with 0.8 scaling (0.01 to 100)
+generate_svg('games/example.ef')                                         # Creates example.svg
+generate_svg('games/example.ef', save_to='custom')                       # Creates custom.svg
+generate_svg('games/example.ef', save_to='mygame', scale_factor=0.8)     # Creates mygame.svg with 0.8 scaling
 ```
 
 ### Rendering in Jupyter Notebooks
@@ -111,12 +124,13 @@ In particular read [Tutorial 4) Creating publication-ready game images](https://
 In short, you can do:
 ```python
 import pygambit as gbt
-from draw_tree import draw_tree, generate_tex, generate_pdf, generate_png
+from draw_tree import draw_tree, generate_tex, generate_pdf, generate_png, generate_svg
 g = gbt.read_efg('somegame.efg')
 draw_tree(g)
 generate_tex(g)
 generate_pdf(g)
 generate_png(g)
+generate_svg(g)
 ```
 
 > Note: Without setting the `save_to` parameter, the saved file will be based on the title field of the pygambit game object.

src/draw_tree/__init__.py

@@ -13,6 +13,7 @@
     generate_tex,
     generate_pdf,
     generate_png,
+    generate_svg,
     ef_to_tex,
     latex_wrapper,
     efg_dl_ef
@@ -26,6 +27,7 @@
     "generate_tex", 
     "generate_pdf",
     "generate_png",
+    "generate_svg",
     "ef_to_tex",
     "latex_wrapper",
     "efg_dl_ef",

src/draw_tree/core.py

@@ -2092,6 +2092,93 @@ def generate_png(
             raise RuntimeError(f"PNG generation failed: {e}")
 
 
+def generate_svg(
+        game: str | "pygambit.gambit.Game",
+        save_to: Optional[str] = None,
+        scale_factor: float = 1.0,
+        level_scaling: int = 1,
+        sublevel_scaling: int = 1,
+        width_scaling: int = 1,
+        hide_action_labels: bool = False,
+        shared_terminal_depth: bool = False,
+        show_grid: bool = False,
+        color_scheme: str = "default",
+        edge_thickness: float = 1.0,
+        action_label_position: float = 0.5,
+) -> str:
+    """
+    Generate an SVG image directly from an extensive form (.ef) file.
+
+    This function creates a PDF first, then converts it to SVG using pdf2svg.
+
+    Requires:
+        - pdflatex
+        - pdf2svg
+
+    Returns:
+        Path to generated SVG file.
+    """
+    # Determine output filename
+    if save_to is None:
+        if isinstance(game, str):
+            game_path = Path(game)
+        else:
+            game_path = Path(game.title + ".ef")
+        output_svg = game_path.with_suffix(".svg").name
+    else:
+        if not save_to.endswith(".svg"):
+            output_svg = save_to + ".svg"
+        else:
+            output_svg = save_to
+
+    final_svg_path = Path(output_svg)
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        temp_pdf_path = Path(temp_dir) / "temp_output.pdf"
+
+        try:
+            # Step 1: Generate PDF explicitly into temp file
+            generate_pdf(
+                game=game,
+                save_to=str(temp_pdf_path.with_suffix("").absolute()),
+                scale_factor=scale_factor,
+                level_scaling=level_scaling,
+                sublevel_scaling=sublevel_scaling,
+                width_scaling=width_scaling,
+                hide_action_labels=hide_action_labels,
+                shared_terminal_depth=shared_terminal_depth,
+                show_grid=show_grid,
+                color_scheme=color_scheme,
+                edge_thickness=edge_thickness,
+                action_label_position=action_label_position,
+            )
+
+            # Step 2: Convert PDF to SVG
+            subprocess.run(
+                ["pdf2svg", str(temp_pdf_path), str(final_svg_path)],
+                check=True,
+                capture_output=True,
+                text=True,
+            )
+
+            if final_svg_path.exists():
+                return str(final_svg_path.absolute())
+            else:
+                raise RuntimeError("SVG was not generated successfully.")
+
+        except FileNotFoundError:
+            raise RuntimeError(
+                "pdf2svg not found. Please install it.\n"
+                "macOS: brew install pdf2svg\n"
+                "Ubuntu: sudo apt install pdf2svg\n"
+                "Windows: Install from official binaries"
+            )
+        except subprocess.CalledProcessError as e:
+            raise RuntimeError(f"SVG conversion failed: {e.stderr}")
+        except Exception as e:
+            raise RuntimeError(f"SVG generation failed: {e}")
+
+
 def efg_dl_ef(efg_file: str) -> str:
     """Convert a Gambit .efg file to the `.ef` format used by generate_tikz.