imgui/extra_fonts/README.txt

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Extra fonts for ImGui.
THOSE FONTS ARE OPTIONAL.
ImGui embeds a copy of 'proggy_clean' that you can use without any external files.
Export your own font with bmfont (www.angelcode.com/products/bmfont).
bmfont reads fonts (.ttf, .fon, etc.) and output a .fnt file and a texture file, e.g:
proggy_clean.fon --> [bmfont] ---> proggy_clean_13.fnt
proggy_clean_13.png
If you need a free font that supports chinese/japanese characters, you can use the M+ fonts.
TTF and sources are availables at http://mplus-fonts.sourceforge.jp/mplus-outline-fonts.
This directory include some of the M+ fonts converted by bmfont.
//-----------------------------------------------------------------------------
Configure bmfont:
- Export .fnt as Binary
- Output .png, 32-bits (or whatever is suitable for your loader/renderer)
- Tip: uncheck "Render from TrueType outline" and "Font Smoothing" for best result with non-anti-aliased type fonts.
But you can experiment with other settings if you want anti-aliased fonts.
- Tip: use pngout.exe (http://advsys.net/ken/utils.htm) to further reduce the file size of .png files
All files in this folder have been optimised with pngout.exe
-----------------------------------------------------------------------------
(A) Use font data embedded in ImGui
// Access embedded font data
const void* fnt_data; // pointer to FNT data
unsigned fnt_size; // size of FNT data
const void* png_data; // pointer to PNG data
unsigned int png_size; // size of PNG data
ImGui::GetDefaultFontData(&fnt_data, &fnt_size, &png_data, &png_size);
1. Load the .FNT data from 'fnt_data' (NB: this is done for you by default if you don't do anything)
ImGuiIO& io = ImGui::GetIO();
io.Font = new ImFont();
io.Font->LoadFromMemory(fnt_data, fnt_size);
2. Load the .PNG data from 'png_data' into a texture
//-----------------------------------------------------------------------------
(B) Use fonts from external files
You need to set io.FontTexUvForWhite to UV coordinates pointing to a white pixel in the texture.
You can either locate a white pixel manually or use code at runtime to find or write one.
The OpenGL example include sample code to find a white pixel given an uncompressed 32-bits texture:
// Automatically find white pixel from the texture we just loaded
// (io.FontTexUvForWhite needs to contains UV coordinates pointing to a white pixel in order to render solid objects)
for (int tex_data_off = 0; tex_data_off < tex_x*tex_y; tex_data_off++)
if (((unsigned int*)tex_data)[tex_data_off] == 0xffffffff)
{
io.FontTexUvForWhite = ImVec2((float)(tex_data_off % tex_x)/(tex_x), (float)(tex_data_off / tex_x)/(tex_y));
break;
}
1. Load the .FNT data, e.g.
ImGuiIO& io = ImGui::GetIO();
// proggy_clean_13 [default]
io.Font = new ImFont();
io.Font->LoadFromFile("proggy_clean_13.fnt");
IM_ASSERT(io.Font->IsLoaded());
io.FontTexUvForWhite = ImVec2(0.0f/256.0f,0.0f/128);
io.FontYOffset = +1;
// proggy_small_12
io.Font = new ImFont();
io.Font->LoadFromFile("proggy_small_12.fnt");
IM_ASSERT(io.Font->IsLoaded());
io.FontTexUvForWhite = ImVec2(84.0f/256.0f,20.0f/64);
io.FontYOffset = +2;
// proggy_small_14
io.Font = new ImFont();
io.Font->LoadFromFile("proggy_small_14.fnt");
IM_ASSERT(io.Font->IsLoaded());
io.FontTexUvForWhite = ImVec2(84.0f/256.0f,20.0f/64);
io.FontYOffset = +3;
// courier_new_16
io.Font->LoadFromFile("courier_new_16.fnt");
io.FontTexUvForWhite = ImVec2(1.0f/256.0f,4.0f/128);
// courier_new_18
io.Font->LoadFromFile("courier_new_18.fnt");
io.FontTexUvForWhite = ImVec2(4.0f/256.0f,5.0f/256);
2. Load the matching .PNG data into a texture
//-----------------------------------------------------------------------------