/*********************************************************************** gdrv.h - header for GDEV back ends Copyright (C) 1991 Dean Rubine This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License. See ../COPYING for the full agreement. **********************************************************************/ /* $Disclaimer: * Permission to use, copy, modify, and distribute this software and its * documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and that * both that copyright notice, this permission notice, and the following * disclaimer appear in supporting documentation, and that the names of * IBM, Carnegie Mellon University, and other copyright holders, not be * used in advertising or publicity pertaining to distribution of the software * without specific, written prior permission. * * IBM, CARNEGIE MELLON UNIVERSITY, AND THE OTHER COPYRIGHT HOLDERS * DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT * SHALL IBM, CARNEGIE MELLON UNIVERSITY, OR ANY OTHER COPYRIGHT HOLDER * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. * $ */ #include #include "gdev.h" /* The purpose of this package is to provide a set of device independent graphics routines for both input and output. Graphics, text output, keyboard input, mice, and menus are supported. An application gets device independence by only calling routines whose name begins with GDEV. For each kind of graphic device supported there is a device driver. The driver must implement a number of functions. Those functions should be (by convention) prefixed with the name of the device, e.g. the function which draws lines using poof is called POOFline. In order for these functions to do their job they will need to call functions whose name begins with GDRV. Device interface: The GDEV kernel and the driver need to refer to multiple windows. They do so by using two handles refered to in this file as W and H, declared as follows: int H; // a window number sent from driver to GDEV Pointer W; // a pointer to (presumably) an internal data structure in the driver for a given window. When GDEVinit() is called to create a new window, it chooses a value for H to refer to this new window. It informs the driver of this H value via the all DEVinit(H). DEVinit(H) returns W, the pointer to its internal data structure for this window, so GDEV can pass W to the driver in subsequent calls (like DEVline). The driver passes H to GDEV in order to tell GDEV that something has happened in window H (e.g. GDRVrefresh(H) tells GDEV that window H need to be refreshed). It is necessary for the driver to keep a mapping from W to H (easily done by including H in the driver's per window data structure). Every device driver needs to supply the following functions (DEV is the name of the particular device). These functions are used to initialize a table in gdev.c. DEVinit(H) initialize, opens a new window, returns W DEVstart(W) clear screen/new page (the first time this must result in GDRVrefresh being called) DEVflush(W) display picture so far DEVstop(W) clean up upon program exit DEVline(W, int x1, y1, x2, y2) DEVpoint(W, int x, y); DEVrect(W, int x1, y1, x2, y2) DEVtext(W, int x1, y1; char *string) DEVsetdim(W, int width, height) sets page dimensions, it may be ignored. The call DEVgetdim(W, int *width, *height) returns the actual dimensions. DEVmenuitem(W, char *itemname, int retval, int addflag) When addflag is TRUE, this should cause itemname to be added to the menu. When addflag is FALSE, itemname should be deleted from the menu. In both cases, retval is guarenteed to be a small integer (and is to be passed to GDRVmenu when the item is selected). DEVmouseinterest(W, event) int event; informs the driver that we are interested in these kinds of mouse events. Upon initialization, an device driver should do the following: For each variable (in the GDEVset sense) an device is interested in, it may call: GDRVvar_fcn(H, varname, function, arg) char *varname; int (*function)(); char *arg; When the client does a GDEVset call, "function" will be called with three args: the name of the variable, value of the variable, and passed arg. If the driver just wants one of its variables set when the user calls GDEVset, it should call: GDRVvar_addr(H, varname, address) char *varname; char *address; The address is treated as a pointer to a value of the type the client specified (i.e. If the client called GDEVseti, the address is treated as a pointer to an integer). For each file descriptor upon which the device driver wants to be notified when input is available he should call GDRVfdnotify(fd, function) int fd; int (*function)(); (*function)(fd) will be called whenever input is available on fd. If fd == FD_POLL, the function will be called just before any select which waits for input, instead of after the select has returned. When a driver sees a mouse event, it should call GDRVmouse(H, event, x, y, t) int event; int x, y; int t; It is OK for the driver to inform GDEV of mouse events in which the client is not interested - these will be discarded. When a driver needs the screen refreshed, it should call GDRVrefresh(H); When a driver sees a menu event, it should call GDRVmenu(H, retval) int retval; where retval is the small integer which refers to the menu item chosen by the user. When a driver notices the user typed a char he should send GDRVwindow(H); GDRVputc(c); */ /* polling fd for GDRVfdnotify */ #define FD_POLL (-1) /* functions */ void GDRV00topleft(); /* int H; a driver should call this function during initialization if it thinks 0,0 is the top left of the window, else 0,0 is bottom left */ void GDRVvar_fcn(); /* H, char *varname; int (*function)(); Pointer arg; */ void GDRVvar_addr(); /* H, char *varname; Pointer address; */ void GDRVfdnotify(); /* int fd; int (*function)(); */ void GDRVmouse(); /* H, int event; int x, y; */ void GDRVrefresh(); /* H */ void GDRVmenu(); /* H, int retval; */