STB sprintf allows extra formats like %b or %$d. If ImGui is configured
to use STB sprintf, it generates warnings with GCC and clang when using
such formats because it keeps applying default printf-style warnings.
This commit disables printf-style warnings when using STB sprintf.
Since the printf-style warnings are defined in imgui.h based on the
compiler, IMGUI_USE_STB_SPRINTF can't just be defined in the cpp file
anymore and it's been moved as a proper config in imconfig.h.
- Begin() [old 5 args version] -> use Begin() [3 args], use SetNextWindowSize() SetNextWindowBgAlpha() if needed
- IsRootWindowOrAnyChildHovered() -> use IsWindowHovered(ImGuiHoveredFlags_RootAndChildWindows)
- AlignFirstTextHeightToWidgets() -> use AlignTextToFramePadding();
- SetNextWindowPosCenter() -> use SetNextWindowPos() with a pivot of (0.5f, 0.5f)
- ImFont::Glyph -> use ImFontGlyph
If you were still using the old names, read "API Breaking Changes" section of imgui.cpp to find out the new names or equivalent features, or see how they were implemented until 1.73.
This changeset implements several pieces of the puzzle that add up to a narrow ellipsis rendering.
## EllipsisCodePoint
`ImFontConfig` and `ImFont` received `ImWchar EllipsisCodePoint = -1;` field. User may configure `ImFontConfig::EllipsisCodePoint` a unicode codepoint that will be used for rendering narrow ellipsis. Not setting this field will automatically detect a suitable character or fall back to rendering 3 dots with minimal spacing between them. Autodetection prefers codepoint 0x2026 (narrow ellipsis) and falls back to 0x0085 (NEXT LINE) when missing. Wikipedia indicates that codepoint 0x0085 was used as ellipsis in some older windows fonts. So does default Dear ImGui font. When user is merging fonts - first configured and present ellipsis codepoint will be used, ellipsis characters from subsequently merged fonts will be ignored.
## Narrow ellipsis
Rendering a narrow ellipsis is surprisingly not straightforward task. There are cases when ellipsis is bigger than the last visible character therefore `RenderTextEllipsis()` has to hide last two characters. In a subset of those cases ellipsis is as big as last visible character + space before it. `RenderTextEllipsis()` tries to work around this case by taking free space between glyph edges into account. Code responsible for this functionality is within `if (text_end_ellipsis != text_end_full) { ... }`.
## Fallback (manually rendered dots)
There are cases when font does not have ellipsis character defined. In this case RenderTextEllipsis() falls back to rendering ellipsis as 3 dots, but with reduced spacing between them. 1 pixel space is used in all cases. This results in a somewhat wider ellipsis, but avoids issues where spaces between dots are uneven (visible in larger/monospace fonts) or squish dots way too much (visible in default font where dot is essentially a pixel). This fallback method obsoleted `RenderPixelEllipsis()` and this function was removed. Note that fallback ellipsis will always be somewhat wider than it could be, however it will fit in visually into every font used unlike what `RenderPixelEllipsis()` produced.
