12. 캔버스, 이미지 데이터 병합

서버에서 가져온 이미지의 단어를 캔버스로 적어서 정답 유무 판별

  -정답을 맞췄을 시 다음 레벨로 넘어가기 버튼 추가

 

page - Game - <Canvas.js>

import React, { useEffect, useRef, useState } from "react";
import axios from "axios";
import "../../css/game.css";

function Canvas({ checkAnswer, newFetch, quiz }) {
  const canvasRef = useRef(null);

  const [isDrawing, setIsDrawing] = useState(false);
  const [checkQuiz, setCheckQuiz] = useState(false);

  const [lastX, setLastX] = useState(0);
  const [lastY, setLastY] = useState(0);

  const [outputImageSrc, setOutputImageSrc] = useState(null);

  const [path, setPath] = useState([]);
  const [paths, setPaths] = useState([]);

  const [imgText, setImgText] = useState("");

  useEffect(() => {
    const canvas = canvasRef.current;
    const ctx = canvas.getContext("2d");

    const drawing = (e) => {
      if (!isDrawing) return;

      const rect = canvas.getBoundingClientRect();
      const offsetX = e.clientX - rect.left;
      const offsetY = e.clientY - rect.top;

      ctx.beginPath();
      ctx.moveTo(lastX, lastY);
      ctx.lineTo(offsetX, offsetY);
      ctx.strokeStyle = "blue";
      ctx.lineWidth = 10;
      ctx.stroke();

      setLastX(offsetX);
      setLastY(offsetY);

      setPath((prevPath) => [...prevPath, { x: offsetX, y: offsetY }]);
    };

    canvas.addEventListener("mousemove", drawing);

    return () => {
      canvas.removeEventListener("mousemove", drawing);
    };
  }, [isDrawing, lastX, lastY]);

  const drawingCanvas = (e) => {
    setIsDrawing(true);
    const rect = e.target.getBoundingClientRect();
    setLastX(e.clientX - rect.left);
    setLastY(e.clientY - rect.top);
    setPath([{ x: e.clientX - rect.left, y: e.clientY - rect.top }]);
  };

  const stopDrawing = () => {
    if (isDrawing) {
      setPaths((prevPaths) => [...prevPaths, path]);
      setPath([]);
    }
    setIsDrawing(false);
  };

  const canvasOut = () => {
    setIsDrawing(false);
  };

  const outputCanvasImage = async () => {
    const canvas = canvasRef.current;
    setOutputImageSrc(canvas.toDataURL());
    const dataURL = canvas.toDataURL("image/png");
    await axios
      .post("http://localhost:5000/canvas", { dataURL: dataURL })
      .then((res) => {
        setImgText(res.data.text); //이미지 데이터 텍스트
        checkAnswer(res.data.text); //제출한 답
      });
    setCheckQuiz(true);
  };

  const clearCanvas = () => {
    const canvas = canvasRef.current;
    const ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    setOutputImageSrc(null);
    setPaths([]);
    setImgText("");
  };

  const returnCurrentLine = () => {
    setPaths((prevPaths) => prevPaths.slice(0, -1));
  };

  const redrawCanvas = () => {
    const canvas = canvasRef.current;
    const ctx = canvas.getContext("2d");
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    paths.forEach((p) => {
      ctx.beginPath();
      ctx.moveTo(p[0].x, p[0].y);
      for (let i = 1; i < p.length; i++) {
        ctx.lineTo(p[i].x, p[i].y);
      }
      ctx.stroke();
    });
  };

  useEffect(redrawCanvas, [paths]);

  const nextLevel = () => { //다음 레벨 함수
    newFetch(); //새 이미지 데이터 불러오기
    clearCanvas();
    setCheckQuiz(false);
  };

  return (
    <div className="canvas">
      <canvas
        ref={canvasRef}
        width={500}
        height={300}
        style={{ border: "1px solid black" }}
        onMouseDown={drawingCanvas}
        onMouseUp={stopDrawing}
        onMouseOut={canvasOut}
      />
      {outputImageSrc && <img src={outputImageSrc} alt="분석된 이미지" />}
      {!checkQuiz && (
        <div>
          <button onClick={outputCanvasImage}>추출</button>
          <button onClick={clearCanvas}>다시 쓰기</button>
          <button onClick={returnCurrentLine}>한 획 지우기</button>
        </div>
      )}
      <div>
        {checkQuiz && (
          <div>
            <h1>정답: {quiz}</h1>
            <h1>제출한 답: {imgText}</h1>
            <button onClick={nextLevel}>다음 레벨</button>
          </div>
        )}
      </div>
    </div>
  );
}

export default Canvas;

 

page - Game - <ImageGame.js>

import axios from "axios";
import React, { useCallback, useEffect, useState } from "react";
import "../../css/game.css";
import Canvas from "./Canvas";

function ImageGame() {
  const [imageData, setImagaData] = useState([]);

  const [quiz, setQuiz] = useState("");
  const [count, setCount] = useState(1);
  const [gameOver, setGameOver] = useState(false);

  const resetButton = () => {
    window.location.reload();
  };

  const checkAnswer = (text) => {
    if (text === quiz) {
      alert("정답입니다.");
    } else {
      alert("오답입니다.");
    }
  };

  const newFetch = () => { //새 데이터 불러오기 함수
    fetchData();
  };

  const fetchData = useCallback(() => {
    axios.get("http://localhost:5000/image").then((res) => {
      if (res.data.game && res.data.game.length > 0) {
        setImagaData(res.data.game[0].image);
        setQuiz(res.data.game[0].title);
        setCount(res.data.count);
        if (count >= 5) {
          setGameOver(true);
          alert(res.data.message);
        }
      } else {
        setGameOver(true);
        alert(res.data.message);
      }
    });
  }, [count]);

  useEffect(() => {
    fetchData();
  }, []);

  return (
    <div className="image">
      <div>
        {gameOver ? (
          <div>
            <h1>Game Over</h1>
            <button onClick={resetButton}>다시하기</button>
          </div>
        ) : (
          <div>
            <div>
              <img
                alt="이미지"
                src={`http://localhost:5000/file/${imageData}`}
              />
            </div>
            <h1>{count}</h1>
          </div>
        )}
      </div>
      {!gameOver && (
        <div>
          <Canvas checkAnswer={checkAnswer} newFetch={newFetch} quiz={quiz} />
        </div>
      )}
    </div>
  );
}

export default ImageGame;