How to use font without ligatures via WinAPI? - c++

Question

I'm trying to create simple application with custom output. I'm using CreateFont function in order to load monospaced font with specific options. As a result, the text has been drawn (DrawText) with ligatures such as fi.
How to disable this?
I am very sorry for my bad English
Creating font
normal = CreateFont(char_height, 0, 0, 0, FW_NORMAL, 0, 0, 0,
RUSSIAN_CHARSET, OUT_DEFAULT_PRECIS,
CLIP_DEFAULT_PRECIS, 5,
FIXED_PITCH | FF_DONTCARE, "Menlo");
bold = CreateFont(char_height, 0, 0, 0, FW_BOLD, 0, 0, 0,
RUSSIAN_CHARSET, OUT_DEFAULT_PRECIS,
CLIP_DEFAULT_PRECIS, 5,
FIXED_PITCH | FF_DONTCARE, "Menlo");
Printing
void Console::Print(string text, int color, int weight) {
RECT r;
r.top = padding + temp_y * (char_height + space_y);
r.bottom = r.top + char_height;
r.left = padding + temp_x * char_width;
r.right = padding + length();
HDC hdc = GetDC(hwnd);
SetTextColor(hdc, color);
SetBkColor(hdc, RGB(43, 48, 59));
SelectObject(GetDC(hwnd), weight == WEIGHT_NORMAL ? normal : bold);
DrawText(GetDC(hwnd), text.c_str(), text.length(), &r, DT_LEFT);
temp_x += text.length();
}
Current output (note the word "offline"):
Desired output:

Answer 1

The root problem seems to be that your font is broken. I'm not sure why a monospace (fixed-pitch) font would have ligature information.
Solution 1
Use ExtTextOutW with ETO_IGNORELANGUAGE. You may lose other functionality (like bi-di, digit substitution, shaping for complex scripts), but it does seem to prevent kerning and ligation, so it may be suitable for your purpose.
::ExtTextOutW(hdc, x, y, ETO_IGNORELANGUAGE, &rc, msg.c_str(), msg.size(), nullptr);
I tested with the font Gabriola, since I don't have Menlo or Meslo. Gabriola is a variable pitch font, but it has distinctive ligatures that make it easy to spot, especially fi.
Solution 2
A second approach, which has the same drawbacks, is to draw the strings character by character with TextOut in a loop. This is a little trickier because you have to worry about Unicode surrogate pairs, clipping, and updating the current position.
const auto old_alignment = ::SetTextAlign(hdc, TA_UPDATECP);
const auto old_mode = ::SetBkMode(hdc, TRANSPARENT);
::MoveToEx(hdc, x, y, nullptr);
// Loop simplified for demo. This doesn't handle Unicode surrogate pairs.
for (auto ch : msg) {
::TextOutW(hdc, 0, 0, &ch, 1);
}
::SetBkMode(hdc, old_mode);
::SetTextAlign(hdc, old_alignment);
This produced identical results to the first solution.
Non-Solution
Note that my earlier idea to use GetCharacterPlacement without the GCP_LIGATE flag followed by ExtTextOut with ETO_GLYPH_INDEX does not work. The glyphs returned from GetCharacterPlacement still included ligatures even without the GCP_LIGATE flag.
// DOES NOT WORK
GCP_RESULTSW results = {sizeof(results)};
WCHAR modified[64] = L""; // FIXED BUFFER LENGTHS JUST FOR TESTING
results.lpOutString = modified;
int deltas[64] = {0};
results.lpDx = deltas;
WCHAR glyphs[64] = L"";
glyphs[0] = 1;
results.lpGlyphs = glyphs;
results.nGlyphs = ARRAYSIZE(glyphs);
const DWORD flags = GCP_REORDER; // but not GCP_LIGATE or GCP_USEKERNING
::GetCharacterPlacementW(hdc, msg.c_str(), msg.size(), 0, &results, flags);
::ExtTextOutW(hdc, x, y, ETO_GLYPH_INDEX, &rc, glyphs, results.nGlyphs, deltas);