feat:提交

tests/dev1/dataHandle/common/bmp.ts

@@ -0,0 +1,176 @@
+const decoder = new TextDecoder()
+export class BmpDecoder {
+  pos: number
+  buffer: ArrayBuffer
+  is_with_alpha: boolean
+  bottom_up: boolean
+  flag: string
+  constructor(buffer: ArrayBuffer, is_with_alpha: boolean) {
+    this.pos = 0
+    this.buffer = buffer
+    this.is_with_alpha = !!is_with_alpha
+    this.bottom_up = true
+
+    this.flag = decoder.decode(this.buffer.slice(0, (this.pos += 2)))
+
+    if (this.flag != 'BM')
+      throw new Error('Invalid BMP File')
+    // this.parseHeader();
+    // this.parseRGBA();
+  }
+
+  parseHeader() {}
+  parseRGBA() {}
+}
+
+export function createBmpFile(
+  imgData: ImageData,
+  paramDic: { [key: string]: string } = {},
+) {
+  let dpi = 300
+  let bitPP = paramDic.bpp ? Number(paramDic.bpp) : 24
+  let printResolution = Math.round(dpi * 39.3701)
+
+  if ([1, 24, 32].includes(bitPP) == false) {
+    throw new Error(`不支持的${bitPP}bpp BMP`)
+  }
+
+  let data = imgData.data
+
+  let width = imgData.width
+  let height = imgData.height
+  let extraBytes = width % 4
+  let rgbSize = data.length
+  switch (bitPP) {
+    case 1:
+      {
+        let rowSize = width / 8 + (width % 8 > 0 ? 1 : 0)
+        extraBytes = rowSize % 4
+        rgbSize = height * (rowSize + extraBytes)
+      }
+      break
+    case 24:
+      {
+        let rowSize = 3 * width
+        extraBytes = rowSize % 4
+        rgbSize = height * (rowSize + extraBytes)
+      }
+      break
+  }
+  let headerInfoSize = 40
+
+  /** ****************header */
+  let flag = 'BM'
+  let reserved = 0
+  let offset = 54
+  let fileSize = rgbSize + offset
+  let planes = 1
+
+  let compress = 0
+  let hr = printResolution
+  let vr = printResolution
+  let colors = 0
+  let importantColors = 0
+  let colorPaletteSize = 0
+  if (bitPP == 1) {
+    colorPaletteSize = 2 * 4
+  }
+  let buffer = new ArrayBuffer(offset + colorPaletteSize + rgbSize)
+  let tempBuffer = new DataView(buffer)
+  let pos = 0
+
+  // BMP Header
+  // ID
+  tempBuffer.setUint8(pos, flag.charCodeAt(0))
+  pos += 1
+  tempBuffer.setUint8(pos, flag.charCodeAt(1))
+  pos += 1
+  // size
+  tempBuffer.setUint32(pos, fileSize, true)
+  pos += 4
+
+  // Application specific
+  tempBuffer.setUint32(pos, reserved, true)
+  pos += 4
+  // Offset
+  tempBuffer.setUint32(pos, offset, true)
+  pos += 4
+
+  // DIB Header
+  // Number of bytes in the DIB header (from this point)
+  tempBuffer.setUint32(pos, headerInfoSize, true)
+  pos += 4
+
+  tempBuffer.setUint32(pos, width, true)
+  pos += 4
+  tempBuffer.setUint32(pos, height, true)
+  pos += 4
+
+  tempBuffer.setUint16(pos, planes, true)
+  pos += 2
+  tempBuffer.setUint16(pos, bitPP, true)
+  pos += 2
+
+  tempBuffer.setUint16(pos, compress, true)
+  pos += 4
+
+  tempBuffer.setUint16(pos, rgbSize, true)
+  pos += 4
+
+  tempBuffer.setUint16(pos, hr, true)
+  pos += 4
+  tempBuffer.setUint16(pos, vr, true)
+  pos += 4
+
+  tempBuffer.setUint16(pos, colors, true)
+  pos += 4
+  tempBuffer.setUint16(pos, importantColors, true)
+  pos += 4
+
+  if (bitPP == 1) {
+    tempBuffer.setUint8(pos++, 0) // b
+    tempBuffer.setUint8(pos++, 0) // g
+    tempBuffer.setUint8(pos++, 0) // r
+    tempBuffer.setUint8(pos++, 0) // a
+
+    tempBuffer.setUint8(pos++, 255) // b
+    tempBuffer.setUint8(pos++, 255) // g
+    tempBuffer.setUint8(pos++, 255) // r
+    tempBuffer.setUint8(pos++, 0) // a
+  }
+
+  let pixData = ''
+  let writeBinData = () => {
+    tempBuffer.setUint8(pos++, Number.parseInt(pixData.padEnd(8, '0'), 2))
+    pixData = ''
+  }
+  for (let y = height - 1; y >= 0; y--) {
+    let rowIndex = y * width * 4
+    for (let x = 0; x < width; x++) {
+      let p = rowIndex + x * 4
+
+      if (bitPP == 1) {
+        if (pixData.length == 8) {
+          writeBinData()
+        }
+        let rgb = [data[p + 0], data[p + 1], data[p + 2]]
+        pixData += rgb.filter((v, i) => v > 170).length == 3 ? '1' : '0' // 170 以下小板缩略图条会断
+      } else {
+        tempBuffer.setUint8(pos++, data[p + 2]) // b
+        tempBuffer.setUint8(pos++, data[p + 1]) // g
+        tempBuffer.setUint8(pos++, data[p + 0]) // r
+        if (bitPP == 32) {
+          tempBuffer.setUint8(pos++, data[p + 3]) // a
+        }
+      }
+    }
+    if (bitPP == 1 && pixData.length > 0) {
+      writeBinData()
+    }
+    for (let index = 0; index < extraBytes; index++) {
+      tempBuffer.setUint8(pos++, 0)
+    }
+  }
+
+  return tempBuffer.buffer
+}