fix missing NULL definitions for MinGW

Sources/kinc/audio2/audio.h

@@ -70,6 +70,7 @@ void kinc_a2_internal_sample_rate_callback(void);
 
 #include <kinc/threads/mutex.h>
 #include <memory.h>
+#include <stddef.h>
 
 static kinc_mutex_t mutex;
 

Sources/kinc/graphics4/pipeline.c.h

@@ -1,5 +1,7 @@
 #include "pipeline.h"
 
+#include <stddef.h>
+
 void kinc_g4_internal_pipeline_set_defaults(kinc_g4_pipeline_t *state) {
 	for (int i = 0; i < 16; ++i)
 		state->input_layout[i] = NULL;

Sources/kinc/input/acceleration.h

@@ -25,6 +25,7 @@ void kinc_internal_on_acceleration(float x, float y, float z);
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 void (*acceleration_callback)(float /*x*/, float /*y*/, float /*z*/) = NULL;
 

Sources/kinc/input/gamepad.h

@@ -63,6 +63,7 @@ void kinc_internal_gamepad_trigger_button(int gamepad, int button, float value);
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*gamepad_axis_callback)(int /*gamepad*/, int /*axis*/, float /*value*/, void * /*userdata*/) = NULL;
 static void *gamepad_axis_callback_userdata = NULL;

Sources/kinc/input/keyboard.h

@@ -245,6 +245,7 @@ void kinc_internal_keyboard_trigger_key_press(unsigned character);
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*keyboard_key_down_callback)(int /*key_code*/, void * /*data*/) = NULL;
 static void *keyboard_key_down_callback_data = NULL;

Sources/kinc/input/mouse.h

@@ -140,6 +140,7 @@ void kinc_internal_mouse_window_deactivated(int window);
 #define KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*mouse_press_callback)(int /*window*/, int /*button*/, int /*x*/, int /*y*/, void * /*data*/) = NULL;
 static void *mouse_press_callback_data = NULL;

Sources/kinc/input/pen.h

@@ -61,6 +61,7 @@ void kinc_internal_eraser_trigger_release(int window, int x, int y, float pressu
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*pen_press_callback)(int /*window*/, int /*x*/, int /*y*/, float /*pressure*/) = NULL;
 static void (*pen_move_callback)(int /*window*/, int /*x*/, int /*y*/, float /*pressure*/) = NULL;

Sources/kinc/input/rotation.h

@@ -25,6 +25,7 @@ void kinc_internal_on_rotation(float x, float y, float z);
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*rotation_callback)(float /*x*/, float /*y*/, float /*z*/) = NULL;
 

Sources/kinc/input/surface.h

@@ -39,6 +39,7 @@ void kinc_internal_surface_trigger_touch_end(int index, int x, int y);
 #ifdef KINC_IMPLEMENTATION
 
 #include <memory.h>
+#include <stddef.h>
 
 static void (*surface_touch_start_callback)(int /*index*/, int /*x*/, int /*y*/) = NULL;
 static void (*surface_move_callback)(int /*index*/, int /*x*/, int /*y*/) = NULL;