Fonts: ImFontConfig::OversampleH now defaults to 2 instead of 3.

docs/CHANGELOG.txt

@@ -52,6 +52,8 @@ Breaking changes:
 
 Other changes:
 
+- Fonts: ImFontConfig::OversampleH now defaults to 2 instead of 3, since the
+  quality increase is largely minimal.
 - ImDrawData: CmdLists[] array is now an ImVector<> owned by ImDrawData rather
   than a pointer to internal state.
   - This makes it easier for user to create their own or append to an existing draw data.

docs/FONTS.md

@@ -52,7 +52,7 @@ All loaded fonts glyphs are rendered into a single texture atlas ahead of time.
 This is often of byproduct of point 3. If you have large number of glyphs or multiple fonts, the texture may become too big for your graphics API. **The typical result of failing to upload a texture is if every glyph or everything appears as empty black or white rectangle.** Mind the fact that some graphics drivers have texture size limitation. If you are building a PC application, mind the fact that your users may use hardware with lower limitations than yours.
 
 Some solutions:
-- You may reduce oversampling, e.g. `font_config.OversampleH = 2`, this will largely reduce your texture size.
+- You may reduce oversampling, e.g. `font_config.OversampleH = 1`, this will half your texture size for a quality looss.
   Note that while OversampleH = 2 looks visibly very close to 3 in most situations, with OversampleH = 1 the quality drop will be noticeable. Read about oversampling [here](https://github.com/nothings/stb/blob/master/tests/oversample).
 - Reduce glyphs ranges by calculating them from source localization data.
   You can use the `ImFontGlyphRangesBuilder` for this purpose and rebuilding your atlas between frames when new characters are needed. This will be the biggest win!

imgui.h

@@ -2773,7 +2773,7 @@ struct ImFontConfig
     bool            FontDataOwnedByAtlas;   // true     // TTF/OTF data ownership taken by the container ImFontAtlas (will delete memory itself).
     int             FontNo;                 // 0        // Index of font within TTF/OTF file
     float           SizePixels;             //          // Size in pixels for rasterizer (more or less maps to the resulting font height).
-    int             OversampleH;            // 3        // Rasterize at higher quality for sub-pixel positioning. Note the difference between 2 and 3 is minimal so you can reduce this to 2 to save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
+    int             OversampleH;            // 2        // Rasterize at higher quality for sub-pixel positioning. Note the difference between 2 and 3 is minimal. You can reduce this to 1 for large glyphs save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
     int             OversampleV;            // 1        // Rasterize at higher quality for sub-pixel positioning. This is not really useful as we don't use sub-pixel positions on the Y axis.
     bool            PixelSnapH;             // false    // Align every glyph to pixel boundary. Useful e.g. if you are merging a non-pixel aligned font with the default font. If enabled, you can set OversampleH/V to 1.
     ImVec2          GlyphExtraSpacing;      // 0, 0     // Extra spacing (in pixels) between glyphs. Only X axis is supported for now.

imgui_draw.cpp

@@ -1961,7 +1961,7 @@ ImFontConfig::ImFontConfig()
 {
     memset(this, 0, sizeof(*this));
     FontDataOwnedByAtlas = true;
-    OversampleH = 3; // FIXME: 2 may be a better default?
+    OversampleH = 2;
     OversampleV = 1;
     GlyphMaxAdvanceX = FLT_MAX;
     RasterizerMultiply = 1.0f;