Added IMGUI_DISABLE_MATH_FUNCTIONS in imconfig.h to make it slightly easier to redefine wrappers to std maths functions such as fabsf(), fmodf(), etc. Comments.

CHANGELOG.txt

@@ -81,6 +81,7 @@ Other Changes:
 - Fonts: When building font atlas, glyphs that are missing in the fonts are not using the glyph slot to render a dummy/default glyph. Saves space and allow merging fonts with 
   overlapping font ranges such as FontAwesome5 which split out the Brands separately from the Solid fonts. (#1703, #1671)
 - Misc: Added IMGUI_CHECKVERSION() macro to compare version string and data structure sizes in order to catch issues with mismatching compilation unit settings. (#1695, #1769)
+- Misc: Added IMGUI_DISABLE_MATH_FUNCTIONS in imconfig.h to make it slightly easier to redefine wrappers to std maths functions such as fabsf(), fmodf(), etc.
 - Misc: Fix to allow compiling in unity builds where stb_rectpack/stb_truetype may be already included in the same compilation unit.
 - Demo: Simple Overlay: Added a context menu item to enable freely moving the window. 
 - Demo: Added demo for DragScalar(), InputScalar(), SliderScalar(). (#643)

imconfig.h

@@ -20,19 +20,19 @@
 //#define IMGUI_API __declspec( dllexport )
 //#define IMGUI_API __declspec( dllimport )
 
-//---- Don't define obsolete functions/enums names. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names
+//---- Don't define obsolete functions/enums names. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names.
 //#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 
-//---- Don't implement default handlers for Windows (so as not to link with certain functions)
-//#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // Don't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc.
-//#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // Don't use and link with ImmGetContext/ImmSetCompositionWindow.
-
 //---- Don't implement demo windows functionality (ShowDemoWindow()/ShowStyleEditor()/ShowUserGuide() methods will be empty)
 //---- It is very strongly recommended to NOT disable the demo windows during development. Please read the comments in imgui_demo.cpp.
 //#define IMGUI_DISABLE_DEMO_WINDOWS
 
-//---- Don't implement ImFormatString(), ImFormatStringV() so you can reimplement them yourself.
+//---- Don't implement some functions to reduce linkage requirements.
-//#define IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS
+//#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc.
+//#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // [Win32] Don't implement default IME handler. Won't use and link with ImmGetContext/ImmSetCompositionWindow.
+//#define IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS             // Don't implement ImFormatString(), ImFormatStringV() so you can reimplement them yourself.      
+//#define IMGUI_DISABLE_MATH_FUNCTIONS                      // Don't implement ImFabs(), ImSqrt(), ImPow(), ImFmod() so you can reimplement them yourself.
+//#define IMGUI_DISABLE_DEFAULT_ALLOCATORS                  // Don't implement default allocators calling malloc()/free(). You will need to call ImGui::SetAllocatorFunctions().
 
 //---- Include imgui_user.h at the end of imgui.h as a convenience
 //#define IMGUI_INCLUDE_IMGUI_USER_H

imgui.cpp

@@ -1436,7 +1436,7 @@ void ImGui::ColorConvertRGBtoHSV(float r, float g, float b, float& out_h, float&
     }
 
     const float chroma = r - (g < b ? g : b);
-    out_h = fabsf(K + (g - b) / (6.f * chroma + 1e-20f));
+    out_h = ImFabs(K + (g - b) / (6.f * chroma + 1e-20f));
     out_s = chroma / (r + 1e-20f);
     out_v = r;
 }
@@ -1452,7 +1452,7 @@ void ImGui::ColorConvertHSVtoRGB(float h, float s, float v, float& out_r, float&
         return;
     }
 
-    h = fmodf(h, 1.0f) / (60.0f/360.0f);
+    h = ImFmod(h, 1.0f) / (60.0f/360.0f);
     int   i = (int)h;
     float f = h - (float)i;
     float p = v * (1.0f - s);
@@ -2210,7 +2210,7 @@ void ImGui::ItemSize(const ImRect& bb, float text_offset_y)
 
 static ImGuiDir inline NavScoreItemGetQuadrant(float dx, float dy)
 {
-    if (fabsf(dx) > fabsf(dy))
+    if (ImFabs(dx) > ImFabs(dy))
         return (dx > 0.0f) ? ImGuiDir_Right : ImGuiDir_Left;
     return (dy > 0.0f) ? ImGuiDir_Down : ImGuiDir_Up;
 }
@@ -2259,12 +2259,12 @@ static bool NavScoreItem(ImGuiNavMoveResult* result, ImRect cand)
     float dby = NavScoreItemDistInterval(ImLerp(cand.Min.y, cand.Max.y, 0.2f), ImLerp(cand.Min.y, cand.Max.y, 0.8f), ImLerp(curr.Min.y, curr.Max.y, 0.2f), ImLerp(curr.Min.y, curr.Max.y, 0.8f)); // Scale down on Y to keep using box-distance for vertically touching items
     if (dby != 0.0f && dbx != 0.0f)
        dbx = (dbx/1000.0f) + ((dbx > 0.0f) ? +1.0f : -1.0f);
-    float dist_box = fabsf(dbx) + fabsf(dby);
+    float dist_box = ImFabs(dbx) + ImFabs(dby);
 
     // Compute distance between centers (this is off by a factor of 2, but we only compare center distances with each other so it doesn't matter)
     float dcx = (cand.Min.x + cand.Max.x) - (curr.Min.x + curr.Max.x);
     float dcy = (cand.Min.y + cand.Max.y) - (curr.Min.y + curr.Max.y);
-    float dist_center = fabsf(dcx) + fabsf(dcy); // L1 metric (need this for our connectedness guarantee)
+    float dist_center = ImFabs(dcx) + ImFabs(dcy); // L1 metric (need this for our connectedness guarantee)
 
     // Determine which quadrant of 'curr' our candidate item 'cand' lies in based on distance
     ImGuiDir quadrant;
@@ -3307,7 +3307,7 @@ static void ImGui::NavUpdate()
     g.NavScoringRectScreen = g.NavWindow ? ImRect(g.NavWindow->Pos + nav_rect_rel.Min, g.NavWindow->Pos + nav_rect_rel.Max) : GetViewportRect();
     g.NavScoringRectScreen.Min.x = ImMin(g.NavScoringRectScreen.Min.x + 1.0f, g.NavScoringRectScreen.Max.x);
     g.NavScoringRectScreen.Max.x = g.NavScoringRectScreen.Min.x;
-    IM_ASSERT(!g.NavScoringRectScreen.IsInverted()); // Ensure if we have a finite, non-inverted bounding box here will allows us to remove extraneous fabsf() calls in NavScoreItem().
+    IM_ASSERT(!g.NavScoringRectScreen.IsInverted()); // Ensure if we have a finite, non-inverted bounding box here will allows us to remove extraneous ImFabs() calls in NavScoreItem().
     //g.OverlayDrawList.AddRect(g.NavScoringRectScreen.Min, g.NavScoringRectScreen.Max, IM_COL32(255,200,0,255)); // [DEBUG]
     g.NavScoringCount = 0;
 #if IMGUI_DEBUG_NAV_RECTS
@@ -4678,7 +4678,7 @@ bool ImGui::IsMouseClicked(int button, bool repeat)
     if (repeat && t > g.IO.KeyRepeatDelay)
     {
         float delay = g.IO.KeyRepeatDelay, rate = g.IO.KeyRepeatRate;
-        if ((fmodf(t - delay, rate) > rate*0.5f) != (fmodf(t - delay - g.IO.DeltaTime, rate) > rate*0.5f))
+        if ((ImFmod(t - delay, rate) > rate*0.5f) != (ImFmod(t - delay - g.IO.DeltaTime, rate) > rate*0.5f))
             return true;
     }
 
@@ -8923,7 +8923,7 @@ static bool ImGui::SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType d
                 {
                     // Positive: rescale to the positive range before powering
                     float a;
-                    if (fabsf(linear_zero_pos - 1.0f) > 1.e-6f)
+                    if (ImFabs(linear_zero_pos - 1.0f) > 1.e-6f)
                         a = (clicked_t - linear_zero_pos) / (1.0f - linear_zero_pos);
                     else
                         a = clicked_t;
@@ -10692,7 +10692,7 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
         draw_window->DrawList->AddText(g.Font, g.FontSize, render_pos - render_scroll, GetColorU32(ImGuiCol_Text), buf_display, buf_display + edit_state.CurLenA, 0.0f, is_multiline ? NULL : &clip_rect);
 
         // Draw blinking cursor
-        bool cursor_is_visible = (!g.IO.OptCursorBlink) || (g.InputTextState.CursorAnim <= 0.0f) || fmodf(g.InputTextState.CursorAnim, 1.20f) <= 0.80f;
+        bool cursor_is_visible = (!g.IO.OptCursorBlink) || (g.InputTextState.CursorAnim <= 0.0f) || ImFmod(g.InputTextState.CursorAnim, 1.20f) <= 0.80f;
         ImVec2 cursor_screen_pos = render_pos + cursor_offset - render_scroll;
         ImRect cursor_screen_rect(cursor_screen_pos.x, cursor_screen_pos.y-g.FontSize+0.5f, cursor_screen_pos.x+1.0f, cursor_screen_pos.y-1.5f);
         if (cursor_is_visible && cursor_screen_rect.Overlaps(clip_rect))
@@ -11540,7 +11540,7 @@ bool ImGui::BeginMenu(const char* label, bool enabled)
                 ImVec2 ta = g.IO.MousePos - g.IO.MouseDelta;
                 ImVec2 tb = (window->Pos.x < next_window->Pos.x) ? next_window_rect.GetTL() : next_window_rect.GetTR();
                 ImVec2 tc = (window->Pos.x < next_window->Pos.x) ? next_window_rect.GetBL() : next_window_rect.GetBR();
-                float extra = ImClamp(fabsf(ta.x - tb.x) * 0.30f, 5.0f, 30.0f); // add a bit of extra slack.
+                float extra = ImClamp(ImFabs(ta.x - tb.x) * 0.30f, 5.0f, 30.0f); // add a bit of extra slack.
                 ta.x += (window->Pos.x < next_window->Pos.x) ? -0.5f : +0.5f;   // to avoid numerical issues
                 tb.y = ta.y + ImMax((tb.y - extra) - ta.y, -100.0f);            // triangle is maximum 200 high to limit the slope and the bias toward large sub-menus // FIXME: Multiply by fb_scale?
                 tc.y = ta.y + ImMin((tc.y + extra) - ta.y, +100.0f);

imgui_draw.cpp

@@ -109,6 +109,10 @@ namespace IMGUI_STB_NAMESPACE
 #define STBTT_malloc(x,u)  ((void)(u), ImGui::MemAlloc(x))
 #define STBTT_free(x,u)    ((void)(u), ImGui::MemFree(x))
 #define STBTT_assert(x)    IM_ASSERT(x)
+#define STBTT_fmod(x,y)    ImFmod(x,y)
+#define STBTT_sqrt(x)      ImSqrt(x)
+#define STBTT_pow(x,y)     ImPow(x,y)
+#define STBTT_fabs(x)      ImFabs(x)
 #define STBTT_STATIC
 #define STB_TRUETYPE_IMPLEMENTATION
 #else
@@ -959,8 +963,8 @@ void ImDrawList::PathBezierCurveTo(const ImVec2& p2, const ImVec2& p3, const ImV
 
 void ImDrawList::PathRect(const ImVec2& a, const ImVec2& b, float rounding, int rounding_corners)
 {
-    rounding = ImMin(rounding, fabsf(b.x - a.x) * ( ((rounding_corners & ImDrawCornerFlags_Top)  == ImDrawCornerFlags_Top)  || ((rounding_corners & ImDrawCornerFlags_Bot)   == ImDrawCornerFlags_Bot)   ? 0.5f : 1.0f ) - 1.0f);
+    rounding = ImMin(rounding, ImFabs(b.x - a.x) * ( ((rounding_corners & ImDrawCornerFlags_Top)  == ImDrawCornerFlags_Top)  || ((rounding_corners & ImDrawCornerFlags_Bot)   == ImDrawCornerFlags_Bot)   ? 0.5f : 1.0f ) - 1.0f);
-    rounding = ImMin(rounding, fabsf(b.y - a.y) * ( ((rounding_corners & ImDrawCornerFlags_Left) == ImDrawCornerFlags_Left) || ((rounding_corners & ImDrawCornerFlags_Right) == ImDrawCornerFlags_Right) ? 0.5f : 1.0f ) - 1.0f);
+    rounding = ImMin(rounding, ImFabs(b.y - a.y) * ( ((rounding_corners & ImDrawCornerFlags_Left) == ImDrawCornerFlags_Left) || ((rounding_corners & ImDrawCornerFlags_Right) == ImDrawCornerFlags_Right) ? 0.5f : 1.0f ) - 1.0f);
 
     if (rounding <= 0.0f || rounding_corners == 0)
     {

imgui_internal.h

@@ -146,11 +146,22 @@ static inline ImVec4 operator*(const ImVec4& lhs, const ImVec4& rhs)
 #endif
 
 // Helpers: Maths
+// - Wrapper for standard libs functions. (Note that imgui_demo.cpp does _not_ use them to keep the code easy to copy)
+#ifndef IMGUI_DISABLE_MATH_FUNCTIONS
+static inline float  ImFabs(float x)                                            { return fabsf(x); }
+static inline float  ImSqrt(float x)                                            { return sqrtf(x); }
+static inline float  ImPow(float x, float y)                                    { return powf(x, y); }
+static inline double ImPow(double x, double y)                                  { return pow(x, y); }
+static inline float  ImFmod(float x, float y)                                   { return fmodf(x, y); }
+static inline double ImFmod(double x, double y)                                 { return fmod(x, y); }
+#endif
+// - ImMin/ImMax/ImClamp/ImLerp/ImSwap are used by widgets which support for variety of types: signed/unsigned int/long long float/double, using templates here but we could also redefine them 6 times
 template<typename T> static inline T ImMin(T lhs, T rhs)                        { return lhs < rhs ? lhs : rhs; }
 template<typename T> static inline T ImMax(T lhs, T rhs)                        { return lhs >= rhs ? lhs : rhs; }
 template<typename T> static inline T ImClamp(T v, T mn, T mx)                   { return (v < mn) ? mn : (v > mx) ? mx : v; }
 template<typename T> static inline T ImLerp(T a, T b, float t)                  { return (T)(a + (b - a) * t); }
 template<typename T> static inline void ImSwap(T& a, T& b)                      { T tmp = a; a = b; b = tmp; }
+// - Misc maths helpers
 static inline ImVec2 ImMin(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x < rhs.x ? lhs.x : rhs.x, lhs.y < rhs.y ? lhs.y : rhs.y); }
 static inline ImVec2 ImMax(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x >= rhs.x ? lhs.x : rhs.x, lhs.y >= rhs.y ? lhs.y : rhs.y); }
 static inline ImVec2 ImClamp(const ImVec2& v, const ImVec2& mn, ImVec2 mx)      { return ImVec2((v.x < mn.x) ? mn.x : (v.x > mx.x) ? mx.x : v.x, (v.y < mn.y) ? mn.y : (v.y > mx.y) ? mx.y : v.y); }
@@ -160,17 +171,13 @@ static inline ImVec4 ImLerp(const ImVec4& a, const ImVec4& b, float t)
 static inline float  ImSaturate(float f)                                        { return (f < 0.0f) ? 0.0f : (f > 1.0f) ? 1.0f : f; }
 static inline float  ImLengthSqr(const ImVec2& lhs)                             { return lhs.x*lhs.x + lhs.y*lhs.y; }
 static inline float  ImLengthSqr(const ImVec4& lhs)                             { return lhs.x*lhs.x + lhs.y*lhs.y + lhs.z*lhs.z + lhs.w*lhs.w; }
-static inline float  ImInvLength(const ImVec2& lhs, float fail_value)           { float d = lhs.x*lhs.x + lhs.y*lhs.y; if (d > 0.0f) return 1.0f / sqrtf(d); return fail_value; }
+static inline float  ImInvLength(const ImVec2& lhs, float fail_value)           { float d = lhs.x*lhs.x + lhs.y*lhs.y; if (d > 0.0f) return 1.0f / ImSqrt(d); return fail_value; }
 static inline float  ImFloor(float f)                                           { return (float)(int)f; }
 static inline ImVec2 ImFloor(const ImVec2& v)                                   { return ImVec2((float)(int)v.x, (float)(int)v.y); }
 static inline float  ImDot(const ImVec2& a, const ImVec2& b)                    { return a.x * b.x + a.y * b.y; }
 static inline ImVec2 ImRotate(const ImVec2& v, float cos_a, float sin_a)        { return ImVec2(v.x * cos_a - v.y * sin_a, v.x * sin_a + v.y * cos_a); }
 static inline float  ImLinearSweep(float current, float target, float speed)    { if (current < target) return ImMin(current + speed, target); if (current > target) return ImMax(current - speed, target); return current; }
 static inline ImVec2 ImMul(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y); }
-static inline float  ImPow(float x, float y)                                    { return powf(x, y); }
-static inline double ImPow(double x, double y)                                  { return pow(x, y); }
-static inline float  ImFmod(float x, float y)                                   { return fmodf(x, y); }
-static inline double ImFmod(double x, double y)                                 { return fmod(x, y); }
 
 //-----------------------------------------------------------------------------
 // Types