twn_util: separate internal c-only features from public header

include/twn_types.h

@@ -0,0 +1,42 @@
+#ifndef TWN_TYPES_H
+#define TWN_TYPES_H
+
+#include <stdint.h>
+
+/* plain data aggregates that are accepted between public procedure boundaries */
+
+/* 32-bit color data */
+typedef struct Color {
+_Alignas(4)
+    uint8_t r;
+    uint8_t g;
+    uint8_t b;
+    uint8_t a;
+} Color;
+
+
+/* a rectangle with the origin at the upper left (integer) */
+typedef struct Recti {
+_Alignas(16)
+    int32_t x;
+    int32_t y;
+    int32_t w;
+    int32_t h;
+} Recti;
+
+
+/* a rectangle with the origin at the upper left (floating point) */
+typedef struct Rect {
+_Alignas(16)
+    float x;
+    float y;
+    float w;
+    float h;
+} Rect;
+
+
+typedef struct Matrix4 {
+    Vec4 row[4];
+} Matrix4;
+
+#endif

include/twn_util.h

@@ -3,11 +3,29 @@
 
 #include "twn_vec.h"
 #include "twn_engine_api.h"
+#include "twn_types.h"
 
 #include <stdint.h>
 #include <stdbool.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
+
+/* multiply by these to convert degrees <---> radians */
+#define DEG2RAD (M_PI / 180)
+#define RAD2DEG (180 / M_PI)
+
+
 /*                   */
 /* GENERAL UTILITIES */
 /*                   */
@@ -36,27 +54,12 @@ TWN_API void *crealloc(void *ptr, size_t size);
 TWN_API void *ccalloc(size_t num, size_t size);
 
 
-/* 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
-
-/* multiply by these to convert degrees <---> radians */
-#define DEG2RAD (M_PI / 180)
-#define RAD2DEG (180 / M_PI)
-
 /* 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);
 TWN_API int clampi(int i, int min, int max);
 
+
 /* sets buf_out to a pointer to a byte buffer which must be freed. */
 /* returns the size of this buffer. */
 TWN_API int64_t file_to_bytes(const char *path, unsigned char **buf_out);
@@ -67,6 +70,7 @@ TWN_API char *file_to_str(const char *path);
 /* returns true if the file exists in the filesystem */
 TWN_API bool file_exists(const char *path);
 
+
 /* saves all texture atlases as BMP files in the write directory */
 TWN_API void textures_dump_atlases(void);
 
@@ -79,36 +83,6 @@ TWN_API TWN_API bool strends(const char *str, const char *suffix);
 /* GAME LOGIC UTILITIES */
 /*                      */
 
-/* 32-bit color data */
-typedef struct Color {
-_Alignas(4)
-    uint8_t r;
-    uint8_t g;
-    uint8_t b;
-    uint8_t a;
-} Color;
-
-
-/* a rectangle with the origin at the upper left (integer) */
-typedef struct Recti {
-_Alignas(16)
-    int32_t x;
-    int32_t y;
-    int32_t w;
-    int32_t h;
-} Recti;
-
-
-/* a rectangle with the origin at the upper left (floating point) */
-typedef struct Rect {
-_Alignas(16)
-    float x;
-    float y;
-    float w;
-    float h;
-} Rect;
-
-
 /* calculates the overlap of two rectangles and places it in result. */
 /* result may be NULL. if this is the case, it will simply be ignored. */
 /* returns true if the rectangles are indeed intersecting. */
@@ -125,11 +99,6 @@ TWN_API Rect to_frect(Recti rect);
 TWN_API Vec2 frect_center(Rect rect);
 
 
-typedef struct Matrix4 {
-    Vec4 row[4];
-} Matrix4;
-
-
 /* decrements an lvalue (which should be an int), stopping at 0 */
 /* meant for tick-based timers in game logic */
 /*
@@ -147,32 +116,4 @@ TWN_API void tick_ftimer(float *value);
 /* returns true if value was cycled */
 TWN_API bool repeat_ftimer(float *value, float at);
 
-/* http://www.azillionmonkeys.com/qed/sqroot.html */
-static inline float fast_sqrt(float x)
-{
-    union {
-        float f;
-        uint32_t u;
-    } pun = {.f = x};
-
-    pun.u += 127 << 23;
-    pun.u >>= 1;
-
-    return pun.f;
-}
-
-
-static inline Vec2 fast_cossine(float a) {
-    const float s = 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
-    };
-}
-
-static inline bool is_power_of_two(int x)
-{
-    return (x != 0) && ((x & (x - 1)) == 0);
-}
-
 #endif

src/rendering/twn_sprites.c

@@ -2,6 +2,7 @@
 #include "twn_rendering_c.h"
 #include "twn_engine_context_c.h"
 #include "twn_util.h"
+#include "twn_util_c.h"
 #include "twn_textures_c.h"
 
 #include <stb_ds.h>

src/twn_textures.c

@@ -1,6 +1,7 @@
 #include "twn_textures_c.h"
 #include "twn_config.h"
 #include "twn_util.h"
+#include "twn_util_c.h"
 #include "twn_engine_context_c.h"
 
 #include <SDL2/SDL.h>

src/twn_util_c.h

@@ -1,7 +1,37 @@
 #ifndef TWN_UTIL_C_H
 #define TWN_UTIL_C_H
 
+#include "twn_types.h"
+
 /* note: you must free the returned string */
 char *expand_asterisk(const char *mask, const char *to);
 
+/* http://www.azillionmonkeys.com/qed/sqroot.html */
+static inline float fast_sqrt(float x)
+{
+    union {
+        float f;
+        uint32_t u;
+    } pun = {.f = x};
+
+    pun.u += 127 << 23;
+    pun.u >>= 1;
+
+    return pun.f;
+}
+
+
+static inline Vec2 fast_cossine(float a) {
+    const float s = 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
+    };
+}
+
+static inline bool is_power_of_two(int x)
+{
+    return (x != 0) && ((x & (x - 1)) == 0);
+}
+
 #endif