Mouse coordinates are floating point

CMakeLists.txt

@@ -962,8 +962,8 @@ if(SDL_LIBC)
             _stricmp _strnicmp sscanf
             acos acosf asin asinf atan atanf atan2 atan2f ceil ceilf
             copysign copysignf cos cosf exp expf fabs fabsf floor floorf fmod fmodf
-            log logf log10 log10f lround lroundf pow powf round roundf scalbn scalbnf
-            sin sinf sqrt sqrtf tan tanf trunc truncf)
+            log logf log10 log10f lround lroundf modf modff pow powf round roundf
+            scalbn scalbnf sin sinf sqrt sqrtf tan tanf trunc truncf)
       string(TOUPPER ${_FN} _UPPER)
       set(HAVE_${_UPPER} 1)
     endforeach()

VisualC-GDK/SDL/SDL.vcxproj

@@ -666,6 +666,7 @@
     <ClCompile Include="..\..\src\libm\s_cos.c" />
     <ClCompile Include="..\..\src\libm\s_fabs.c" />
     <ClCompile Include="..\..\src\libm\s_floor.c" />
+    <ClCompile Include="..\..\src\libm\s_modf.c" />
     <ClCompile Include="..\..\src\libm\s_scalbn.c" />
     <ClCompile Include="..\..\src\libm\s_sin.c" />
     <ClCompile Include="..\..\src\libm\s_tan.c" />

VisualC-GDK/SDL/SDL.vcxproj.filters

@@ -976,6 +976,9 @@
     <ClCompile Include="..\..\src\libm\s_floor.c">
       <Filter>libm</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\libm\s_modf.c">
+      <Filter>libm</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\libm\s_scalbn.c">
       <Filter>libm</Filter>
     </ClCompile>

VisualC/SDL/SDL.vcxproj

@@ -546,6 +546,7 @@
     <ClCompile Include="..\..\src\libm\s_cos.c" />
     <ClCompile Include="..\..\src\libm\s_fabs.c" />
     <ClCompile Include="..\..\src\libm\s_floor.c" />
+    <ClCompile Include="..\..\src\libm\s_modf.c" />
     <ClCompile Include="..\..\src\libm\s_scalbn.c" />
     <ClCompile Include="..\..\src\libm\s_sin.c" />
     <ClCompile Include="..\..\src\libm\s_tan.c" />

VisualC/SDL/SDL.vcxproj.filters

@@ -964,6 +964,9 @@
     <ClCompile Include="..\..\src\libm\s_floor.c">
       <Filter>libm</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\libm\s_modf.c">
+      <Filter>libm</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\libm\s_scalbn.c">
       <Filter>libm</Filter>
     </ClCompile>

WhatsNew.txt

@@ -19,3 +19,4 @@ General:
 * Added SDL_GetTicksNS() to return the number of nanoseconds since the SDL library initialized
 * Added SDL_DelayNS() to specify a delay in nanoseconds, to the highest precision the system will support
 * The timestamp member of the SDL_Event structure is now in nanoseconds, filled in with the time the event was generated, or the time it was queued if that's not available
+* Added SDL_modf() and SDL_modff() to separate the whole and fractional portions of a floating point number

docs/README-migration.md

@@ -82,6 +82,8 @@ The timestamp_us member of the sensor events has been renamed sensor_timestamp a
 
 You should set the event.common.timestamp field before passing an event to SDL_PushEvent(). If the timestamp is 0 it will be filled in with SDL_GetTicksNS().
 
+Mouse events use floating point values for mouse coordinates and relative motion values. You can get sub-pixel motion depending on the platform and display scaling.
+
 The SDL_DISPLAYEVENT_* events have been moved to top level events, and SDL_DISPLAYEVENT has been removed. In general, handling this change just means checking for the individual events instead of first checking for SDL_DISPLAYEVENT and then checking for display events. You can compare the event >= SDL_DISPLAYEVENT_FIRST and <= SDL_DISPLAYEVENT_LAST if you need to see whether it's a display event.
 
 The SDL_WINDOWEVENT_* events have been moved to top level events, and SDL_WINDOWEVENT has been removed. In general, handling this change just means checking for the individual events instead of first checking for SDL_WINDOWEVENT and then checking for window events. You can compare the event >= SDL_WINDOWEVENT_FIRST and <= SDL_WINDOWEVENT_LAST if you need to see whether it's a window event.
@@ -411,6 +413,8 @@ used by additional platforms that didn't have a SDL_RunApp-like function before)
 
 SDL_ShowCursor() has been split into three functions: SDL_ShowCursor(), SDL_HideCursor(), and SDL_CursorVisible()
 
+SDL_GetMouseState(), SDL_GetGlobalMouseState(), SDL_GetRelativeMouseState(), SDL_WarpMouseInWindow(), and SDL_WarpMouseGlobal() all use floating point mouse positions, to provide sub-pixel precision on platforms that support it.
+
 The following functions have been renamed:
 * SDL_FreeCursor() => SDL_DestroyCursor()
 
@@ -463,6 +467,8 @@ which index is the "opengl" or whatnot driver, you can just pass that string dir
 here, now. Passing NULL is the same as passing -1 here in SDL2, to signify you want SDL
 to decide for you.
 
+SDL_RenderWindowToLogical() and SDL_RenderLogicalToWindow() take floating point coordinates in both directions.
+
 The following functions have been renamed:
 * SDL_RenderCopy() => SDL_RenderTexture()
 * SDL_RenderCopyEx() => SDL_RenderTextureRotated()

include/SDL3/SDL_events.h

@@ -297,12 +297,12 @@ typedef struct SDL_MouseMotionEvent
     Uint32 type;        /**< ::SDL_MOUSEMOTION */
     Uint64 timestamp;   /**< In nanoseconds, populated using SDL_GetTicksNS() */
     Uint32 windowID;    /**< The window with mouse focus, if any */
-    SDL_MouseID which;       /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
+    SDL_MouseID which;  /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
     Uint32 state;       /**< The current button state */
-    Sint32 x;           /**< X coordinate, relative to window */
-    Sint32 y;           /**< Y coordinate, relative to window */
-    Sint32 xrel;        /**< The relative motion in the X direction */
-    Sint32 yrel;        /**< The relative motion in the Y direction */
+    float x;            /**< X coordinate, relative to window */
+    float y;            /**< Y coordinate, relative to window */
+    float xrel;         /**< The relative motion in the X direction */
+    float yrel;         /**< The relative motion in the Y direction */
 } SDL_MouseMotionEvent;
 
 /**
@@ -313,13 +313,13 @@ typedef struct SDL_MouseButtonEvent
     Uint32 type;        /**< ::SDL_MOUSEBUTTONDOWN or ::SDL_MOUSEBUTTONUP */
     Uint64 timestamp;   /**< In nanoseconds, populated using SDL_GetTicksNS() */
     Uint32 windowID;    /**< The window with mouse focus, if any */
-    SDL_MouseID which;       /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
+    SDL_MouseID which;  /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
     Uint8 button;       /**< The mouse button index */
     Uint8 state;        /**< ::SDL_PRESSED or ::SDL_RELEASED */
     Uint8 clicks;       /**< 1 for single-click, 2 for double-click, etc. */
-    Uint8 padding1;
-    Sint32 x;           /**< X coordinate, relative to window */
-    Sint32 y;           /**< Y coordinate, relative to window */
+    Uint8 padding;
+    float x;            /**< X coordinate, relative to window */
+    float y;            /**< Y coordinate, relative to window */
 } SDL_MouseButtonEvent;
 
 /**
@@ -330,14 +330,12 @@ typedef struct SDL_MouseWheelEvent
     Uint32 type;        /**< ::SDL_MOUSEWHEEL */
     Uint64 timestamp;   /**< In nanoseconds, populated using SDL_GetTicksNS() */
     Uint32 windowID;    /**< The window with mouse focus, if any */
-    SDL_MouseID which;       /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
-    Sint32 x;           /**< The amount scrolled horizontally, positive to the right and negative to the left */
-    Sint32 y;           /**< The amount scrolled vertically, positive away from the user and negative toward the user */
+    SDL_MouseID which;  /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
+    float x;            /**< The amount scrolled horizontally, positive to the right and negative to the left */
+    float y;            /**< The amount scrolled vertically, positive away from the user and negative toward the user */
     Uint32 direction;   /**< Set to one of the SDL_MOUSEWHEEL_* defines. When FLIPPED the values in X and Y will be opposite. Multiply by -1 to change them back */
-    float preciseX;     /**< The amount scrolled horizontally, positive to the right and negative to the left, with float precision (added in 2.0.18) */
-    float preciseY;     /**< The amount scrolled vertically, positive away from the user and negative toward the user, with float precision (added in 2.0.18) */
-    Sint32 mouseX;      /**< X coordinate, relative to window (added in 2.26.0) */
-    Sint32 mouseY;      /**< Y coordinate, relative to window (added in 2.26.0) */
+    float mouseX;       /**< X coordinate, relative to window */
+    float mouseY;       /**< Y coordinate, relative to window */
 } SDL_MouseWheelEvent;
 
 /**

include/SDL3/SDL_mouse.h

@@ -103,7 +103,7 @@ extern DECLSPEC SDL_Window * SDLCALL SDL_GetMouseFocus(void);
  * \sa SDL_GetRelativeMouseState
  * \sa SDL_PumpEvents
  */
-extern DECLSPEC Uint32 SDLCALL SDL_GetMouseState(int *x, int *y);
+extern DECLSPEC Uint32 SDLCALL SDL_GetMouseState(float *x, float *y);
 
 /**
  * Get the current state of the mouse in relation to the desktop.
@@ -132,7 +132,7 @@ extern DECLSPEC Uint32 SDLCALL SDL_GetMouseState(int *x, int *y);
  *
  * \sa SDL_CaptureMouse
  */
-extern DECLSPEC Uint32 SDLCALL SDL_GetGlobalMouseState(int *x, int *y);
+extern DECLSPEC Uint32 SDLCALL SDL_GetGlobalMouseState(float *x, float *y);
 
 /**
  * Retrieve the relative state of the mouse.
@@ -151,7 +151,7 @@ extern DECLSPEC Uint32 SDLCALL SDL_GetGlobalMouseState(int *x, int *y);
  *
  * \sa SDL_GetMouseState
  */
-extern DECLSPEC Uint32 SDLCALL SDL_GetRelativeMouseState(int *x, int *y);
+extern DECLSPEC Uint32 SDLCALL SDL_GetRelativeMouseState(float *x, float *y);
 
 /**
  * Move the mouse cursor to the given position within the window.
@@ -173,7 +173,7 @@ extern DECLSPEC Uint32 SDLCALL SDL_GetRelativeMouseState(int *x, int *y);
  * \sa SDL_WarpMouseGlobal
  */
 extern DECLSPEC void SDLCALL SDL_WarpMouseInWindow(SDL_Window * window,
-                                                   int x, int y);
+                                                   float x, float y);
 
 /**
  * Move the mouse to the given position in global screen space.
@@ -195,7 +195,7 @@ extern DECLSPEC void SDLCALL SDL_WarpMouseInWindow(SDL_Window * window,
  *
  * \sa SDL_WarpMouseInWindow
  */
-extern DECLSPEC int SDLCALL SDL_WarpMouseGlobal(int x, int y);
+extern DECLSPEC int SDLCALL SDL_WarpMouseGlobal(float x, float y);
 
 /**
  * Set relative mouse mode.

include/SDL3/SDL_render.h

@@ -1034,10 +1034,10 @@ extern DECLSPEC void SDLCALL SDL_GetRenderScale(SDL_Renderer * renderer,
  * \sa SDL_GetRenderLogicalSize
  * \sa SDL_SetRenderLogicalSize
  */
-extern DECLSPEC void SDLCALL SDL_RenderWindowToLogical(SDL_Renderer * renderer, 
-                                                            int windowX, int windowY, 
-                                                            float *logicalX, float *logicalY);
-                                                  
+extern DECLSPEC void SDLCALL SDL_RenderWindowToLogical(SDL_Renderer *renderer,
+                                                       float windowX, float windowY,
+                                                       float *logicalX, float *logicalY);
+
 
 /**
  * Get real coordinates of point in window when given logical coordinates of
@@ -1060,9 +1060,9 @@ extern DECLSPEC void SDLCALL SDL_RenderWindowToLogical(SDL_Renderer * renderer,
  * \sa SDL_GetRenderLogicalSize
  * \sa SDL_SetRenderLogicalSize
  */
-extern DECLSPEC void SDLCALL SDL_RenderLogicalToWindow(SDL_Renderer * renderer, 
-                                                            float logicalX, float logicalY,
-                                                            int *windowX, int *windowY);
+extern DECLSPEC void SDLCALL SDL_RenderLogicalToWindow(SDL_Renderer *renderer,
+                                                       float logicalX, float logicalY,
+                                                       float *windowX, float *windowY);
 
 /**
  * Set the color used for drawing operations (Rect, Line and Clear).

include/SDL3/SDL_stdinc.h

@@ -580,6 +580,8 @@ extern DECLSPEC double SDLCALL SDL_log(double x);
 extern DECLSPEC float SDLCALL SDL_logf(float x);
 extern DECLSPEC double SDLCALL SDL_log10(double x);
 extern DECLSPEC float SDLCALL SDL_log10f(float x);
+extern DECLSPEC double SDLCALL SDL_modf(double x, double *y);
+extern DECLSPEC float SDLCALL SDL_modff(float x, float *y);
 extern DECLSPEC double SDLCALL SDL_pow(double x, double y);
 extern DECLSPEC float SDLCALL SDL_powf(float x, float y);
 extern DECLSPEC double SDLCALL SDL_round(double x);

include/build_config/SDL_build_config.h.cmake

@@ -171,6 +171,8 @@
 #cmakedefine HAVE_LOG10F 1
 #cmakedefine HAVE_LROUND 1
 #cmakedefine HAVE_LROUNDF 1
+#cmakedefine HAVE_MODF 1
+#cmakedefine HAVE_MODFF 1
 #cmakedefine HAVE_POW 1
 #cmakedefine HAVE_POWF 1
 #cmakedefine HAVE_ROUND 1

include/build_config/SDL_build_config_android.h

@@ -120,6 +120,7 @@
 #define HAVE_LOG10F 1
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
+#define HAVE_MODF   1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1

include/build_config/SDL_build_config_ios.h

@@ -114,6 +114,7 @@
 #define HAVE_LOG10F 1
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
+#define HAVE_MODF   1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1

include/build_config/SDL_build_config_macos.h

@@ -116,6 +116,7 @@
 #define HAVE_LOG10F 1
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
+#define HAVE_MODF   1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1

include/build_config/SDL_build_config_winrt.h

@@ -134,6 +134,7 @@
 #define HAVE_LOG10F 1
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
+#define HAVE_MODF   1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND 1

src/core/haiku/SDL_BApp.h

@@ -254,12 +254,12 @@ class SDL_BApp : public BApplication
             SDL_GetWindowPosition(win, &winPosX, &winPosY);
             int dx = x - (winWidth / 2);
             int dy = y - (winHeight / 2);
-            SDL_SendMouseMotion(0, win, 0, SDL_GetMouse()->relative_mode, dx, dy);
+            SDL_SendMouseMotion(0, win, 0, SDL_GetMouse()->relative_mode, (float)dx, (float)dy);
             set_mouse_position((winPosX + winWidth / 2), (winPosY + winHeight / 2));
             if (!be_app->IsCursorHidden())
                 be_app->HideCursor();
         } else {
-            SDL_SendMouseMotion(0, win, 0, 0, x, y);
+            SDL_SendMouseMotion(0, win, 0, 0, (float)x, (float)y);
             if (SDL_CursorVisible() && be_app->IsCursorHidden())
                 be_app->ShowCursor();
         }

src/core/linux/SDL_evdev.c

@@ -448,7 +448,7 @@ void SDL_EVDEV_Poll(void)
                     case SYN_REPORT:
                         /* Send mouse axis changes together to ensure consistency and reduce event processing overhead */
                         if (item->mouse_x != 0 || item->mouse_y != 0) {
-                            SDL_SendMouseMotion(SDL_EVDEV_GetEventTimestamp(event), mouse->focus, (SDL_MouseID)item->fd, item->relative_mouse, item->mouse_x, item->mouse_y);
+                            SDL_SendMouseMotion(SDL_EVDEV_GetEventTimestamp(event), mouse->focus, (SDL_MouseID)item->fd, item->relative_mouse, (float)item->mouse_x, (float)item->mouse_y);
                             item->mouse_x = item->mouse_y = 0;
                         }
                         if (item->mouse_wheel != 0 || item->mouse_hwheel != 0) {

src/core/openbsd/SDL_wscons_mouse.c

@@ -100,12 +100,12 @@ void updateMouse(SDL_WSCONS_mouse_input_data *inputData)
             } break;
             case WSCONS_EVENT_MOUSE_DELTA_X:
             {
-                SDL_SendMouseMotion(0, mouse->focus, mouse->mouseID, 1, events[i].value, 0);
+                SDL_SendMouseMotion(0, mouse->focus, mouse->mouseID, 1, (float)events[i].value, 0.0f);
                 break;
             }
             case WSCONS_EVENT_MOUSE_DELTA_Y:
             {
-                SDL_SendMouseMotion(0, mouse->focus, mouse->mouseID, 1, 0, -events[i].value);
+                SDL_SendMouseMotion(0, mouse->focus, mouse->mouseID, 1, 0.0f, -(float)events[i].value);
                 break;
             }
             case WSCONS_EVENT_MOUSE_DELTA_W:

src/core/winrt/SDL_winrtapp_direct3d.cpp

@@ -547,7 +547,7 @@ void SDL_WinRTApp::OnWindowActivated(CoreWindow ^ sender, WindowActivatedEventAr
              */
 #if (WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP) || (NTDDI_VERSION >= NTDDI_WINBLUE)
             Point cursorPos = WINRT_TransformCursorPosition(window, sender->PointerPosition, TransformToSDLWindowSize);
-            SDL_SendMouseMotion(0, window, 0, 0, (int)cursorPos.X, (int)cursorPos.Y);
+            SDL_SendMouseMotion(0, window, 0, 0, cursorPos.X, cursorPos.Y);
 #endif
 
             /* TODO, WinRT: see if the Win32 bugfix from https://hg.libsdl.org/SDL/rev/d278747da408 needs to be applied (on window activation) */

src/dynapi/SDL_dynapi.sym

@@ -859,6 +859,8 @@ SDL3_0.0.0 {
     SDL_wcsncasecmp;
     SDL_wcsncmp;
     SDL_wcsstr;
+    SDL_modf;
+    SDL_modff;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -887,3 +887,5 @@
 #define SDL_wcsstr SDL_wcsstr_REAL
 
 /* New API symbols are added at the end */
+#define SDL_modf SDL_modf_REAL
+#define SDL_modff SDL_modff_REAL