diff --git a/docs/interop.txt b/docs/interop.txt
index 2048066..f539d64 100644
--- a/docs/interop.txt
+++ b/docs/interop.txt
@@ -4,6 +4,7 @@ for that certain steps are taken:
 * number of public api calls is kept at the minimum
 * procedure signatures can only use basic types, no aggregates, with exception of Vec/Matrix types and alike,
   with no expectation on new additions (see /include/twn_types.h)
+* optionals can be expressed via pointer passage of value primitives, with NULL expressive default
 * /include/twn_game_api.json file is hand-kept with a schema to aid automatic generation and other tooling
 
 one of main inspirations for that is opengl model
diff --git a/include/twn_camera.h b/include/twn_camera.h
index fb8ca28..ff3031d 100644
--- a/include/twn_camera.h
+++ b/include/twn_camera.h
@@ -1,7 +1,7 @@
 #ifndef TWN_CAMERA_H
 #define TWN_CAMERA_H
 
-#include "twn_util.h"
+#include "twn_types.h"
 #include "twn_engine_api.h"
 
 /* TODO: make it cached? */
diff --git a/include/twn_context.h b/include/twn_context.h
index 9ae0037..bda9b58 100644
--- a/include/twn_context.h
+++ b/include/twn_context.h
@@ -1,7 +1,7 @@
 #ifndef TWN_CONTEXT_H
 #define TWN_CONTEXT_H
 
-#include "twn_input.h"
+#include "twn_types.h"
 #include "twn_engine_api.h"
 
 #include <stdbool.h>
diff --git a/include/twn_draw.h b/include/twn_draw.h
index 9eeff65..58f1930 100644
--- a/include/twn_draw.h
+++ b/include/twn_draw.h
@@ -1,7 +1,7 @@
 #ifndef TWN_DRAW_H
 #define TWN_DRAW_H
 
-#include "twn_util.h"
+#include "twn_types.h"
 #include "twn_option.h"
 #include "twn_camera.h"
 #include "twn_engine_api.h"
diff --git a/include/twn_game_api.h b/include/twn_game_api.h
index b835a72..9c8975e 100644
--- a/include/twn_game_api.h
+++ b/include/twn_game_api.h
@@ -2,21 +2,22 @@
 #ifndef TWN_GAME_API_H
 #define TWN_GAME_API_H
 
-
+#include "twn_input.h"
 #include "twn_context.h"
 #include "twn_draw.h"
 #include "twn_audio.h"
-#include "twn_util.h"
-#include "twn_input.h"
 #include "twn_engine_api.h"
+#include "twn_util.h"
 
+#ifndef TWN_NOT_C
 
-/* sole game logic and display function.
-   all state must be used from and saved to supplied state pointer. */
-TWN_API extern void game_tick(void);
-
-/* called when application is closing. */
-TWN_API extern void game_end(void);
+   /* sole game logic and display function.
+      all state must be used from and saved to supplied state pointer. */
+   TWN_API extern void game_tick(void);
 
+   /* called when application is closing. */
+   TWN_API extern void game_end(void);
+
+#endif
 
 #endif
diff --git a/include/twn_util.h b/include/twn_util.h
index 1e43c5d..454825c 100644
--- a/include/twn_util.h
+++ b/include/twn_util.h
@@ -3,21 +3,13 @@
 
 #include "twn_types.h"
 #include "twn_engine_api.h"
-#include "twn_types.h"
 
 #include <stdint.h>
+#include <stddef.h>
 #include <stdbool.h>
 #include <math.h>
 
 
-/* DON'T FORGET ABOUT DOUBLE EVALUATION */
-/* YOU THINK YOU WON'T, AND THEN YOU DO */
-/* C23's typeof could fix it, so i will */
-/* leave them as macros to be replaced. */
-/* use the macro in tgmath.h for floats */
-#define MAX SDL_max
-#define MIN SDL_min
-
 #ifndef M_PI
 #define M_PI 3.14159265358979323846264338327950288   /**< pi */
 #endif
@@ -26,16 +18,13 @@
 #define DEG2RAD (M_PI / 180)
 #define RAD2DEG (180 / M_PI)
 
+#ifndef TWN_NOT_C
 
-/*                   */
-/* GENERAL UTILITIES */
-/*                   */
+    TWN_API void *cmalloc(size_t size);
+    TWN_API void *crealloc(void *ptr, size_t size);
+    TWN_API void *ccalloc(size_t num, size_t size);
 
-TWN_API void cry_impl(const char *file, const int line, const char *title, const char *text);
-#define CRY(title, text) cry_impl(__FILE__, __LINE__, title, text)
-#define CRY_SDL(title) cry_impl(__FILE__, __LINE__, title, SDL_GetError())
-#define CRY_PHYSFS(title)                                               \
-cry_impl(__FILE__, __LINE__, title, PHYSFS_getErrorByCode(PHYSFS_getLastErrorCode()))
+#endif /* TWN_NOT_C */
 
 
 TWN_API void log_info(const char *restrict format, ...);
@@ -43,18 +32,6 @@ TWN_API void log_critical(const char *restrict format, ...);
 TWN_API void log_warn(const char *restrict format, ...);
 
 
-/* for when there's absolutely no way to continue */
-TWN_API _Noreturn void die_abruptly(void);
-
-
-/* "critical" allocation functions which will log and abort() on failure. */
-/* if it is reasonable to handle this gracefully, use the standard versions. */
-/* the stb implementations will be configured to use these */
-TWN_API void *cmalloc(size_t size);
-TWN_API void *crealloc(void *ptr, size_t size);
-TWN_API void *ccalloc(size_t num, size_t size);
-
-
 /* TODO: this is why generics were invented. sorry, i'm tired today */
 TWN_API double clamp(double d, double min, double max);
 TWN_API float clampf(float f, float min, float max);
diff --git a/src/game_object/twn_linux_game_object.c b/src/game_object/twn_linux_game_object.c
index 5de0e1f..d54ccc0 100644
--- a/src/game_object/twn_linux_game_object.c
+++ b/src/game_object/twn_linux_game_object.c
@@ -1,5 +1,6 @@
 #include "twn_game_object_c.h"
 #include "twn_engine_context_c.h"
+#include "twn_util_c.h"
 
 #include <x-watcher.h>
 #include <SDL2/SDL.h>
diff --git a/src/game_object/twn_win32_game_object.c b/src/game_object/twn_win32_game_object.c
index ea40ff5..a9f3ec3 100644
--- a/src/game_object/twn_win32_game_object.c
+++ b/src/game_object/twn_win32_game_object.c
@@ -1,5 +1,6 @@
 #include "twn_game_object_c.h"
 #include "twn_engine_context_c.h"
+#include "twn_util_c.h"
 
 #include <errhandlingapi.h>
 #include <libloaderapi.h>
diff --git a/src/rendering/twn_gl_15_gpu_texture.c b/src/rendering/twn_gl_15_gpu_texture.c
index 7d6301c..99b4dfc 100644
--- a/src/rendering/twn_gl_15_gpu_texture.c
+++ b/src/rendering/twn_gl_15_gpu_texture.c
@@ -1,5 +1,5 @@
 #include "twn_gpu_texture_c.h"
-#include "twn_util.h"
+#include "twn_util_c.h"
 
 
 GPUTexture create_gpu_texture(TextureFilter filter, bool generate_mipmaps) {
diff --git a/src/rendering/twn_gl_any_rendering.c b/src/rendering/twn_gl_any_rendering.c
index a7795c9..a710583 100644
--- a/src/rendering/twn_gl_any_rendering.c
+++ b/src/rendering/twn_gl_any_rendering.c
@@ -1,6 +1,6 @@
 #include "twn_draw_c.h"
 #include "twn_engine_context_c.h"
-#include "twn_util.h"
+#include "twn_util_c.h"
 
 #ifdef EMSCRIPTEN
 #include <GLES2/gl2.h>
diff --git a/src/rendering/twn_text.c b/src/rendering/twn_text.c
index 2a13bb8..478ad96 100644
--- a/src/rendering/twn_text.c
+++ b/src/rendering/twn_text.c
@@ -1,6 +1,7 @@
 #include "twn_draw_c.h"
 #include "twn_draw.h"
 #include "twn_util.h"
+#include "twn_util_c.h"
 #include "twn_engine_context_c.h"
 
 #include <stb_truetype.h>
diff --git a/src/twn_audio.c b/src/twn_audio.c
index c8d53c2..a9b48a3 100644
--- a/src/twn_audio.c
+++ b/src/twn_audio.c
@@ -1,6 +1,7 @@
 #include "twn_audio_c.h"
 #include "twn_engine_context_c.h"
 #include "twn_util.h"
+#include "twn_util_c.h"
 
 #include <SDL2/SDL.h>
 #include <stb_ds.h>
diff --git a/src/twn_loop.c b/src/twn_loop.c
index c5ff5d5..5eeff38 100644
--- a/src/twn_loop.c
+++ b/src/twn_loop.c
@@ -2,6 +2,7 @@
 #include "twn_engine_context_c.h"
 #include "twn_input_c.h"
 #include "twn_util.h"
+#include "twn_util_c.h"
 #include "twn_game_object_c.h"
 #include "twn_audio_c.h"
 #include "twn_textures_c.h"
diff --git a/src/twn_util_c.h b/src/twn_util_c.h
index 14f237d..a094ef9 100644
--- a/src/twn_util_c.h
+++ b/src/twn_util_c.h
@@ -3,6 +3,23 @@
 
 #include "twn_types.h"
 
+#include <SDL2/SDL.h>
+
+#include <stdbool.h>
+
+
+#define MAX SDL_max
+#define MIN SDL_min
+
+void cry_impl(const char *file, const int line, const char *title, const char *text);
+#define CRY(title, text) cry_impl(__FILE__, __LINE__, title, text)
+#define CRY_SDL(title) cry_impl(__FILE__, __LINE__, title, SDL_GetError())
+#define CRY_PHYSFS(title)                                               \
+cry_impl(__FILE__, __LINE__, title, PHYSFS_getErrorByCode(PHYSFS_getLastErrorCode()))
+
+/* for when there's absolutely no way to continue */
+_Noreturn void die_abruptly(void);
+
 /* note: you must free the returned string */
 char *expand_asterisk(const char *mask, const char *to);
 
@@ -22,7 +39,7 @@ static inline float fast_sqrt(float x)
 
 
 static inline Vec2 fast_cossine(float a) {
-    const float s = sinf(a);
+    const float s = SDL_sinf(a);
     return (Vec2){
         .x = fast_sqrt(1.0f - s * s) * (a >= (float)M_PI_2 && a < (float)(M_PI + M_PI_2) ? -1 : 1),
         .y = s