feat: Batch SVG render for pose packs (Closes #30)

poseguide/svg_renderer.py

@@ -0,0 +1,183 @@
+"""
+Batch SVG renderer for pose packs.
+Renders pose joint skeletons as SVG overlays for documentation and preview.
+"""
+
+import json
+import os
+from pathlib import Path
+from typing import Dict, List, Optional, Tuple
+from dataclasses import dataclass
+from xml.etree import ElementTree as ET
+
+
+@dataclass
+class PoseJoint:
+    id: int
+    name: str
+    x: float
+    y: float
+    visibility: float = 1.0
+
+
+@dataclass 
+class PoseConnection:
+    joint_a: int
+    joint_b: int
+    label: str = ""
+
+
+class SVGPoseRenderer:
+    """Renders pose skeletons as SVG files."""
+
+    JOINT_RADIUS = 4.0
+    BONE_WIDTH = 2.0
+    LABEL_OFFSET = 10
+
+    # Standard MediaPipe pose connections
+    STANDARD_CONNECTIONS = [
+        (0, 1), (1, 2), (2, 3), (3, 7),     # left arm
+        (0, 4), (4, 5), (5, 6), (6, 8),     # right arm
+        (9, 10),                              # shoulders
+        (11, 12), (11, 13), (13, 15),        # left leg
+        (12, 14), (14, 16),                   # right leg
+        (11, 23), (12, 24), (23, 24),        # torso
+    ]
+
+    COLORS = {
+        "joint": "#FF6B35",
+        "bone": "#004E89",
+        "label": "#333333",
+        "background": "#FFFFFF",
+    }
+
+    def __init__(self, width: int = 400, height: int = 600, padding: int = 40):
+        self.width = width
+        self.height = height
+        self.padding = padding
+
+    def render_single(self, joints: List[PoseJoint],
+                      connections: Optional[List[Tuple[int, int]]] = None,
+                      title: str = "") -> str:
+        """Render a single pose as SVG string."""
+        if connections is None:
+            connections = self.STANDARD_CONNECTIONS
+
+        svg = ET.Element("svg", {
+            "xmlns": "http://www.w3.org/2000/svg",
+            "viewBox": f"0 0 {self.width} {self.height}",
+            "width": str(self.width),
+            "height": str(self.height),
+        })
+
+        # Background
+        ET.SubElement(svg, "rect", {
+            "width": "100%", "height": "100%",
+            "fill": self.COLORS["background"],
+        })
+
+        # Connections (bones)
+        for a, b in connections:
+            ja = next((j for j in joints if j.id == a), None)
+            jb = next((j for j in joints if j.id == b), None)
+            if ja and jb and ja.visibility > 0.1 and jb.visibility > 0.1:
+                ET.SubElement(svg, "line", {
+                    "x1": str(ja.x), "y1": str(ja.y),
+                    "x2": str(jb.x), "y2": str(jb.y),
+                    "stroke": self.COLORS["bone"],
+                    "stroke-width": str(self.BONE_WIDTH),
+                    "stroke-linecap": "round",
+                })
+
+        # Joints
+        for j in joints:
+            if j.visibility > 0.1:
+                ET.SubElement(svg, "circle", {
+                    "cx": str(j.x), "cy": str(j.y),
+                    "r": str(self.JOINT_RADIUS),
+                    "fill": self.COLORS["joint"],
+                    "opacity": str(j.visibility),
+                })
+                # Label
+                label = ET.SubElement(svg, "text", {
+                    "x": str(j.x + self.LABEL_OFFSET),
+                    "y": str(j.y - self.LABEL_OFFSET),
+                    "fill": self.COLORS["label"],
+                    "font-size": "10",
+                    "font-family": "sans-serif",
+                })
+                label.text = j.name
+
+        # Title
+        if title:
+            title_el = ET.SubElement(svg, "text", {
+                "x": str(self.width // 2),
+                "y": "20",
+                "text-anchor": "middle",
+                "fill": self.COLORS["label"],
+                "font-size": "14",
+                "font-weight": "bold",
+                "font-family": "sans-serif",
+            })
+            title_el.text = title
+
+        ET.indent(svg)
+        return ET.tostring(svg, encoding="unicode")
+
+    def render_batch(self, pose_pack_path: str, output_dir: str) -> List[str]:
+        """Render all poses in a pose pack directory to SVG files."""
+        pack_path = Path(pose_pack_path)
+        out_path = Path(output_dir)
+        out_path.mkdir(parents=True, exist_ok=True)
+
+        rendered = []
+
+        for json_file in sorted(pack_path.glob("*.json")):
+            try:
+                data = json.loads(json_file.read_text())
+                joints = [
+                    PoseJoint(
+                        id=p["id"],
+                        name=p.get("name", str(p["id"])),
+                        x=p["x"],
+                        y=p["y"],
+                        visibility=p.get("visibility", 1.0),
+                    )
+                    for p in data.get("joints", [])
+                ]
+
+                connections = data.get("connections")
+                title = data.get("name", json_file.stem)
+
+                svg_content = self.render_single(joints, connections, title)
+
+                out_file = out_path / f"{json_file.stem}.svg"
+                out_file.write_text(svg_content)
+                rendered.append(str(out_file))
+
+            except Exception as e:
+                print(f"  Warning: Skipping {json_file}: {e}")
+
+        return rendered
+
+
+def batch_render_pose_pack(pack_dir: str, output_dir: str,
+                           width: int = 400, height: int = 600) -> List[str]:
+    """CLI-friendly batch render entry point."""
+    renderer = SVGPoseRenderer(width=width, height=height)
+    return renderer.render_batch(pack_dir, output_dir)
+
+
+if __name__ == "__main__":
+    import argparse
+    parser = argparse.ArgumentParser(description="Batch SVG renderer for PoseGuide pose packs")
+    parser.add_argument("--pack-dir", "-p", required=True, help="Directory containing pose JSON files")
+    parser.add_argument("--output", "-o", required=True, help="Output directory for SVG files")
+    parser.add_argument("--width", type=int, default=400)
+    parser.add_argument("--height", type=int, default=600)
+    args = parser.parse_args()
+
+    rendered = batch_render_pose_pack(args.pack_dir, args.output, args.width, args.height)
+    print(f"Rendered {len(rendered)} SVGs to {args.output}:")
+    for f in rendered:
+        print(f"  {f}")