Internals: added FontScale storage.

Author: ocornut

imgui.cpp

@@ -3505,7 +3505,7 @@ void ImGui::RenderTextEllipsis(ImDrawList* draw_list, const ImVec2& pos_min, con
 
         const ImFont* font = draw_list->_Data->Font;
         const float font_size = draw_list->_Data->FontSize;
-        const float font_scale = font_size / font->FontSize;
+        const float font_scale = draw_list->_Data->FontScale;
         const char* text_end_ellipsis = NULL;
         const float ellipsis_width = font->EllipsisWidth * font_scale;
 
@@ -3903,6 +3903,7 @@ static void SetCurrentWindow(ImGuiWindow* window)
     if (window)
     {
         g.FontSize = g.DrawListSharedData.FontSize = window->CalcFontSize();
+        g.FontScale = g.FontSize / g.Font->FontSize;
         ImGui::NavUpdateCurrentWindowIsScrollPushableX();
     }
 }
@@ -7507,12 +7508,14 @@ void ImGui::SetCurrentFont(ImFont* font)
     g.Font = font;
     g.FontBaseSize = ImMax(1.0f, g.IO.FontGlobalScale * g.Font->FontSize * g.Font->Scale);
     g.FontSize = g.CurrentWindow ? g.CurrentWindow->CalcFontSize() : 0.0f;
+    g.FontScale = g.FontSize / g.FontSize;
 
     ImFontAtlas* atlas = g.Font->ContainerAtlas;
     g.DrawListSharedData.TexUvWhitePixel = atlas->TexUvWhitePixel;
     g.DrawListSharedData.TexUvLines = atlas->TexUvLines;
     g.DrawListSharedData.Font = g.Font;
     g.DrawListSharedData.FontSize = g.FontSize;
+    g.DrawListSharedData.FontScale = g.FontScale;
 }
 
 void ImGui::PushFont(ImFont* font)
@@ -8057,6 +8060,7 @@ void ImGui::SetWindowFontScale(float scale)
     ImGuiWindow* window = GetCurrentWindow();
     window->FontWindowScale = scale;
     g.FontSize = g.DrawListSharedData.FontSize = window->CalcFontSize();
+    g.FontScale = g.DrawListSharedData.FontScale = g.FontSize / g.Font->FontSize;
 }
 
 void ImGui::PushFocusScope(ImGuiID id)

imgui.h

@@ -3203,7 +3203,7 @@ struct ImFont
     float                       EllipsisCharStep;   // 4     // out               // Step between characters when EllipsisCount > 0
     bool                        DirtyLookupTables;  // 1     // out //
     float                       Scale;              // 4     // in  // = 1.f      // Base font scale, multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
-    float                       Ascent, Descent;    // 4+4   // out //            // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize]
+    float                       Ascent, Descent;    // 4+4   // out //            // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled)
     int                         MetricsTotalSurface;// 4     // out //            // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
     ImU8                        Used4kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/4096/8]; // 2 bytes if ImWchar=ImWchar16, 34 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints.
 

imgui_internal.h

@@ -775,6 +775,7 @@ struct IMGUI_API ImDrawListSharedData
     ImVec2          TexUvWhitePixel;            // UV of white pixel in the atlas
     ImFont*         Font;                       // Current/default font (optional, for simplified AddText overload)
     float           FontSize;                   // Current/default font size (optional, for simplified AddText overload)
+    float           FontScale;                  // Current/default font scale (== FontSize / Font->FontSize)
     float           CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo()
     float           CircleSegmentMaxError;      // Number of circle segments to use per pixel of radius for AddCircle() etc
     ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
@@ -1927,6 +1928,7 @@ struct ImGuiContext
     ImFont*                 Font;                               // (Shortcut) == FontStack.empty() ? IO.Font : FontStack.back()
     float                   FontSize;                           // (Shortcut) == FontBaseSize * g.CurrentWindow->FontWindowScale == window->FontSize(). Text height for current window.
     float                   FontBaseSize;                       // (Shortcut) == IO.FontGlobalScale * Font->Scale * Font->FontSize. Base text height.
+    float                   FontScale;                          // == FontSize / Font->FontSize
     float                   CurrentDpiScale;                    // Current window/viewport DpiScale
     ImDrawListSharedData    DrawListSharedData;
     double                  Time;

imgui_tables.cpp

@@ -3269,7 +3269,7 @@ void ImGui::TableAngledHeadersRowEx(ImGuiID row_id, float angle, float max_label
     ButtonBehavior(row_r, row_id, NULL, NULL);
     KeepAliveID(row_id);
 
-    const float ascent_scaled = g.Font->Ascent * (g.FontSize / g.Font->FontSize); // FIXME: Standardize those scaling factors better
+    const float ascent_scaled = g.Font->Ascent * g.FontScale; // FIXME: Standardize those scaling factors better
     const float line_off_for_ascent_x = (ImMax((g.FontSize - ascent_scaled) * 0.5f, 0.0f) / -sin_a) * (flip_label ? -1.0f : 1.0f);
     const ImVec2 padding = g.Style.CellPadding; // We will always use swapped component
     const ImVec2 align = g.Style.TableAngledHeadersTextAlign;

imgui_widgets.cpp

@@ -3778,7 +3778,7 @@ namespace ImStb
 
 static int     STB_TEXTEDIT_STRINGLEN(const ImGuiInputTextState* obj)                             { return obj->CurLenW; }
 static ImWchar STB_TEXTEDIT_GETCHAR(const ImGuiInputTextState* obj, int idx)                      { IM_ASSERT(idx <= obj->CurLenW); return obj->TextW[idx]; }
-static float   STB_TEXTEDIT_GETWIDTH(ImGuiInputTextState* obj, int line_start_idx, int char_idx)  { ImWchar c = obj->TextW[line_start_idx + char_idx]; if (c == '\n') return IMSTB_TEXTEDIT_GETWIDTH_NEWLINE; ImGuiContext& g = *obj->Ctx; return g.Font->GetCharAdvance(c) * (g.FontSize / g.Font->FontSize); }
+static float   STB_TEXTEDIT_GETWIDTH(ImGuiInputTextState* obj, int line_start_idx, int char_idx)  { ImWchar c = obj->TextW[line_start_idx + char_idx]; if (c == '\n') return IMSTB_TEXTEDIT_GETWIDTH_NEWLINE; ImGuiContext& g = *obj->Ctx; return g.Font->GetCharAdvance(c) * g.FontScale; }
 static int     STB_TEXTEDIT_KEYTOTEXT(int key)                                                    { return key >= 0x200000 ? 0 : key; }
 static ImWchar STB_TEXTEDIT_NEWLINE = '\n';
 static void    STB_TEXTEDIT_LAYOUTROW(StbTexteditRow* r, ImGuiInputTextState* obj, int line_start_idx)