Widgets: Added SliderFloatRange2(), SliderIntRange2() for range selection. (#76)

- Two-handle slider for selecting a min/max range
- Middle bar dragging to move both handles together while maintaining range
- Hover highlighting to show which handle will be selected on click
- Ctrl+Click text input with "XXX...YYYY" parsing to set both values
- Per-handle format strings for different precision on each handle
- Optional step parameter for snapping

Author: Entrpi

imgui.h

@@ -704,6 +704,9 @@ namespace ImGui
     IMGUI_API bool          SliderInt4(const char* label, int v[4], int v_min, int v_max, const char* format = "%d", ImGuiSliderFlags flags = 0);
     IMGUI_API bool          SliderScalar(const char* label, ImGuiDataType data_type, void* p_data, const void* p_min, const void* p_max, const char* format = NULL, ImGuiSliderFlags flags = 0);
     IMGUI_API bool          SliderScalarN(const char* label, ImGuiDataType data_type, void* p_data, int components, const void* p_min, const void* p_max, const char* format = NULL, ImGuiSliderFlags flags = 0);
+    IMGUI_API bool          SliderScalarRange2(const char* label, ImGuiDataType data_type, void* p_v_min, void* p_v_max, const void* p_min, const void* p_max, const char* format = NULL, const char* format_max = NULL, ImGuiSliderFlags flags = 0, const void* p_step = NULL);
+    IMGUI_API bool          SliderFloatRange2(const char* label, float* v_current_min, float* v_current_max, float v_min = 0.0f, float v_max = 1.0f, const char* format = "%.3f", const char* format_max = NULL, ImGuiSliderFlags flags = 0, float step = 0.0f);
+    IMGUI_API bool          SliderIntRange2(const char* label, int* v_current_min, int* v_current_max, int v_min = 0, int v_max = 100, const char* format = "%d", const char* format_max = NULL, ImGuiSliderFlags flags = 0, int step = 0);
     IMGUI_API bool          VSliderFloat(const char* label, const ImVec2& size, float* v, float v_min, float v_max, const char* format = "%.3f", ImGuiSliderFlags flags = 0);
     IMGUI_API bool          VSliderInt(const char* label, const ImVec2& size, int* v, int v_min, int v_max, const char* format = "%d", ImGuiSliderFlags flags = 0);
     IMGUI_API bool          VSliderScalar(const char* label, const ImVec2& size, ImGuiDataType data_type, void* p_data, const void* p_min, const void* p_max, const char* format = NULL, ImGuiSliderFlags flags = 0);

imgui_demo.cpp

@@ -974,6 +974,13 @@ static void DemoWindowWidgetsBasic()
             const char* elem_name = (elem >= 0 && elem < Element_COUNT) ? elems_names[elem] : "Unknown";
             ImGui::SliderInt("slider enum", &elem, 0, Element_COUNT - 1, elem_name); // Use ImGuiSliderFlags_NoInput flag to disable Ctrl+Click here.
             ImGui::SameLine(); HelpMarker("Using the format string parameter to display a name instead of the underlying integer.");
+
+            IMGUI_DEMO_MARKER("Widgets/Basic/SliderFloatRange2, SliderIntRange2");
+            static float fmin = 0.25f, fmax = 0.75f;
+            static int imin = 25, imax = 75;
+            ImGui::SliderFloatRange2("range float", &fmin, &fmax, 0.0f, 1.0f);
+            ImGui::SliderIntRange2("range int", &imin, &imax, 0, 100);
+            ImGui::SameLine(); HelpMarker("Click and drag handles individually, or drag the bar between them to move both.");
         }
 
         ImGui::SeparatorText("Selectors/Pickers");

imgui_internal.h

@@ -2469,6 +2469,7 @@ struct ImGuiContext
     float                   SliderGrabClickOffset;
     float                   SliderCurrentAccum;                 // Accumulated slider delta when using navigation controls.
     bool                    SliderCurrentAccumDirty;            // Has the accumulated slider delta changed since last time we tried to apply it?
+    ImS8                    SliderRangeActiveHandle;            // For SliderScalarRange2: which handle is active (0=min, 1=max, -1=bar)
     bool                    DragCurrentAccumDirty;
     float                   DragCurrentAccum;                   // Accumulator for dragging modification. Always high-precision, not rounded by end-user precision settings
     float                   DragSpeedDefaultRatio;              // If speed == 0.0f, uses (max-min) * DragSpeedDefaultRatio