Linux Cubed Series 8: LINUX Games/Linux Cubed Series 8 - LINUX Games.iso/games/video/fly8111-.000/fly8111-/fly8/shapes/f8shape.awk

Text File | 1979-12-31 | 5KB | 313 lines

# --------------------------------- f8shape.awk -------------------------------

#
# This is part of the flight simulator 'fly8'.
# Author: Eyal Lebedinsky ([e-mail]).
#

#
# Convert a (cpp processed) object description to a simple list of numbers.
# The input should be a comma separated list of quadruplets.
# Evaluates expressions using '+ - * / % ( )'. All other characters are
# removed. A vertex count is added to the beginning.
#


BEGIN    {
    name = ARGV[1]
    fin  = name ".i"
    fout = name ".003"

    lineno = 0
    n = 0
    advance()
    while (1) {
        x = int(expression())
        eat(",")

        y = int(expression())
        eat(",")

        z = int(expression())
        eat(",")

        f = int(expression())
        if (0 == f)
            break;

        printf ("%d %d %d %d\n", x, y, z, f) >fout
        ++n

        if (tok == "(eof)")
            break
        eat(",")
    }

    close(fin)
    close(fout)

    fin  = name ".003"
    fout = name ".vxx"

    print n, 2 >fout        # V_METERS = 2
    while (getline<fin != 0) {
        print $0 >fout
    }

    close(fin)
    close(fout)
}

function advance() {
    if (tok == "(eof)")
        return tok
    while (1) {
        while (1) {
            if (length(line) == 0 || line ~ /^static VERTEX/)
                ++lineno
            else if (substr(line,1,1) == "#") {
                split(line,a)
                if (a[1] == "#line")
                    lineno = a[2]+0
                else
                    ++lineno
            } else
                break
            if (getline line <fin == 0)
                return tok = "(eof)"
        }
        if (match(line, /^[ \t;\n{}]/))
                line = substr(line, 2)
        else
                break
    }
    if (match(line, /^[0-9]+/) ||
        match(line, /^(<=|==|!=|>=|\|\||&&|>>|<<)/) ||
        match(line, /^./)) {
            tok = substr(line, 1, RLENGTH)
            line = substr(line, RLENGTH+1)
            return tok
    }
    error("line " lineno " incomprehensible at " line)
}

function eat(s) {
    if (tok != s)
        error("line " lineno ": saw \"" tok "\" expected \"" s "\"")
    advance()
}

function error(s) {
    print "Error: " s
    exit 1
}

function expression(  e, e1, e2) {
    e = logical_or()
    if (tok == "?") {
        advance()
        e1 = expression()
        eat(":")
        e2 = expression()
        if (e)
            e = e1
        else
            e = e2
# This fails!:    e = e ? e1 : e2
    }
    return e
}

function logical_or(  e, e1) {
    e = logical_and()
    while (tok == "||") {
        advance()
        e1 = logical_and()
        e = e || e1
    }
    return e
}

function logical_and(  e, e1) {
    e = inclusive_or()
    while (tok == "&&") {
        advance()
        e1 = inclusive_or()
        e = e && e1
    }
    return e
}

function bitwise(a, b, op,  abit, bbit, asign, bsign, rbit, r, t, n) {
    a = int(a)
    asign = (a < 0) ? 1 : 0;
    b = int(b)
    bsign = (b < 0) ? 1 : 0;
    r = 0
    rpos = 1
    for (n = 0; n < 32; ++n) {
        t = int((a-asign)/2)
        abit = a != t+t
        a = t
        t = int((b-bsign)/2)
        bbit = b != t+t
        b = t
        if (op == "|")
            rbit = abit || bbit
        else if (op == "&")
            rbit = abit && bbit
        else if (op == "^")
            rbit = abit != bbit
        else # unary ~
            rbit = !bbit
        r += rpos*rbit
        rpos += rpos
    }
    return r
}

function inclusive_or(  e, e1) {
    e = exclusive_or()
    while (tok == "|") {
        advance()
        e1 = exclusive_or()
        e = bitwise(e, e1, "|");
    }
    return e
}

function exclusive_or(  e, e1) {
    e = and()
    while (tok == "^") {
        advance()
        e1 = and()
        e = bitwise(e, e1, "^");
    }
    return e
}

function and(  e, e1) {
    e = equality()
    while (tok == "&") {
        advance()
        e1 = equality()
        e = bitwise(e, e1, "&");
    }
    return e
}

function equality(  op, e, e1) {
    e = relational()
    while (tok == "==" || tok == "!=") {
        op = tok
        advance()
        e1 = relational()
        if (op == "==")
            e = e == e1
        else
            e = e != e1
    }
    return e
}

function relational(  op, e, e1) {
    e = shift()
    while (tok ~ /<|<=|>=|>/) {
        op = tok
        advance()
        e1 = shift()
        if (op == "<")
            e = e < e1
        else if (op == "<=")
            e = e <= e1
        else if (op == ">=")
            e = e >= e1
        else
            e = e > e1
    }
    return e
}

function shift(  op, e, e1) {
    e = additive()
    while (tok == "<<" || tok == ">>") {
        op = tok
        advance()
        e1 = additive()
        if (op == ">>")
            e1 = -e1
        if (e1 > 0) {
            for (e1 = int(e1); e1 > 0; --e1)
                e *= 2;
        } else {
            for (e1 = int(-e1); e1 > 0; --e1)
                e /= 2;
        }
    }
    return e
}

function additive(  op, e, e1) {
    e = multiplicative()
    while (tok == "+" || tok == "-") {
        op = tok
        advance()
        e1 = multiplicative()
        if (op == "+")
            e = e + e1
        else
            e = e - e1
    }
    return e
}

function multiplicative(  op, e, e1) {
    e = unary()
    while (tok == "*" || tok == "/" || tok == "%") {
        op = tok
        advance()
        e1 = unary()
        if (op == "*")
            e = e * e1
        else if (op == "/")
            e = e / e1
        else
            e = e % e1
    }
    return e
}

function unary() {
    if (tok == "-") {
        advance()
        return -primary()
    } else if (tok == "~") {
        advance()
        return bitwise(0, primary(), "~")
    } else if (tok == "!") {
        advance()
        return !primary()
    } else if (tok == "+") {
        advance()
        return primary()
    } else
        return primary()
}

function primary(  e) {
    if (tok == "(") {
        advance()
        e = expression()
        eat(")")
        return e
    }

    if (tok ~ /^[0-9]+/) {
        e = tok
        advance()
        return e+0
    }

    error("unexpected \"" tok "\" at line " lineno)
}