/**
 ** setdrvr.c ---- video driver setup
 **
 ** Copyright (c) 1995 Csaba Biegl, 820 Stirrup Dr, Nashville, TN 37221
 ** [e-mail: csaba@vuse.vanderbilt.edu]
 **
 ** This file is part of the GRX graphics library.
 **
 ** The GRX graphics library is free software; you can redistribute it
 ** and/or modify it under some conditions; see the "copying.grx" file
 ** for details.
 **
 ** This library is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 **
 **/

#include <ctype.h>

#include "libgrx.h"
#include "grdriver.h"
#include "arith.h"

static char * nxtoken(char *p,char *token)
{
	while(*p == ' ') p++;
	while(*p && (*p != ' ')) *token++ = *p++;
	*token = '\0';
	return(p);
}

int GrSetDriver(char *drvspec)
{
	static int firsttime = TRUE;
	GrVideoDriver *drv = NULL;
	char options[100];
	char *biggdims;

	if ((biggdims = getenv("MGRXBIGG")) != NULL) {
	    sscanf(biggdims, "%d %d", &DRVINFO->biggw, &DRVINFO->biggh);
        }

	if(!drvspec) drvspec = getenv("MGRXDRV");
	options[0] = '\0';
	if(drvspec) {
	    char t[100],name[100],*p = drvspec;
	    name[0] = '\0';
	    while(p = nxtoken(p,t),t[0] != '\0') {
		if(strlen(t) == 2) {
#                   define CH16(c1,c2)  (((c1) << 8) | (c2))
		    void *oaddr = NULL;
		    int  cf = FALSE;
		    switch(CH16(tolower(t[0]),tolower(t[1]))) {
			case CH16('n','c'):
			case CH16('g','c'): oaddr = &DRVINFO->defgc; cf = TRUE; break;
			case CH16('t','c'): oaddr = &DRVINFO->deftc; cf = TRUE; break;
			case CH16('g','w'): oaddr = &DRVINFO->defgw; break;
			case CH16('t','w'): oaddr = &DRVINFO->deftw; break;
			case CH16('g','h'): oaddr = &DRVINFO->defgh; break;
			case CH16('t','h'): oaddr = &DRVINFO->defth; break;
		    }
		    if(oaddr) {
			long optval;
			p = nxtoken(p,t);
			if(sscanf(t,"%ld",&optval) > 0) {
			    if(cf) {
				switch(toupper(t[strlen(t) - 1])) {
				    case 'K': optval <<= 10; break;
				    case 'M': optval <<= 20; break;
				}
				*((long *)oaddr) = optval;
				continue;
			    }
			    *((int *)oaddr) = (int)optval;
			}
			continue;
		    }
		}
		strcpy(name,t);
	    }
	    for(p = name; (p = strchr(p,':')) != NULL; p++) {
		if(p[1] == ':') {
		    strcpy(options,&p[2]);
		    *p = '\0';
		    break;
		}
	    }
	    if(name[0] != '\0') {
		int ii = 0,found = FALSE;
		while(!found && ((drv = _GrVideoDriverTable[ii++]) != NULL)) {
		    char *n = name;
		    for(p = drv->name; ; p++,n++) {
			if(tolower(*p) != tolower(*n)) break;
			if(*p == '\0') { found = TRUE; break; }
		    }
		}
		if(!found) return(FALSE);
	    }
	}
	if(!drv) {
	    GrVideoDriver *dp;
	    int ii,maxmodes = 0;
	    for(ii = 0; (dp = _GrVideoDriverTable[ii]) != NULL; ii++) {
		if(dp->detect && (*dp->detect)()) {
		    int nm = 0;
		    for( ; dp; dp = dp->inherit) nm += dp->nmodes;
		    if(nm > maxmodes) {
			drv = _GrVideoDriverTable[ii];
			maxmodes = nm;
		    }
		}
	    }
	    if(!drv) return(FALSE);
	}
	_GrCloseVideoDriver();
	if(firsttime) {
	    atexit(_GrCloseVideoDriver);
	    firsttime = FALSE;
	}
	if(!drv->init || drv->init(options)) {
	    DRVINFO->vdriver = drv;
	    return(TRUE);
	}
	return(FALSE);
}

void _GrCloseVideoDriver(void)
{
	sttcopy(&DRVINFO->fdriver,&DRVINFO->tdriver);
	if(DRVINFO->vdriver != NULL) {
	    if(DRVINFO->vdriver->reset) (*DRVINFO->vdriver->reset)();
	    DRVINFO->vdriver = NULL;
	}
}