Comments about using "power curves". Demo tweaks. (#648)

imgui.cpp

@@ -8752,7 +8752,7 @@ bool ImGui::SliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v
     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;
 
-    // For logarithmic sliders that cross over sign boundary we want the exponential increase to be symmetric around 0.0f
+    // For power curve sliders that cross over sign boundary we want the curve to be symmetric around 0.0f
     float linear_zero_pos = 0.0f;   // 0.0->1.0f
     if (v_min * v_max < 0.0f)
     {
@@ -8827,7 +8827,7 @@ bool ImGui::SliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v
             float new_value;
             if (is_non_linear)
             {
-                // Account for logarithmic scale on both sides of the zero
+                // Account for power curve scale on both sides of the zero
                 if (clicked_t < linear_zero_pos)
                 {
                     // Negative: rescale to the negative range before powering
@@ -8878,11 +8878,11 @@ bool ImGui::SliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v
     return value_changed;
 }
 
-// Use power!=1.0 for logarithmic sliders.
 // Adjust format to decorate the value with a prefix or a suffix.
 //   "%.3f"         1.234
 //   "%5.2f secs"   01.23 secs
 //   "Gold: %.0f"   Gold: 1
+// Use power != 1.0f for non-linear sliders.
 bool ImGui::SliderFloat(const char* label, float* v, float v_min, float v_max, const char* format, float power)
 {
     ImGuiWindow* window = GetCurrentWindow();
@@ -9159,7 +9159,7 @@ bool ImGui::DragBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v_s
     {
         if (fabsf(power - 1.0f) > 0.001f)
         {
-            // Logarithmic curve on both side of 0.0
+            // Power curve on both side of 0.0
             float v0_abs = v_cur >= 0.0f ? v_cur : -v_cur;
             float v0_sign = v_cur >= 0.0f ? 1.0f : -1.0f;
             float v1 = powf(v0_abs, 1.0f / power) + (adjust_delta * v0_sign);

imgui.h

@@ -361,7 +361,7 @@ namespace ImGui
     IMGUI_API bool          InputDouble(const char* label, double* v, double step = 0.0f, double step_fast = 0.0f, const char* format = "%.6f", ImGuiInputTextFlags extra_flags = 0);
 
     // Widgets: Sliders (tip: ctrl+click on a slider to input with keyboard. manually input values aren't clamped, can go off-bounds)
-    IMGUI_API bool          SliderFloat(const char* label, float* v, float v_min, float v_max, const char* format = "%.3f", float power = 1.0f);     // adjust format to decorate the value with a prefix or a suffix for in-slider labels or unit display. Use power!=1.0 for logarithmic sliders
+    IMGUI_API bool          SliderFloat(const char* label, float* v, float v_min, float v_max, const char* format = "%.3f", float power = 1.0f);     // adjust format to decorate the value with a prefix or a suffix for in-slider labels or unit display. Use power!=1.0 for power curve sliders
     IMGUI_API bool          SliderFloat2(const char* label, float v[2], float v_min, float v_max, const char* format = "%.3f", float power = 1.0f);
     IMGUI_API bool          SliderFloat3(const char* label, float v[3], float v_min, float v_max, const char* format = "%.3f", float power = 1.0f);
     IMGUI_API bool          SliderFloat4(const char* label, float v[4], float v_min, float v_max, const char* format = "%.3f", float power = 1.0f);

imgui_demo.cpp

@@ -1856,8 +1856,8 @@ void ImGui::ShowDemoWindow(bool* p_open)
         ImGui::Checkbox("io.MouseDrawCursor", &io.MouseDrawCursor);
         ImGui::SameLine(); ShowHelpMarker("Instruct ImGui to render a mouse cursor for you in software. Note that a mouse cursor rendered via your application GPU rendering path will feel more laggy than hardware cursor, but will be more in sync with your other visuals.\n\nSome desktop applications may use both kinds of cursors (e.g. enable software cursor only when resizing/dragging something).");
 
-        ImGui::CheckboxFlags("io.ConfigFlags: NavEnableGamepad", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NavEnableGamepad);
-        ImGui::CheckboxFlags("io.ConfigFlags: NavEnableKeyboard", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NavEnableKeyboard);
+        ImGui::CheckboxFlags("io.ConfigFlags: NavEnableGamepad [beta]", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NavEnableGamepad);
+        ImGui::CheckboxFlags("io.ConfigFlags: NavEnableKeyboard [beta]", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NavEnableKeyboard);
         ImGui::CheckboxFlags("io.ConfigFlags: NavEnableSetMousePos", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NavEnableSetMousePos); 
         ImGui::SameLine(); ShowHelpMarker("Instruct navigation to move the mouse cursor. See comment for ImGuiConfigFlags_NavEnableSetMousePos.");
         ImGui::CheckboxFlags("io.ConfigFlags: NoMouseCursorChange", (unsigned int *)&io.ConfigFlags, ImGuiConfigFlags_NoMouseCursorChange);