新增：绘画功能，已处理PC端和移动端兼容性问题

src/main/resources/static/css/game.css

@@ -33,6 +33,7 @@
   background-color: #ffffff;
   box-shadow: #000000 0 0 1px;
   border-radius: 10px;
+  touch-action: none;
 }
 
 .color-btn {

src/main/resources/static/index.html

@@ -47,17 +47,31 @@
                 <div>题目：<span id="topic-name">坐井观天</span></div>
                 <div>提示：<span id="topic-tip">成语，四个字</span></div>
             </div>
-            <canvas id="board" width="300" height="300"></canvas>
+            <canvas id="board" width="600" height="600"></canvas>
         </div>
         <div>
-            <button id="black-btn" class="color-btn" style="background-color: #000000;"></button>
+            <button class="color-btn" onclick="changeBrushColor('#000000')"
-            <button id="red-btn" class="color-btn" style="background-color: #ff0000;"></button>
+                    style="background-color: #000000;"></button>
-            <button id="green-btn" class="color-btn" style="background-color: #00ff00;"></button>
+            <button class="color-btn" onclick="changeBrushColor('#ff0000')"
-            <button id="blue-btn" class="color-btn" style="background-color: #0000ff;"></button>
+                    style="background-color: #ff0000;"></button>
-            <button id="yellow-btn" class="color-btn" style="background-color: #ffff00;"></button>
+            <button class="color-btn" onclick="changeBrushColor('#00ff00')"
+                    style="background-color: #00ff00;"></button>
+            <button class="color-btn" onclick="changeBrushColor('#0000ff')"
+                    style="background-color: #0000ff;"></button>
+            <button class="color-btn" onclick="changeBrushColor('#ffff00')"
+                    style="background-color: #ffff00;"></button>
         </div>
-        <div><label for="widthPicker">选择画笔宽度：</label>
+        <div>
-            <input type="range" id="widthPicker" value="1" min="1">
+            <button class="color-btn" onclick="changeBrushWidth(4)"
+                    style="background-color: #888888;"></button>
+            <button class="color-btn" onclick="changeBrushWidth(8)"
+                    style="background-color: #666666;"></button>
+            <button class="color-btn" onclick="changeBrushWidth(12)"
+                    style="background-color: #444444;"></button>
+            <button class="color-btn" onclick="changeBrushWidth(16)"
+                    style="background-color: #222222;"></button>
+            <button class="color-btn" onclick="changeBrushWidth(20)"
+                    style="background-color: #000000;"></button>
         </div>
         <div id="player-box">
             <div class="player-item">张</div>
@@ -88,8 +102,10 @@
     let playerId = "";
     // 当前房间id
     let roomId = "";
-    let backendAddr = "192.168.31.222:8080"
+    const backendAddr = "192.168.31.222:8080"
     const api = "http://" + backendAddr + "/api"
+
+
     init();
 
     function init() {
@@ -312,6 +328,28 @@
                         if (result.type === "room-chat") {
                             $("#chat-box").append("<p>" + result.data + "</p>")
                         }
+                        if (result.type === "room-draw") {
+                            let brush = JSON.parse(result.data);
+                            console.log("收到坐标: ", brush.x, brush.y);
+                            if (brush.isPoint) {
+                                brushPoint = {x: brush.x, y: brush.y}
+                                drawPoint(brush.x, brush.y, brush.width, brush.color);
+                            } else {
+                                // 移动端若按下事件坐标为空，则在划线事件中处理，将新的坐标作为点补充画点事件
+                                if (brushPoint.x == null || brushPoint.y == null) {
+                                    drawPoint(brush.x, brush.y, brush.width, brush.color);
+                                    brushPoint = {x: brush.x, y: brush.y};
+                                    return;
+                                }
+                                drawLine(brushPoint, {
+                                    x: brush.x,
+                                    y: brush.y
+                                }, brush.width, brush.color);
+                                brushPoint = {x: brush.x, y: brush.y};
+                            }
+
+                        }
+
                     };
                     ws.onclose = function () {
                         // 关闭 websocket
@@ -412,4 +450,6 @@
     }
 
 
-</script>
+</script>
+
+<script src="./js/draw.js"></script>

src/main/resources/static/js/draw.js

@@ -0,0 +1,127 @@
+// canvas画板
+let canvas = document.getElementById("board");
+let context = canvas.getContext("2d");
+context.imageSmoothingEnabled = true;
+let brushColor = "#000000";
+let brushWidth = 2;
+let brushPoint = {x: 0, y: 0};
+let isDrawing = false;
+// PC端 *******************************
+// 鼠标按下事件处理程序
+canvas.addEventListener("mousedown", function (event) {
+    isDrawing = true;
+    brushPoint = getBrushPoint(event);
+    // 广播绘画数据
+    sendDrawData(brushPoint.x, brushPoint.y, true);
+    drawPoint(brushPoint.x, brushPoint.y, brushWidth, brushColor);
+});
+
+// 鼠标移动事件处理程序
+canvas.addEventListener("mousemove", function (event) {
+    if (isDrawing) {
+        let newPoint = getBrushPoint(event);
+        // 广播绘画数据
+        sendDrawData(newPoint.x, newPoint.y, false);
+        drawLine(brushPoint, newPoint, brushWidth, brushColor);
+        brushPoint = newPoint;
+    }
+});
+
+// 鼠标释放事件处理程序
+canvas.addEventListener("mouseup", function () {
+    isDrawing = false;
+});
+
+// 移动端 *******************************
+// 触摸开始事件处理程序
+canvas.addEventListener("touchstart", function (event) {
+    isDrawing = true;
+    brushPoint = getTouchPoint(event);
+    // 广播绘画数据
+    sendDrawData(brushPoint.x, brushPoint.y, true);
+    drawPoint(brushPoint.x, brushPoint.y, brushWidth, brushColor);
+});
+
+// 触摸移动事件处理程序
+canvas.addEventListener("touchmove", function (event) {
+    event.preventDefault(); // 防止滚动页面
+    if (isDrawing) {
+        let newPoint = getTouchPoint(event.touches[0]); // 使用第一个触摸点
+        // 广播绘画数据
+        sendDrawData(newPoint.x, newPoint.y, false);
+        drawLine(brushPoint, newPoint, brushWidth, brushColor);
+        brushPoint = newPoint;
+    }
+});
+
+// 触摸结束事件处理程序
+canvas.addEventListener("touchend", function () {
+    isDrawing = false;
+});
+
+// 计算画笔在画布上的坐标
+function getBrushPoint(event) {
+    let rect = canvas.getBoundingClientRect();
+    return {
+        x: (event.clientX - rect.left) * 2,
+        y: (event.clientY - rect.top) * 2
+    };
+}
+// 计算画笔在画布上的触摸坐标
+function getTouchPoint(touch) {
+    let rect = canvas.getBoundingClientRect();
+    return {
+        x: (touch.clientX - rect.left) * (canvas.width / rect.width),
+        y: (touch.clientY - rect.top) * (canvas.height / rect.height)
+    };
+}
+// 绘制单个点
+function drawPoint(x, y, width, color) {
+    context.beginPath();
+    context.fillStyle = color;
+    context.arc(x, y, width / 2, 0, Math.PI * 2);
+    context.fill();
+    context.closePath();
+}
+
+// 绘制线段
+function drawLine(startPoint, endPoint, whidth, color) {
+    context.beginPath();
+    context.strokeStyle = color;
+    context.lineWidth = whidth;
+    context.lineCap = "round";
+    context.moveTo(startPoint.x, startPoint.y);
+    context.lineTo(endPoint.x, endPoint.y);
+    context.stroke();
+    context.closePath();
+}
+
+// 发送绘图信息的函数
+function sendDrawData(x, y, isPoint) {
+    // 构造绘图信息对象
+    const drawData = {
+        x,
+        y,
+        color: brushColor,
+        width: brushWidth,
+        isPoint
+    };
+
+    sendMessage("room-draw", JSON.stringify(drawData));
+}
+
+/**
+ * 切换画笔颜色
+ * @param color
+ */
+function changeBrushColor(color) {
+    brushColor = color;
+}
+
+/**
+ * 切换画笔宽度
+ * @param width 整数
+ */
+function changeBrushWidth(width) {
+    brushWidth = width;
+}