Font atlas builder is off by one in some font configurations about imgui HOT 2 CLOSED

#include <imgui.h>
#include <imgui_internal.h>
#include <imstb_truetype.h>

namespace ImGuiEx
{

	bool GetOrCalculateFontMetrics( const ImFont* font, float* size, float* ascent, float* descent, float* offsetY )
	{
		if ( font->FontSize != 0.0f )
		{
			if ( size != nullptr )
				*size = font->FontSize;
			if ( ascent != nullptr )
				*ascent = font->Ascent;
			if ( descent != nullptr )
				*descent = font->Descent;
		}
		else
		{
			if ( font->ConfigData == nullptr )
				return false;

			const ImFontConfig& config = *font->ConfigData;

			if ( size != nullptr )
				*size = config.SizePixels;

			if ( ( ascent != nullptr ) || ( descent != nullptr ) )
			{
				const unsigned char* fontData = (const unsigned char*)config.FontData;
				if ( fontData == nullptr )
					return false;

				const int fontOffset = stbtt_GetFontOffsetForIndex( fontData, config.FontNo );

				stbtt_fontinfo fontInfo;
				if ( !stbtt_InitFont( &fontInfo, (unsigned char*)font->ConfigData->FontData, fontOffset ) )
					return false;

				const float fontScale = stbtt_ScaleForPixelHeight( &fontInfo, config.SizePixels );
				int         unscaledAscent, unscaledDescent, unscaledLineGap;

				stbtt_GetFontVMetrics( &fontInfo, &unscaledAscent, &unscaledDescent, &unscaledLineGap );

#if 0
				// off by one calculation
				if ( ascent != nullptr )
					*ascent = ImTrunc( unscaledAscent * fontScale + ( ( unscaledAscent > 0.0f ) ? +1 : -1 ) );
				if ( descent != nullptr )
					*descent = ImTrunc( unscaledDescent * fontScale + ( ( unscaledDescent > 0.0f ) ? +1 : -1 ) );
#else
				// fixed calculation
				if ( ascent != nullptr )
					*ascent = ImCeil( unscaledAscent * fontScale );
				if ( descent != nullptr )
					*descent = ImFloor( unscaledDescent * fontScale );
#endif
			}
		}

		if ( offsetY != nullptr )
		{
			if ( font->ConfigData == nullptr )
				return false;
			*offsetY = font->ConfigData->GlyphOffset.y;
		}

		return true;
	}

} // namespace ImGuiEx