Usenet 1994 October/usenetsourcesnewsgroupsinfomagicoctober1994disk2.iso/misc/volume5/mapper

Text File | 1989-02-03 | 21KB | 803 lines

Path: xanth!nic.MR.NET!hal!ncoast!allbery
From: [e-mail] (Steve Sampson)
Newsgroups: comp.sources.misc
Subject: v05i072: CGA/EGA Perspective Map Program
Keywords: Source, Doc
Message-ID: <[e-mail]>
Date: 7 Dec 88 00:30:44 GMT
Sender: [e-mail]
Reply-To: [e-mail] (Steve Sampson)
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 789
Approved: [e-mail]

Posting-number: Volume 5, Issue 72
Submitted-by: "Steve Sampson" <[e-mail]>
Archive-name: mapper

This is for Turbo-C users, no binaries included.  Easily modified for
other compilers.


#! /bin/sh
# Contents:  mapper.doc mapper.c
# Wrapped by sampson on Mon Dec 05 15:07:18 1988
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f mapper.doc -a "${1}" != "-c" ; then
  echo shar: Will not over-write existing file \"mapper.doc\"
else
echo shar: Extracting \"mapper.doc\" \(4532 characters\)
sed "s/^X//" >mapper.doc <<'END_OF_mapper.doc'
X
X                             The Mapper Program
X
X                                 Version 1.7
X
X                              22 November 1988
X
X
X         I was interested in techniques  for producing maps, and  found
X      the article by William D. Johnston in the May and June 1979  Byte
X      Magazine.    This   two  part  article   provided  an   excellent
X      introduction and source  code in Basic  Language.   His code  was
X      restricted to the algorithms and  did not get involved with  user
X      interface.  To evaluate his algorithms and try out the displays I
X      coded the program and a simple interface in Turbo-C Version  1.5.
X      The program in its current form is highly based on Mr. Johnston's
X      algorithms and provides no significant additional capabilities.
X
X      I also found  a high resolution database  called the Micro  World
X      Data Bank II (MWDBII).   This database was  1 megabyte in  length
X      and good down  to minutes  of a degree.   See the  C source  code
X      comments for availability.
X
X      To run the  program and receive  help you  use the DOS  common
X      method of the question option "/?".  Just type "mapper/?" and the
X      following usage help will be displayed:
X
X              Usage: mapper [/bcdgilmrsx]
X
X                /b   Boundaries Off
X                /c   Countries On
X                /dn  Database ('MWDBII' Default)
X                /g   Grid lines On
X                /i   Islands Off
X                /l   Lakes Off
X                /mn  Map Resolution (5 Default)
X                /r   Rivers On
X                /s   States On
X                /x   Colors On
X
X              Defaults to Boundaries and Islands On
X
X      The defaults are what I thought should be fairly common.  The map
X      database has  5 resolutions,  and can  be selected  with the  'm'
X      option.  5 is the  lowest resolution and 1  is the greatest.   If
X      you have several different databases  you can use the 'd'  option
X      and provide the path and filename (128 Characters max).  The  'm'
X      and 'd' options  should be placed at  the end.   They can be  put
X      anywhere  but  it's  a  little  easier  at  the  end.    Example:
X      mapper/glrsm1.  If you use the option in the middle you will need
X      to put a  space between it  and the  remaining options.  Example:
X      mapper/glddata /rs.  These are the most foolproof methods.  Note:
X      The level 5 database included doesn't really use the options yet.
X      The program works as advertised on level 1. There are some errors
X      with the database as you'll see.  I've converted the database  to
X      ASCII, and am working on cleaning up the errors and redundancies.
X
X         A little about the speed of the result.  The program is  quite
X      slow on an 8088 without a math coprocessor, and speed is  getting
X      acceptable on  an 80286.   The  C language  standard uses  double
X      precision math.    This is  a  waste  with the  current  database
X      resolution.  An integer version  of the math routines would  sure
X      speed up  the program  quite  a bit.    The mapper  program  uses
X      Turbo-C auto detect  of a  math coprocessor  and graphics  device
X      type (CGA, EGA, and VGA).
X
X         If you want to quit the  plotting on the screen, just hit  any
X      key and the bell will  sound and exit you back  to DOS.  You  can
X      also use Control-C to get out.
X
X         The C program  lists three sources  for the  Micro World  Data
X      Bank II database.  The  database is 1 Megabyte (800K  Compressed)
X      and is just too much data for reasonable downloading.   To see if
X      the program  would  be  useful  for you  I  included  a  level  5
X      resolution map (the lowest resolution).  This particular database
X      has all  the data  thrown together  so the  command line  options
X      aren't fully functional.  They  become functional at about  level
X      3 I believe.
X
X         This program was tested  on a PC XT  Clone, 640K, and NSI  EGA
X      board.  Also a Zenith Z-248 with 512k and CGA was tested.   Other
X      configurations will need to be tested.
X
X      Due to  the  grid  method used,  it  shouldn't  be used  with  an
X      Azimuthal Equidistant map.   You can  try it once  to see what  I
X      mean.  There's lots of room for improvements, "Handle It!".
X
X      Thanks to Mr. Johnston for his article and algorithms.
X
X      USMail: Steve R. Sampson, Box 45668, Tinker AFB, Oklahoma, 73145
X      Compuserve: 75136,626  Unix: [e-mail]
END_OF_mapper.doc
if test 4532 -ne `wc -c <mapper.doc`; then
    echo shar: \"mapper.doc\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f mapper.c -a "${1}" != "-c" ; then
  echo shar: Will not over-write existing file \"mapper.c\"
else
echo shar: Extracting \"mapper.c\" \(13949 characters\)
sed "s/^X//" >mapper.c <<'END_OF_mapper.c'
X/*
X *    mapper.c
X *
X *    Version 1.7 by Steven R. Sampson, November 1988
X *
X *    Based on a program and article by William D. Johnston
X *    Copyright (c) May-June 1979 BYTE, All Rights Reserved
X *
X *    This program draws three types of map projections:
X *    Perspective, Modified Perspective, and Azimuthal Equidistant.
X *
X *    Compiled with Turbo-C V1.5
X */
X
X#include <dos.h>
X#include <math.h>
X#include <stdio.h>
X#include <conio.h>
X#include <string.h>
X#include <stdlib.h>
X#include <graphics.h>
X
Xtypedef int    bool;
X
X/* Program Constants */
X
X#define    FALSE    (bool) 0
X#define    TRUE    (bool) ~FALSE
X
X#define    PI    (3.141593F)
X#define    HALFPI    (1.570796F)
X#define    TWOPI    (2.0F * PI)        /* Two Pi alias 360 Degrees         */
X
X#define    RADIAN    (180.0F / PI )        /* One radian                 */
X#define    TWO    (2.0F / RADIAN)        /* 2 degrees in radians             */
X#define    TEN    (10.0F / RADIAN)    /* 10 degrees in radians         */
X#define    EIGHTY    (80.0F / RADIAN)    /* 80 degrees in radians         */
X#define    EARTH    (6378.0F)        /* Mean radius of earth (Kilometers) */
X
X/* Program Globals */
X
XFILE    *fp;
X
Xfloat    angle, maxplot, center_lat, center_lon, lat, lon, distance,
X    sin_of_distance, cos_of_distance, sin_of_center_lat, cos_of_center_lat,
X    scale, g, h2, facing_azimuth, aspect;
X
Xint    option, center_x, center_y, grid_color, level = 5;
Xint    GraphDriver = DETECT, GraphMode;
X
Xchar    optstring[] = "bcd:gilm:rsx?";
Xchar    database[128] = "mwdbii";    /* default name 'MWDBII'         */
X                    /* leave room for pathname!         */
Xbool    boundaries = TRUE,        /* defaults to Boundaries, Islands   */
X    countries  = FALSE,
X    grids      = FALSE,
X    islands    = TRUE,
X    lakes      = FALSE,
X    rivers     = FALSE,
X    states     = FALSE,
X    colors     = FALSE;
X
X/* Forward Declarations, Prototypes */
X
Xextern    int    getopt(int, char **, char *);
Xextern    int    optind, opterr;
Xextern    char    *optarg;
X
Xfloat    parse(char *);
Xvoid    grid(void), plotmap(void), prompts(void), quit(void);
Xbool    compute(float *, float *, int *, int *);
X
X
Xmain(argc, argv)
Xint    argc;
Xchar    *argv[];
X{
X    register int    i;
X    int        err, xasp, yasp;
X
X    registerbgidriver(EGAVGA_driver);
X    registerbgidriver(CGA_driver);
X
X    setcbrk(TRUE);        /* Allow Control-C checking             */
X    ctrlbrk(quit);        /* Execute quit() if Control-C detected         */
X
X    while ((i = getopt(argc, argv, optstring)) != -1)  {
X        switch (i)  {
X        case 'b':
X            boundaries = FALSE;
X            break;
X        case 'c':
X            countries = TRUE;
X            break;
X        case 'd':
X            strcpy(database, optarg);
X            break;
X        case 'g':
X            grids = TRUE;
X            break;
X        case 'i':
X            islands = FALSE;
X            break;
X        case 'l':
X            lakes = TRUE;
X            break;
X        case 'm':
X            level = atoi(optarg);
X            break;
X        case 'r':
X            rivers = TRUE;
X            break;
X        case 's':
X            states = TRUE;
X            break;
X        case 'x':
X            colors = FALSE;
X            break;
X        case '?':
X        default:
X              printf("Usage: mapper [/bcdgilmrsx]\n\n");
X              printf("  /b   Boundaries Off\n");
X              printf("  /c   Countries On\n");
X              printf("  /dn  Database ('MWDBII' Default)\n");
X              printf("  /g   Grid lines On\n");
X              printf("  /i   Islands Off\n");
X              printf("  /l   Lakes On\n");
X              printf("  /mn  Map Resolution (5 Default)\n");
X              printf("  /r   Rivers On\n");
X              printf("  /s   States On\n");
X              printf("  /x   Colors On\n\n");
X              printf("Defaults to Boundaries and Islands On\n");
X              exit(0);
X        }
X    }
X
X    if ((fp = fopen(database, "rb")) == (FILE *)NULL)  {
X        printf("\007Error: Can't locate Database '%s'\n", database);
X        exit(1);
X    }
X
X    initgraph(&GraphDriver, &GraphMode, "");/* initialize graphics         */
X    err = graphresult();
X
X    restorecrtmode();            /* get back to text mode     */
X
X    if (err < 0)  {
X        printf("Graphics Error - %s\n", grapherrormsg(err));
X        exit(-1);
X    }
X
X    center_x = getmaxx() / 2;        /* get screen size for x, y  */
X    center_y = getmaxy() / 2;
X    getaspectratio(&xasp, &yasp);        /* squish factor for y axis  */
X    aspect = (float)xasp / (float)yasp;
X
X    prompts();                /* get the basic map info    */
X    setgraphmode(GraphMode);        /*  and go to graphics mode  */
X
X    if (GraphMode != CGAHI)  {
X        setbkcolor(BLACK);        /* must be EGA or VGA then   */
X        if (colors)
X            grid_color = EGA_LIGHTRED;
X        else
X            grid_color = EGA_LIGHTGRAY;
X    } else
X        grid_color = LIGHTGRAY;        /* CGA only has two colors   */
X
X    setcolor(LIGHTGRAY);
X
X    /*
X     *    See if data plotting is even needed
X     */
X
X    if (boundaries || countries || islands || lakes || rivers || states)
X        plotmap();            /* display map on screen     */
X
X    if (grids)
X        grid();                /* draw lat & long ref lines */
X
X    if (print)
X        printscreen();            /* relay screen to printer   */
X
X    sound(800);                /* 800 Hz for 1/4 a second   */
X    delay(125);
X    nosound();
X
X    getch();                /* pause until key pressed   */
X    closegraph();                /* graphics off             */
X    fclose(fp);                /* close database file         */
X
X    exit(0);
X}
X
X/*
X *    Return to operator following Control-C
X */
X
Xvoid quit()
X{
X    closegraph();
X    fclose(fp);
X
X    exit(0);
X}
X
X/*
X *    Operator prompts and input.
X */
X
Xvoid prompts()
X{
X    char    temp[16];
X    float    ret, altitude;
X
X    printf("West Longitudes and South Lattitudes are negative\n");
X
X    /* input the world Lat & Long that is to be centered on */
X    /*   then convert the human notation to radians         */
X
X    do  {
X        printf("\nLatitude of the map center [+-]dd.mm : ");
X        scanf("%s", temp);
X        ret = parse(temp);
X    } while (ret > 90.0F || ret < -90.0F);
X
X    /* the arcosine function has trouble at 90 degrees */
X
X    if (ret == 90.0F)
X        ret = 89.9F;
X
X    if (ret == -90.0F)
X        ret = -89.9F;
X
X    center_lat = ret / RADIAN;
X    sin_of_center_lat = sin(center_lat);
X    cos_of_center_lat = cos(center_lat);
X
X    do  {
X        printf("Longitude of the map center [+-]ddd.mm : ");
X        scanf("%s", temp);
X        ret = parse(temp);
X    } while (ret > 180.0F || ret < -180.0F);
X
X    center_lon = ret / RADIAN;
X
X    do  {
X        printf("\nSelect from the following options:\n\n");
X        printf("  1 - Perspective Projection\n");
X        printf("  2 - Modified Perspective Projection\n");
X        printf("  3 - Azimuthal Equidistant Projection\n\n");
X        printf("Choice : ");
X        scanf("%d", &option);
X    } while (option < 1 || option > 3);
X
X    if (option == 3)  {
X        maxplot = PI;        /* use HALFPI for less area        */
X        scale = (float)center_y / maxplot;
X        return;
X    }
X
X    /* input the height above the terrain */
X
X    printf("\nObserver altitude (km) : ");
X    scanf("%f", &altitude);
X
X    h2 = EARTH + altitude;
X    maxplot = acos(EARTH / h2);
X
X    /* the operator can orient the world upside down if they want */
X
X    do  {
X        printf("Observer facing azimuth (0 - 359 degrees) : ");
X        scanf("%f", &facing_azimuth);
X    } while (facing_azimuth < 0.0F || facing_azimuth > 360.0F);
X
X    facing_azimuth = -facing_azimuth / RADIAN;
X
X    /* calculate the scale for the polar coordinates */
X
X    scale = (float)center_y / (EARTH * sin(maxplot));
X
X    /* for the perspective projection */
X
X    g = EARTH * (h2 - EARTH * cos(maxplot));
X}
X
X
X/*
X *    Convert the database to the desired projection by computation.
X *
X *    This code is a hand translation from BASIC to C based on Mr. Johnstons
X *    code.  It is a non-mathematicians idea of what he meant.
X *
X *    Return TRUE if offscale else FALSE.
X */
X
Xbool compute(lat, lon, x, y)
Xregister float    *lat, *lon;
Xregister int    *x, *y;
X{
X    float    sin_of_lat,
X        cos_of_lat,
X        abs_delta_lon,            /* absolute value         */
X        delta_lon,            /* x distance from center    */
X        delta_lat,            /* y distance from center    */
X        temp;                /* temporary storage         */
X
X    /* normalize the longitude to +/- PI */
X
X    delta_lon = *lon - center_lon;
X
X    if (delta_lon < -PI)
X        delta_lon = delta_lon + TWOPI;
X
X    if (delta_lon > PI)
X        delta_lon = delta_lon - TWOPI;
X
X    abs_delta_lon = fabs(delta_lon);
X
X    /*
X     *    If the delta_lon is within .00015 radians of 0 then
X     *    the difference is considered exactly zero.
X     *
X     *    This also simplifys the great circle bearing calculation.
X     */
X
X    if (abs_delta_lon <= 0.00015F)  {
X        delta_lat = fabs(center_lat - *lat);
X
X        if (delta_lat > maxplot)
X            return TRUE;        /* offscale             */
X
X        if (*lat < center_lat)
X            angle = PI;
X        else
X            angle = 0.0F;
X
X        sin_of_distance = sin(delta_lat);
X        cos_of_distance = cos(delta_lat);
X    }
X
X    /*
X     *    Check if delta_lon is within .00015 radians of PI.
X     */
X
X    else if (fabs(PI - abs_delta_lon) <= 0.00015F)  {
X        delta_lat = PI - center_lat - *lat;
X
X        if (delta_lat > PI)  {
X            delta_lat = TWOPI - delta_lat;
X            angle = PI;
X        } else
X            angle = 0.0F;
X
X        if (delta_lat > maxplot)
X            return TRUE;        /* offscale             */
X
X        sin_of_distance = sin(delta_lat);
X        cos_of_distance = cos(delta_lat);
X    }
X
X    /*
X     *    Simple calculations are out, now get cosmic.
X     */
X
X    else  {
X        sin_of_lat = sin(*lat);
X        cos_of_lat = cos(*lat);
X
X        cos_of_distance = sin_of_center_lat * sin_of_lat +
X                    cos_of_center_lat * cos_of_lat *
X                      cos(delta_lon);
X
X        distance = acos(cos_of_distance);
X
X        if (distance > maxplot)
X            return TRUE;        /* offscale             */
X
X        sin_of_distance = sin(distance);
X
X        temp = (sin_of_lat - sin_of_center_lat * cos_of_distance) /
X            (cos_of_center_lat * sin_of_distance);
X
X        if (temp < -1.0F || temp > 1.0F)
X            return TRUE;        /* offscale             */
X
X        angle = acos(temp);
X
X        if (delta_lon < 0.0F)
X            angle = TWOPI - angle;
X    }
X
X    if (facing_azimuth != 0.0F)  {
X        angle = angle - facing_azimuth;
X        if (angle < 0.0F)
X            angle = TWOPI + angle;
X    }
X
X    angle = HALFPI - angle;
X
X    if (angle < -PI)
X        angle = angle + TWOPI;
X
X    switch (option)  {
X    case 1:
X        temp  = (scale * (g * sin_of_distance)) /
X                (h2 - EARTH * cos_of_distance);
X        break;
X    case 2:
X        temp = scale * EARTH * sin_of_distance;
X        break;
X    case 3:
X        temp = scale * distance;
X    }
X
X    /* convert polar to rectangular, correct for screen aspect */
X
X    *x = center_x + (int)(temp * cos(angle));
X    *y = center_y - (int)(temp * sin(angle) * aspect);
X
X    return FALSE;
X}
X
X/*
X *    Read the database and plot points or lines.
X *
X *    The database is Micro World Data Bank II.  It's based on the
X *    CIA WDB-II tape available from NTIS.  Micro WDB-II was created
X *    by Micro Doc.  Placed in the public domain by Fred Pospeschil
X *    and Antonio Riveria.  Check on availability at:
X *    1-402-291-0795  (6-9 PM Central)
X *
X *    Austin Code Works has something called: The World Digitized
X *    that sounds like the same thing ($30.00), 1-512-258-0785
X *
X *    Lone Star Software has something called: The World Digitized
X *    that sounds like the same thing ($6.00), 1-800-445-6172.
X *
X *    Database is in Intel word order:
X *    code_lsb, code_msb, lat_lsb, lat_msb, lon_lsb, lon_msb
X *
X *    Code:    Integer, two meanings:
X *        1.  Detail Level (1 Highest - 5 Lowest)
X *
X *        2.  Header (1xxx - 7xxx)    Command Line Options
X *
X *            1xxx    Boundaries        /b
X *            2xxx    Countries        /c
X *    (decimal)    4xxx    States            /s
X *            5xxx    Islands            /i
X *            6xxx    Lakes            /l
X *            7xxx    Rivers            /r
X *
X *    Lat & Long:  Integer
X *        Representing Minutes of degree
X */
X
Xvoid plotmap()
X{
X    struct    { short code, lat, lon; } coord;
X    float    lat, lon;
X    int    x, y;
X    bool    point;
X
X    point = TRUE;
X    while (fread(&coord, sizeof coord, 1, fp) > 0)  {
X
X        if (kbhit())  {
X            grids = print = FALSE;
X            getch();
X            return;
X        }
X
X        /*
X         *    Skip data that has been optioned out.
X         */
X
X        if (coord.code < level)
X            continue;
X
X        if (coord.code > 5)  {        /* must be a header         */
X
X            point = TRUE;
X
X            switch (coord.code / 1000)  {
X            case 1:
X                if (boundaries)  {
X                    if (colors)
X                        setcolor(EGA_LIGHTGRAY);
X                    break;
X                }
X                else
X                    continue;
X            case 2:
X                if (countries)  {
X                    if (colors)
X                        setcolor(EGA_BROWN);
X                    break;
X                }
X                else
X                    continue;
X            case 4:
X                if (states)  {
X                    if (colors)
X                        setcolor(EGA_BROWN);
X                    break;
X                }
X                else
X                    continue;
X            case 5:
X                if (islands)  {
X                    if (colors)
X                        setcolor(EGA_LIGHTGRAY);
X                    break;
X                }
X                else
X                    continue;
X            case 6:
X                if (lakes)  {
X                    if (colors)
X                        setcolor(EGA_BLUE);
X                    break;
X                }
X                else
X                    continue;
X            case 7:
X                if (rivers)  {
X                    if (colors)
X                        setcolor(EGA_GREEN);
X                    break;
X                }
X                else
X                    continue;
X            }
X        }
X
X        /*  Convert database minutes of a degree to radians */
X
X        lat =  (float) coord.lat / 60.0F / RADIAN;
X        lon =  (float) coord.lon / 60.0F / RADIAN;
X
X        if (compute(&lat, &lon, &x, &y))  {
X            point = TRUE;        /* offscale             */
X            continue;
X        }
X
X        if (point)  {
X            putpixel(x, y, getcolor());/* put down a dot         */
X            moveto(x, y);
X            point = FALSE;
X        }
X        else
X            lineto(x, y);        /* connect the dots         */
X    }
X}
X
X/*
X *    parse +-ddd.mm
X *
X *    Change human degrees, and minutes to computer decimal.
X *    Probably designed a monster for a simple solution here...
X */
X
Xfloat parse(string)
Xchar    *string;
X{
X    char    *ptr, degrees[8], minutes[8];
X    float    num;
X
X    strcpy(degrees, "       ");        /* pre-load with blanks      */
X    strcpy(minutes, "       ");
X
X    /* if no decimal point we assume a whole number */
X
X    if ( (ptr = strchr(string, '.')) == (char *)NULL )
X        return atof(string);
X
X    /* else use the decimal point to offset */
X
X    *ptr++ = '\0';
X
X    strcpy(degrees, string);
X    num = atof(degrees);
X
X    switch (strlen(ptr))  {
X    case 0:
X        return atof(string);
X    case 1:
X    case 2:
X        strcpy(minutes, ptr);
X        break;
X    default:
X        return 361.0F;    /* This will produce an error             */
X    }
X
X    if (num >= 0.0F)
X        num += atof(minutes) / 60.0F;
X    else
X        num -= atof(minutes) / 60.0F;
X
X    return num;
X}
X
X
X/*
X *    Draw grid lines from -180 to +180 Degrees (Longitude Lines),
X *    as well as +80 to -80 Degrees (Lattitude Lines).
X */
X
Xvoid grid()
X{
X    float    lat, lon;
X    int    x, y, pass1;
X
X    setcolor(grid_color);
X
X    for (lon = -PI; lon <= PI; lon += TEN)  {
X        pass1 = TRUE;
X        for (lat = EIGHTY; lat > -EIGHTY; lat -= TEN)  {
X            if (!compute(&lat, &lon, &x, &y))  {
X                if (pass1)  {
X                    putpixel(x, y, grid_color);
X                    moveto(x, y);
X                    pass1 = FALSE;
X                } else
X                    lineto(x, y);
X            } else
X                pass1 = TRUE;
X        }
X
X        if (kbhit())  {
X            print = FALSE;
X            getch();
X            return;
X        }
X    }
X
X    for (lat = EIGHTY; lat > -EIGHTY; lat -= TEN)  {
X        pass1 = TRUE;
X        for (lon = -PI; lon <= PI; lon += TEN)  {
X            if (!compute(&lat, &lon, &x, &y))  {
X                if (pass1)  {
X                    putpixel(x, y, grid_color);
X                    moveto(x, y);
X                    pass1 = FALSE;
X                } else
X                    lineto(x, y);
X            } else
X                pass1 = TRUE;
X
X        }
X
X        if (kbhit())  {
X            print = FALSE;
X            getch();
X            return;
X        }
X    }
X}
X
X/* EOF */
END_OF_mapper.c
if test 13949 -ne `wc -c <mapper.c`; then
    echo shar: \"mapper.c\" unpacked with wrong size!
fi
# end of overwriting check
fi
echo shar: End of shell archive.
exit 0