ImFontConfig: Added GlyphOffset to explicitely offset glyphs at font build time, useful for merged fonts. May remove MergeGlyphCenterV soon.

imgui.h

@@ -1270,9 +1270,10 @@ struct ImFontConfig
     int             OversampleH, OversampleV;   // 3, 1     // Rasterize at higher quality for sub-pixel positioning. 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
+    ImVec2          GlyphOffset;                // 0, 0     // Offset all glyphs from this font input
     const ImWchar*  GlyphRanges;                //          // Pointer to a user-provided list of Unicode range (2 value per range, values are inclusive, zero-terminated list). THE ARRAY DATA NEEDS TO PERSIST AS LONG AS THE FONT IS ALIVE.
     bool            MergeMode;                  // false    // Merge into previous ImFont, so you can combine multiple inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs).
-    bool            MergeGlyphCenterV;          // false    // When merging (multiple ImFontInput for one ImFont), vertically center new glyphs instead of aligning their baseline
+    bool            MergeGlyphCenterV;          // false    // When merging (multiple ImFontInput for one ImFont), vertically center new glyphs instead of aligning their baseline. Prefer using an explicit GlyphOffset.y setting instead, may obsolete MergeGlyphCenterV.
 
     // [Internal]
     char            Name[32];                               // Name (strictly for debugging)

imgui_draw.cpp

@@ -1043,6 +1043,7 @@ ImFontConfig::ImFontConfig()
     OversampleV = 1;
     PixelSnapH = false;
     GlyphExtraSpacing = ImVec2(0.0f, 0.0f);
+    GlyphOffset = ImVec2(0.0f, 0.0f);
     GlyphRanges = NULL;
     MergeMode = false;
     MergeGlyphCenterV = false;
@@ -1426,7 +1427,8 @@ bool    ImFontAtlas::Build()
             dst_font->MetricsTotalSurface = 0;
         }
         dst_font->ConfigDataCount++;
-        float off_y = (cfg.MergeMode && cfg.MergeGlyphCenterV) ? (ascent - dst_font->Ascent) * 0.5f : 0.0f;
+        float off_x = cfg.GlyphOffset.x, off_y = cfg.GlyphOffset.y;
+        float merge_off_y = (cfg.MergeMode && cfg.MergeGlyphCenterV) ? (ascent - dst_font->Ascent) * 0.5f : 0.0f;
 
         dst_font->FallbackGlyph = NULL; // Always clear fallback so FindGlyph can return NULL. It will be set again in BuildLookupTable()
         for (int i = 0; i < tmp.RangesCount; i++)
@@ -1449,10 +1451,10 @@ bool    ImFontAtlas::Build()
                 dst_font->Glyphs.resize(dst_font->Glyphs.Size + 1);
                 ImFont::Glyph& glyph = dst_font->Glyphs.back();
                 glyph.Codepoint = (ImWchar)codepoint;
-                glyph.X0 = q.x0; glyph.Y0 = q.y0; glyph.X1 = q.x1; glyph.Y1 = q.y1;
+                glyph.X0 = q.x0 + off_x; glyph.Y0 = q.y0 + off_y; glyph.X1 = q.x1 + off_x; glyph.Y1 = q.y1 + off_y;
                 glyph.U0 = q.s0; glyph.V0 = q.t0; glyph.U1 = q.s1; glyph.V1 = q.t1;
-                glyph.Y0 += (float)(int)(dst_font->Ascent + off_y + 0.5f);
-                glyph.Y1 += (float)(int)(dst_font->Ascent + off_y + 0.5f);
+                glyph.Y0 += (float)(int)(dst_font->Ascent + merge_off_y + 0.5f);
+                glyph.Y1 += (float)(int)(dst_font->Ascent + merge_off_y + 0.5f);
                 glyph.XAdvance = (pc.xadvance + cfg.GlyphExtraSpacing.x);  // Bake spacing into XAdvance
                 if (cfg.PixelSnapH)
                     glyph.XAdvance = (float)(int)(glyph.XAdvance + 0.5f);