SliderInt(): Fixed reverse direction mode when (v_max-v_min)==-1 (#854) (+ ref #919)

imgui.cpp

@@ -6489,7 +6489,7 @@ bool ImGui::SliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v
     if (decimal_precision > 0)
         grab_sz = ImMin(style.GrabMinSize, slider_sz);
     else
-        grab_sz = ImMin(ImMax(1.0f * (slider_sz / (v_max-v_min+1.0f)), style.GrabMinSize), slider_sz);  // Integer sliders, if possible have the grab size represent 1 unit
+        grab_sz = ImMin(ImMax(1.0f * (slider_sz / ((v_min < v_max ? v_max - v_min : v_min - v_max) + 1.0f)), style.GrabMinSize), slider_sz);  // Integer sliders, if possible have the grab size represent 1 unit
     const float slider_usable_sz = slider_sz - grab_sz;
     const float slider_usable_pos_min = (is_horizontal ? frame_bb.Min.x : frame_bb.Min.y) + grab_padding + grab_sz*0.5f;
     const float slider_usable_pos_max = (is_horizontal ? frame_bb.Max.x : frame_bb.Max.y) - grab_padding - grab_sz*0.5f;