diff --git a/src/bmp.h b/src/bmp.h
index ab37a92..08d66c7 100644
--- a/src/bmp.h
+++ b/src/bmp.h
@@ -1,3 +1,4 @@
+typedef void line_fn(unsigned long y, char *data_buffer);
+
 void bmp_generate(unsigned long width, unsigned long height,
-                  unsigned int color_depth, char *file_path,
-                  void generate_line(unsigned long y, char *data_buffer));
\ No newline at end of file
+                  unsigned int color_depth, char *file_path, line_fn);
\ No newline at end of file
diff --git a/src/generator.c b/src/generator.c
new file mode 100644
index 0000000..8e42236
--- /dev/null
+++ b/src/generator.c
@@ -0,0 +1,14 @@
+#include "bmp.h"
+#include <string.h>
+
+#define WIDTH 256
+#define HEIGHT 256
+#define COLOR_DEPTH 3
+
+void generate_line(unsigned long y, char *data_buffer) {
+  memset(data_buffer, y, WIDTH * COLOR_DEPTH);
+}
+
+void generate() {
+  bmp_generate(WIDTH, HEIGHT, COLOR_DEPTH, "test.bmp", generate_line);
+}
\ No newline at end of file
diff --git a/src/generator.h b/src/generator.h
new file mode 100644
index 0000000..f8ca05d
--- /dev/null
+++ b/src/generator.h
@@ -0,0 +1 @@
+void generate();
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 0588d24..c0c82e7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,16 +1,6 @@
-#include <string.h>
-
-#include "bmp.h"
-
-#define WIDTH 256
-#define HEIGHT 256
-#define COLOR_DEPTH 3
-
-void generate_line(unsigned long y, char *data_buffer) {
-  memset(data_buffer, y, WIDTH * COLOR_DEPTH);
-}
+#include "generator.h"
 
 int main(int argc, char **argv) {
-  bmp_generate(WIDTH, HEIGHT, COLOR_DEPTH, "test.bmp", generate_line);
+  generate();
   return 0;
 }
\ No newline at end of file