add image crop support

html/css/main.css

@@ -257,6 +257,11 @@ code {
     margin: 0 auto;
 }
 
+.canvas-container.crop #canvas {
+    border: 2px dashed var(--primary-color);
+    cursor: grab;
+}
+
 button {
     padding: 0.375rem 0.75rem;
     border: 1px solid var(--primary-color);
@@ -367,10 +372,21 @@ canvas.text-placement-mode {
     justify-content: center;
 }
 
-.text-tools {
+.text-tools,
+.crop-tools {
     display: none;
 }
 
+.canvas-container.crop .tool-buttons,
+.canvas-container.crop .brush-buttons,
+.canvas-container.crop .text-tools {
+    display: none;
+}
+
+.canvas-container.crop .crop-tools {
+    display: flex;
+}
+
 .tool-button {
     width: 36px;
     height: 36px;

html/index.html

@@ -51,7 +51,7 @@
 			</div>
 		</fieldset>
 		<fieldset>
-        	<legend>图片处理</legend>
+        	<legend>蓝牙传图</legend>
 			<div class="flex-container">
 				<input type="file" id="imageFile" accept=".png,.jpg,.bmp,.webp,.jpeg">
 			</div>
@@ -120,8 +120,9 @@
 			<div class="status-bar"><b>状态：</b><span id="status"></span></div>
 			<div class="flex-container">
 				<div class="flex-group">
-					<button id="clearcanvasbutton" type="button" class="secondary" onclick="clearCanvas()">清除画布</button>
+					<button type="button" class="secondary debug" onclick="rotateCanvas()">旋转画布</button>
-					<button id="downloadArray" type="button" class="secondary debug" onclick="downloadDataArray()">下载数组</button>
+					<button type="button" class="secondary" onclick="clearCanvas()">清除画布</button>
+					<button type="button" class="secondary debug" onclick="downloadDataArray()">下载数组</button>
 					<button id="sendimgbutton" type="button" class="primary" onclick="sendimg()">发送图片</button>
 				</div>
 			</div>
@@ -129,7 +130,7 @@
 				<div class="canvas-title"></div>
 				<canvas id="canvas" width="400" height="300"></canvas>
 				<div class="flex-container canvas-tools">
-					<div class="flex-group">
+					<div class="flex-group tool-buttons">
 						<button id="brush-mode" title="画笔" class="tool-button">✏️</button>
 						<button id="eraser-mode" title="橡皮擦" class="tool-button">🧽</button>
 						<button id="text-mode" title="添加文字" class="tool-button">T</button>
@@ -191,6 +192,15 @@
 						<button id="text-italic" title="斜体">I</button>
 						<button id="add-text-btn" class="primary">添加文字</button>
 					</div>
+					<div class="flex-group crop-tools">
+						<button id="crop-zoom-in" title="放大" class="secondary">+</button>
+						<button id="crop-zoom-out" title="缩小" class="secondary">-</button>
+						<button id="crop-move-left" title="左移">⇦</button>
+						<button id="crop-move-up" title="上移">⇧</button>
+						<button id="crop-move-down" title="下移">⇩</button>
+						<button id="crop-move-right" title="右移">⇨</button>
+						<button class="primary" onclick="finishCrop()">完成</button>
+					</div>
 				</div>
 			</div>
         </fieldset>
@@ -205,6 +215,7 @@
     </div>
     <script type="text/javascript" src="js/dithering.js?v=20250731"></script>
     <script type="text/javascript" src="js/paint.js?v=20250731"></script>
+    <script type="text/javascript" src="js/crop.js?v=20250731"></script>
     <script type="text/javascript" src="js/main.js?v=20250731"></script>
 </body>
 

html/js/crop.js

@@ -0,0 +1,211 @@
+let backgroundZoom = 1;
+let backgroundPanX = 0;
+let backgroundPanY = 0;
+let isPanning = false;
+let lastPanX = 0;
+let lastPanY = 0;
+let lastTouchDistance = 0;
+
+function resetCropStates() {
+  backgroundZoom = 1;
+  backgroundPanX = 0;
+  backgroundPanY = 0;
+  isPanning = false;
+  lastPanX = 0;
+  lastPanY = 0;
+}
+
+function removeEventListeners() {
+  canvas.removeEventListener('wheel', handleBackgroundZoom);
+  canvas.removeEventListener('mousedown', handleBackgroundPanStart);
+  canvas.removeEventListener('mousemove', handleBackgroundPan);
+  canvas.removeEventListener('mouseup', handleBackgroundPanEnd);
+  canvas.removeEventListener('mouseleave', handleBackgroundPanEnd);
+
+  canvas.removeEventListener('touchstart', handleTouchStart);
+  canvas.removeEventListener('touchmove', handleTouchMove);
+  canvas.removeEventListener('touchend', handleBackgroundPanEnd);
+  canvas.removeEventListener('touchcancel', handleBackgroundPanEnd);
+}
+
+function isCropMode() {
+  return canvas.parentNode.classList.contains('crop');
+}
+
+function exitCropMode() {
+  removeEventListeners();
+  canvas.parentNode.classList.remove('crop');
+  setCanvasTitle("");
+}
+
+function initializeCrop() {
+  const imageFile = document.getElementById('imageFile');
+  if (imageFile.files.length == 0) {
+    fillCanvas('white');
+    return;
+  }
+
+  resetCropStates();
+  removeEventListeners();
+
+  canvas.style.backgroundImage = `url(${URL.createObjectURL(imageFile.files[0])})`;
+  canvas.style.backgroundSize = '100%';
+  canvas.style.backgroundPosition = '';
+  canvas.style.backgroundRepeat = 'no-repeat';
+
+  // add event listeners for zoom and pan
+  canvas.addEventListener('wheel', handleBackgroundZoom);
+  canvas.addEventListener('mousedown', handleBackgroundPanStart);
+  canvas.addEventListener('mousemove', handleBackgroundPan);
+  canvas.addEventListener('mouseup', handleBackgroundPanEnd);
+  canvas.addEventListener('mouseleave', handleBackgroundPanEnd);
+
+  // Touch events for mobile devices
+  canvas.addEventListener('touchstart', handleTouchStart);
+  canvas.addEventListener('touchmove', handleTouchMove);
+  canvas.addEventListener('touchend', handleBackgroundPanEnd);
+  canvas.addEventListener('touchcancel', handleBackgroundPanEnd);
+
+  // Make the canvas transparent
+  ctx.clearRect(0, 0, canvas.width, canvas.height);
+
+  setCanvasTitle("裁剪模式: 可用鼠标或触摸缩放移动图片");
+  canvas.parentNode.classList.add('crop');
+}
+
+function finishCrop() {
+  const imageFile = document.getElementById('imageFile');
+  if (imageFile.files.length == 0) return;
+
+  const image = new Image();
+  image.onload = function () {
+    URL.revokeObjectURL(this.src);
+
+    const fieldsetRect = canvas.getBoundingClientRect();
+    const scale = (image.width / fieldsetRect.width) / backgroundZoom;
+
+    const sx = -backgroundPanX * scale;
+    const sy = -backgroundPanY * scale;
+    const sWidth = fieldsetRect.width * scale;
+    const sHeight = fieldsetRect.height * scale;
+
+    fillCanvas('white');
+    ctx.drawImage(image, sx, sy, sWidth, sHeight, 0, 0, canvas.width, canvas.height);
+
+    redrawTextElements();
+    redrawLineSegments();
+    convertDithering();
+
+    exitCropMode();
+  };
+  image.src = URL.createObjectURL(imageFile.files[0]);
+}
+
+function handleTouchStart(e) {
+  e.preventDefault();
+  if (e.touches.length === 1) {
+    handleBackgroundPanStart(e.touches[0]);
+  } else if (e.touches.length === 2) {
+    isPanning = false; // Stop panning when zooming
+    lastTouchDistance = getTouchDistance(e.touches);
+  }
+}
+
+function handleTouchMove(e) {
+  e.preventDefault();
+  if (isPanning && e.touches.length === 1) {
+    handleBackgroundPan(e.touches[0]);
+  } else if (e.touches.length === 2) {
+    const newDist = getTouchDistance(e.touches);
+    if (lastTouchDistance > 0) {
+      const zoomFactor = newDist / lastTouchDistance;
+      backgroundZoom *= zoomFactor;
+      backgroundZoom = Math.max(0.1, Math.min(5, backgroundZoom)); // Limit zoom range
+      updateBackgroundTransform();
+    }
+    lastTouchDistance = newDist;
+  }
+}
+
+function handleBackgroundZoom(e) {
+  e.preventDefault();
+  const zoomFactor = e.deltaY > 0 ? 0.9 : 1.1;
+  backgroundZoom *= zoomFactor;
+  backgroundZoom = Math.max(0.1, Math.min(5, backgroundZoom)); // Limit zoom range
+  updateBackgroundTransform();
+}
+
+function handleBackgroundPanStart(e) {
+  isPanning = true;
+  lastPanX = e.clientX;
+  lastPanY = e.clientY;
+  canvas.style.cursor = 'grabbing';
+}
+
+function handleBackgroundPan(e) {
+  if (isPanning) {
+    const deltaX = e.clientX - lastPanX;
+    const deltaY = e.clientY - lastPanY;
+    backgroundPanX += deltaX;
+    backgroundPanY += deltaY;
+    lastPanX = e.clientX;
+    lastPanY = e.clientY;
+    updateBackgroundTransform();
+  }
+}
+
+function handleBackgroundPanEnd() {
+  isPanning = false;
+  lastTouchDistance = 0; // Reset touch distance
+  canvas.style.cursor = 'grab';
+}
+
+function updateBackgroundTransform() {
+  canvas.style.backgroundSize = `${100 * backgroundZoom}%`;
+  canvas.style.backgroundPosition = `${backgroundPanX}px ${backgroundPanY}px`;
+}
+
+function getTouchDistance(touches) {
+  const touch1 = touches[0];
+  const touch2 = touches[1];
+  return Math.sqrt(
+    Math.pow(touch2.clientX - touch1.clientX, 2) +
+    Math.pow(touch2.clientY - touch1.clientY, 2)
+  );
+}
+
+function initCropTools() {
+  document.getElementById('crop-zoom-in').addEventListener('click', (e) => {
+    e.preventDefault();
+    handleBackgroundZoom({ preventDefault: () => {}, deltaY: -1 });
+  });
+
+  document.getElementById('crop-zoom-out').addEventListener('click', (e) => {
+    e.preventDefault();
+    handleBackgroundZoom({ preventDefault: () => {}, deltaY: 1 });
+  });
+
+  document.getElementById('crop-move-left').addEventListener('click', (e) => {
+    e.preventDefault();
+    backgroundPanX -= 10;
+    updateBackgroundTransform();
+  });
+
+  document.getElementById('crop-move-right').addEventListener('click', (e) => {
+    e.preventDefault();
+    backgroundPanX += 10;
+    updateBackgroundTransform();
+  });
+
+  document.getElementById('crop-move-up').addEventListener('click', (e) => {
+    e.preventDefault();
+    backgroundPanY -= 10;
+    updateBackgroundTransform();
+  });
+
+  document.getElementById('crop-move-down').addEventListener('click', (e) => {
+    e.preventDefault();
+    backgroundPanY += 10;
+    updateBackgroundTransform();
+  });
+}

html/js/main.js

@@ -159,6 +159,11 @@ async function sendcmd() {
 }
 
 async function sendimg() {
+  if (isCropMode()) {
+    addLog("请先完成图片裁剪！发送已取消。");
+    return;
+  }
+
   const canvasSize = document.getElementById('canvasSize').value;
   const ditherMode = document.getElementById('ditherMode').value;
   const epdDriverSelect = document.getElementById('epddriver');
@@ -207,6 +212,11 @@ async function sendimg() {
 }
 
 function downloadDataArray() {
+  if (isCropMode()) {
+    addLog("请先完成图片裁剪！下载已取消。");
+    return;
+  }
+
   const mode = document.getElementById('ditherMode').value;
   const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
   const processedData = processImageData(imageData, mode);
@@ -417,6 +427,35 @@ function clearLog() {
   document.getElementById("log").innerHTML = '';
 }
 
+function fillCanvas(style) {
+  ctx.fillStyle = style;
+  ctx.fillRect(0, 0, canvas.width, canvas.height);
+}
+
+function updateImage() {
+  const imageFile = document.getElementById('imageFile');
+  if (imageFile.files.length == 0) {
+    fillCanvas('white');
+    return;
+  }
+
+  const image = new Image();
+  image.onload = function () {
+    URL.revokeObjectURL(this.src);
+    if (image.width / image.height == canvas.width / canvas.height) {
+      if (isCropMode()) exitCropMode();
+      ctx.drawImage(image, 0, 0, image.width, image.height, 0, 0, canvas.width, canvas.height);
+      redrawTextElements();
+      redrawLineSegments();
+      convertDithering();
+    } else {
+      addLog("图片宽高比例与画布不匹配，已进入裁剪模式。");
+      initializeCrop();
+    }
+  };
+  image.src = URL.createObjectURL(imageFile.files[0]);
+}
+
 function updateCanvasSize() {
   const selectedSizeName = document.getElementById('canvasSize').value;
   const selectedSize = canvasSizes.find(size => size.name === selectedSizeName);
@@ -424,7 +463,7 @@ function updateCanvasSize() {
   canvas.width = selectedSize.width;
   canvas.height = selectedSize.height;
 
-  updateImage(false);
+  updateImage();
 }
 
 function updateDitcherOptions() {
@@ -439,33 +478,21 @@ function updateDitcherOptions() {
   updateCanvasSize(); // always update image
 }
 
-function updateImage(clear = false) {
+function rotateCanvas() {
-  const imageFile = document.getElementById('imageFile');
+  const currentWidth = canvas.width;
-  if (imageFile.files.length == 0) return;
+  const currentHeight = canvas.height;
-  const file = imageFile.files[0];
+  canvas.width = currentHeight;
-
+  canvas.height = currentWidth;
-  if (clear) clearCanvas();
+  addLog(`画布已旋转: ${currentWidth}x${currentHeight} -> ${canvas.width}x${canvas.height}`);
-
+  updateImage();
-  let image = new Image();
-  image.src = URL.createObjectURL(file);
-  image.onload = function (event) {
-    URL.revokeObjectURL(this.src);
-    ctx.drawImage(image, 0, 0, image.width, image.height, 0, 0, canvas.width, canvas.height);
-
-    // Redraw text and lines
-    redrawTextElements();
-    redrawLineSegments();
-
-    convertDithering()
-  }
 }
 
 function clearCanvas() {
-  if (confirm('清除画布已有内容?')) {
+  if (confirm('清除画布内容?')) {
-    ctx.fillStyle = 'white';
+    fillCanvas('white');
-    ctx.fillRect(0, 0, canvas.width, canvas.height);
     textElements = []; // Clear stored text positions
     lineSegments = []; // Clear stored line segments
+    if (isCropMode()) exitCropMode();
     return true;
   }
   return false;
@@ -492,15 +519,15 @@ function convertDithering() {
 
 function initEventHandlers() {
   document.getElementById("epddriver").addEventListener("change", updateDitcherOptions);
-  document.getElementById("imageFile").addEventListener("change", function () { updateImage(true); });
+  document.getElementById("imageFile").addEventListener("change", updateImage);
-  document.getElementById("ditherMode").addEventListener("change", function () { updateImage(false); });
+  document.getElementById("ditherMode").addEventListener("change", finishCrop);
-  document.getElementById("ditherAlg").addEventListener("change", function () { updateImage(false); });
+  document.getElementById("ditherAlg").addEventListener("change", finishCrop);
   document.getElementById("ditherStrength").addEventListener("input", function () {
-    updateImage(false);
+    finishCrop();
     document.getElementById("ditherStrengthValue").innerText = parseFloat(this.value).toFixed(1);
   });
   document.getElementById("ditherContrast").addEventListener("input", function () {
-    updateImage(false);
+    finishCrop();
     document.getElementById("ditherContrastValue").innerText = parseFloat(this.value).toFixed(1);
   });
   document.getElementById("canvasSize").addEventListener("change", updateCanvasSize);
@@ -532,6 +559,7 @@ document.body.onload = () => {
   ctx.fillRect(0, 0, canvas.width, canvas.height);
 
   initPaintTools();
+  initCropTools();
   initEventHandlers();
   updateButtonStatus();
   checkDebugMode();