generate_icons

Instructions

Args:
    prompts: List of icon descriptions (e.g., ["sword", "shield", "potion"])
    preset: Style preset to use (default: icon). Options: icon, icon_item, flat_ui
    size: Icon size in pixels (square)
    seed: Base seed for reproducibility (each icon gets seed+index)
    create_atlas: Whether to combine icons into a single spritesheet
    save_to_file: Whether to save images to disk

Returns:
    JSON with base64 images for each icon and optional atlas

Implementation Reference

• server/main.py:218-299 (handler)

  Handler function for the 'generate_icons' tool. Decorated with @mcp.tool() for registration. Generates multiple icons from prompts using the backend, applies resizing, optionally creates a spritesheet atlas, and handles file saving. Input schema defined by function parameters.

  @mcp.tool()
  async def generate_icons(
      prompts: List[str],
      preset: str = "icon",
      size: int = 64,
      seed: Optional[int] = None,
      create_atlas: bool = False,
      save_to_file: bool = False
  ) -> str:
      """Generate multiple game icons from a list of descriptions.
      
      Args:
          prompts: List of icon descriptions (e.g., ["sword", "shield", "potion"])
          preset: Style preset to use (default: icon). Options: icon, icon_item, flat_ui
          size: Icon size in pixels (square)
          seed: Base seed for reproducibility (each icon gets seed+index)
          create_atlas: Whether to combine icons into a single spritesheet
          save_to_file: Whether to save images to disk
      
      Returns:
          JSON with base64 images for each icon and optional atlas
      """
      if not prompts:
          return json.dumps({"success": False, "error": "No prompts provided"}, indent=2)
      
      preset_config = get_preset(preset)
      
      icons = []
      for i, prompt in enumerate(prompts):
          full_prompt = f"{preset_config.prompt_prefix}{prompt}{preset_config.prompt_suffix}"
          gen_seed = (seed + i) if seed is not None else None
          
          image_bytes = await backend.generate_image(
              prompt=full_prompt,
              negative_prompt=preset_config.negative_prompt,
              width=preset_config.default_width,
              height=preset_config.default_height,
              seed=gen_seed,
              steps=preset_config.steps,
              cfg_scale=preset_config.cfg_scale,
              sampler=preset_config.sampler,
              scheduler=preset_config.scheduler
          )
          
          resample = Image.Resampling.NEAREST if preset.startswith("pixel") else Image.Resampling.LANCZOS
          image_bytes = resize_image(image_bytes, size, size, resample=resample)
          
          icon_data = {
              "index": i,
              "prompt": prompt,
              "image_base64": image_to_base64(image_bytes),
              "size": size
          }
          
          if save_to_file:
              output_dir = ensure_directory(OUTPUT_DIR / "icons")
              fname = generate_filename(prefix=f"icon_{i}", suffix=prompt[:20].replace(" ", "_"))
              file_path = output_dir / fname
              file_path.write_bytes(image_bytes)
              icon_data["file_path"] = str(file_path)
          
          icons.append(icon_data)
      
      result = {
          "success": True,
          "count": len(icons),
          "icons": icons
      }
      
      # Create atlas if requested
      if create_atlas and icons:
          all_images = [base64.b64decode(icon["image_base64"]) for icon in icons]
          atlas_bytes = create_spritesheet(all_images, columns=min(4, len(icons)))
          result["atlas_base64"] = image_to_base64(atlas_bytes)
          
          if save_to_file:
              output_dir = ensure_directory(OUTPUT_DIR / "atlases")
              atlas_path = output_dir / generate_filename(prefix="icon_atlas")
              atlas_path.write_bytes(atlas_bytes)
              result["atlas_file_path"] = str(atlas_path)
      
      return json.dumps(result, indent=2)