"""Entry point: starts MCP server thread + pygame main loop."""
import os
# Suppress pygame welcome message before importing — it prints to stdout
# which would corrupt the MCP stdio JSON-RPC stream.
os.environ["PYGAME_HIDE_SUPPORT_PROMPT"] = "1"
import sys
import time
import queue
import threading
import pygame
from canvas import Canvas
from tools import create_mcp_server
WIDTH, HEIGHT = 800, 600
TOOLBAR_H = 40
WINDOW_H = HEIGHT + TOOLBAR_H
FPS = 30
# Toolbar colours
TB_BG = (220, 220, 220)
TB_BTN = (180, 180, 180)
TB_BTN_HOVER = (160, 160, 160)
TB_TEXT = (30, 30, 30)
def run_mcp_server(mcp_server):
"""Target for the daemon thread — runs the MCP stdio server."""
mcp_server.run(transport="stdio")
def _save_dialog_and_write(surface: pygame.Surface):
"""Open a Tk file-save dialog (runs on main thread) and write the PNG."""
import tkinter as tk
from tkinter import filedialog
root = tk.Tk()
root.withdraw()
path = filedialog.asksaveasfilename(
defaultextension=".png",
filetypes=[("PNG image", "*.png"), ("All files", "*.*")],
title="Save canvas as…",
)
root.destroy()
if path:
pygame.image.save(surface, path)
def _handle_request(cmd: dict, canvas: Canvas):
"""Process a request/response command from the MCP tool thread."""
event: threading.Event = cmd["_event"]
result: dict = cmd["_result"]
action = cmd.get("action")
try:
if action == "get_pixels":
data = canvas.get_pixels_rgb(
cmd.get("x", 0), cmd.get("y", 0),
cmd.get("w"), cmd.get("h"),
)
result["data"] = data
elif action == "save_file":
path = cmd["path"]
pygame.image.save(canvas.surface, path)
result["data"] = f"Canvas saved to {path}"
else:
result["error"] = f"Unknown request action: {action}"
except Exception as e:
result["error"] = str(e)
finally:
event.set()
def main():
# Shared command queue between MCP thread and pygame main thread
command_queue = queue.Queue()
# Create MCP server with tool definitions
mcp_server = create_mcp_server(command_queue, WIDTH, HEIGHT)
# Start MCP server in a background daemon thread
mcp_thread = threading.Thread(target=run_mcp_server, args=(mcp_server,), daemon=True)
mcp_thread.start()
# Initialize pygame on the main thread
pygame.init()
screen = pygame.display.set_mode((WIDTH, WINDOW_H))
pygame.display.set_caption("Paint MCP")
canvas = Canvas(WIDTH, HEIGHT)
font = pygame.font.SysFont(None, 24)
save_btn_rect = pygame.Rect(10, 8, 70, 26)
frame_interval = 1.0 / FPS
last_render = time.monotonic()
running = True
while running:
# Handle pygame events (non-blocking pump)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.MOUSEBUTTONDOWN and event.button == 1:
if save_btn_rect.collidepoint(event.pos):
_save_dialog_and_write(canvas.surface)
# Drain all pending commands from the queue — always, regardless of
# window focus, so MCP drawing commands are never blocked.
while True:
try:
cmd = command_queue.get_nowait()
except queue.Empty:
break
# Request/response bridge commands have an _event key
if "_event" in cmd:
_handle_request(cmd, canvas)
else:
try:
canvas.execute(cmd)
except Exception as e:
print(f"Command error: {e}", file=sys.stderr)
# --- Render at FPS, but don't sleep long ---
now = time.monotonic()
if now - last_render >= frame_interval:
last_render = now
mouse_pos = pygame.mouse.get_pos()
# Toolbar
pygame.draw.rect(screen, TB_BG, (0, 0, WIDTH, TOOLBAR_H))
# Save button
btn_color = TB_BTN_HOVER if save_btn_rect.collidepoint(mouse_pos) else TB_BTN
pygame.draw.rect(screen, btn_color, save_btn_rect, border_radius=4)
pygame.draw.rect(screen, TB_TEXT, save_btn_rect, width=1, border_radius=4)
label = font.render("Save", True, TB_TEXT)
label_rect = label.get_rect(center=save_btn_rect.center)
screen.blit(label, label_rect)
# Canvas (offset below toolbar)
screen.blit(canvas.surface, (0, TOOLBAR_H))
pygame.display.flip()
# Short sleep to avoid CPU spin while still processing commands promptly.
# Much shorter than clock.tick(30)'s ~33ms sleep, so the queue is drained
# frequently even when the window is unfocused.
pygame.time.wait(2)
pygame.quit()
if __name__ == "__main__":
main()
