added the rgb function to upiwin and started building the demo script

src/Makefile

@@ -2,7 +2,7 @@ BUILDUTILS=../buildutils
 RESOURCES=../resources
 SPLASHSCREEN=splash-vmwcblk.png
 
-OBJS=main.o sysinput.o ep_init.o ep_upiwin.o ep_backlight.o ep_msg.o ep_devctxt.o ep_bitmap.o \
+OBJS=main.o sysinput.o ep_init.o ep_upiwin.o ep_backlight.o ep_msg.o ep_graphics.o ep_devctxt.o ep_bitmap.o \
      ep_upiwin_tmp.o ep_util.o fbinit.o rect.o gfxobj.o devctxt.o dc_screen.o fontengine.o \
 	 bitmap.o fbprimitive.o log.o gpio.o msg_queue.o time_func.o config.o splash.o
 LIBS=-lpython3.7m -lcrypt -lfreetype -lbcm2835 -lpthread -ldl -lutil -lm

src/ep_graphics.c

@@ -0,0 +1,13 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#include "wintype.h"
+#include "gfxtype.h"
+
+PyObject *Epython_rgb(PyObject *self, PyObject *args)
+{
+  UINT32 r, g, b;
+  
+  if (!PyArg_ParseTuple(args, "kkk", &r, &g, &b))
+    return NULL;
+  return PyLong_FromUnsignedLong(RGB(r, g, b));
+}

src/ep_upiwin.c

@@ -23,6 +23,9 @@ static PyMethodDef UPIWINMethods[] = {
    "Retrieves a message from the message queue, blocking if necessary."},
   {"post_quit_message", Epython_post_quit_message, METH_VARARGS,
    "Posts a WM_QUIT message to the message queue, with an exit code."},
+  /* Graphics functions */
+  {"rgb", Epython_rgb, METH_VARARGS,
+   "Creates a color value from separate red, green, and blue indexes."},
   {NULL, NULL, 0, NULL}
 };
 

src/ep_upiwin.h

@@ -22,5 +22,7 @@ extern PyObject *Epython_set_backlight_level(PyObject *self, PyObject *args);
 extern PyObject *Epython_get_message(PyObject *self, PyObject *args);
 extern PyObject *Epython_post_quit_message(PyObject *self, PyObject *args);
 
+/* ep_graphics.c */
+extern PyObject *Epython_rgb(PyObject *self, PyObject *args);
 
 #endif /* __EP_UPIWIN_H_INCLUDED */