How to list uniquely font names installed on system?

Question

I'm setting lf.lfFaceName[0] = '\0'; and lf.lfCharSet = DEFAULT_CHARSET; to enumerate uniquely font names installed on system but I'm still getting duplicates. What am I missing? I'm getting duplicates like this:

font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]
font-name: [Cascadia Mono SemiBold]

I'm enumerating like this:

#pragma comment(lib, "user32.lib")
#pragma comment(lib, "Comctl32.lib")
#pragma comment(lib, "Gdi32.lib")
#pragma comment(lib, "UxTheme.lib")
#pragma comment(lib, "Comdlg32.lib")

#define WIN32_LEAN_AND_MEAN
#define UNICODE
#define _UNICODE

#include <windows.h>
#include <stdio.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, 
        WPARAM wParam, LPARAM lParam);

int CALLBACK enumFontsCallback(const LOGFONT *lpelfe, 
                               const TEXTMETRIC *lpntme,
                               DWORD      FontType,
                               LPARAM     lParam)
{
    wprintf(L"font-name: [%s]\r\n", lpelfe->lfFaceName);
    return 1;
}

void list()
{
    LOGFONT lf = {0};
    lf.lfWeight = FW_DONTCARE;
    lf.lfOutPrecision = OUT_OUTLINE_PRECIS;
    lf.lfQuality = DEFAULT_QUALITY;
    lf.lfCharSet = DEFAULT_CHARSET;
    lf.lfClipPrecision = CLIP_DEFAULT_PRECIS;
    lf.lfPitchAndFamily = FF_DONTCARE;
    lf.lfFaceName[0] = '\0';

    HDC dc = GetDC(NULL);
    EnumFontFamiliesEx(dc, &lf, (FONTENUMPROC)enumFontsCallback, 0, 0);
    ReleaseDC(NULL, dc);
}

int main()
{
    list();
    return 0;
}

Answer 1

The reason for the duplications is given in the docs under remarks: "EnumFontFamiliesEx will enumerate the same font as many times as there are distinct character sets in the font. [...] To avoid this, an application should filter the list of fonts".

To filter the list down to unique font names, the LPARAM of the callback can be used to build a running list of previously encountered font names, and skip over duplicates.

• The EnumFontFamiliesEx call would need to be changed to something like the following.

    unordered_set<wstring> wsFonts;
    EnumFontFamiliesEx(dc, &lf, (FONTENUMPROC)enumFontsCallback, (LPARAM)&wsFonts, 0);
  

• The callback could then check the current font name against the list.

    wstring wsFont = lpelfe->lfFaceName;
    if(((unordered_set<wstring> *)lParam)->insert(wsFont).second)
        wcout << L"font-name: " << wsFont << endl;
  

The above assumes C++ for the convenience of std::unordered_set, but could of course be written into plain C using a handcrafted list of unique strings.