Add support to draw images via MCP on the RLCD display

mcp_bridge.py

@@ -24,6 +24,74 @@ def main():
             # Parse request to ensure it's valid JSON
             req_data = json.loads(line.strip())
             
+            # Intercept draw_image tool and pre-process the image on the host PC
+            if req_data.get("method") == "tools/call" and req_data.get("params", {}).get("name") == "draw_image":
+                try:
+                    args = req_data.get("params", {}).get("arguments", {})
+                    image_base64 = args.get("image_base64")
+                    
+                    if not image_base64:
+                        raise ValueError("Missing image_base64 parameter")
+                        
+                    # Strip data URI prefix if present
+                    if image_base64.startswith("data:"):
+                        if ";base64," in image_base64:
+                            image_base64 = image_base64.split(";base64,")[1]
+                            
+                    import base64
+                    import io
+                    from PIL import Image
+                    
+                    img_bytes = base64.b64decode(image_base64)
+                    img = Image.open(io.BytesIO(img_bytes))
+                    
+                    # Convert to grayscale
+                    img = img.convert("L")
+                    
+                    # Resize to fit screen dimensions (400x300 max)
+                    max_w = int(args.get("maxWidth", 400))
+                    max_h = int(args.get("maxHeight", 300))
+                    
+                    # Prevent going over physical screen bounds
+                    max_w = min(max_w, 400)
+                    max_h = min(max_h, 300)
+                    
+                    img.thumbnail((max_w, max_h))
+                    
+                    # Convert to 1-bit monochrome (with optional Floyd-Steinberg dithering)
+                    dither = args.get("dither", True)
+                    img_1bit = img.convert("1", dither=Image.FLOYDSTEINBERG if dither else Image.NONE)
+                    
+                    # Save as binary PBM (P4 format) using PPM format writer on mode 1
+                    pbm_io = io.BytesIO()
+                    img_1bit.save(pbm_io, format="PPM")
+                    pbm_data = pbm_io.getvalue()
+                    
+                    # Encode processed PBM to base64
+                    pbm_b64 = base64.b64encode(pbm_data).decode("utf-8")
+                    
+                    # Substitute arguments for ESP32
+                    new_args = {
+                        "pbm_base64": pbm_b64,
+                        "x": args.get("x", 0),
+                        "y": args.get("y", 0)
+                    }
+                    req_data["params"]["arguments"] = new_args
+                    
+                except Exception as e:
+                    # Return error response directly to client without contacting ESP32
+                    err_resp = {
+                        "jsonrpc": "2.0",
+                        "error": {
+                            "code": -32602,
+                            "message": f"Bridge image preprocessing failed: {str(e)}"
+                        },
+                        "id": req_data.get("id")
+                    }
+                    sys.stdout.write(json.dumps(err_resp) + "\n")
+                    sys.stdout.flush()
+                    continue
+            
             # Forward the JSON-RPC request to the ESP32 board via HTTP POST
             req = urllib.request.Request(
                 url,

mcp_server.py

@@ -169,6 +169,20 @@ class MCPServer:
                             "name": "get_screenshot",
                             "description": "Capture the current reflective LCD screen rendering as a PNG image.",
                             "inputSchema": {"type": "object", "properties": {}}
+                        },
+                        {
+                            "name": "draw_image",
+                            "description": "Draw an image (PNG, JPEG, GIF, BMP, etc.) on the screen. The image will be converted to 1-bit monochrome and fit to display boundaries.",
+                            "inputSchema": {
+                                "type": "object",
+                                "properties": {
+                                    "image_base64": {"type": "string", "description": "Base64 encoded string of the source image file"},
+                                    "x": {"type": "integer", "description": "X coordinate to place the image (default 0)", "default": 0},
+                                    "y": {"type": "integer", "description": "Y coordinate to place the image (default 0)", "default": 0},
+                                    "dither": {"type": "boolean", "description": "Whether to use Floyd-Steinberg dithering (default true)", "default": True}
+                                },
+                                "required": ["image_base64"]
+                            }
                         }
                     ]
                 },
@@ -281,5 +295,34 @@ class MCPServer:
             except Exception as e:
                 raise RuntimeError(f"Screenshot capture failed: {e}")
                 
+        elif name == "draw_image":
+            self.override_active = True
+            self.override_timeout = time.ticks_ms() + 30000 # 30-sec override
+            
+            pbm_b64 = args.get("pbm_base64")
+            x = int(args.get("x", 0))
+            y = int(args.get("y", 0))
+            
+            if not pbm_b64:
+                raise ValueError("Missing pbm_base64 parameter (preprocessed by bridge)")
+                
+            import binascii
+            pbm_bytes = binascii.a2b_base64(pbm_b64)
+            
+            filename = 'temp_recv.pbm'
+            with open(filename, 'wb') as f:
+                f.write(pbm_bytes)
+                
+            try:
+                self.display.draw_pbm(filename, x, y, scale=1)
+                self.display.show()
+            finally:
+                import os
+                try:
+                    os.remove(filename)
+                except:
+                    pass
+            return "Image displayed successfully."
+            
         else:
             raise ValueError(f"Unknown tool: {name}")