Log/Capture: Added LogTextV, a va_list variant of LogText. (#3828)

docs/CHANGELOG.txt

@@ -59,6 +59,7 @@ Other Changes:
 - Examples: Reworked setup of clear color to be compatible with transparent values.
 - CI: Use a dedicated "scheduled" workflow to trigger scheduled builds. Forks may disable this workflow if
   scheduled builds builds are not required. [@rokups]
+- Log/Capture: Added LogTextV, a va_list variant of LogText. [@PathogenDavid]
 
 
 -----------------------------------------------------------------------

imgui.cpp

@@ -9911,14 +9911,8 @@ void ImGui::EndDragDropTarget()
 //-----------------------------------------------------------------------------
 
 // Pass text data straight to log (without being displayed)
-void ImGui::LogText(const char* fmt, ...)
+static inline void LogTextV(ImGuiContext& g, const char* fmt, va_list args)
 {
-    ImGuiContext& g = *GImGui;
-    if (!g.LogEnabled)
-        return;
-
-    va_list args;
-    va_start(args, fmt);
     if (g.LogFile)
     {
         g.LogBuffer.Buf.resize(0);
@@ -9929,9 +9923,29 @@ void ImGui::LogText(const char* fmt, ...)
     {
         g.LogBuffer.appendfv(fmt, args);
     }
+}
+
+void ImGui::LogText(const char* fmt, ...)
+{
+    ImGuiContext& g = *GImGui;
+    if (!g.LogEnabled)
+        return;
+
+    va_list args;
+    va_start(args, fmt);
+    LogTextV(g, fmt, args);
     va_end(args);
 }
 
+void ImGui::LogTextV(const char* fmt, va_list args)
+{
+    ImGuiContext& g = *GImGui;
+    if (!g.LogEnabled)
+        return;
+
+    LogTextV(g, fmt, args);
+}
+
 // Internal version that takes a position to decide on newline placement and pad items according to their depth.
 // We split text into individual lines to add current tree level padding
 // FIXME: This code is a little complicated perhaps, considering simplifying the whole system.

imgui.h

@@ -748,6 +748,7 @@ namespace ImGui
     IMGUI_API void          LogFinish();                                                        // stop logging (close file, etc.)
     IMGUI_API void          LogButtons();                                                       // helper to display buttons for logging to tty/file/clipboard
     IMGUI_API void          LogText(const char* fmt, ...) IM_FMTARGS(1);                        // pass text data straight to log (without being displayed)
+    IMGUI_API void          LogTextV(const char* fmt, va_list args) IM_FMTLIST(1);
 
     // Drag and Drop
     // - If you stop calling BeginDragDropSource() the payload is preserved however it won't have a preview tooltip (we currently display a fallback "..." tooltip as replacement)