add color

src/components/Canvas.vue

@@ -7,15 +7,18 @@ const props = defineProps<{
   hMargin: number;
   imageWidth: number;
   imageHeight: number;
+  imageBackgroundColor: string;
 }>();
 
 const ctx = ref<null | CanvasRenderingContext2D>(null);
 
 const clearCanvas = () => {
-  const { imageWidth, imageHeight } = props;
+  const { imageWidth, imageHeight, imageBackgroundColor } = props;
 
   if (ctx.value) {
-    ctx.value.clearRect(0, 0, imageWidth * ONE_MM, imageHeight * ONE_MM);
+    ctx.value.shadowColor
+    ctx.value.fillStyle = imageBackgroundColor;
+    ctx.value.fillRect(0, 0, imageWidth * ONE_MM, imageHeight * ONE_MM);
     ctx.value.beginPath();
   }
 };
@@ -58,11 +61,7 @@ onUpdated(() => {
 </script>
 
 <template>
-  <canvas
-    id="canvas"
-    :width="imageWidth * ONE_MM"
-    :height="imageHeight * ONE_MM"
-  />
+  <canvas id="canvas" :width="imageWidth * ONE_MM" :height="imageHeight * ONE_MM" />
 </template>
 
 <style scoped>