Internals: Added support for overriding locale decimal point, undocumented. (#2278) + Misc doc update.

Doc: Mention IMGUI_VERSION_NUM in recent api breaking changes + textwrap some demo code.

docs/CHANGELOG.txt

@@ -88,6 +88,7 @@ Breaking Changes:
     - You can replace the >1.0f value with ImGuiSliderFlags_Logarithmic to fix the warning/assert
       and get a _similar_ effect as previous uses of power >1.0f.
   See https://github.com/ocornut/imgui/issues/3361 for all details.
+  For shared code, you can version check at compile-time with `#if IMGUI_VERSION_NUM >= 17704`.
   Kept inline redirection functions (will obsolete) apart for: DragFloatRange2(), VSliderFloat(), VSliderScalar().
   For those three the 'float power=1.0f' version was removed directly as they were most unlikely ever used.
 - DragInt, DragFloat, DragScalar: Obsoleted use of v_min > v_max to lock edits (introduced in 1.73, this was not

imgui.cpp

@@ -380,6 +380,7 @@ CODE
                        - if you set the 'power' parameter to >1.0f (to enable non-linear editing): 1/ your compiler may warn on float>int conversion, 2/ code will assert at runtime, 3/ in case asserts are disabled, the code will not crash and enable the _Logarithmic flag. 4/ you can replace the >1.0f value with ImGuiSliderFlags_Logarithmic to fix the warning/assert and get a _similar_ effect as previous uses of power >1.0f.
                        see https://github.com/ocornut/imgui/issues/3361 for all details.
                        kept inline redirection functions (will obsolete) apart for: DragFloatRange2(), VSliderFloat(), VSliderScalar(). For those three the 'float power=1.0f' version were removed directly as they were most unlikely ever used.
+                       for shared code, you can version check at compile-time with `#if IMGUI_VERSION_NUM >= 17704`.
                      - obsoleted use of v_min > v_max in DragInt, DragFloat, DragScalar to lock edits (introduced in 1.73, was not demoed nor documented very), will be replaced by a more generic ReadOnly feature. You may use the ImGuiSliderFlags_ReadOnly internal flag in the meantime.
  - 2020/06/23 (1.77) - removed BeginPopupContextWindow(const char*, int mouse_button, bool also_over_items) in favor of BeginPopupContextWindow(const char*, ImGuiPopupFlags flags) with ImGuiPopupFlags_NoOverItems.
  - 2020/06/15 (1.77) - renamed OpenPopupOnItemClick() to OpenPopupContextItem(). Kept inline redirection function (will obsolete).

imgui.h

@@ -1712,7 +1712,8 @@ struct ImGuiPayload
 namespace ImGui
 {
     // OBSOLETED in 1.78 (from August 2020)
-    // Old drag/sliders functions that took a 'float power = 1.0' argument instead of flags
+    // Old drag/sliders functions that took a 'float power = 1.0' argument instead of flags.
+    // For shared code, you can version check at compile-time with `#if IMGUI_VERSION_NUM >= 17704`.
     IMGUI_API bool      DragScalar(const char* label, ImGuiDataType data_type, void* p_data, float v_speed, const void* p_min, const void* p_max, const char* format, float power);
     IMGUI_API bool      DragScalarN(const char* label, ImGuiDataType data_type, void* p_data, int components, float v_speed, const void* p_min, const void* p_max, const char* format, float power);
     static inline bool  DragFloat(const char* label, float* v, float v_speed, float v_min, float v_max, const char* format, float power)    { return DragScalar(label, ImGuiDataType_Float, v, v_speed, &v_min, &v_max, format, power); }

imgui_demo.cpp

@@ -560,7 +560,9 @@ static void ShowDemoWindowWidgets()
             const char* items[] = { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIIIIII", "JJJJ", "KKKKKKK" };
             static int item_current = 0;
             ImGui::Combo("combo", &item_current, items, IM_ARRAYSIZE(items));
-            ImGui::SameLine(); HelpMarker("Refer to the \"Combo\" section below for an explanation of the full BeginCombo/EndCombo API, and demonstration of various flags.\n");
+            ImGui::SameLine(); HelpMarker(
+                "Refer to the \"Combo\" section below for an explanation of the full BeginCombo/EndCombo API, "
+                "and demonstration of various flags.\n");
         }
 
         {
@@ -834,7 +836,9 @@ static void ShowDemoWindowWidgets()
         if (ImGui::TreeNode("Word Wrapping"))
         {
             // Using shortcut. You can use PushTextWrapPos()/PopTextWrapPos() for more flexibility.
-            ImGui::TextWrapped("This text should automatically wrap on the edge of the window. The current implementation for text wrapping follows simple rules suitable for English and possibly other languages.");
+            ImGui::TextWrapped(
+                "This text should automatically wrap on the edge of the window. The current implementation "
+                "for text wrapping follows simple rules suitable for English and possibly other languages.");
             ImGui::Spacing();
 
             static float wrap_width = 200.0f;
@@ -891,7 +895,10 @@ static void ShowDemoWindowWidgets()
     if (ImGui::TreeNode("Images"))
     {
         ImGuiIO& io = ImGui::GetIO();
-        ImGui::TextWrapped("Below we are displaying the font texture (which is the only texture we have access to in this demo). Use the 'ImTextureID' type as storage to pass pointers or identifier to your own texture data. Hover the texture for a zoomed view!");
+        ImGui::TextWrapped(
+            "Below we are displaying the font texture (which is the only texture we have access to in this demo). "
+            "Use the 'ImTextureID' type as storage to pass pointers or identifier to your own texture data. "
+            "Hover the texture for a zoomed view!");
 
         // Below we are displaying the font texture because it is the only texture we have access to inside the demo!
         // Remember that ImTextureID is just storage for whatever you want it to be. It is essentially a value that
@@ -1000,9 +1007,9 @@ static void ShowDemoWindowWidgets()
         ImGui::Combo("combo 3 (array)", &item_current_3, items, IM_ARRAYSIZE(items));
 
         // Simplified one-liner Combo() using an accessor function
-        struct FuncHolder { static bool ItemGetter(void* data, int idx, const char** out_str) { *out_str = ((const char**)data)[idx]; return true; } };
+        struct Funcs { static bool ItemGetter(void* data, int n, const char** out_str) { *out_str = ((const char**)data)[n]; return true; } };
         static int item_current_4 = 0;
-        ImGui::Combo("combo 4 (function)", &item_current_4, &FuncHolder::ItemGetter, items, IM_ARRAYSIZE(items));
+        ImGui::Combo("combo 4 (function)", &item_current_4, &Funcs::ItemGetter, items, IM_ARRAYSIZE(items));
 
         ImGui::TreePop();
     }
@@ -1640,7 +1647,10 @@ static void ShowDemoWindowWidgets()
         const float drag_speed = 0.2f;
         static bool drag_clamp = false;
         ImGui::Text("Drags:");
-        ImGui::Checkbox("Clamp integers to 0..50", &drag_clamp); ImGui::SameLine(); HelpMarker("As with every widgets in dear imgui, we never modify values unless there is a user interaction.\nYou can override the clamping limits by using CTRL+Click to input a value.");
+        ImGui::Checkbox("Clamp integers to 0..50", &drag_clamp);
+        ImGui::SameLine(); HelpMarker(
+            "As with every widgets in dear imgui, we never modify values unless there is a user interaction.\n"
+            "You can override the clamping limits by using CTRL+Click to input a value.");
         ImGui::DragScalar("drag s8",        ImGuiDataType_S8,     &s8_v,  drag_speed, drag_clamp ? &s8_zero  : NULL, drag_clamp ? &s8_fifty  : NULL);
         ImGui::DragScalar("drag u8",        ImGuiDataType_U8,     &u8_v,  drag_speed, drag_clamp ? &u8_zero  : NULL, drag_clamp ? &u8_fifty  : NULL, "%u ms");
         ImGui::DragScalar("drag s16",       ImGuiDataType_S16,    &s16_v, drag_speed, drag_clamp ? &s16_zero : NULL, drag_clamp ? &s16_fifty : NULL);
@@ -3957,9 +3967,13 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
         if (ImGui::BeginTabItem("Rendering"))
         {
             ImGui::Checkbox("Anti-aliased lines", &style.AntiAliasedLines);
-            ImGui::SameLine(); HelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
+            ImGui::SameLine();
+            HelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
+
             ImGui::Checkbox("Anti-aliased lines use texture", &style.AntiAliasedLinesUseTex);
-            ImGui::SameLine(); HelpMarker("Faster lines using texture data. Require back-end to render with bilinear filtering (not point/nearest filtering).");
+            ImGui::SameLine();
+            HelpMarker("Faster lines using texture data. Require back-end to render with bilinear filtering (not point/nearest filtering).");
+
             ImGui::Checkbox("Anti-aliased fill", &style.AntiAliasedFill);
             ImGui::PushItemWidth(100);
             ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, 10.0f, "%.2f");
@@ -3972,12 +3986,13 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                 ImGui::SetNextWindowPos(ImGui::GetCursorScreenPos());
                 ImGui::BeginTooltip();
                 ImVec2 p = ImGui::GetCursorScreenPos();
+                ImDrawList* draw_list = ImGui::GetWindowDrawList();
                 float RAD_MIN = 10.0f, RAD_MAX = 80.0f;
                 float off_x = 10.0f;
                 for (int n = 0; n < 7; n++)
                 {
                     const float rad = RAD_MIN + (RAD_MAX - RAD_MIN) * (float)n / (7.0f - 1.0f);
-                    ImGui::GetWindowDrawList()->AddCircle(ImVec2(p.x + off_x + rad, p.y + RAD_MAX), rad, ImGui::GetColorU32(ImGuiCol_Text), 0);
+                    draw_list->AddCircle(ImVec2(p.x + off_x + rad, p.y + RAD_MAX), rad, ImGui::GetColorU32(ImGuiCol_Text), 0);
                     off_x += 10.0f + rad * 2.0f;
                 }
                 ImGui::Dummy(ImVec2(off_x, RAD_MAX * 2.0f));
@@ -4200,9 +4215,12 @@ struct ExampleAppConsole
 
         // TODO: display items starting from the bottom
 
-        if (ImGui::SmallButton("Add Debug Text"))  { AddLog("%d some text", Items.Size); AddLog("some more text"); AddLog("display very important message here!"); } ImGui::SameLine();
+        if (ImGui::SmallButton("Add Debug Text"))  { AddLog("%d some text", Items.Size); AddLog("some more text"); AddLog("display very important message here!"); }
-        if (ImGui::SmallButton("Add Debug Error")) { AddLog("[error] something went wrong"); } ImGui::SameLine();
+        ImGui::SameLine();
-        if (ImGui::SmallButton("Clear"))           { ClearLog(); } ImGui::SameLine();
+        if (ImGui::SmallButton("Add Debug Error")) { AddLog("[error] something went wrong"); }
+        ImGui::SameLine();
+        if (ImGui::SmallButton("Clear"))           { ClearLog(); }
+        ImGui::SameLine();
         bool copy_to_clipboard = ImGui::SmallButton("Copy");
         //static float t = 0.0f; if (ImGui::GetTime() - t > 0.02f) { t = ImGui::GetTime(); AddLog("Spam %f", t); }
 
@@ -4695,7 +4713,9 @@ static void ShowPlaceholderObject(const char* prefix, int uid)
 {
     // Use object uid as identifier. Most commonly you could also use the object pointer as a base ID.
     ImGui::PushID(uid);
-    ImGui::AlignTextToFramePadding();   // Text and Tree nodes are less high than framed widgets, here we add vertical spacing to make the tree lines equal high.
+
+    // Text and Tree nodes are less high than framed widgets, using AlignTextToFramePadding() we add vertical spacing to make the tree lines equal high.
+    ImGui::AlignTextToFramePadding();
     bool node_open = ImGui::TreeNode("Object", "%s_%u", prefix, uid);
     ImGui::NextColumn();
     ImGui::AlignTextToFramePadding();

imgui_internal.h

@@ -1290,6 +1290,7 @@ struct ImGuiContext
     // Platform support
     ImVec2                  PlatformImePos;                     // Cursor position request & last passed to the OS Input Method Editor
     ImVec2                  PlatformImeLastPos;
+    char                    PlatformLocaleDecimalPoint;         // '.' or *localeconv()->decimal_point
 
     // Settings
     bool                    SettingsLoaded;
@@ -1440,6 +1441,7 @@ struct ImGuiContext
         TooltipOverrideCount = 0;
 
         PlatformImePos = PlatformImeLastPos = ImVec2(FLT_MAX, FLT_MAX);
+        PlatformLocaleDecimalPoint = '.';
 
         SettingsLoaded = false;
         SettingsDirtyTimer = 0.0f;

imgui_widgets.cpp

@@ -3691,14 +3691,22 @@ static bool InputTextFilterCharacter(unsigned int* p_char, ImGuiInputTextFlags f
     // Generic named filters
     if (flags & (ImGuiInputTextFlags_CharsDecimal | ImGuiInputTextFlags_CharsHexadecimal | ImGuiInputTextFlags_CharsUppercase | ImGuiInputTextFlags_CharsNoBlank | ImGuiInputTextFlags_CharsScientific))
     {
+        // The libc allows overriding locale, with e.g. 'setlocale(LC_NUMERIC, "de_DE.UTF-8");' which affect the output/input of printf/scanf.
+        // The standard mandate that programs starts in the "C" locale where the decimal point is '.'.
+        // We don't really intend to provide widespread support for it, but out of empathy for people stuck with using odd API, we support the bare minimum aka overriding the decimal point.
+        // Change the default decimal_point with:
+        //   ImGui::GetCurrentContext()->PlatformLocaleDecimalPoint = *localeconv()->decimal_point;
+        ImGuiContext& g = *GImGui;
+        const unsigned c_decimal_point = (unsigned int)g.PlatformLocaleDecimalPoint;
+
         // Allow 0-9 . - + * /
         if (flags & ImGuiInputTextFlags_CharsDecimal)
-            if (!(c >= '0' && c <= '9') && (c != '.') && (c != '-') && (c != '+') && (c != '*') && (c != '/'))
+            if (!(c >= '0' && c <= '9') && (c != c_decimal_point) && (c != '-') && (c != '+') && (c != '*') && (c != '/'))
                 return false;
 
         // Allow 0-9 . - + * / e E
         if (flags & ImGuiInputTextFlags_CharsScientific)
-            if (!(c >= '0' && c <= '9') && (c != '.') && (c != '-') && (c != '+') && (c != '*') && (c != '/') && (c != 'e') && (c != 'E'))
+            if (!(c >= '0' && c <= '9') && (c != c_decimal_point) && (c != '-') && (c != '+') && (c != '*') && (c != '/') && (c != 'e') && (c != 'E'))
                 return false;
 
         // Allow 0-9 a-F A-F