(freeType2)ttf字体怎样转换成图片

#include "stdafx.h"
#include
#include
#include
#include
#include
#include FT_FREETYPE_H
#include
#include

#pragma comment(lib , "lib/freetype2110.lib")

int bmp_write(unsigned char *image, int xsize, int ysize, char *filename)
{
 unsigned char header[54] =
 {
  0x42, 0x4d, 0, 0, 0, 0, 0, 0, 0, 0,
   54, 0, 0, 0, 40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 24, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0
 };

 long file_size = (long)xsize * (long)ysize * 3 + 54;
 header[2] = (unsigned char)(file_size &0x000000ff);
 header[3] = (file_size >> 8) & 0x000000ff;
 header[4] = (file_size >> 16) & 0x000000ff;
 header[5] = (file_size >> 24) & 0x000000ff;

 long width = xsize;
 header[18] = width & 0x000000ff;
 header[19] = (width >> 8) &0x000000ff;
 header[20] = (width >> 16) &0x000000ff;
 header[21] = (width >> 24) &0x000000ff;

 long height = -ysize; //数据倒着填充的
 header[22] = height &0x000000ff;
 header[23] = (height >> 24) &0x000000ff;
 header[24] = (height >> 16) &0x000000ff;
 header[25] = (height >> 8) &0x000000ff;

 char fname_bmp[128];
 sprintf(fname_bmp, "%s.bmp", filename);

 FILE *fp;
 if (!(fp = fopen(fname_bmp, "wb")))
  return -1;

 fwrite(header, sizeof(unsigned char), 54, fp);
 fwrite(image, sizeof(unsigned char), (size_t)(long)xsize * ysize * 3, fp);

 fclose(fp);
 return 0;
}
//以下为FT2_Obj的代码.
//主要参考了Nehe的Lesson 43
class FT2_Obj
{
 FT_Library library;
 int h ;
 FT_Face face;

public:
 void Init(const char * fname, unsigned int h);
 void Free();
 void DrawAUnicode(wchar_t ch);
};

void FT2_Obj::Init(const char * fname, unsigned int h)
{
 this->h=h;

 //初始化FreeType库..

 if (FT_Init_FreeType( &library ))
  throw std::runtime_error("FT_Init_FreeType failed");

 //加载一个字体,取默认的Face,一般为Regualer
 if (FT_New_Face( library, fname, 0, &face ))
  throw std::runtime_error("FT_New_Face failed (there is probably a problem with your font file)");
 
 //大小要乘64.这是规定。照做就可以了。
 //FT_Set_Char_Size( face,h<< 6, h << 6, 96, 96);
 FT_Set_Pixel_Sizes(face, 0, 64);
 FT_Matrix matrix; /* transformation matrix */
 FT_UInt glyph_index;
 FT_Vector pen;

 //给它设置个旋转矩阵
 float angle = 0/360* 3.14;
 matrix.xx = (FT_Fixed)( cos( angle ) * 0x10000L );
 matrix.xy = (FT_Fixed)(-sin( angle ) * 0x10000L );
 matrix.yx = (FT_Fixed)( sin( angle ) * 0x10000L );
 matrix.yy = (FT_Fixed)( cos( angle ) * 0x10000L );

 //FT_Set_Transform( face, &matrix, &pen );
}

int main()
{
 FT2_Obj font;

// 改用其它字体，生成的字会变斜，不知为什么，中文也会变斜
 font.Init("c:\\windows\\fonts\\arial.ttf",24);
 //font.Init("c:\\windows\\fonts\\simhei.ttf",24);
 //wchar_t pText[]=L"米";
 //wchar_t pText[]=L"\x4E2D";
 wchar_t pText[]=L"A";
 for(int n = 0 ; n< wcslen(pText);n++)
 {
  font.DrawAUnicode(pText[n]);
 }
 font.Free();
 return 1;
}

 

/*
绘制操作.
*/
void FT2_Obj::DrawAUnicode(wchar_t ch)
{
 if(FT_Load_Glyph( face, FT_Get_Char_Index( face, ch ), FT_LOAD_DEFAULT ))
  throw std::runtime_error("FT_Load_Glyph failed");

 //得到字模
 FT_Glyph glyph;
 if(FT_Get_Glyph( face->glyph, &glyph ))
  throw std::runtime_error("FT_Get_Glyph failed");

 //转化成位图
 FT_Render_Glyph( face->glyph, FT_RENDER_MODE_NORMAL );
 FT_Glyph_To_Bitmap( &glyph, ft_render_mode_normal, 0, 1 );
 FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph)glyph;

 //取道位图数据
 FT_Bitmap& bitmap=bitmap_glyph->bitmap;

 //把位图数据拷贝自己定义的数据区里.这样旧可以画到需要的东西上面了。
 int width = bitmap.width;
 int height = bitmap.rows;

// 4字节对齐
 int pitch = bitmap.pitch + 4 -1;
 pitch -= pitch%4;
 unsigned char* expanded_data = new unsigned char[ 3 * pitch * height];
 memset(expanded_data, 0x00, 3 * pitch * height);
 for(int j=0; j < height ; j++)
 {
  for(int i=0; i < width; i++)
  {
   //int n = 3*(i+(height-j-1)*width);
   /*expanded_data[3*(i+(height-j-1)*width)]=
   expanded_data[3*(i+(height-j-1)*width)+1] =
   expanded_data[3*(i+(height-j-1)*width)+2] = bitmap.buffer[i + bitmap.width*j]; */
    //(i>=bitmap.width || j>=bitmap.rows) ? 0 : bitmap.buffer[i + bitmap.width*j];
   int n = *bitmap.buffer++;
   if (n>0)
   {
    int nPos = j*pitch*3 + 3*i;
    expanded_data[ nPos ] =
    expanded_data[nPos+1] =
    expanded_data[nPos+2] = 0xFF;//bitmap.buffer[i + bitmap.width*j];
   }
  }
 }

 bmp_write(expanded_data, width, height, "E:/22");
 delete []expanded_data;
}

void FT2_Obj::Free()
{
 FT_Done_Face(face);
 FT_Done_FreeType(library);
}