make vec4 and matrix types internal

src/rendering/twn_draw_c.h

@@ -4,6 +4,7 @@
 /* TODO: structure more categorically */
 
 #include "twn_textures_c.h"
+#include "twn_types_c.h"
 #include "twn_text_c.h"
 #include "twn_option.h"
 #include "twn_deferred_commands.h"

src/twn_camera_c.h

@@ -2,6 +2,7 @@
 #define TWN_CAMERA_H
 
 #include "twn_types.h"
+#include "twn_types_c.h"
 
 /* TODO: make it cached? */
 /*       for example, perspective matrix only needs recaluclation on FOV change */

src/twn_types_c.h

@@ -0,0 +1,19 @@
+#ifndef TWN_TYPES_C_H
+#define TWN_TYPES_C_H
+
+#include <stdint.h>
+
+typedef struct Vec4 {
+    float x;
+    float y;
+    float z;
+    float w;
+} Vec4;
+
+
+typedef struct Matrix4 {
+    Vec4 row[4];
+} Matrix4;
+
+
+#endif