Removed ImFont::DisplayOffset in favor of ImFontConfig::GlyphOffset. (#1619)

+ Fonts: AddFontDefault() adjust its vertical offset based on floor(size/13) instead of always +1.

docs/CHANGELOG.txt

@@ -35,6 +35,14 @@ HOW TO UPDATE?
  VERSION 1.79 WIP (In Progress)
 -----------------------------------------------------------------------
 
+Breaking Changes:
+
+- Fonts: Removed ImFont::DisplayOffset in favor of ImFontConfig::GlyphOffset. DisplayOffset was applied
+  after scaling and not very meaningful/useful outside of being needed by the default ProggyClean font.
+  It was also getting in the way of better font scaling, so let's get rid of it now! 
+  If you used DisplayOffset it was probably in association to rasterizing a font at a specific size,
+  in which case the corresponding offset may be reported into GlyphOffset. (#1619)
+
 Other Changes:
 
 - Window: Fixed using non-zero pivot in SetNextWindowPos() when the window is collapsed. (#3433)
@@ -72,6 +80,7 @@ Other Changes:
   a fully clipped column. (#3475) [@szreder]
 - Popups, Tooltips: Fix edge cases issues with positionning popups and tooltips when they are larger than
   viewport on either or both axises. [@Rokups]
+- Fonts: AddFontDefault() adjust its vertical offset based on floor(size/13) instead of always +1.
 - Metrics: Various tweaks, listing windows front-to-back, greying inactive items when possible.
 - Demo: Add simple InputText() callbacks demo (aside from the more elaborate ones in 'Examples->Console').
 - Backends: OpenGL3: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 contexts which have 
@@ -1481,7 +1490,7 @@ Breaking Changes:
   - removed the default global context and font atlas instance, which were confusing for users of DLL reloading and users of multiple contexts.
 - Renamed ImGuiStyleVar_Count_ to ImGuiStyleVar_COUNT and ImGuiMouseCursor_Count_ to ImGuiMouseCursor_COUNT for consistency with other public enums.
 - Fonts: Moved sample TTF files from extra_fonts/ to misc/fonts/. If you loaded files directly from the imgui repo you may need to update your paths.
-- Fonts: changed ImFont::DisplayOffset.y to defaults to 0 instead of +1. Fixed vertical rounding of Ascent/Descent to match TrueType renderer.
+- Fonts: Changed ImFont::DisplayOffset.y to defaults to 0 instead of +1. Fixed vertical rounding of Ascent/Descent to match TrueType renderer.
   If you were adding or subtracting (not assigning) to ImFont::DisplayOffset check if your fonts are correctly aligned vertically. (#1619)
 - BeginDragDropSource(): temporarily removed the optional mouse_button=0 parameter because it is not really usable in many situations at the moment.
 - Obsoleted IsAnyWindowHovered() in favor of IsWindowHovered(ImGuiHoveredFlags_AnyWindow). Kept redirection function (will obsolete).

docs/FONTS.md

@@ -142,13 +142,6 @@ ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
 ![sample code output](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v160/code_sample_02_jp.png)
 <br>_(settings: Dark style (left), Light style (right) / Font: NotoSansCJKjp-Medium, 20px / Rounding: 5)_
 
-
-**Offset font vertically by altering the `io.Font->DisplayOffset` value:**
-```cpp
-ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
-font->DisplayOffset.y = 1;   // Render 1 pixel down
-```
-
 **Font Atlas too large?**
 
 - If you have very 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 glyphs appears as white rectangles.
@@ -337,13 +330,13 @@ DroidSans.ttf
 ProggyClean.ttf
   Copyright (c) 2004, 2005 Tristan Grimmer
   MIT License
-  recommended loading setting: Size = 13.0, DisplayOffset.Y = +1
+  recommended loading setting: Size = 13.0, GlyphOffset.y = +1
   http://www.proggyfonts.net/
 
 ProggyTiny.ttf
   Copyright (c) 2004, 2005 Tristan Grimmer
   MIT License
-  recommended loading setting: Size = 10.0, DisplayOffset.Y = +1
+  recommended loading setting: Size = 10.0, GlyphOffset.y = +1
   http://www.proggyfonts.net/
 
 Karla-Regular.ttf

docs/README.md

@@ -114,7 +114,7 @@ Officially maintained bindings (in repository):
 - Frameworks: Emscripten, Allegro5, Marmalade.
 
 Third-party bindings (see [Bindings](https://github.com/ocornut/imgui/wiki/Bindings/) page):
-- Languages: C, C# and: Beef, ChaiScript, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lua, Odin, Pascal, PureBasic, Python, Ruby, Rust, Swift...
+- Languages: C, C# and: Beef, ChaiScript, Crystal, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lua, Odin, Pascal, PureBasic, Python, Ruby, Rust, Swift...
 - Frameworks: AGS/Adventure Game Studio, Amethyst, bsf, Cinder, Cocos2d-x, Diligent Engine, Flexium, GML/Game Maker Studio2, Godot, GTK3+OpenGL3, Irrlicht Engine, LÖVE+LUA, Magnum, NanoRT, nCine, Nim Game Lib, Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, SFML, Sokol, Unity, Unreal Engine 4, vtk, Win32 GDI, WxWidgets.
 - Note that C bindings ([cimgui](https://github.com/cimgui/cimgui)) are auto-generated, you can use its json/lua output to generate bindings for other languages.
 

imgui.cpp

@@ -372,6 +372,7 @@ CODE
  When you are not sure about a old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2020/09/17 (1.79) - removed ImFont::DisplayOffset in favor of ImFontConfig::GlyphOffset. DisplayOffset was applied after scaling and not very meaningful/useful outside of being needed by the default ProggyClean font. It was also getting in the way of better font scaling, so let's get rid of it now!
  - 2020/08/17 (1.78) - obsoleted use of the trailing 'float power=1.0f' parameter for DragFloat(), DragFloat2(), DragFloat3(), DragFloat4(), DragFloatRange2(), DragScalar(), DragScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4(), SliderScalar(), SliderScalarN(), VSliderFloat() and VSliderScalar().
                        replaced the 'float power=1.0f' argument with integer-based flags defaulting to 0 (as with all our flags).
                        worked out a backward-compatibility scheme so hopefully most C++ codebase should not be affected. in short, when calling those functions:

imgui.h

@@ -2406,11 +2406,10 @@ struct ImFont
     float                       FallbackAdvanceX;   // 4     // out // = FallbackGlyph->AdvanceX
     float                       FontSize;           // 4     // in  //            // Height of characters/line, set during loading (don't change after loading)
 
-    // Members: Hot ~36/48 bytes (for CalcTextSize + render loop)
+    // Members: Hot ~28/40 bytes (for CalcTextSize + render loop)
     ImVector<ImWchar>           IndexLookup;        // 12-16 // out //            // Sparse. Index glyphs by Unicode code-point.
     ImVector<ImFontGlyph>       Glyphs;             // 12-16 // out //            // All glyphs.
     const ImFontGlyph*          FallbackGlyph;      // 4-8   // out // = FindGlyph(FontFallbackChar)
-    ImVec2                      DisplayOffset;      // 8     // in  // = (0,0)    // Offset font rendering by xx pixels
 
     // Members: Cold ~32/40 bytes
     ImFontAtlas*                ContainerAtlas;     // 4-8   // out //            // What we has been loaded into

imgui_demo.cpp

@@ -3715,7 +3715,6 @@ static void NodeFont(ImFont* font)
         "You may oversample them to get some flexibility with scaling. "
         "You can also render at multiple sizes and select which one to use at runtime.\n\n"
         "(Glimmer of hope: the atlas system will be rewritten in the future to make scaling more flexible.)");
-    ImGui::InputFloat("Font offset", &font->DisplayOffset.y, 1, 1, "%.0f");
     ImGui::Text("Ascent: %f, Descent: %f, Height: %f", font->Ascent, font->Descent, font->Ascent - font->Descent);
     ImGui::Text("Fallback character: '%c' (U+%04X)", font->FallbackChar, font->FallbackChar);
     ImGui::Text("Ellipsis character: '%c' (U+%04X)", font->EllipsisChar, font->EllipsisChar);
@@ -3724,8 +3723,8 @@ static void NodeFont(ImFont* font)
     for (int config_i = 0; config_i < font->ConfigDataCount; config_i++)
         if (font->ConfigData)
             if (const ImFontConfig* cfg = &font->ConfigData[config_i])
-                ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d",
-                    config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH);
+                ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d, Offset: (%.1f,%.1f)",
+                    config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH, cfg->GlyphOffset.x, cfg->GlyphOffset.y);
     if (ImGui::TreeNode("Glyphs", "Glyphs (%d)", font->Glyphs.Size))
     {
         // Display all glyphs of the fonts in separate pages of 256 characters

imgui_draw.cpp

@@ -1891,11 +1891,11 @@ ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
     if (font_cfg.Name[0] == '\0')
         ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "ProggyClean.ttf, %dpx", (int)font_cfg.SizePixels);
     font_cfg.EllipsisChar = (ImWchar)0x0085;
+    font_cfg.GlyphOffset.y = 1.0f * IM_FLOOR(font_cfg.SizePixels / 13.0f);  // Add +1 offset per 13 units
 
     const char* ttf_compressed_base85 = GetDefaultCompressedFontDataTTFBase85();
     const ImWchar* glyph_ranges = font_cfg.GlyphRanges != NULL ? font_cfg.GlyphRanges : GetGlyphRangesDefault();
     ImFont* font = AddFontFromMemoryCompressedBase85TTF(ttf_compressed_base85, font_cfg.SizePixels, &font_cfg, glyph_ranges);
-    font->DisplayOffset.y = 1.0f;
     return font;
 }
 
@@ -2768,7 +2768,6 @@ ImFont::ImFont()
     FallbackAdvanceX = 0.0f;
     FallbackChar = (ImWchar)'?';
     EllipsisChar = (ImWchar)-1;
-    DisplayOffset = ImVec2(0.0f, 0.0f);
     FallbackGlyph = NULL;
     ContainerAtlas = NULL;
     ConfigData = NULL;
@@ -3163,8 +3162,8 @@ void ImFont::RenderChar(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
     if (!glyph || !glyph->Visible)
         return;
     float scale = (size >= 0.0f) ? (size / FontSize) : 1.0f;
-    pos.x = IM_FLOOR(pos.x + DisplayOffset.x);
-    pos.y = IM_FLOOR(pos.y + DisplayOffset.y);
+    pos.x = IM_FLOOR(pos.x);
+    pos.y = IM_FLOOR(pos.y);
     draw_list->PrimReserve(6, 4);
     draw_list->PrimRectUV(ImVec2(pos.x + glyph->X0 * scale, pos.y + glyph->Y0 * scale), ImVec2(pos.x + glyph->X1 * scale, pos.y + glyph->Y1 * scale), ImVec2(glyph->U0, glyph->V0), ImVec2(glyph->U1, glyph->V1), col);
 }
@@ -3175,8 +3174,8 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
         text_end = text_begin + strlen(text_begin); // ImGui:: functions generally already provides a valid text_end, so this is merely to handle direct calls.
 
     // Align to be pixel perfect
-    pos.x = IM_FLOOR(pos.x + DisplayOffset.x);
-    pos.y = IM_FLOOR(pos.y + DisplayOffset.y);
+    pos.x = IM_FLOOR(pos.x);
+    pos.y = IM_FLOOR(pos.y);
     float x = pos.x;
     float y = pos.y;
     if (y > clip_rect.w)

imgui_widgets.cpp

@@ -3958,7 +3958,6 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         ImFont* password_font = &g.InputTextPasswordFont;
         password_font->FontSize = g.Font->FontSize;
         password_font->Scale = g.Font->Scale;
-        password_font->DisplayOffset = g.Font->DisplayOffset;
         password_font->Ascent = g.Font->Ascent;
         password_font->Descent = g.Font->Descent;
         password_font->ContainerAtlas = g.Font->ContainerAtlas;