ImDrawList: Added ImDrawListFlags for AA settings. ImDrawList doesn't directly depends on GImGui anymore.

TODO.txt

@@ -30,12 +30,10 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
 !- scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet.
  - scrolling/clipping: separator on the initial position of a window is not visible (cursorpos.y <= clippos.y). (2017-08-20: can't repro)
 
- - drawlist: move Font, FontSize, FontTexUvWhitePixel inside ImDrawList and make it self-contained (apart from drawing settings?)
- - drawlist: make it easier to toggle AA per primitive, so we can use e.g. non-AA fill + AA borders more naturally
  - drawlist: end-user probably can't call Clear() directly because we expect a texture to be pushed in the stack.
  - drawlist: maintaining bounding box per command would allow to merge draw command when clipping isn't relied on (typical non-scrolling window or non-overflowing column would merge with previous command).
- - drawlist: avoid passing null (-9999,+9999) rectangle to end-user, instead perhaps pass rectangle based on io.DisplaySize?
  - drawlist: primtiives/helpers to manipulate vertices post submission, so e.g. a quad/rect can be resized to fit later submitted content, _without_ using the ChannelSplit api
+ - drawlist: make it easier to toggle AA per primitive, so we can use e.g. non-AA fill + AA borders more naturally
  - drawlist: non-AA strokes have gaps between points (#593, #288), especially RenderCheckmark().
  - drawlist: would be good to be able to deep copy a draw list (ImVector= op?).
  - drawlist/opt: AddRect() axis aligned pixel aligned (no-aa) could use 8 triangles instead of 16 and no normal calculation.

imgui.cpp

@@ -213,7 +213,8 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
- - 2017/12/21 (1.53) - removed 'bool anti_aliased = true' final parameter of ImDrawList::AddPolyline() and ImDrawList::AddConvexPolyFilled(). Anti-aliasing is controlled via the regular style.AntiAliased flags.
+ - 2017/12/21 (1.53) - renamed style.AntiAliasedShapes to style.AntiAliasedFill for consistency and as a way to explicitly break code that manipulate those flag at runtime. You can now manipulate ImDrawList::Flags
+ - 2017/12/21 (1.53) - removed 'bool anti_aliased = true' final parameter of ImDrawList::AddPolyline() and ImDrawList::AddConvexPolyFilled(). Prefer manipulating ImDrawList::Flags.
  - 2017/12/14 (1.53) - using the ImGuiWindowFlags_NoScrollWithMouse flag on a child window forwards the mouse wheel event to the parent window, unless either ImGuiWindowFlags_NoInputs or ImGuiWindowFlags_NoScrollbar are also set.
  - 2017/12/13 (1.53) - renamed GetItemsLineHeightWithSpacing() to GetFrameHeightWithSpacing(). Kept redirection function (will obsolete).
  - 2017/12/13 (1.53) - obsoleted IsRootWindowFocused() in favor of using IsWindowFocused(ImGuiFocusedFlags_RootWindow). Kept redirection function (will obsolete).
@@ -735,7 +736,7 @@ ImGuiStyle::ImGuiStyle()
     DisplayWindowPadding    = ImVec2(22,22);    // Window positions are clamped to be visible within the display area by at least this amount. Only covers regular windows.
     DisplaySafeAreaPadding  = ImVec2(4,4);      // If you cannot see the edge of your screen (e.g. on a TV) increase the safe area padding. Covers popups/tooltips as well regular windows.
     AntiAliasedLines        = true;             // Enable anti-aliasing on lines/borders. Disable if you are really short on CPU/GPU.
-    AntiAliasedShapes       = true;             // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
+    AntiAliasedFill         = true;             // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
     CurveTessellationTol    = 1.25f;            // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
 
     ImGui::StyleColorsClassic(this);
@@ -2290,6 +2291,7 @@ void ImGui::NewFrame()
     g.OverlayDrawList.Clear();
     g.OverlayDrawList.PushTextureID(g.IO.Fonts->TexID);
     g.OverlayDrawList.PushClipRectFullScreen();
+    g.OverlayDrawList.Flags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
 
     // Mark rendering data as invalid to prevent user who may have a handle on it to use it
     g.RenderDrawData.Valid = false;
@@ -4475,8 +4477,9 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->LastFrameActive = current_frame;
         window->IDStack.resize(1);
 
-        // Clear draw list, setup texture, outer clipping rectangle
+        // Setup draw list and outer clipping rectangle
         window->DrawList->Clear();
+        window->DrawList->Flags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
         window->DrawList->PushTextureID(g.Font->ContainerAtlas->TexID);
         ImRect fullscreen_rect(GetVisibleRect());
         if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & ImGuiWindowFlags_Popup))
@@ -11662,11 +11665,10 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                             ImGui::Selectable(buf, false);
                             if (ImGui::IsItemHovered())
                             {
-                                ImGuiStyle& style = ImGui::GetStyle();
+                                ImDrawListFlags backup_flags = overlay_draw_list->Flags;
-                                bool backup_aa_lines = style.AntiAliasedLines;
+                                overlay_draw_list->Flags &= ~ImDrawListFlags_AntiAliasedLines; // Disable AA on triangle outlines at is more readable for very large and thin triangles.
-                                style.AntiAliasedLines = false; // Disable AA on triangle outlines at is more readable for very large and thin triangles.
                                 overlay_draw_list->AddPolyline(triangles_pos, 3, IM_COL32(255,255,0,255), true, 1.0f);
-                                style.AntiAliasedLines = backup_aa_lines;
+                                overlay_draw_list->Flags = backup_flags;
                             }
                         }
                     ImGui::TreePop();

imgui.h

@@ -79,6 +79,7 @@ typedef int ImGuiKey;               // enum: a key identifier (ImGui-side enum)
 typedef int ImGuiMouseCursor;       // enum: a mouse cursor identifier          // enum ImGuiMouseCursor_
 typedef int ImGuiStyleVar;          // enum: a variable identifier for styling  // enum ImGuiStyleVar_
 typedef int ImDrawCornerFlags;      // flags: for ImDrawList::AddRect*() etc.   // enum ImDrawCornerFlags_
+typedef int ImDrawListFlags;        // flags: for ImDrawList                    // enum ImDrawListFlags_
 typedef int ImGuiColorEditFlags;    // flags: for ColorEdit*(), ColorPicker*()  // enum ImGuiColorEditFlags_
 typedef int ImGuiColumnsFlags;      // flags: for *Columns*()                   // enum ImGuiColumnsFlags_
 typedef int ImGuiDragDropFlags;     // flags: for *DragDrop*()                  // enum ImGuiDragDropFlags_
@@ -855,7 +856,7 @@ struct ImGuiStyle
     ImVec2      DisplayWindowPadding;       // Window positions are clamped to be visible within the display area by at least this amount. Only covers regular windows.
     ImVec2      DisplaySafeAreaPadding;     // If you cannot see the edge of your screen (e.g. on a TV) increase the safe area padding. Covers popups/tooltips as well regular windows.
     bool        AntiAliasedLines;           // Enable anti-aliasing on lines/borders. Disable if you are really tight on CPU/GPU.
-    bool        AntiAliasedShapes;          // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
+    bool        AntiAliasedFill;            // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
     float       CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
     ImVec4      Colors[ImGuiCol_COUNT];
 
@@ -1372,6 +1373,12 @@ enum ImDrawCornerFlags_
     ImDrawCornerFlags_All       = 0xF     // In your function calls you may use ~0 (= all bits sets) instead of ImDrawCornerFlags_All, as a convenience
 };
 
+enum ImDrawListFlags_
+{
+    ImDrawListFlags_AntiAliasedLines = 1 << 0,
+    ImDrawListFlags_AntiAliasedFill  = 1 << 1
+};
+
 // Draw command list
 // This is the low-level list of polygons that ImGui functions are filling. At the end of the frame, all command lists are passed to your ImGuiIO::RenderDrawListFn function for rendering.
 // Each ImGui window contains its own ImDrawList. You can use ImGui::GetWindowDrawList() to access the current window draw list and draw custom primitives.
@@ -1386,6 +1393,7 @@ struct ImDrawList
     ImVector<ImDrawVert>    VtxBuffer;          // Vertex buffer.
 
     // [Internal, used while building lists]
+    ImDrawListFlags         Flags;              // Flags, you may poke into these to adjust anti-aliasing settings per-primitive.
     const ImDrawListSharedData* _Data;          // Pointer to shared draw data (you can use ImGui::GetDrawListSharedData() to get the one from current ImGui context)
     const char*             _OwnerName;         // Pointer to owner window's name for debugging
     unsigned int            _VtxCurrentIdx;     // [Internal] == VtxBuffer.Size

imgui_demo.cpp

@@ -1983,7 +1983,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
     if (ImGui::TreeNode("Rendering"))
     {
         ImGui::Checkbox("Anti-aliased lines", &style.AntiAliasedLines); ImGui::SameLine(); ShowHelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
-        ImGui::Checkbox("Anti-aliased shapes", &style.AntiAliasedShapes);
+        ImGui::Checkbox("Anti-aliased fill", &style.AntiAliasedFill);
         ImGui::PushItemWidth(100);
         ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, FLT_MAX, NULL, 2.0f);
         if (style.CurveTessellationTol < 0.0f) style.CurveTessellationTol = 0.10f;

imgui_draw.cpp

@@ -304,6 +304,7 @@ void ImDrawList::Clear()
     CmdBuffer.resize(0);
     IdxBuffer.resize(0);
     VtxBuffer.resize(0);
+    Flags = ImDrawListFlags_AntiAliasedLines | ImDrawListFlags_AntiAliasedFill;
     _VtxCurrentIdx = 0;
     _VtxWritePtr = NULL;
     _IdxWritePtr = NULL;
@@ -598,15 +599,13 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
         return;
 
     const ImVec2 uv = _Data->TexUvWhitePixel;
-    bool anti_aliased = GImGui->Style.AntiAliasedLines;
-    //if (ImGui::GetIO().KeyCtrl) anti_aliased = false; // Debug
 
     int count = points_count;
     if (!closed)
         count = points_count-1;
 
     const bool thick_line = thickness > 1.0f;
-    if (anti_aliased)
+    if (Flags & ImDrawListFlags_AntiAliasedLines)
     {
         // Anti-aliased stroke
         const float AA_SIZE = 1.0f;
@@ -776,10 +775,8 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
 void ImDrawList::AddConvexPolyFilled(const ImVec2* points, const int points_count, ImU32 col)
 {
     const ImVec2 uv = _Data->TexUvWhitePixel;
-    bool anti_aliased = GImGui->Style.AntiAliasedShapes;
-    //if (ImGui::GetIO().KeyCtrl) anti_aliased = false; // Debug
 
-    if (anti_aliased)
+    if (Flags & ImDrawListFlags_AntiAliasedFill)
     {
         // Anti-aliased Fill
         const float AA_SIZE = 1.0f;