Update ImGui to 1.78 + docking.

1 files changed, 237 insertions, 103 deletions

diff --git a/imgui/imgui_draw.cpp b/imgui/imgui_draw.cpp
index 7fd5e2f4..ceb9079d 100644
--- a/imgui/imgui_draw.cpp
+++ b/imgui/imgui_draw.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.77
+// dear imgui, v1.78
 // (drawing and font code)
 
 /*
@@ -364,6 +364,7 @@ ImDrawListSharedData::ImDrawListSharedData()
         ArcFastVtx[i] = ImVec2(ImCos(a), ImSin(a));
     }
     memset(CircleSegmentCounts, 0, sizeof(CircleSegmentCounts)); // This will be set by SetCircleSegmentMaxError()
+    TexUvLines = NULL;
 }
 
 void ImDrawListSharedData::SetCircleSegmentMaxError(float max_error)
@@ -522,7 +523,7 @@ void ImDrawList::_OnChangedVtxOffset()
     // We don't need to compare curr_cmd->VtxOffset != _CmdHeader.VtxOffset because we know it'll be different at the time we call this.
     _VtxCurrentIdx = 0;
     ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1];
-    IM_ASSERT(curr_cmd->VtxOffset != _CmdHeader.VtxOffset);
+    //IM_ASSERT(curr_cmd->VtxOffset != _CmdHeader.VtxOffset); // See #3349
     if (curr_cmd->ElemCount != 0)
     {
         AddDrawCmd();
@@ -587,6 +588,9 @@ void ImDrawList::PrimReserve(int idx_count, int vtx_count)
     IM_ASSERT_PARANOID(idx_count >= 0 && vtx_count >= 0);
     if (sizeof(ImDrawIdx) == 2 && (_VtxCurrentIdx + vtx_count >= (1 << 16)) && (Flags & ImDrawListFlags_AllowVtxOffset))
     {
+        // FIXME: In theory we should be testing that vtx_count <64k here.
+        // In practice, RenderText() relies on reserving ahead for a worst case scenario so it is currently useful for us
+        // to not make that check until we rework the text functions to handle clipping and large horizontal lines better.
         _CmdHeader.VtxOffset = VtxBuffer.Size;
         _OnChangedVtxOffset();
     }
@@ -672,25 +676,38 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
         return;
 
     const ImVec2 opaque_uv = _Data->TexUvWhitePixel;
-    int count = points_count;
-    if (!closed)
-        count = points_count - 1;
-
+    const int count = closed ? points_count : points_count - 1; // The number of line segments we need to draw
     const bool thick_line = (thickness > 1.0f);
+
     if (Flags & ImDrawListFlags_AntiAliasedLines)
     {
         // Anti-aliased stroke
         const float AA_SIZE = 1.0f;
         const ImU32 col_trans = col & ~IM_COL32_A_MASK;
 
-        const int idx_count = thick_line ? count * 18 : count * 12;
-        const int vtx_count = thick_line ? points_count * 4 : points_count * 3;
+        // Thicknesses <1.0 should behave like thickness 1.0
+        thickness = ImMax(thickness, 1.0f);
+        const int integer_thickness = (int)thickness;
+        const float fractional_thickness = thickness - integer_thickness;
+
+        // Do we want to draw this line using a texture?
+        // - For now, only draw integer-width lines using textures to avoid issues with the way scaling occurs, could be improved.
+        // - If AA_SIZE is not 1.0f we cannot use the texture path.
+        const bool use_texture = (Flags & ImDrawListFlags_AntiAliasedLinesUseTex) && (integer_thickness < IM_DRAWLIST_TEX_LINES_WIDTH_MAX) && (fractional_thickness <= 0.00001f);
+
+        // We should never hit this, because NewFrame() doesn't set ImDrawListFlags_AntiAliasedLinesUseTex unless ImFontAtlasFlags_NoBakedLines is off
+        IM_ASSERT_PARANOID(!use_texture || !(_Data->Font->ContainerAtlas->Flags & ImFontAtlasFlags_NoBakedLines));
+
+        const int idx_count = use_texture ? (count * 6) : (thick_line ? count * 18 : count * 12);
+        const int vtx_count = use_texture ? (points_count * 2) : (thick_line ? points_count * 4 : points_count * 3);
         PrimReserve(idx_count, vtx_count);
 
         // Temporary buffer
-        ImVec2* temp_normals = (ImVec2*)alloca(points_count * (thick_line ? 5 : 3) * sizeof(ImVec2)); //-V630
+        // The first <points_count> items are normals at each line point, then after that there are either 2 or 4 temp points for each line point
+        ImVec2* temp_normals = (ImVec2*)alloca(points_count * ((use_texture || !thick_line) ? 3 : 5) * sizeof(ImVec2)); //-V630
         ImVec2* temp_points = temp_normals + points_count;
 
+        // Calculate normals (tangents) for each line segment
         for (int i1 = 0; i1 < count; i1++)
         {
             const int i2 = (i1 + 1) == points_count ? 0 : i1 + 1;
@@ -703,59 +720,111 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
         if (!closed)
             temp_normals[points_count - 1] = temp_normals[points_count - 2];
 
-        if (!thick_line)
+        // If we are drawing a one-pixel-wide line without a texture, or a textured line of any width, we only need 2 or 3 vertices per point
+        if (use_texture || !thick_line)
         {
+            // [PATH 1] Texture-based lines (thick or non-thick)
+            // [PATH 2] Non texture-based lines (non-thick)
+
+            // The width of the geometry we need to draw - this is essentially <thickness> pixels for the line itself, plus "one pixel" for AA.
+            // - In the texture-based path, we don't use AA_SIZE here because the +1 is tied to the generated texture
+            //   (see ImFontAtlasBuildRenderLinesTexData() function), and so alternate values won't work without changes to that code.
+            // - In the non texture-based paths, we would allow AA_SIZE to potentially be != 1.0f with a patch (e.g. fringe_scale patch to
+            //   allow scaling geometry while preserving one-screen-pixel AA fringe).
+            const float half_draw_size = use_texture ? ((thickness * 0.5f) + 1) : AA_SIZE;
+
+            // If line is not closed, the first and last points need to be generated differently as there are no normals to blend
             if (!closed)
             {
-                temp_points[0] = points[0] + temp_normals[0] * AA_SIZE;
-                temp_points[1] = points[0] - temp_normals[0] * AA_SIZE;
-                temp_points[(points_count-1)*2+0] = points[points_count-1] + temp_normals[points_count-1] * AA_SIZE;
-                temp_points[(points_count-1)*2+1] = points[points_count-1] - temp_normals[points_count-1] * AA_SIZE;
+                temp_points[0] = points[0] + temp_normals[0] * half_draw_size;
+                temp_points[1] = points[0] - temp_normals[0] * half_draw_size;
+                temp_points[(points_count-1)*2+0] = points[points_count-1] + temp_normals[points_count-1] * half_draw_size;
+                temp_points[(points_count-1)*2+1] = points[points_count-1] - temp_normals[points_count-1] * half_draw_size;
             }
 
+            // Generate the indices to form a number of triangles for each line segment, and the vertices for the line edges
+            // This takes points n and n+1 and writes into n+1, with the first point in a closed line being generated from the final one (as n+1 wraps)
             // FIXME-OPT: Merge the different loops, possibly remove the temporary buffer.
-            unsigned int idx1 = _VtxCurrentIdx;
-            for (int i1 = 0; i1 < count; i1++)
+            unsigned int idx1 = _VtxCurrentIdx; // Vertex index for start of line segment
+            for (int i1 = 0; i1 < count; i1++) // i1 is the first point of the line segment
             {
-                const int i2 = (i1 + 1) == points_count ? 0 : i1 + 1;
-                unsigned int idx2 = (i1 + 1) == points_count ? _VtxCurrentIdx : idx1 + 3;
+                const int i2 = (i1 + 1) == points_count ? 0 : i1 + 1; // i2 is the second point of the line segment
+                const unsigned int idx2 = ((i1 + 1) == points_count) ? _VtxCurrentIdx : (idx1 + (use_texture ? 2 : 3)); // Vertex index for end of segment
 
                 // Average normals
                 float dm_x = (temp_normals[i1].x + temp_normals[i2].x) * 0.5f;
                 float dm_y = (temp_normals[i1].y + temp_normals[i2].y) * 0.5f;
                 IM_FIXNORMAL2F(dm_x, dm_y);
-                dm_x *= AA_SIZE;
-                dm_y *= AA_SIZE;
+                dm_x *= half_draw_size; // dm_x, dm_y are offset to the outer edge of the AA area
+                dm_y *= half_draw_size;
 
-                // Add temporary vertices
+                // Add temporary vertexes for the outer edges
                 ImVec2* out_vtx = &temp_points[i2 * 2];
                 out_vtx[0].x = points[i2].x + dm_x;
                 out_vtx[0].y = points[i2].y + dm_y;
                 out_vtx[1].x = points[i2].x - dm_x;
                 out_vtx[1].y = points[i2].y - dm_y;
 
-                // Add indexes
-                _IdxWritePtr[0] = (ImDrawIdx)(idx2+0); _IdxWritePtr[1] = (ImDrawIdx)(idx1+0); _IdxWritePtr[2] = (ImDrawIdx)(idx1+2);
-                _IdxWritePtr[3] = (ImDrawIdx)(idx1+2); _IdxWritePtr[4] = (ImDrawIdx)(idx2+2); _IdxWritePtr[5] = (ImDrawIdx)(idx2+0);
-                _IdxWritePtr[6] = (ImDrawIdx)(idx2+1); _IdxWritePtr[7] = (ImDrawIdx)(idx1+1); _IdxWritePtr[8] = (ImDrawIdx)(idx1+0);
-                _IdxWritePtr[9] = (ImDrawIdx)(idx1+0); _IdxWritePtr[10]= (ImDrawIdx)(idx2+0); _IdxWritePtr[11]= (ImDrawIdx)(idx2+1);
-                _IdxWritePtr += 12;
+                if (use_texture)
+                {
+                    // Add indices for two triangles
+                    _IdxWritePtr[0] = (ImDrawIdx)(idx2 + 0); _IdxWritePtr[1] = (ImDrawIdx)(idx1 + 0); _IdxWritePtr[2] = (ImDrawIdx)(idx1 + 1); // Right tri
+                    _IdxWritePtr[3] = (ImDrawIdx)(idx2 + 1); _IdxWritePtr[4] = (ImDrawIdx)(idx1 + 1); _IdxWritePtr[5] = (ImDrawIdx)(idx2 + 0); // Left tri
+                    _IdxWritePtr += 6;
+                }
+                else
+                {
+                    // Add indexes for four triangles
+                    _IdxWritePtr[0] = (ImDrawIdx)(idx2 + 0); _IdxWritePtr[1] = (ImDrawIdx)(idx1 + 0); _IdxWritePtr[2] = (ImDrawIdx)(idx1 + 2); // Right tri 1
+                    _IdxWritePtr[3] = (ImDrawIdx)(idx1 + 2); _IdxWritePtr[4] = (ImDrawIdx)(idx2 + 2); _IdxWritePtr[5] = (ImDrawIdx)(idx2 + 0); // Right tri 2
+                    _IdxWritePtr[6] = (ImDrawIdx)(idx2 + 1); _IdxWritePtr[7] = (ImDrawIdx)(idx1 + 1); _IdxWritePtr[8] = (ImDrawIdx)(idx1 + 0); // Left tri 1
+                    _IdxWritePtr[9] = (ImDrawIdx)(idx1 + 0); _IdxWritePtr[10] = (ImDrawIdx)(idx2 + 0); _IdxWritePtr[11] = (ImDrawIdx)(idx2 + 1); // Left tri 2
+                    _IdxWritePtr += 12;
+                }
 
                 idx1 = idx2;
             }
 
-            // Add vertices
-            for (int i = 0; i < points_count; i++)
+            // Add vertexes for each point on the line
+            if (use_texture)
             {
-                _VtxWritePtr[0].pos = points[i];          _VtxWritePtr[0].uv = opaque_uv; _VtxWritePtr[0].col = col;
-                _VtxWritePtr[1].pos = temp_points[i*2+0]; _VtxWritePtr[1].uv = opaque_uv; _VtxWritePtr[1].col = col_trans;
-                _VtxWritePtr[2].pos = temp_points[i*2+1]; _VtxWritePtr[2].uv = opaque_uv; _VtxWritePtr[2].col = col_trans;
-                _VtxWritePtr += 3;
+                // If we're using textures we only need to emit the left/right edge vertices
+                ImVec4 tex_uvs = _Data->TexUvLines[integer_thickness];
+                if (fractional_thickness != 0.0f)
+                {
+                    const ImVec4 tex_uvs_1 = _Data->TexUvLines[integer_thickness + 1];
+                    tex_uvs.x = tex_uvs.x + (tex_uvs_1.x - tex_uvs.x) * fractional_thickness; // inlined ImLerp()
+                    tex_uvs.y = tex_uvs.y + (tex_uvs_1.y - tex_uvs.y) * fractional_thickness;
+                    tex_uvs.z = tex_uvs.z + (tex_uvs_1.z - tex_uvs.z) * fractional_thickness;
+                    tex_uvs.w = tex_uvs.w + (tex_uvs_1.w - tex_uvs.w) * fractional_thickness;
+                }
+                ImVec2 tex_uv0(tex_uvs.x, tex_uvs.y);
+                ImVec2 tex_uv1(tex_uvs.z, tex_uvs.w);
+                for (int i = 0; i < points_count; i++)
+                {
+                    _VtxWritePtr[0].pos = temp_points[i * 2 + 0]; _VtxWritePtr[0].uv = tex_uv0; _VtxWritePtr[0].col = col; // Left-side outer edge
+                    _VtxWritePtr[1].pos = temp_points[i * 2 + 1]; _VtxWritePtr[1].uv = tex_uv1; _VtxWritePtr[1].col = col; // Right-side outer edge
+                    _VtxWritePtr += 2;
+                }
+            }
+            else
+            {
+                // If we're not using a texture, we need the center vertex as well
+                for (int i = 0; i < points_count; i++)
+                {
+                    _VtxWritePtr[0].pos = points[i];              _VtxWritePtr[0].uv = opaque_uv; _VtxWritePtr[0].col = col;       // Center of line
+                    _VtxWritePtr[1].pos = temp_points[i * 2 + 0]; _VtxWritePtr[1].uv = opaque_uv; _VtxWritePtr[1].col = col_trans; // Left-side outer edge
+                    _VtxWritePtr[2].pos = temp_points[i * 2 + 1]; _VtxWritePtr[2].uv = opaque_uv; _VtxWritePtr[2].col = col_trans; // Right-side outer edge
+                    _VtxWritePtr += 3;
+                }
             }
         }
         else
         {
+            // [PATH 2] Non texture-based lines (thick): we need to draw the solid line core and thus require four vertices per point
             const float half_inner_thickness = (thickness - AA_SIZE) * 0.5f;
+
+            // If line is not closed, the first and last points need to be generated differently as there are no normals to blend
             if (!closed)
             {
                 const int points_last = points_count - 1;
@@ -769,9 +838,11 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
                 temp_points[points_last * 4 + 3] = points[points_last] - temp_normals[points_last] * (half_inner_thickness + AA_SIZE);
             }
 
+            // Generate the indices to form a number of triangles for each line segment, and the vertices for the line edges
+            // This takes points n and n+1 and writes into n+1, with the first point in a closed line being generated from the final one (as n+1 wraps)
             // FIXME-OPT: Merge the different loops, possibly remove the temporary buffer.
-            unsigned int idx1 = _VtxCurrentIdx;
-            for (int i1 = 0; i1 < count; i1++)
+            unsigned int idx1 = _VtxCurrentIdx; // Vertex index for start of line segment
+            for (int i1 = 0; i1 < count; i1++) // i1 is the first point of the line segment
             {
                 const int i2 = (i1 + 1) == points_count ? 0 : (i1 + 1); // i2 is the second point of the line segment
                 const unsigned int idx2 = (i1 + 1) == points_count ? _VtxCurrentIdx : (idx1 + 4); // Vertex index for end of segment
@@ -822,7 +893,7 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
     }
     else
     {
-        // Non Anti-aliased Stroke
+        // [PATH 4] Non texture-based, Non anti-aliased lines
         const int idx_count = count * 6;
         const int vtx_count = count * 4;    // FIXME-OPT: Not sharing edges
         PrimReserve(idx_count, vtx_count);
@@ -1176,7 +1247,7 @@ void ImDrawList::AddCircle(const ImVec2& center, float radius, ImU32 col, int nu
     // Because we are filling a closed shape we remove 1 from the count of segments/points
     const float a_max = (IM_PI * 2.0f) * ((float)num_segments - 1.0f) / (float)num_segments;
     if (num_segments == 12)
-        PathArcToFast(center, radius - 0.5f, 0, 12);
+        PathArcToFast(center, radius - 0.5f, 0, 12 - 1);
     else
         PathArcTo(center, radius - 0.5f, 0.0f, a_max, num_segments - 1);
     PathStroke(col, true, thickness);
@@ -1206,7 +1277,7 @@ void ImDrawList::AddCircleFilled(const ImVec2& center, float radius, ImU32 col,
     // Because we are filling a closed shape we remove 1 from the count of segments/points
     const float a_max = (IM_PI * 2.0f) * ((float)num_segments - 1.0f) / (float)num_segments;
     if (num_segments == 12)
-        PathArcToFast(center, radius, 0, 12);
+        PathArcToFast(center, radius, 0, 12 - 1);
     else
         PathArcTo(center, radius, 0.0f, a_max, num_segments - 1);
     PathFillConvex(col);
@@ -1602,10 +1673,10 @@ ImFontConfig::ImFontConfig()
 //-----------------------------------------------------------------------------
 
 // A work of art lies ahead! (. = white layer, X = black layer, others are blank)
-// The white texels on the top left are the ones we'll use everywhere in Dear ImGui to render filled shapes.
-const int FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF = 108;
-const int FONT_ATLAS_DEFAULT_TEX_DATA_H      = 27;
-static const char FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF * FONT_ATLAS_DEFAULT_TEX_DATA_H + 1] =
+// The 2x2 white texels on the top left are the ones we'll use everywhere in Dear ImGui to render filled shapes.
+const int FONT_ATLAS_DEFAULT_TEX_DATA_W = 108; // Actual texture will be 2 times that + 1 spacing.
+const int FONT_ATLAS_DEFAULT_TEX_DATA_H = 27;
+static const char FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[FONT_ATLAS_DEFAULT_TEX_DATA_W * FONT_ATLAS_DEFAULT_TEX_DATA_H + 1] =
 {
     "..-         -XXXXXXX-    X    -           X           -XXXXXXX          -          XXXXXXX-     XX          "
     "..-         -X.....X-   X.X   -          X.X          -X.....X          -          X.....X-    X..X         "
@@ -1662,8 +1733,7 @@ ImFontAtlas::ImFontAtlas()
     TexWidth = TexHeight = 0;
     TexUvScale = ImVec2(0.0f, 0.0f);
     TexUvWhitePixel = ImVec2(0.0f, 0.0f);
-    for (int n = 0; n < IM_ARRAYSIZE(CustomRectIds); n++)
-        CustomRectIds[n] = -1;
+    PackIdMouseCursors = PackIdLines = -1;
 }
 
 ImFontAtlas::~ImFontAtlas()
@@ -1691,8 +1761,7 @@ void    ImFontAtlas::ClearInputData()
         }
     ConfigData.clear();
     CustomRects.clear();
-    for (int n = 0; n < IM_ARRAYSIZE(CustomRectIds); n++)
-        CustomRectIds[n] = -1;
+    PackIdMouseCursors = PackIdLines = -1;
 }
 
 void    ImFontAtlas::ClearTexData()
@@ -1932,15 +2001,15 @@ bool ImFontAtlas::GetMouseCursorTexData(ImGuiMouseCursor cursor_type, ImVec2* ou
     if (Flags & ImFontAtlasFlags_NoMouseCursors)
         return false;
 
-    IM_ASSERT(CustomRectIds[0] != -1);
-    ImFontAtlasCustomRect& r = CustomRects[CustomRectIds[0]];
-    ImVec2 pos = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][0] + ImVec2((float)r.X, (float)r.Y);
+    IM_ASSERT(PackIdMouseCursors != -1);
+    ImFontAtlasCustomRect* r = GetCustomRectByIndex(PackIdMouseCursors);
+    ImVec2 pos = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][0] + ImVec2((float)r->X, (float)r->Y);
     ImVec2 size = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][1];
     *out_size = size;
     *out_offset = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][2];
     out_uv_border[0] = (pos) * TexUvScale;
     out_uv_border[1] = (pos + size) * TexUvScale;
-    pos.x += FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF + 1;
+    pos.x += FONT_ATLAS_DEFAULT_TEX_DATA_W + 1;
     out_uv_fill[0] = (pos) * TexUvScale;
     out_uv_fill[1] = (pos + size) * TexUvScale;
     return true;
@@ -2222,8 +2291,11 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         if (src_tmp.GlyphsCount == 0)
             continue;
 
+        // When merging fonts with MergeMode=true:
+        // - We can have multiple input fonts writing into a same destination font.
+        // - dst_font->ConfigData is != from cfg which is our source configuration.
         ImFontConfig& cfg = atlas->ConfigData[src_i];
-        ImFont* dst_font = cfg.DstFont; // We can have multiple input fonts writing into a same destination font (when using MergeMode=true)
+        ImFont* dst_font = cfg.DstFont;
 
         const float font_scale = stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels);
         int unscaled_ascent, unscaled_descent, unscaled_line_gap;
@@ -2237,20 +2309,13 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
         {
+            // Register glyph
             const int codepoint = src_tmp.GlyphsList[glyph_i];
             const stbtt_packedchar& pc = src_tmp.PackedChars[glyph_i];
-
-            const float char_advance_x_org = pc.xadvance;
-            const float char_advance_x_mod = ImClamp(char_advance_x_org, cfg.GlyphMinAdvanceX, cfg.GlyphMaxAdvanceX);
-            float char_off_x = font_off_x;
-            if (char_advance_x_org != char_advance_x_mod)
-                char_off_x += cfg.PixelSnapH ? ImFloor((char_advance_x_mod - char_advance_x_org) * 0.5f) : (char_advance_x_mod - char_advance_x_org) * 0.5f;
-
-            // Register glyph
             stbtt_aligned_quad q;
-            float dummy_x = 0.0f, dummy_y = 0.0f;
-            stbtt_GetPackedQuad(src_tmp.PackedChars, atlas->TexWidth, atlas->TexHeight, glyph_i, &dummy_x, &dummy_y, &q, 0);
-            dst_font->AddGlyph((ImWchar)codepoint, q.x0 + char_off_x, q.y0 + font_off_y, q.x1 + char_off_x, q.y1 + font_off_y, q.s0, q.t0, q.s1, q.t1, char_advance_x_mod);
+            float unused_x = 0.0f, unused_y = 0.0f;
+            stbtt_GetPackedQuad(src_tmp.PackedChars, atlas->TexWidth, atlas->TexHeight, glyph_i, &unused_x, &unused_y, &q, 0);
+            dst_font->AddGlyph(&cfg, (ImWchar)codepoint, q.x0 + font_off_x, q.y0 + font_off_y, q.x1 + font_off_x, q.y1 + font_off_y, q.s0, q.t0, q.s1, q.t1, pc.xadvance);
         }
     }
 
@@ -2262,17 +2327,6 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
     return true;
 }
 
-// Register default custom rectangles (this is called/shared by both the stb_truetype and the FreeType builder)
-void ImFontAtlasBuildInit(ImFontAtlas* atlas)
-{
-    if (atlas->CustomRectIds[0] >= 0)
-        return;
-    if (!(atlas->Flags & ImFontAtlasFlags_NoMouseCursors))
-        atlas->CustomRectIds[0] = atlas->AddCustomRectRegular(FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF * 2 + 1, FONT_ATLAS_DEFAULT_TEX_DATA_H);
-    else
-        atlas->CustomRectIds[0] = atlas->AddCustomRectRegular(2, 2);
-}
-
 void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* font_config, float ascent, float descent)
 {
     if (!font_config->MergeMode)
@@ -2280,6 +2334,7 @@ void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* f
         font->ClearOutputData();
         font->FontSize = font_config->SizePixels;
         font->ConfigData = font_config;
+        font->ConfigDataCount = 0;
         font->ContainerAtlas = atlas;
         font->Ascent = ascent;
         font->Descent = descent;
@@ -2314,52 +2369,113 @@ void ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opa
         }
 }
 
+void ImFontAtlasBuildRender1bppRectFromString(ImFontAtlas* atlas, int x, int y, int w, int h, const char* in_str, char in_marker_char, unsigned char in_marker_pixel_value)
+{
+    IM_ASSERT(x >= 0 && x + w <= atlas->TexWidth);
+    IM_ASSERT(y >= 0 && y + h <= atlas->TexHeight);
+    unsigned char* out_pixel = atlas->TexPixelsAlpha8 + x + (y * atlas->TexWidth);
+    for (int off_y = 0; off_y < h; off_y++, out_pixel += atlas->TexWidth, in_str += w)
+        for (int off_x = 0; off_x < w; off_x++)
+            out_pixel[off_x] = (in_str[off_x] == in_marker_char) ? in_marker_pixel_value : 0x00;
+}
+
 static void ImFontAtlasBuildRenderDefaultTexData(ImFontAtlas* atlas)
 {
-    IM_ASSERT(atlas->CustomRectIds[0] >= 0);
-    IM_ASSERT(atlas->TexPixelsAlpha8 != NULL);
-    ImFontAtlasCustomRect& r = atlas->CustomRects[atlas->CustomRectIds[0]];
-    IM_ASSERT(r.IsPacked());
+    ImFontAtlasCustomRect* r = atlas->GetCustomRectByIndex(atlas->PackIdMouseCursors);
+    IM_ASSERT(r->IsPacked());
 
     const int w = atlas->TexWidth;
     if (!(atlas->Flags & ImFontAtlasFlags_NoMouseCursors))
     {
         // Render/copy pixels
-        IM_ASSERT(r.Width == FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF * 2 + 1 && r.Height == FONT_ATLAS_DEFAULT_TEX_DATA_H);
-        for (int y = 0, n = 0; y < FONT_ATLAS_DEFAULT_TEX_DATA_H; y++)
-            for (int x = 0; x < FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF; x++, n++)
-            {
-                const int offset0 = (int)(r.X + x) + (int)(r.Y + y) * w;
-                const int offset1 = offset0 + FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF + 1;
-                atlas->TexPixelsAlpha8[offset0] = FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[n] == '.' ? 0xFF : 0x00;
-                atlas->TexPixelsAlpha8[offset1] = FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[n] == 'X' ? 0xFF : 0x00;
-            }
+        IM_ASSERT(r->Width == FONT_ATLAS_DEFAULT_TEX_DATA_W * 2 + 1 && r->Height == FONT_ATLAS_DEFAULT_TEX_DATA_H);
+        const int x_for_white = r->X;
+        const int x_for_black = r->X + FONT_ATLAS_DEFAULT_TEX_DATA_W + 1;
+        ImFontAtlasBuildRender1bppRectFromString(atlas, x_for_white, r->Y, FONT_ATLAS_DEFAULT_TEX_DATA_W, FONT_ATLAS_DEFAULT_TEX_DATA_H, FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS, '.', 0xFF);
+        ImFontAtlasBuildRender1bppRectFromString(atlas, x_for_black, r->Y, FONT_ATLAS_DEFAULT_TEX_DATA_W, FONT_ATLAS_DEFAULT_TEX_DATA_H, FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS, 'X', 0xFF);
     }
     else
     {
-        IM_ASSERT(r.Width == 2 && r.Height == 2);
-        const int offset = (int)(r.X) + (int)(r.Y) * w;
+        // Render 4 white pixels
+        IM_ASSERT(r->Width == 2 && r->Height == 2);
+        const int offset = (int)r->X + (int)r->Y * w;
         atlas->TexPixelsAlpha8[offset] = atlas->TexPixelsAlpha8[offset + 1] = atlas->TexPixelsAlpha8[offset + w] = atlas->TexPixelsAlpha8[offset + w + 1] = 0xFF;
     }
-    atlas->TexUvWhitePixel = ImVec2((r.X + 0.5f) * atlas->TexUvScale.x, (r.Y + 0.5f) * atlas->TexUvScale.y);
+    atlas->TexUvWhitePixel = ImVec2((r->X + 0.5f) * atlas->TexUvScale.x, (r->Y + 0.5f) * atlas->TexUvScale.y);
+}
+
+static void ImFontAtlasBuildRenderLinesTexData(ImFontAtlas* atlas)
+{
+    if (atlas->Flags & ImFontAtlasFlags_NoBakedLines)
+        return;
+
+    // This generates a triangular shape in the texture, with the various line widths stacked on top of each other to allow interpolation between them
+    ImFontAtlasCustomRect* r = atlas->GetCustomRectByIndex(atlas->PackIdLines);
+    IM_ASSERT(r->IsPacked());
+    for (unsigned int n = 0; n < IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 1; n++) // +1 because of the zero-width row
+    {
+        // Each line consists of at least two empty pixels at the ends, with a line of solid pixels in the middle
+        unsigned int y = n;
+        unsigned int line_width = n;
+        unsigned int pad_left = (r->Width - line_width) / 2;
+        unsigned int pad_right = r->Width - (pad_left + line_width);
+
+        // Write each slice
+        IM_ASSERT(pad_left + line_width + pad_right == r->Width && y < r->Height); // Make sure we're inside the texture bounds before we start writing pixels
+        unsigned char* write_ptr = &atlas->TexPixelsAlpha8[r->X + ((r->Y + y) * atlas->TexWidth)];
+        memset(write_ptr, 0x00, pad_left);
+        memset(write_ptr + pad_left, 0xFF, line_width);
+        memset(write_ptr + pad_left + line_width, 0x00, pad_right);
+
+        // Calculate UVs for this line
+        ImVec2 uv0 = ImVec2((float)(r->X + pad_left - 1), (float)(r->Y + y)) * atlas->TexUvScale;
+        ImVec2 uv1 = ImVec2((float)(r->X + pad_left + line_width + 1), (float)(r->Y + y + 1)) * atlas->TexUvScale;
+        float half_v = (uv0.y + uv1.y) * 0.5f; // Calculate a constant V in the middle of the row to avoid sampling artifacts
+        atlas->TexUvLines[n] = ImVec4(uv0.x, half_v, uv1.x, half_v);
+    }
 }
 
+// Note: this is called / shared by both the stb_truetype and the FreeType builder
+void ImFontAtlasBuildInit(ImFontAtlas* atlas)
+{
+    // Register texture region for mouse cursors or standard white pixels
+    if (atlas->PackIdMouseCursors < 0)
+    {
+        if (!(atlas->Flags & ImFontAtlasFlags_NoMouseCursors))
+            atlas->PackIdMouseCursors = atlas->AddCustomRectRegular(FONT_ATLAS_DEFAULT_TEX_DATA_W * 2 + 1, FONT_ATLAS_DEFAULT_TEX_DATA_H);
+        else
+            atlas->PackIdMouseCursors = atlas->AddCustomRectRegular(2, 2);
+    }
+
+    // Register texture region for thick lines
+    // The +2 here is to give space for the end caps, whilst height +1 is to accommodate the fact we have a zero-width row
+    if (atlas->PackIdLines < 0)
+    {
+        if (!(atlas->Flags & ImFontAtlasFlags_NoBakedLines))
+            atlas->PackIdLines = atlas->AddCustomRectRegular(IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 2, IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 1);
+    }
+}
+
+// This is called/shared by both the stb_truetype and the FreeType builder.
 void ImFontAtlasBuildFinish(ImFontAtlas* atlas)
 {
-    // Render into our custom data block
+    // Render into our custom data blocks
+    IM_ASSERT(atlas->TexPixelsAlpha8 != NULL);
     ImFontAtlasBuildRenderDefaultTexData(atlas);
+    ImFontAtlasBuildRenderLinesTexData(atlas);
 
     // Register custom rectangle glyphs
     for (int i = 0; i < atlas->CustomRects.Size; i++)
     {
-        const ImFontAtlasCustomRect& r = atlas->CustomRects[i];
-        if (r.Font == NULL || r.GlyphID == 0)
+        const ImFontAtlasCustomRect* r = &atlas->CustomRects[i];
+        if (r->Font == NULL || r->GlyphID == 0)
             continue;
 
-        IM_ASSERT(r.Font->ContainerAtlas == atlas);
+        // Will ignore ImFontConfig settings: GlyphMinAdvanceX, GlyphMinAdvanceY, GlyphExtraSpacing, PixelSnapH
+        IM_ASSERT(r->Font->ContainerAtlas == atlas);
         ImVec2 uv0, uv1;
-        atlas->CalcCustomRectUV(&r, &uv0, &uv1);
-        r.Font->AddGlyph((ImWchar)r.GlyphID, r.GlyphOffset.x, r.GlyphOffset.y, r.GlyphOffset.x + r.Width, r.GlyphOffset.y + r.Height, uv0.x, uv0.y, uv1.x, uv1.y, r.GlyphAdvanceX);
+        atlas->CalcCustomRectUV(r, &uv0, &uv1);
+        r->Font->AddGlyph(NULL, (ImWchar)r->GlyphID, r->GlyphOffset.x, r->GlyphOffset.y, r->GlyphOffset.x + r->Width, r->GlyphOffset.y + r->Height, uv0.x, uv0.y, uv1.x, uv1.y, r->GlyphAdvanceX);
     }
 
     // Build all fonts lookup tables
@@ -2769,8 +2885,29 @@ void ImFont::GrowIndex(int new_size)
 
 // x0/y0/x1/y1 are offset from the character upper-left layout position, in pixels. Therefore x0/y0 are often fairly close to zero.
 // Not to be mistaken with texture coordinates, which are held by u0/v0/u1/v1 in normalized format (0.0..1.0 on each texture axis).
-void ImFont::AddGlyph(ImWchar codepoint, float x0, float y0, float x1, float y1, float u0, float v0, float u1, float v1, float advance_x)
+// 'cfg' is not necessarily == 'this->ConfigData' because multiple source fonts+configs can be used to build one target font.
+void ImFont::AddGlyph(ImFontConfig* cfg, ImWchar codepoint, float x0, float y0, float x1, float y1, float u0, float v0, float u1, float v1, float advance_x)
 {
+    if (cfg != NULL)
+    {
+        // Clamp & recenter if needed
+        const float advance_x_original = advance_x;
+        advance_x = ImClamp(advance_x, cfg->GlyphMinAdvanceX, cfg->GlyphMaxAdvanceX);
+        if (advance_x != advance_x_original)
+        {
+            float char_off_x = cfg->PixelSnapH ? ImFloor((advance_x - advance_x_original) * 0.5f) : (advance_x - advance_x_original) * 0.5f;
+            x0 += char_off_x;
+            x1 += char_off_x;
+        }
+
+        // Snap to pixel
+        if (cfg->PixelSnapH)
+            advance_x = IM_ROUND(advance_x);
+
+        // Bake spacing
+        advance_x += cfg->GlyphExtraSpacing.x;
+    }
+
     Glyphs.resize(Glyphs.Size + 1);
     ImFontGlyph& glyph = Glyphs.back();
     glyph.Codepoint = (unsigned int)codepoint;
@@ -2783,14 +2920,13 @@ void ImFont::AddGlyph(ImWchar codepoint, float x0, float y0, float x1, float y1,
     glyph.V0 = v0;
     glyph.U1 = u1;
     glyph.V1 = v1;
-    glyph.AdvanceX = advance_x + ConfigData->GlyphExtraSpacing.x;  // Bake spacing into AdvanceX
-
-    if (ConfigData->PixelSnapH)
-        glyph.AdvanceX = IM_ROUND(glyph.AdvanceX);
+    glyph.AdvanceX = advance_x;
 
     // Compute rough surface usage metrics (+1 to account for average padding, +0.99 to round)
+    // We use (U1-U0)*TexWidth instead of X1-X0 to account for oversampling.
+    float pad = ContainerAtlas->TexGlyphPadding + 0.99f;
     DirtyLookupTables = true;
-    MetricsTotalSurface += (int)((glyph.U1 - glyph.U0) * ContainerAtlas->TexWidth + 1.99f) * (int)((glyph.V1 - glyph.V0) * ContainerAtlas->TexHeight + 1.99f);
+    MetricsTotalSurface += (int)((glyph.U1 - glyph.U0) * ContainerAtlas->TexWidth + pad) * (int)((glyph.V1 - glyph.V0) * ContainerAtlas->TexHeight + pad);
 }
 
 void ImFont::AddRemapChar(ImWchar dst, ImWchar src, bool overwrite_dst)
@@ -3399,8 +3535,6 @@ void ImGui::RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, Im
     draw_list->PathFillConvex(col);
 }
 
-// For CTRL+TAB within a docking node we need to render the dimming background in 8 steps
-// (Because the root node renders the background in one shot, in order to avoid flickering when a child dock node is not submitted)
 void ImGui::RenderRectFilledWithHole(ImDrawList* draw_list, ImRect outer, ImRect inner, ImU32 col, float rounding)
 {
     const bool fill_L = (inner.Min.x > outer.Min.x);