通用点阵显示代码

前几天，工作上需要在 YUV 图像上显示中英文混显的点阵，在网上一阵搜索，结果很不理想。后来，自己花时间考虑了一下，其实就是个点阵匹配的问题，完全可以写成通用的代码(网上要么是16X16,要么是24X24,12X12还没找到，有的还分中文和英文)。

以下便是个人完成的较为通用的点阵显示代码，也许叫点阵匹配更贴切一些，它完全和具体的绘图环境(GDI, DOS)无关，

 

// pTxt,   为点阵的 Buffer,
// funCallBack, 为回调函数,
// lUserData,  为传回给回调函数的参数,

template <size_t nTxtWidth, size_t nTxtHeight, class FunDrawPoint>
void DrawPoint(char *pTxt, FunDrawPoint funCallBack, unsigned long lUserData)
{
 char cFlag = 0;
 size_t nLineBytes = ((nTxtWidth >> 3) + ((nTxtWidth % 0x08) != 0));

 if (pTxt == NULL) {
  return;
 }

 for (long i = 0; i < nTxtHeight; ++i) {
  for (long j = 0; j < nLineBytes; ++j) {
   cFlag = pTxt[i * nLineBytes + j];
   if (cFlag == 0) {
    continue;
   }

   for (long k = 0; k < 8; ++k) {
    if (cFlag & 0x01) {
     funCallBack(j * 8 + 7 - k, i, lUserData);
    }

    cFlag >>= 1;

    if (cFlag == 0) {
     break;
    }
   }
  }
 }
}

 

使用方法如下:

 

// 上下文件环境参数(这里以GDI的环境为例)
struct Param
{
 HDC hDC;
 long x; // 目标图上的 X 坐标
 long y; // 目标图上的 Y 坐标
};

// 回调函数
void _DrawPoint(long x, long y, unsigned long lUserData)
{
 Param *pParam = (Param *) lUserData;
 SetPixel(pParam->hDC, pParam->x + x, pParam->y + y, RGB(0, 0, 0));
}

// pBuffer, 为从点阵文件读出的字的 Buffer,
// _DrawPoint, 为回调函数,
// param,  为上下文环境,

DrawPoint<8, 8>(pBuffer, _DrawPoint, (unsigned long) &param);

DrawPoint<12, 12>(pBuffer, _DrawPoint, (unsigned long) &param);

DrawPoint<16, 16>(pBuffer, _DrawPoint, (unsigned long) &param);

DrawPoint<24, 24>(pBuffer, _DrawPoint, (unsigned long) &param);

DrawPoint<32, 32>(pBuffer, _DrawPoint, (unsigned long) &param);

DrawPoint<64, 64>(pBuffer, _DrawPoint, (unsigned long) &param);

 

除了以上几种字体大小，DrawPoint也支持非标准字体大小，只要提供的pBuffer是正确的，也可以把DrawPoint非模板函数，