This file contains the beginnings of a "library" (not in the true

sense) of functions to be used by drivers.  Things like freeing a
framebuffer, creating a frame buffer, andding characters or strings
to a framebuffer, et al, are here...

server/drivers/lcd_lib.c

@@ -0,0 +1,89 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/errno.h>
+#include "lcd.h"
+
+// ==================================================
+// LCD library of useful functions for drivers
+// ==================================================
+
+// Drawn from the "base driver" which really was the precursor
+// to this library....
+
+void
+free_framebuf (struct lcd_logical_driver *driver) {
+	if (!driver)
+		return;
+
+	if (driver->framebuf != NULL)
+		free (driver->framebuf);
+
+	driver->framebuf = NULL;
+}
+
+void
+clear_framebuf (struct lcd_logical_driver *driver) {
+	int framebuf_size;
+
+	if (!driver)
+		return;
+
+	framebuf_size = driver->wid * driver->hgt;
+	memset (driver->framebuf, ' ', framebuf_size);
+}
+
+int
+new_framebuf (struct lcd_logical_driver *driver, char *oldbuf) {
+	if (driver->framebuf == NULL)
+		return 1;
+	if (oldbuf == NULL)
+		return 1;
+	return (strncpy(driver->framebuf, oldbuf, driver->wid * driver->hgt) != 0);
+}
+
+void
+insert_str_framebuf (struct lcd_logical_driver *driver, int x, int y, char *string) {
+	int i;
+	char buf[64];
+	char *pos;
+
+	if (!driver)
+		return;
+
+	x--; y--; // convert to zero-indexing
+
+	if (x >= driver->wid) return;
+	if (x < 0) x = 0;
+
+	if (y >= driver->hgt) y = driver->hgt;
+	if (y < 0) y = 0;
+
+	if ((x + strlen(string)) > driver->wid)
+		strncpy(buf, string, driver->wid - x - 1);
+	else
+		strncpy(buf, string, sizeof(string));
+
+	pos = (driver->framebuf + (y * driver->wid) + x);
+	strcpy(pos, buf);
+}
+
+void
+insert_chr_framebuf (struct lcd_logical_driver *driver, int x, int y, char c) {
+	if (!driver)
+		return;
+
+	x--; y--;
+
+	if (x >= driver->wid) driver->wid;
+	if (x < 0) x = 0;
+
+	if (y >= driver->hgt) y = driver->hgt;
+	if (y < 0) y = 0;
+
+	driver->framebuf[(y * driver->wid) + x] = c;
+}
+