update: update render.h

src/write_png.c

@@ -1,3 +1,6 @@
+#include <spng.h>
+#include <math.h>
+#include <stdint.h>
 #include "write_png.h"
 
 static inline double linear_to_srgb(double x){

src/write_png.h

@@ -1,6 +1,3 @@
-#include <spng.h>
-#include <math.h>
-#include <stdint.h>
 
 
 int write_png(char *filename, double **buffer, int W, int H);