Implement simple line drawing

main.c

@@ -5,9 +5,17 @@
 #include <sys/select.h>
 
 #define MAX(a, b) ((a) < (b) ? (b) : (a))
+#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
 
 static bool quit = false;
 
+static const vec2_t ship[] = {
+	{ 0.0, 0.1 },
+	{ 0.05, -0.1 },
+	{ 0.0, -0.05 },
+	{ -0.05, -0.1 },
+};
+
 static void key_press_callback(int key)
 {
 	switch (key) {
@@ -45,7 +53,8 @@ int main()
 
 		if (FD_ISSET(drm_fd, &set)) {
 			renderer_handle();
-			renderer_draw();
+			renderer_clear();
+			renderer_draw(ship, NELEMS(ship));
 			renderer_swap();
 		}
 	}