Enable ClearType fonts with the winapi

Question

I'm trying to add ClearType to fonts in the vile editor GUI mode "winvile". I'm not familiar with the code.

I searched for all LOGFONT structs and found some in ntwinio.c and w32cmd.c

I couldn't find any other places with LOGFONT so I just tried adding CLEARTYPE_QUALITY (docs) where the structs are initialized. Ended up with:

diff --git a/ntwinio.c b/ntwinio.c
index 4b73176..c3a9871 100644
--- a/ntwinio.c
+++ b/ntwinio.c
@@ -848,6 +848,7 @@ GetMyFont(VIDEO_ATTR attr)
        LOGFONT logfont = vile_logfont;
        logfont.lfItalic = (BYTE) ((attr & VAITAL) != 0);
        logfont.lfUnderline = (BYTE) ((attr & VAUL) != 0);
+       logfont.lfQuality = CLEARTYPE_QUALITY;
        if (attr & VABOLD)
            logfont.lfWeight = FW_SEMIBOLD;
        if ((MyFonts[n].font = CreateFontIndirect(&logfont)) != 0) {
@@ -1218,6 +1219,7 @@ set_font(void)

     vile_logfont.lfPitchAndFamily = FIXED_PITCH | FF_MODERN;
     vile_logfont.lfCharSet = ANSI_CHARSET;
+    vile_logfont.lfQuality = CLEARTYPE_QUALITY;
     TRACE(("LOGFONT Facename:%s\n", vile_logfont.lfFaceName));

     if (ChooseFont(&choose)) {
@@ -1346,6 +1348,7 @@ ntwinio_font_frm_str(const char *fontstr,
        /* Build up LOGFONT data structure. */
        memset(&logfont, 0, sizeof(logfont));
        logfont.lfWeight = (str_rslts.bold) ? FW_BOLD : FW_NORMAL;
+       logfont.lfQuality = CLEARTYPE_QUALITY;
        logfont.lfHeight = -MulDiv(str_rslts.size,
                                   GetDeviceCaps(hdc, LOGPIXELSY),
                                   72);
diff --git a/w32cmd.c b/w32cmd.c
index 50276af..e9223ad 100644
--- a/w32cmd.c
+++ b/w32cmd.c
@@ -1626,6 +1626,7 @@ w32_init_logfont(LOGFONT * logfont, FONTSTR_OPTIONS * str_rslts, int height)

     logfont->lfWeight = (str_rslts->bold) ? FW_BOLD : FW_NORMAL;
     logfont->lfHeight = height;
+    logfont->lfQuality = CLEARTYPE_QUALITY;

     if (str_rslts->italic)
        logfont->lfItalic = TRUE;

That didn't seem to work and fonts still look bad, compared to cmd.exe:

I also tried other quality settings, they all look the same to me. Am I missing something in the winapi calls, or maybe missunderstanding how ClearType works?

I'm building with Visual Studio 2010 Express on Windows 10.

Answer 1

Wasn't ClearType but compatibility DPI settings for winvile.exe. Thanks to IInspectable for the pointer.