/* 
   mkspace.c
	
   Changes by Harald Deischinger to compile with cthugha-L under Linux.
   Changes:
       int -> short
       random

       short -> tint
       unsigned tint -> utint

       const buff
*/

/*
// Create a "space flight" translation table for Cthugha.
// The effect is that of a fast forward motion. A small region at the center
// of the screen is Randomized to make the screen less empty and more
// tinteresting. A backward flight option is also available.
//
// Compiled using Borland C 3.1.
//
// By Ofer Faigon, Sep 1994.
//     ofer@brm.co.il
//     (or oferf@itexjct.jct.ac.il)
//
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>

int Random(int range) {
    if ( range > 0)
	return rand() % range;
    else
	return 0;
}

typedef enum {FALSE=0, TRUE=1} bool;

#define CONST_BUFF
#include "../src/cthugha.h"
#include "../src/cth_buffer.h"

#define Y_CENTER  (BUFF_HEIGHT / 2)
#define X_CENTER  (BUFF_WIDTH / 2)

#define DEFAULT_SPEED 100
#define DEFAULT_RAND   70

int main (int argc, char **argv) {
    char   *fileName;
    FILE   *fp;
    tint    x, y, dx, dy, map_x, map_y;
    tint    speed, Randomness;
    bool   reverse;
    utint map;

    if (argc < 2  ||  argc > 5) {
	char  *p = strrchr(argv[0], '\\');
	p = p ? p+1 : argv[0];
	printf ("\"Space flight\" table generator for CTHUGHA.\n");
	printf ("The generated table creates an effect of flying forward through a\n");
	printf ("3-D space.\n");
	printf ("\n");
	printf ("Usage:  %s outfile.tab [speed [Randomness ['r']]]\n", p);
	printf ("  Speed should be 30..300 (default %d)\n", DEFAULT_SPEED);
	printf ("  Randomness should be 0..100 (default %d)\n", DEFAULT_RAND);
	printf ("  Adding a fourth argument will create a backward movement.\n");
	return 1;
    }

    fileName = argv[1];
    speed = (argc > 2) ? atoi(argv[2]) : DEFAULT_SPEED;
    Randomness = (argc > 3) ? atoi(argv[3]) : DEFAULT_RAND;
    reverse = (argc > 4);

    speed = min(max(speed,30),300);
    Randomness = min(max(Randomness,0),100);

    if ((fp = fopen(fileName, "wb")) == NULL) {
	printf ("*** Failed to create output file %s\n", fileName);
	return 2;
    }

    printf ("Generating table %s with %sspeed=%d and Randomness=%d\n",
	    fileName, reverse ? "reverse " : "", speed, Randomness);

    for (y = 0; y < BUFF_HEIGHT; y++) {
	printf ("Generating line %d of %d...\r", y + 1, BUFF_HEIGHT);

	for (x = 0; x < BUFF_WIDTH; x++) {
	    dx = x - X_CENTER;
	    dy = y - Y_CENTER;

	    if (! reverse  &&  abs(dx) < 30  &&  abs(dy) < 20  &&
	    Random(abs(dx)+abs(dy)) < 4) {

		map_x = Random(BUFF_WIDTH);
		map_y = Random(BUFF_HEIGHT);
	    } else {
		tint  speedFactor;
		long sp;

		if (Randomness == 0)
		    sp = speed;
		else {
		    speedFactor = Random(Randomness + 1) - Randomness / 3;
		    sp = speed * (100L + speedFactor) / 100L;
		}

		if (reverse)
		    sp = (-sp);

		map_x = (tint)(x - (dx * sp) / 700);
		map_y = (tint)(y - (dy * sp) / 700);
	    }

	    if (map_y >= BUFF_HEIGHT || map_y < 0  ||
		map_x >= BUFF_WIDTH  || map_x < 0 ) {
		map_x = 0;
		map_y = 0;
	    }

	    map = map_y * BUFF_WIDTH + map_x;

	    if (fwrite (&map, sizeof(tint), 1, fp) != 1) {
		printf ("\n*** Error while writing to output file (disk full?)\n");
		fclose (fp);
		return 3;
	    }
	}
    }

    printf ("Done.%26s\n", "");

    fclose (fp);

    return 0;
}