diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 15c396eb..9c84eea1 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -103,6 +103,11 @@ Breaking Changes:
 
 Other Changes:
 - Added .editorconfig file for text editors to standardize using spaces. (#2038) [@kudaba]
+- ImDrawData: Added FramebufferScale field (currently a copy of the value from io.DisplayFramebufferScale).
+  This is to allow render functions being written without pulling any data from ImGuiIO, allowing incoming
+  multi-viewport feature to behave on Retina display and with multiple displays.
+  If you are not using a custom binding, please update your render function code ahead of time,
+  and use draw_data->FramebufferScale instead of io.DisplayFramebufferScale. (#2306, #1676)
 - InputText: Fixed a bug where ESCAPE would not restore the initial value in all situations. (#2321) [@relick]
 - InputText: Fixed a bug where ESCAPE would be first captured by the Keyboard Navigation code. (#2321, #787)
 - InputText: Fixed redo buffer exhaustion handling (rare) which could corrupt the undo character buffer. (#2333)
@@ -114,10 +119,12 @@ Other Changes:
 - Tabs: Added ImGuiTabBarFlags_TabListPopupButton flag to show a popup button on manual tab bars. (#261, #351)
 - Tabs: Removed ImGuiTabBarFlags_NoTabListPopupButton which was available in 1.67 but actually had zero use.
 - Tabs: Fixed a minor clipping glitch when changing style's FramePadding from frame to frame.
+- Tabs: Fixed border (when enabled) so it is aligned correctly mid-pixel and appears as bright as other borders.
 - Menus: Tweaked horizontal overlap between parent and child menu (to help convey relative depth)
   from using style.ItemSpacing.x to style.ItemInnerSpacing.x, the later being expected to be smaller. (#1086)
 - RadioButton: Fixed label horizontal alignment to precisely match Checkbox().
 - Window: When resizing from an edge, the border is more visible and better follow the rounded corners.
+- Window: Fixed initial width of collapsed windows not taking account of contents width (broken in 1.67). (#2336, #176)
 - ListBox: Better optimized when clipped / non-visible.
 - InputTextMultiline: Better optimized when clipped / non-visible.
 - ImDrawList: Fixed AddCircle(), AddCircleFilled() angle step being off, which was visible when drawing a "circle"
@@ -127,8 +134,14 @@ Other Changes:
 - ImFontAtlas: FreeType: Added support for imgui allocators + custom FreeType only SetAllocatorFunctions. (#2285) [@Vuhdo]
 - ImFontAtlas: FreeType: Fixed using imgui_freetype.cpp in unity builds. (#2302)
 - Demo: Fixed "Log" demo not initializing properly, leading to the first line not showing before a Clear. (#2318) [@bluescan]
+- Examples: Metal, OpenGL2, OpenGL3: Fixed offsetting of clipping rectangle with ImDrawData::DisplayPos != (0,0) when
+  the display frame-buffer scale scale is not (1,1). While this doesn't make a difference when using master branch,
+  this is effectively fixing support for multi-viewport with Mac Retina Displays on those examples. (#2306) [@rasky, @ocornut]
+  Also using ImDrawData::FramebufferScale instead of io.DisplayFramebufferScale.
+- Examples: Clarified the use the ImDrawData::DisplayPos to offset clipping rectangles.
 - Examples: Win32: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created
   in a different thread or parent. (#1951, #2087, #2156, #2232) [many people]
+- Examples: SDL: Using the SDL_WINDOW_ALLOW_HIGHDPI flag. (#2306, #1676) [@rasky]
 - Examples: Win32: Added support for XInput games (if ImGuiConfigFlags_NavEnableGamepad is enabled).
 - Examples: Win32: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages. (#2264)
 - Examples: DirectX9: Explicitly disable fog (D3DRS_FOGENABLE) before drawing in case user state has it set. (#2288, #2230)
diff --git a/examples/example_apple_opengl2/main.mm b/examples/example_apple_opengl2/main.mm
index d4d7a0a9..25316be8 100644
--- a/examples/example_apple_opengl2/main.mm
+++ b/examples/example_apple_opengl2/main.mm
@@ -92,13 +92,14 @@
 	[[self openGLContext] makeCurrentContext];
 
     ImGuiIO& io = ImGui::GetIO();
-    GLsizei width  = (GLsizei)(io.DisplaySize.x * io.DisplayFramebufferScale.x);
-    GLsizei height = (GLsizei)(io.DisplaySize.y * io.DisplayFramebufferScale.y);
+    ImDrawData* draw_data = ImGui::GetDrawData();
+    GLsizei width  = (GLsizei)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    GLsizei height = (GLsizei)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
     glViewport(0, 0, width, height);
 
 	glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
 	glClear(GL_COLOR_BUFFER_BIT);
-	ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+	ImGui_ImplOpenGL2_RenderDrawData(draw_data);
 
     // Present
     [[self openGLContext] flushBuffer];
diff --git a/examples/example_sdl_opengl2/main.cpp b/examples/example_sdl_opengl2/main.cpp
index c69c9489..bb3eaca8 100644
--- a/examples/example_sdl_opengl2/main.cpp
+++ b/examples/example_sdl_opengl2/main.cpp
@@ -30,7 +30,8 @@ int main(int, char**)
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
     SDL_DisplayMode current;
     SDL_GetCurrentDisplayMode(0, &current);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     SDL_GL_MakeCurrent(window, gl_context);
     SDL_GL_SetSwapInterval(1); // Enable vsync
diff --git a/examples/example_sdl_opengl3/main.cpp b/examples/example_sdl_opengl3/main.cpp
index a6e164a3..44fa4025 100644
--- a/examples/example_sdl_opengl3/main.cpp
+++ b/examples/example_sdl_opengl3/main.cpp
@@ -54,7 +54,8 @@ int main(int, char**)
     SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
     SDL_DisplayMode current;
     SDL_GetCurrentDisplayMode(0, &current);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     SDL_GL_MakeCurrent(window, gl_context);
     SDL_GL_SetSwapInterval(1); // Enable vsync
diff --git a/examples/example_sdl_vulkan/main.cpp b/examples/example_sdl_vulkan/main.cpp
index 87ed6265..b5d32bb9 100644
--- a/examples/example_sdl_vulkan/main.cpp
+++ b/examples/example_sdl_vulkan/main.cpp
@@ -308,7 +308,8 @@ int main(int, char**)
     // Setup window
     SDL_DisplayMode current;
     SDL_GetCurrentDisplayMode(0, &current);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+Vulkan example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, SDL_WINDOW_VULKAN|SDL_WINDOW_RESIZABLE);
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+Vulkan example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
 
     // Setup Vulkan
     uint32_t extensions_count = 0;
diff --git a/examples/imgui_impl_allegro5.cpp b/examples/imgui_impl_allegro5.cpp
index 8d534516..ad0e5a35 100644
--- a/examples/imgui_impl_allegro5.cpp
+++ b/examples/imgui_impl_allegro5.cpp
@@ -122,8 +122,9 @@ void ImGui_ImplAllegro5_RenderDrawData(ImDrawData* draw_data)
             indices = (const int*)cmd_list->IdxBuffer.Data;
         }
 
+        // Render command lists
         int idx_offset = 0;
-        ImVec2 pos = draw_data->DisplayPos;
+        ImVec2 clip_off = draw_data->DisplayPos;
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
@@ -134,7 +135,7 @@ void ImGui_ImplAllegro5_RenderDrawData(ImDrawData* draw_data)
             else
             {
                 ALLEGRO_BITMAP* texture = (ALLEGRO_BITMAP*)pcmd->TextureId;
-                al_set_clipping_rectangle(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pcmd->ClipRect.x, pcmd->ClipRect.w - pcmd->ClipRect.y);
+                al_set_clipping_rectangle(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y, pcmd->ClipRect.z - pcmd->ClipRect.x, pcmd->ClipRect.w - pcmd->ClipRect.y);
                 al_draw_prim(&vertices[0], g_VertexDecl, texture, idx_offset, idx_offset + pcmd->ElemCount, ALLEGRO_PRIM_TRIANGLE_LIST);
             }
             idx_offset += pcmd->ElemCount;
diff --git a/examples/imgui_impl_dx10.cpp b/examples/imgui_impl_dx10.cpp
index de3c9e38..7bcecba4 100644
--- a/examples/imgui_impl_dx10.cpp
+++ b/examples/imgui_impl_dx10.cpp
@@ -205,7 +205,7 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     // Render command lists
     int vtx_offset = 0;
     int idx_offset = 0;
-    ImVec2 pos = draw_data->DisplayPos;
+    ImVec2 clip_off = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -220,7 +220,7 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
             else
             {
                 // Apply scissor/clipping rectangle
-                const D3D10_RECT r = { (LONG)(pcmd->ClipRect.x - pos.x), (LONG)(pcmd->ClipRect.y - pos.y), (LONG)(pcmd->ClipRect.z - pos.x), (LONG)(pcmd->ClipRect.w - pos.y)};
+                const D3D10_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y)};
                 ctx->RSSetScissorRects(1, &r);
 
                 // Bind texture, Draw
diff --git a/examples/imgui_impl_dx11.cpp b/examples/imgui_impl_dx11.cpp
index 9a242784..0bccfb76 100644
--- a/examples/imgui_impl_dx11.cpp
+++ b/examples/imgui_impl_dx11.cpp
@@ -210,7 +210,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
     // Render command lists
     int vtx_offset = 0;
     int idx_offset = 0;
-    ImVec2 pos = draw_data->DisplayPos;
+    ImVec2 clip_off = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -225,7 +225,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
             else
             {
                 // Apply scissor/clipping rectangle
-                const D3D11_RECT r = { (LONG)(pcmd->ClipRect.x - pos.x), (LONG)(pcmd->ClipRect.y - pos.y), (LONG)(pcmd->ClipRect.z - pos.x), (LONG)(pcmd->ClipRect.w - pos.y) };
+                const D3D11_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
                 ctx->RSSetScissorRects(1, &r);
 
                 // Bind texture, Draw
diff --git a/examples/imgui_impl_dx12.cpp b/examples/imgui_impl_dx12.cpp
index 0325435e..a39fad85 100644
--- a/examples/imgui_impl_dx12.cpp
+++ b/examples/imgui_impl_dx12.cpp
@@ -203,7 +203,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     // Render command lists
     int vtx_offset = 0;
     int idx_offset = 0;
-    ImVec2 pos = draw_data->DisplayPos;
+    ImVec2 clip_off = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -216,7 +216,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
             }
             else
             {
-                const D3D12_RECT r = { (LONG)(pcmd->ClipRect.x - pos.x), (LONG)(pcmd->ClipRect.y - pos.y), (LONG)(pcmd->ClipRect.z - pos.x), (LONG)(pcmd->ClipRect.w - pos.y) };
+                const D3D12_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
                 ctx->SetGraphicsRootDescriptorTable(1, *(D3D12_GPU_DESCRIPTOR_HANDLE*)&pcmd->TextureId);
                 ctx->RSSetScissorRects(1, &r);
                 ctx->DrawIndexedInstanced(pcmd->ElemCount, 1, idx_offset, vtx_offset, 0);
diff --git a/examples/imgui_impl_dx9.cpp b/examples/imgui_impl_dx9.cpp
index 3653ec25..378524e0 100644
--- a/examples/imgui_impl_dx9.cpp
+++ b/examples/imgui_impl_dx9.cpp
@@ -166,7 +166,7 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
     // Render command lists
     int vtx_offset = 0;
     int idx_offset = 0;
-    ImVec2 pos = draw_data->DisplayPos;
+    ImVec2 clip_off = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -179,7 +179,7 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
-                const RECT r = { (LONG)(pcmd->ClipRect.x - pos.x), (LONG)(pcmd->ClipRect.y - pos.y), (LONG)(pcmd->ClipRect.z - pos.x), (LONG)(pcmd->ClipRect.w - pos.y) };
+                const RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
                 const LPDIRECT3DTEXTURE9 texture = (LPDIRECT3DTEXTURE9)pcmd->TextureId;
                 g_pd3dDevice->SetTexture(0, texture);
                 g_pd3dDevice->SetScissorRect(&r);
diff --git a/examples/imgui_impl_marmalade.cpp b/examples/imgui_impl_marmalade.cpp
index 45435977..f1eaa99a 100644
--- a/examples/imgui_impl_marmalade.cpp
+++ b/examples/imgui_impl_marmalade.cpp
@@ -3,6 +3,8 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'CIwTexture*' as ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
+// Missing features:
+//  [ ] Renderer: Clipping rectangles are not honored.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
@@ -38,10 +40,6 @@ static ImVec2       g_RenderScale = ImVec2(1.0f,1.0f);
 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
 void ImGui_Marmalade_RenderDrawData(ImDrawData* draw_data)
 {
-    // Handle cases of screen coordinates != from framebuffer coordinates (e.g. retina displays)
-    ImGuiIO& io = ImGui::GetIO();
-    draw_data->ScaleClipRects(io.DisplayFramebufferScale);
-
     // Render command lists
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
@@ -54,7 +52,7 @@ void ImGui_Marmalade_RenderDrawData(ImDrawData* draw_data)
 
         for (int i = 0; i < nVert; i++)
         {
-            // TODO: optimize multiplication on gpu using vertex shader/projection matrix.
+            // FIXME-OPT: optimize multiplication on GPU using vertex shader/projection matrix.
             pVertStream[i].x = cmd_list->VtxBuffer[i].pos.x * g_RenderScale.x;
             pVertStream[i].y = cmd_list->VtxBuffer[i].pos.y * g_RenderScale.y;
             pUVStream[i].x = cmd_list->VtxBuffer[i].uv.x;
@@ -76,6 +74,7 @@ void ImGui_Marmalade_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
+                // FIXME: Not honoring ClipRect fields.
                 CIwMaterial* pCurrentMaterial = IW_GX_ALLOC_MATERIAL();
                 pCurrentMaterial->SetShadeMode(CIwMaterial::SHADE_FLAT);
                 pCurrentMaterial->SetCullMode(CIwMaterial::CULL_NONE);
diff --git a/examples/imgui_impl_metal.mm b/examples/imgui_impl_metal.mm
index 24b9bf68..246765a7 100644
--- a/examples/imgui_impl_metal.mm
+++ b/examples/imgui_impl_metal.mm
@@ -12,6 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2019-02-11: Metal: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
 //  2018-07-05: Metal: Added new Metal backend implementation.
 
@@ -403,12 +404,10 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
         commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder
 {
     // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-    ImGuiIO &io = ImGui::GetIO();
-    int fb_width = (int)(drawData->DisplaySize.x * io.DisplayFramebufferScale.x);
-    int fb_height = (int)(drawData->DisplaySize.y * io.DisplayFramebufferScale.y);
+    int fb_width = (int)(drawData->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(drawData->DisplaySize.y * draw_data->FramebufferScale.y);
     if (fb_width <= 0 || fb_height <= 0 || drawData->CmdListsCount == 0)
         return;
-    drawData->ScaleClipRects(io.DisplayFramebufferScale);
 
     [commandEncoder setCullMode:MTLCullModeNone];
     [commandEncoder setDepthStencilState:g_sharedMetalContext.depthStencilState];
@@ -442,26 +441,23 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
 
     [commandEncoder setVertexBytes:&ortho_projection length:sizeof(ortho_projection) atIndex:1];
 
-    size_t vertexBufferLength = 0;
-    size_t indexBufferLength = 0;
-    for (int n = 0; n < drawData->CmdListsCount; n++)
-    {
-        const ImDrawList* cmd_list = drawData->CmdLists[n];
-        vertexBufferLength += cmd_list->VtxBuffer.Size * sizeof(ImDrawVert);
-        indexBufferLength += cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx);
-    }
-
-    MetalBuffer *vertexBuffer = [self dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device];
-    MetalBuffer *indexBuffer = [self dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device];
+    size_t vertexBufferLength = drawData->TotalVtxCount * sizeof(ImDrawVert);
+    size_t indexBufferLength = drawData->TotalIdxCount * sizeof(ImDrawIdx);
+    MetalBuffer* vertexBuffer = [self dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device];
+    MetalBuffer* indexBuffer = [self dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device];
 
     id<MTLRenderPipelineState> renderPipelineState = [self renderPipelineStateForFrameAndDevice:commandBuffer.device];
     [commandEncoder setRenderPipelineState:renderPipelineState];
 
     [commandEncoder setVertexBuffer:vertexBuffer.buffer offset:0 atIndex:0];
 
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
+    // Render command lists
     size_t vertexBufferOffset = 0;
     size_t indexBufferOffset = 0;
-    ImVec2 pos = drawData->DisplayPos;
     for (int n = 0; n < drawData->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = drawData->CmdLists[n];
@@ -482,14 +478,23 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
             }
             else
             {
-                ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y);
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec4 clip_rect;
+                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
+                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
+                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
+                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+
                 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
                 {
                     // Apply scissor/clipping rectangle
-                    MTLScissorRect scissorRect = { .x = NSUInteger(clip_rect.x),
+                    MTLScissorRect scissorRect =
+                    {
+                        .x = NSUInteger(clip_rect.x),
                         .y = NSUInteger(clip_rect.y),
                         .width = NSUInteger(clip_rect.z - clip_rect.x),
-                        .height = NSUInteger(clip_rect.w - clip_rect.y) };
+                        .height = NSUInteger(clip_rect.w - clip_rect.y)
+                    };
                     [commandEncoder setScissorRect:scissorRect];
 
 
diff --git a/examples/imgui_impl_opengl2.cpp b/examples/imgui_impl_opengl2.cpp
index 9e32ea2f..425d3bea 100644
--- a/examples/imgui_impl_opengl2.cpp
+++ b/examples/imgui_impl_opengl2.cpp
@@ -20,6 +20,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
 //  2018-08-03: OpenGL: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications.
 //  2018-06-08: Misc: Extracted imgui_impl_opengl2.cpp/.h away from the old combined GLFW/SDL+OpenGL2 examples.
@@ -87,12 +88,10 @@ void    ImGui_ImplOpenGL2_NewFrame()
 void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
 {
     // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-    ImGuiIO& io = ImGui::GetIO();
-    int fb_width = (int)(draw_data->DisplaySize.x * io.DisplayFramebufferScale.x);
-    int fb_height = (int)(draw_data->DisplaySize.y * io.DisplayFramebufferScale.y);
+    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
     if (fb_width == 0 || fb_height == 0)
         return;
-    draw_data->ScaleClipRects(io.DisplayFramebufferScale);
 
     // We are using the OpenGL fixed pipeline to make the example code simpler to read!
     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill.
@@ -133,8 +132,11 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
     glPushMatrix();
     glLoadIdentity();
 
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
     // Render command lists
-    ImVec2 pos = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -154,7 +156,13 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
-                ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y);
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec4 clip_rect;
+                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
+                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
+                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
+                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+
                 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
                 {
                     // Apply scissor/clipping rectangle
diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp
index 4bf10b18..d31744e0 100644
--- a/examples/imgui_impl_opengl3.cpp
+++ b/examples/imgui_impl_opengl3.cpp
@@ -13,6 +13,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
 //  2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
 //  2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT).
@@ -149,12 +150,10 @@ void    ImGui_ImplOpenGL3_NewFrame()
 void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
 {
     // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-    ImGuiIO& io = ImGui::GetIO();
-    int fb_width = (int)(draw_data->DisplaySize.x * io.DisplayFramebufferScale.x);
-    int fb_height = (int)(draw_data->DisplaySize.y * io.DisplayFramebufferScale.y);
+    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
     if (fb_width <= 0 || fb_height <= 0)
         return;
-    draw_data->ScaleClipRects(io.DisplayFramebufferScale);
 
     // Backup GL state
     GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
@@ -232,8 +231,11 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
     glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
 
-    // Draw
-    ImVec2 pos = draw_data->DisplayPos;
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
+    // Render command lists
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -255,7 +257,13 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
-                ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y);
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec4 clip_rect;
+                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
+                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
+                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
+                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+
                 if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
                 {
                     // Apply scissor/clipping rectangle
diff --git a/examples/imgui_impl_vulkan.cpp b/examples/imgui_impl_vulkan.cpp
index 77675b2c..5797e60b 100644
--- a/examples/imgui_impl_vulkan.cpp
+++ b/examples/imgui_impl_vulkan.cpp
@@ -294,7 +294,7 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
     // Render the command lists:
     int vtx_offset = 0;
     int idx_offset = 0;
-    ImVec2 display_pos = draw_data->DisplayPos;
+    ImVec2 clip_off = draw_data->DisplayPos;
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -310,8 +310,8 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
                 // Apply scissor/clipping rectangle
                 // FIXME: We could clamp width/height based on clamped min/max values.
                 VkRect2D scissor;
-                scissor.offset.x = (int32_t)(pcmd->ClipRect.x - display_pos.x) > 0 ? (int32_t)(pcmd->ClipRect.x - display_pos.x) : 0;
-                scissor.offset.y = (int32_t)(pcmd->ClipRect.y - display_pos.y) > 0 ? (int32_t)(pcmd->ClipRect.y - display_pos.y) : 0;
+                scissor.offset.x = (int32_t)(pcmd->ClipRect.x - clip_off.x) > 0 ? (int32_t)(pcmd->ClipRect.x - clip_off.x) : 0;
+                scissor.offset.y = (int32_t)(pcmd->ClipRect.y - clip_off.y) > 0 ? (int32_t)(pcmd->ClipRect.y - clip_off.y) : 0;
                 scissor.extent.width = (uint32_t)(pcmd->ClipRect.z - pcmd->ClipRect.x);
                 scissor.extent.height = (uint32_t)(pcmd->ClipRect.w - pcmd->ClipRect.y + 1); // FIXME: Why +1 here?
                 vkCmdSetScissor(command_buffer, 0, 1, &scissor);
diff --git a/imgui.cpp b/imgui.cpp
index dfdb4601..9f94fefb 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -3934,6 +3934,7 @@ static void SetupViewportDrawData(ImGuiViewportP* viewport, ImVector<ImDrawList*
     draw_data->TotalVtxCount = draw_data->TotalIdxCount = 0;
     draw_data->DisplayPos = viewport->Pos;
     draw_data->DisplaySize = viewport->Size;
+    draw_data->FramebufferScale = ImGui::GetIO().DisplayFramebufferScale; // FIXME-VIEWPORT: This may vary on a per-monitor/viewport basis?
     for (int n = 0; n < draw_lists->Size; n++)
     {
         draw_data->TotalVtxCount += draw_lists->Data[n]->VtxBuffer.Size;
@@ -4882,7 +4883,8 @@ static ImVec2 CalcSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size)
 static ImVec2 CalcSizeContents(ImGuiWindow* window)
 {
     if (window->Collapsed)
-        return window->SizeContents;
+        if (window->AutoFitFramesX <= 0 && window->AutoFitFramesY <= 0)
+            return window->SizeContents;
     if (window->Hidden && window->HiddenFramesForResize == 0 && window->HiddenFramesRegular > 0)
         return window->SizeContents;
 
diff --git a/imgui.h b/imgui.h
index f633e559..bcaae461 100644
--- a/imgui.h
+++ b/imgui.h
@@ -1369,7 +1369,7 @@ struct ImGuiIO
     float       FontGlobalScale;                // = 1.0f           // Global scale all fonts
     bool        FontAllowUserScaling;           // = false          // Allow user scaling text of individual window with CTRL+Wheel.
     ImFont*     FontDefault;                    // = NULL           // Font to use on NewFrame(). Use NULL to uses Fonts->Fonts[0].
-    ImVec2      DisplayFramebufferScale;        // = (1.0f,1.0f)    // For hi-dpi/retina display or other situations where window coordinates are different from framebuffer coordinates. User storage only, presently not used by ImGui.
+    ImVec2      DisplayFramebufferScale;        // = (1, 1)         // For retina display or other situations where window coordinates are different from framebuffer coordinates. This generally ends up in ImDrawData::FramebufferScale.
 
     // Docking options (when ImGuiConfigFlags_DockingEnable is set)
     bool        ConfigDockingNoSplit;           // = false          // Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.
@@ -1983,13 +1983,14 @@ struct ImDrawData
     int             TotalVtxCount;          // For convenience, sum of all ImDrawList's VtxBuffer.Size
     ImVec2          DisplayPos;             // Upper-left position of the viewport to render (== upper-left of the orthogonal projection matrix to use)
     ImVec2          DisplaySize;            // Size of the viewport to render (== io.DisplaySize for the main viewport) (DisplayPos + DisplaySize == lower-right of the orthogonal projection matrix to use)
+    ImVec2          FramebufferScale;       // Amount of pixels for each unit of DisplaySize. Based on io.DisplayFramebufferScale. Generally (1,1) on normal display, (2,2) on OSX with Retina display.
 
     // Functions
     ImDrawData()    { Valid = false; Clear(); }
     ~ImDrawData()   { Clear(); }
-    void Clear()    { Valid = false; CmdLists = NULL; CmdListsCount = TotalVtxCount = TotalIdxCount = 0; DisplayPos = DisplaySize = ImVec2(0.f, 0.f); } // The ImDrawList are owned by ImGuiContext!
-    IMGUI_API void  DeIndexAllBuffers();                // Helper to convert all buffers from indexed to non-indexed, in case you cannot render indexed. Note: this is slow and most likely a waste of resources. Always prefer indexed rendering!
-    IMGUI_API void  ScaleClipRects(const ImVec2& sc);   // Helper to scale the ClipRect field of each ImDrawCmd. Use if your final output buffer is at a different scale than ImGui expects, or if there is a difference between your window resolution and framebuffer resolution.
+    void Clear()    { Valid = false; CmdLists = NULL; CmdListsCount = TotalVtxCount = TotalIdxCount = 0; DisplayPos = DisplaySize = FramebufferScale = ImVec2(0.f, 0.f); } // The ImDrawList are owned by ImGuiContext!
+    IMGUI_API void  DeIndexAllBuffers();                    // Helper to convert all buffers from indexed to non-indexed, in case you cannot render indexed. Note: this is slow and most likely a waste of resources. Always prefer indexed rendering!
+    IMGUI_API void  ScaleClipRects(const ImVec2& fb_scale); // Helper to scale the ClipRect field of each ImDrawCmd. Use if your final output buffer is at a different scale than ImGui expects, or if there is a difference between your window resolution and framebuffer resolution.
 };
 
 //-----------------------------------------------------------------------------
@@ -2168,24 +2169,26 @@ struct ImFontAtlas
 // ImFontAtlas automatically loads a default embedded font for you when you call GetTexDataAsAlpha8() or GetTexDataAsRGBA32().
 struct ImFont
 {
-    // Members: Hot ~62/78 bytes
-    float                       FontSize;           // <user set>   // Height of characters, set during loading (don't change after loading)
-    float                       Scale;              // = 1.f        // Base font scale, multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
-    ImVec2                      DisplayOffset;      // = (0.f,0.f)  // Offset font rendering by xx pixels
-    ImVector<ImFontGlyph>       Glyphs;             //              // All glyphs.
-    ImVector<float>             IndexAdvanceX;      //              // Sparse. Glyphs->AdvanceX in a directly indexable way (more cache-friendly, for CalcTextSize functions which are often bottleneck in large UI).
-    ImVector<ImWchar>           IndexLookup;        //              // Sparse. Index glyphs by Unicode code-point.
-    const ImFontGlyph*          FallbackGlyph;      // == FindGlyph(FontFallbackChar)
-    float                       FallbackAdvanceX;   // == FallbackGlyph->AdvanceX
-    ImWchar                     FallbackChar;       // = '?'        // Replacement glyph if one isn't found. Only set via SetFallbackChar()
+    // Members: Hot ~24/32 bytes (for CalcTextSize)
+    ImVector<float>             IndexAdvanceX;      // 12/16 // out //            // Sparse. Glyphs->AdvanceX in a directly indexable way (more cache-friendly, for CalcTextSize functions which are often bottleneck in large UI).
+    float                       FontSize;           // 4     // in  // <user set> // Height of characters, set during loading (don't change after loading)
+    float                       FallbackAdvanceX;   // 4     // out // = FallbackGlyph->AdvanceX
+    ImWchar                     FallbackChar;       // 2     // in  // = '?'      // Replacement glyph if one isn't found. Only set via SetFallbackChar()
 
-    // Members: Cold ~18/26 bytes
-    short                       ConfigDataCount;    // ~ 1          // Number of ImFontConfig involved in creating this font. Bigger than 1 when merging multiple font sources into one ImFont.
-    ImFontConfig*               ConfigData;         //              // Pointer within ContainerAtlas->ConfigData
-    ImFontAtlas*                ContainerAtlas;     //              // What we has been loaded into
-    float                       Ascent, Descent;    //              // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize]
-    bool                        DirtyLookupTables;
-    int                         MetricsTotalSurface;//              // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
+    // Members: Hot ~36/48 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.
+    ImVec2                      DisplayOffset;      // 8     // in  // = (0,0)    // Offset font rendering by xx pixels
+    const ImFontGlyph*          FallbackGlyph;      // 4-8   // out // = FindGlyph(FontFallbackChar)
+
+    // Members: Cold ~28/40 bytes
+    ImFontAtlas*                ContainerAtlas;     // 4-8   // out //            // What we has been loaded into
+    ImFontConfig*               ConfigData;         // 4-8   // in  //            // Pointer within ContainerAtlas->ConfigData
+    short                       ConfigDataCount;    // 2     // in  // ~ 1        // Number of ImFontConfig involved in creating this font. Bigger than 1 when merging multiple font sources into one ImFont.
+    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;    // 8     // out               // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize]
+    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)
 
     // Methods
     IMGUI_API ImFont();
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index e9953b2e..6238544f 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -2818,8 +2818,13 @@ void ImGui::ShowFontSelector(const char* label)
     if (ImGui::BeginCombo(label, font_current->GetDebugName()))
     {
         for (int n = 0; n < io.Fonts->Fonts.Size; n++)
-            if (ImGui::Selectable(io.Fonts->Fonts[n]->GetDebugName(), io.Fonts->Fonts[n] == font_current))
-                io.FontDefault = io.Fonts->Fonts[n];
+        {
+            ImFont* font = io.Fonts->Fonts[n];
+            ImGui::PushID((void*)font);
+            if (ImGui::Selectable(font->GetDebugName(), font == font_current))
+                io.FontDefault = font;
+            ImGui::PopID();
+        }
         ImGui::EndCombo();
     }
     ImGui::SameLine();
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 09f40469..44626926 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -1293,8 +1293,10 @@ void ImDrawData::DeIndexAllBuffers()
     }
 }
 
-// Helper to scale the ClipRect field of each ImDrawCmd. Use if your final output buffer is at a different scale than ImGui expects, or if there is a difference between your window resolution and framebuffer resolution.
-void ImDrawData::ScaleClipRects(const ImVec2& scale)
+// Helper to scale the ClipRect field of each ImDrawCmd. 
+// Use if your final output buffer is at a different scale than draw_data->DisplaySize, 
+// or if there is a difference between your window resolution and framebuffer resolution.
+void ImDrawData::ScaleClipRects(const ImVec2& fb_scale)
 {
     for (int i = 0; i < CmdListsCount; i++)
     {
@@ -1302,7 +1304,7 @@ void ImDrawData::ScaleClipRects(const ImVec2& scale)
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
         {
             ImDrawCmd* cmd = &cmd_list->CmdBuffer[cmd_i];
-            cmd->ClipRect = ImVec4(cmd->ClipRect.x * scale.x, cmd->ClipRect.y * scale.y, cmd->ClipRect.z * scale.x, cmd->ClipRect.w * scale.y);
+            cmd->ClipRect = ImVec4(cmd->ClipRect.x * fb_scale.x, cmd->ClipRect.y * fb_scale.y, cmd->ClipRect.z * fb_scale.x, cmd->ClipRect.w * fb_scale.y);
         }
     }
 }
@@ -2396,38 +2398,36 @@ void ImFontGlyphRangesBuilder::BuildRanges(ImVector<ImWchar>* out_ranges)
 
 ImFont::ImFont()
 {
-    Scale = 1.0f;
+    FontSize = 0.0f;
+    FallbackAdvanceX = 0.0f;
     FallbackChar = (ImWchar)'?';
     DisplayOffset = ImVec2(0.0f, 0.0f);
-    ClearOutputData();
+    FallbackGlyph = NULL;
+    ContainerAtlas = NULL;
+    ConfigData = NULL;
+    ConfigDataCount = 0;
+    DirtyLookupTables = false;
+    Scale = 1.0f;
+    Ascent = Descent = 0.0f;
+    MetricsTotalSurface = 0;
 }
 
 ImFont::~ImFont()
 {
-    // Invalidate active font so that the user gets a clear crash instead of a dangling pointer.
-    // If you want to delete fonts you need to do it between Render() and NewFrame().
-    // FIXME-CLEANUP
-    /*
-    ImGuiContext& g = *GImGui;
-    if (g.Font == this)
-        g.Font = NULL;
-    */
     ClearOutputData();
 }
 
 void    ImFont::ClearOutputData()
 {
     FontSize = 0.0f;
+    FallbackAdvanceX = 0.0f;
     Glyphs.clear();
     IndexAdvanceX.clear();
     IndexLookup.clear();
     FallbackGlyph = NULL;
-    FallbackAdvanceX = 0.0f;
-    ConfigDataCount = 0;
-    ConfigData = NULL;
     ContainerAtlas = NULL;
-    Ascent = Descent = 0.0f;
     DirtyLookupTables = true;
+    Ascent = Descent = 0.0f;
     MetricsTotalSurface = 0;
 }
 
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 79e1fef2..fb1c58e0 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -6346,7 +6346,7 @@ static ImGuiTabItem* ImGui::TabBarTabListPopupButton(ImGuiTabBar* tab_bar)
 // - TabItemEx() [Internal]
 // - SetTabItemClosed()
 // - TabItemCalcSize() [Internal]
-// - TabItemRenderBackground() [Internal]
+// - TabItemBackground() [Internal]
 // - TabItemLabelAndCloseButton() [Internal]
 //-------------------------------------------------------------------------
 
@@ -6576,7 +6576,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         // Enlarge tab display when hovering
         bb.Max.x = bb.Min.x + (float)(int)ImLerp(bb.GetWidth(), tab->WidthContents, ImSaturate((g.HoveredIdNotActiveTimer - 0.40f) * 6.0f));
         display_draw_list = GetOverlayDrawList(window);
-        TabItemRenderBackground(display_draw_list, bb, flags, GetColorU32(ImGuiCol_TitleBgActive));
+        TabItemBackground(display_draw_list, bb, flags, GetColorU32(ImGuiCol_TitleBgActive));
     }
 #endif
 
@@ -6661,16 +6661,21 @@ void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabI
     IM_UNUSED(flags);
     IM_ASSERT(width > 0.0f);
     const float rounding = ImMax(0.0f, ImMin(g.Style.TabRounding, width * 0.5f - 1.0f));
-    float y1 = bb.Min.y + 1.0f;
-    float y2 = bb.Max.y + ((flags & ImGuiTabItemFlags_Preview) ? 0.0f : -1.0f);
+    const float y1 = bb.Min.y + 1.0f;
+    const float y2 = bb.Max.y + ((flags & ImGuiTabItemFlags_Preview) ? 0.0f : -1.0f);
     draw_list->PathLineTo(ImVec2(bb.Min.x, y2));
     draw_list->PathArcToFast(ImVec2(bb.Min.x + rounding, y1 + rounding), rounding, 6, 9);
     draw_list->PathArcToFast(ImVec2(bb.Max.x - rounding, y1 + rounding), rounding, 9, 12);
     draw_list->PathLineTo(ImVec2(bb.Max.x, y2));
-    draw_list->AddConvexPolyFilled(draw_list->_Path.Data, draw_list->_Path.Size, col);
+    draw_list->PathFillConvex(col);
     if (g.Style.TabBorderSize > 0.0f)
-        draw_list->AddPolyline(draw_list->_Path.Data, draw_list->_Path.Size, GetColorU32(ImGuiCol_Border), false, g.Style.TabBorderSize);
-    draw_list->PathClear();
+    {
+        draw_list->PathLineTo(ImVec2(bb.Min.x + 0.5f, y2));
+        draw_list->PathArcToFast(ImVec2(bb.Min.x + rounding + 0.5f, y1 + rounding + 0.5f), rounding, 6, 9);
+        draw_list->PathArcToFast(ImVec2(bb.Max.x - rounding - 0.5f, y1 + rounding + 0.5f), rounding, 9, 12);
+        draw_list->PathLineTo(ImVec2(bb.Max.x - 0.5f, y2));
+        draw_list->PathStroke(GetColorU32(ImGuiCol_Border), false, g.Style.TabBorderSize);
+    }
 }
 
 // Render text label (with custom clipping) + Unsaved Document marker + Close Button logic
diff --git a/imstb_rectpack.h b/imstb_rectpack.h
index 2b07dcc8..23f922a5 100644
--- a/imstb_rectpack.h
+++ b/imstb_rectpack.h
@@ -1,4 +1,10 @@
-// stb_rect_pack.h - v0.11 - public domain - rectangle packing
+// [DEAR IMGUI] 
+// This is a slightly modified version of stb_rect_pack.h 0.99. 
+// Those changes would need to be pushed into nothings/stb:
+// - Added STBRP__CDECL
+// Grep for [DEAR IMGUI] to find the changes.
+
+// stb_rect_pack.h - v0.99 - public domain - rectangle packing
 // Sean Barrett 2014
 //
 // Useful for e.g. packing rectangular textures into an atlas.
@@ -34,6 +40,7 @@
 //
 // Version history:
 //
+//     0.99  (2019-02-07)  warning fixes
 //     0.11  (2017-03-03)  return packing success/fail result
 //     0.10  (2016-10-25)  remove cast-away-const to avoid warnings
 //     0.09  (2016-08-27)  fix compiler warnings
@@ -204,6 +211,7 @@ struct stbrp_context
 #define STBRP_ASSERT assert
 #endif
 
+// [DEAR IMGUI] Added STBRP__CDECL
 #ifdef _MSC_VER
 #define STBRP__NOTUSED(v)  (void)(v)
 #define STBRP__CDECL __cdecl
@@ -512,6 +520,7 @@ static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, i
    return res;
 }
 
+// [DEAR IMGUI] Added STBRP__CDECL
 static int STBRP__CDECL rect_height_compare(const void *a, const void *b)
 {
    const stbrp_rect *p = (const stbrp_rect *) a;
@@ -523,6 +532,7 @@ static int STBRP__CDECL rect_height_compare(const void *a, const void *b)
    return (p->w > q->w) ? -1 : (p->w < q->w);
 }
 
+// [DEAR IMGUI] Added STBRP__CDECL
 static int STBRP__CDECL rect_original_order(const void *a, const void *b)
 {
    const stbrp_rect *p = (const stbrp_rect *) a;
@@ -543,9 +553,6 @@ STBRP_DEF int stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int nu
    // we use the 'was_packed' field internally to allow sorting/unsorting
    for (i=0; i < num_rects; ++i) {
       rects[i].was_packed = i;
-      #ifndef STBRP_LARGE_RECTS
-      STBRP_ASSERT(rects[i].w <= 0xffff && rects[i].h <= 0xffff);
-      #endif
    }
 
    // sort according to heuristic
diff --git a/imstb_textedit.h b/imstb_textedit.h
index d79c7730..d7fcbd62 100644
--- a/imstb_textedit.h
+++ b/imstb_textedit.h
@@ -1,9 +1,10 @@
-// [ImGui] this is a slightly modified version of stb_textedit.h 1.12. Those changes would need to be pushed into nothings/stb
-// [ImGui] - 2018-06: fixed undo/redo after pasting large amount of text (over 32 kb). Redo will still fail when undo buffers are exhausted, but text won't be corrupted (see nothings/stb issue #620)
-// [ImGui] - 2018-06: fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
-// [ImGui] - fixed some minor warnings
+// [DEAR IMGUI] 
+// This is a slightly modified version of stb_textedit.h 1.13. 
+// Those changes would need to be pushed into nothings/stb:
+// - Fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
+// Grep for [DEAR IMGUI] to find the changes.
 
-// stb_textedit.h - v1.12  - public domain - Sean Barrett
+// stb_textedit.h - v1.13  - public domain - Sean Barrett
 // Development of this library was sponsored by RAD Game Tools
 //
 // This C header file implements the guts of a multi-line text-editing
@@ -34,6 +35,7 @@
 //
 // VERSION HISTORY
 //
+//   1.13 (2019-02-07) fix bug in undo size management
 //   1.12 (2018-01-29) user can change STB_TEXTEDIT_KEYTYPE, fix redo to avoid crash
 //   1.11 (2017-03-03) fix HOME on last line, dragging off single-line textfield
 //   1.10 (2016-10-25) supress warnings about casting away const with -Wcast-qual
@@ -692,7 +694,7 @@ static void stb_textedit_prep_selection_at_cursor(STB_TexteditState *state)
 static int stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
 {
    if (STB_TEXT_HAS_SELECTION(state)) {
-      stb_textedit_delete_selection(str,state); // implicity clamps
+      stb_textedit_delete_selection(str,state); // implicitly clamps
       state->has_preferred_x = 0;
       return 1;
    }
@@ -744,7 +746,7 @@ retry:
                   state->has_preferred_x = 0;
                }
             } else {
-               stb_textedit_delete_selection(str,state); // implicity clamps
+               stb_textedit_delete_selection(str,state); // implicitly clamps
                if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
                   stb_text_makeundo_insert(state, state->cursor, 1);
                   ++state->cursor;
@@ -1132,6 +1134,7 @@ static void stb_textedit_discard_redo(StbUndoState *state)
                state->undo_rec[i].char_storage += n;
       }
       // now move all the redo records towards the end of the buffer; the first one is at 'redo_point'
+      // {DEAR IMGUI]
       size_t move_size = (size_t)((STB_TEXTEDIT_UNDOSTATECOUNT - state->redo_point - 1) * sizeof(state->undo_rec[0]));
       const char* buf_begin = (char*)state->undo_rec; (void)buf_begin;
       const char* buf_end   = (char*)state->undo_rec + sizeof(state->undo_rec); (void)buf_end;
diff --git a/imstb_truetype.h b/imstb_truetype.h
index 0b65350a..95631323 100644
--- a/imstb_truetype.h
+++ b/imstb_truetype.h
@@ -1,7 +1,9 @@
-// [ImGui] this is a slightly modified version of stb_truetype.h 1.19. Those changes would need to be pushed into nothings/stb
-// grep for [ImGui] to find the changes.
+// [DEAR IMGUI] 
+// This is a slightly modified version of stb_truetype.h 1.20.
+// Mostly fixing for compiler and static analyzer warnings.
+// Grep for [DEAR IMGUI] to find the changes.
 
-// stb_truetype.h - v1.19 - public domain
+// stb_truetype.h - v1.20 - public domain
 // authored from 2009-2016 by Sean Barrett / RAD Game Tools
 //
 //   This library processes TrueType files:
@@ -52,6 +54,7 @@
 //       
 // VERSION HISTORY
 //
+//   1.20 (2019-02-07) PackFontRange skips missing codepoints; GetScaleFontVMetrics()
 //   1.19 (2018-02-11) GPOS kerning, STBTT_fmod
 //   1.18 (2018-01-29) add missing function
 //   1.17 (2017-07-23) make more arguments const; doc fix
@@ -78,7 +81,7 @@
 //
 // USAGE
 //
-//   Include this file in whatever places neeed to refer to it. In ONE C/C++
+//   Include this file in whatever places need to refer to it. In ONE C/C++
 //   file, write:
 //      #define STB_TRUETYPE_IMPLEMENTATION
 //   before the #include of this file. This expands out the actual
@@ -250,8 +253,8 @@
 //   Documentation & header file        520 LOC  \___ 660 LOC documentation
 //   Sample code                        140 LOC  /
 //   Truetype parsing                   620 LOC  ---- 620 LOC TrueType
-//   Software rasterization             240 LOC  \                           .
-//   Curve tesselation                  120 LOC   \__ 550 LOC Bitmap creation
+//   Software rasterization             240 LOC  \
+//   Curve tessellation                 120 LOC   \__ 550 LOC Bitmap creation
 //   Bitmap management                  100 LOC   /
 //   Baked bitmap interface              70 LOC  /
 //   Font name matching & access        150 LOC  ---- 150 
@@ -559,6 +562,8 @@ STBTT_DEF void stbtt_GetBakedQuad(const stbtt_bakedchar *chardata, int pw, int p
 //
 // It's inefficient; you might want to c&p it and optimize it.
 
+STBTT_DEF void stbtt_GetScaledFontVMetrics(const unsigned char *fontdata, int index, float size, float *ascent, float *descent, float *lineGap);
+// Query the font vertical metrics without having to create a font first.
 
 
 //////////////////////////////////////////////////////////////////////////////
@@ -644,6 +649,12 @@ STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h
 // To use with PackFontRangesGather etc., you must set it before calls
 // call to PackFontRangesGatherRects.
 
+STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip);
+// If skip != 0, this tells stb_truetype to skip any codepoints for which
+// there is no corresponding glyph. If skip=0, which is the default, then
+// codepoints without a glyph recived the font's "missing character" glyph,
+// typically an empty box by convention.
+
 STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph,  // same data as above
                                int char_index,             // character to display
                                float *xpos, float *ypos,   // pointers to current position in screen pixel space
@@ -672,6 +683,7 @@ struct stbtt_pack_context {
    int   height;
    int   stride_in_bytes;
    int   padding;
+   int   skip_missing;
    unsigned int   h_oversample, v_oversample;
    unsigned char *pixels;
    void  *nodes;
@@ -697,7 +709,7 @@ STBTT_DEF int stbtt_GetFontOffsetForIndex(const unsigned char *data, int index);
 // file will only define one font and it always be at offset 0, so it will
 // return '0' for index 0, and -1 for all other indices.
 
-// The following structure is defined publically so you can declare one on
+// The following structure is defined publicly so you can declare one on
 // the stack or as a global or etc, but you should treat it as opaque.
 struct stbtt_fontinfo
 {
@@ -736,6 +748,7 @@ STBTT_DEF int stbtt_FindGlyphIndex(const stbtt_fontinfo *info, int unicode_codep
 // and you want a speed-up, call this function with the character you're
 // going to process, then use glyph-based functions instead of the
 // codepoint-based functions.
+// Returns 0 if the character codepoint is not defined in the font.
 
 
 //////////////////////////////////////////////////////////////////////////////
@@ -823,7 +836,7 @@ STBTT_DEF int stbtt_GetGlyphShape(const stbtt_fontinfo *info, int glyph_index, s
 // returns # of vertices and fills *vertices with the pointer to them
 //   these are expressed in "unscaled" coordinates
 //
-// The shape is a series of countours. Each one starts with
+// The shape is a series of contours. Each one starts with
 // a STBTT_moveto, then consists of a series of mixed
 // STBTT_lineto and STBTT_curveto segments. A lineto
 // draws a line from previous endpoint to its x,y; a curveto
@@ -919,7 +932,7 @@ STBTT_DEF unsigned char * stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float sc
 STBTT_DEF unsigned char * stbtt_GetCodepointSDF(const stbtt_fontinfo *info, float scale, int codepoint, int padding, unsigned char onedge_value, float pixel_dist_scale, int *width, int *height, int *xoff, int *yoff);
 // These functions compute a discretized SDF field for a single character, suitable for storing
 // in a single-channel texture, sampling with bilinear filtering, and testing against
-// larger than some threshhold to produce scalable fonts.
+// larger than some threshold to produce scalable fonts.
 //        info              --  the font
 //        scale             --  controls the size of the resulting SDF bitmap, same as it would be creating a regular bitmap
 //        glyph/codepoint   --  the character to generate the SDF for
@@ -2371,7 +2384,7 @@ static stbtt_int32  stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
             if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount)
                 return (stbtt_int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID));
 
-            // [ImGui: commented to fix static analyzer warning]
+            // [DEAR IMGUI] Commented to fix static analyzer warning
             //classDefTable = classDef1ValueArray + 2 * glyphCount;
         } break;
 
@@ -2396,7 +2409,7 @@ static stbtt_int32  stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
                     return (stbtt_int32)ttUSHORT(classRangeRecord + 4);
             }
 
-            // [ImGui: commented to fix static analyzer warning]
+            // [DEAR IMGUI] Commented to fix static analyzer warning
             //classDefTable = classRangeRecords + 6 * classRangeCount;
         } break;
 
@@ -3029,6 +3042,7 @@ static void stbtt__fill_active_edges_new(float *scanline, float *scanline_fill,
                   dx = -dx;
                   dy = -dy;
                   t = x0, x0 = xb, xb = t;
+                  // [DEAR IMGUI] Fix static analyzer warning
                   (void)dx; // [ImGui: fix static analyzer warning]
                }
 
@@ -3167,7 +3181,13 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e,
          if (e->y0 != e->y1) {
             stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y_top, userdata);
             if (z != NULL) {
-               STBTT_assert(z->ey >= scan_y_top);
+               if (j == 0 && off_y != 0) {
+                  if (z->ey < scan_y_top) {
+                     // this can happen due to subpixel positioning and some kind of fp rounding error i think
+                     z->ey = scan_y_top;
+                  }
+               }
+               STBTT_assert(z->ey >= scan_y_top); // if we get really unlucky a tiny bit of an edge can be out of bounds
                // insert at front
                z->next = active;
                active = z;
@@ -3236,7 +3256,7 @@ static void stbtt__sort_edges_ins_sort(stbtt__edge *p, int n)
 
 static void stbtt__sort_edges_quicksort(stbtt__edge *p, int n)
 {
-   /* threshhold for transitioning to insertion sort */
+   /* threshold for transitioning to insertion sort */
    while (n > 12) {
       stbtt__edge t;
       int c01,c12,c,m,i,j;
@@ -3371,7 +3391,7 @@ static void stbtt__add_point(stbtt__point *points, int n, float x, float y)
    points[n].y = y;
 }
 
-// tesselate until threshhold p is happy... @TODO warped to compensate for non-linear stretching
+// tessellate until threshold p is happy... @TODO warped to compensate for non-linear stretching
 static int stbtt__tesselate_curve(stbtt__point *points, int *num_points, float x0, float y0, float x1, float y1, float x2, float y2, float objspace_flatness_squared, int n)
 {
    // midpoint
@@ -3796,6 +3816,7 @@ STBTT_DEF int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, in
    spc->stride_in_bytes = stride_in_bytes != 0 ? stride_in_bytes : pw;
    spc->h_oversample = 1;
    spc->v_oversample = 1;
+   spc->skip_missing = 0;
 
    stbrp_init_target(context, pw-padding, ph-padding, nodes, num_nodes);
 
@@ -3821,6 +3842,11 @@ STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h
       spc->v_oversample = v_oversample;
 }
 
+STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip)
+{
+   spc->skip_missing = skip;
+}
+
 #define STBTT__OVER_MASK  (STBTT_MAX_OVERSAMPLE-1)
 
 static void stbtt__h_prefilter(unsigned char *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width)
@@ -3974,13 +4000,17 @@ STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, const stb
          int x0,y0,x1,y1;
          int codepoint = ranges[i].array_of_unicode_codepoints == NULL ? ranges[i].first_unicode_codepoint_in_range + j : ranges[i].array_of_unicode_codepoints[j];
          int glyph = stbtt_FindGlyphIndex(info, codepoint);
-         stbtt_GetGlyphBitmapBoxSubpixel(info,glyph,
-                                         scale * spc->h_oversample,
-                                         scale * spc->v_oversample,
-                                         0,0,
-                                         &x0,&y0,&x1,&y1);
-         rects[k].w = (stbrp_coord) (x1-x0 + spc->padding + spc->h_oversample-1);
-         rects[k].h = (stbrp_coord) (y1-y0 + spc->padding + spc->v_oversample-1);
+         if (glyph == 0 && spc->skip_missing) {
+            rects[k].w = rects[k].h = 0;
+         } else {
+            stbtt_GetGlyphBitmapBoxSubpixel(info,glyph,
+                                            scale * spc->h_oversample,
+                                            scale * spc->v_oversample,
+                                            0,0,
+                                            &x0,&y0,&x1,&y1);
+            rects[k].w = (stbrp_coord) (x1-x0 + spc->padding + spc->h_oversample-1);
+            rects[k].h = (stbrp_coord) (y1-y0 + spc->padding + spc->v_oversample-1);
+         }
          ++k;
       }
    }
@@ -4033,7 +4063,7 @@ STBTT_DEF int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, const
       sub_y = stbtt__oversample_shift(spc->v_oversample);
       for (j=0; j < ranges[i].num_chars; ++j) {
          stbrp_rect *r = &rects[k];
-         if (r->was_packed) {
+         if (r->was_packed && r->w != 0 && r->h != 0) {
             stbtt_packedchar *bc = &ranges[i].chardata_for_range[j];
             int advance, lsb, x0,y0,x1,y1;
             int codepoint = ranges[i].array_of_unicode_codepoints == NULL ? ranges[i].first_unicode_codepoint_in_range + j : ranges[i].array_of_unicode_codepoints[j];
@@ -4147,6 +4177,19 @@ STBTT_DEF int stbtt_PackFontRange(stbtt_pack_context *spc, const unsigned char *
    return stbtt_PackFontRanges(spc, fontdata, font_index, &range, 1);
 }
 
+STBTT_DEF void stbtt_GetScaledFontVMetrics(const unsigned char *fontdata, int index, float size, float *ascent, float *descent, float *lineGap)
+{
+   int i_ascent, i_descent, i_lineGap;
+   float scale;
+   stbtt_fontinfo info;
+   stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata, index));
+   scale = size > 0 ? stbtt_ScaleForPixelHeight(&info, size) : stbtt_ScaleForMappingEmToPixels(&info, -size);
+   stbtt_GetFontVMetrics(&info, &i_ascent, &i_descent, &i_lineGap);
+   *ascent  = (float) i_ascent  * scale;
+   *descent = (float) i_descent * scale;
+   *lineGap = (float) i_lineGap * scale;
+}
+
 STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph, int char_index, float *xpos, float *ypos, stbtt_aligned_quad *q, int align_to_integer)
 {
    float ipw = 1.0f / pw, iph = 1.0f / ph;
@@ -4259,7 +4302,7 @@ static int stbtt__compute_crossings_x(float x, float y, int nverts, stbtt_vertex
    int winding = 0;
 
    orig[0] = x;
-   //orig[1] = y; // [ImGui] commmented double assignment without reading
+   //orig[1] = y; // [DEAR IMGUI] commmented double assignment
 
    // make sure y never passes through a vertex of the shape
    y_frac = (float) STBTT_fmod(y, 1.0f);