add networking, 3d improvements, reorganize src structure

src/core/pxl8_rng.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "pxl8_types.h"
+
+typedef struct pxl8_rng {
+    u32 state;
+} pxl8_rng;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void pxl8_rng_seed(pxl8_rng* rng, u32 seed);
+u32 pxl8_rng_next(pxl8_rng* rng);
+f32 pxl8_rng_f32(pxl8_rng* rng);
+i32 pxl8_rng_range(pxl8_rng* rng, i32 min, i32 max);
+
+#ifdef __cplusplus
+}
+#endif