add networking, 3d improvements, reorganize src structure

src/core/pxl8_macros.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <string.h>
+
+#ifndef pxl8_min
+#define pxl8_min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+#ifndef pxl8_max
+#define pxl8_max(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef pxl8_strncpy
+#define pxl8_strncpy(dst, src, size) do { \
+    strncpy((dst), (src), (size) - 1); \
+    (dst)[(size) - 1] = '\0'; \
+} while (0)
+#endif