cairo draw chinese text on windows

/*
 * cheungmine
 * 2013-5-5
 */
#include 
#include 
#include 

#ifdef _MSC_VER
 #include 
 #pragma warning (disable : 4996)
#endif

/* cairo api */

#include "../lib/cairo/include/cairo.h"
#include "../lib/cairo/include/cairo-features.h"
#include "../lib/cairo/include/cairo-svg.h"
#include "../lib/cairo/include/cairo-pdf.h"
#include "../lib/cairo/include/cairo-ps.h"
#include "../lib/cairo/include/cairo-ft.h"
#include "../lib/cairo/include/cairo-version.h"
#include "../lib/cairo/include/cairo-win32.h"

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

#ifdef _MSC_VER
static int bstr2utf8(BSTR bstrIn, int bstrLen, byte *pOut)
{
  int cbSize;

    if (!bstrIn) {
        return  0;
  }

    cbSize = WideCharToMultiByte(CP_UTF8, 0, bstrIn, bstrLen, 0, 0, 0, 0);
  if (pOut) {
      cbSize = WideCharToMultiByte(CP_UTF8, 0, bstrIn, bstrLen, (LPSTR) pOut, cbSize, 0, 0);
    assert(pOut[cbSize-1]==0);
  }

    return cbSize;
}

static int bytes2bstr(UINT uCodePage, byte* pBytesIn, DWORD cbSizeIn, BSTR *pBstrOut)
{
  int   cchNeeded;
  LPSTR    pstr;

  *pBstrOut = 0;

    cchNeeded = MultiByteToWideChar(uCodePage, 0, (LPCSTR)pBytesIn, cbSizeIn, 0, 0);
    if (0 == cchNeeded) {
        return (0);
  }

    pstr = (LPSTR) CoTaskMemAlloc (sizeof(DWORD) + sizeof(WCHAR)*cchNeeded);
    if (!pstr) {
        return (-1);
  }

    if (cchNeeded != MultiByteToWideChar(uCodePage, 0, (LPCSTR)pBytesIn, cbSizeIn, 
    (LPWSTR)(pstr+sizeof(DWORD)), cchNeeded)) {
        CoTaskMemFree(pstr);
        return (-2);
    }

    *((DWORD*)pstr) = sizeof(WCHAR)*(cchNeeded-1);
    *pBstrOut = (BSTR)(pstr + sizeof(DWORD));

    return cchNeeded;
}

char * ansi2utf8(char *str)
{
  BSTR bstr = 0;
  byte *utf8 = 0;
  int len, cb;

  len = bytes2bstr(CP_ACP, (byte*) str, strlen(str)+1, &bstr);
  if (len > 0) {
    cb = bstr2utf8(bstr, len, utf8);
    if (cb > 0) {
      utf8 = (byte*) malloc(cb);
      bstr2utf8(bstr, len, utf8);
    }

    SysFreeString(bstr);
    return (char*) utf8;
  }

  return 0;
}
#else

#endif

int drawChinaText(char *shapefile, char *shapeid, int width, int length, gde_drawsurface_format format)
{
  cairo_surface_t *surface;
  cairo_t *cr;

  char *font;
  char *text;

  font = ansi2utf8("文泉驿等宽正黑");  //"Arial Unicode MS"
  text = ansi2utf8("Hello, Chinese! 你好，中国人！");

  surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, width, length);
  cr = cairo_create (surface);


  cairo_select_font_face (cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
  cairo_set_font_size (cr, 32.0);
  cairo_set_source_rgb (cr, 0.0, 0.0, 1.0);
  cairo_move_to (cr, 10.0, 50.0);

  cairo_show_text (cr, text);

  cairo_destroy (cr);

  cairo_surface_write_to_png (surface, "c:/temp/hello-cairo.png");
  cairo_surface_destroy (surface);

  free(font);
  free(text);

  return 0;
}