Message-ID: <361BFA9E.6C32AF71@cue.satnet.net>
Date: Wed, 07 Oct 1998 18:34:55 -0500
From: "Ronald Patiņo G" <logan AT cue DOT satnet DOT net>
X-Mailer: Mozilla 4.04 [en] (Win95; I)
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To: "djgpp AT delorie DOT com" <djgpp AT delorie DOT com>
Subject: Raycasting help
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Reply-To: djgpp AT delorie DOT com

Hello .
Can somebody help me with this raycaster

                            (1440)
                             270
                                |
                                |
        (960)180 -------o-------- 0 / 360  (0) (1920)
                                |
                                |
                              90
                            (480)

this is the coordinate sistem i'm using.

I'm a bit confused in the type of vars i should use for trig tables.

I'm using a 7 * 7 (from 0 to 6) array as a map, only the borders have a
1 number and the rest are 0s
, when i run the program the values calculed for the array subindex are
mistaken .

I'd appreaciate it a lot if you point out the mistakes i'm making .

float _sin[1920];
float _cos[1920];
float _tan[1920];
void calc_tables()
{
double ang,radian;
int angle;
 ang=0.1875;
 for(angle=0;angle <=angle_360; angulo++)
 { radian = ang * TO_RAD;
  _tan[angulo]=(float)tan(radian);
  _cos[angulo]=(float)cos(radian);
  _sin[angulo] =(float)sin(radian);
  ang=+0.1875;
 }
}


void xray(double x, double y, int ang_vis)
{
double vposx;
double vposy;
double vstepx;
double vstepy;
double vdistx;
int    vposmapx;
int    vposmapy;
int    wall_found=0;

if ((ang_vis > angulo_270 ) || (ang_vis < angulo_90))//right
   vposx = (x/64) * 64 + 64;
else
   vposx =(x/64) * 64 - 1;

   vposy = (y + (vposx - x)) * (_tan[ang_vis]);

//step
if ((ang_vis > angulo_270) || (ang_vis < angulo_90))//right
    vstepx =  64;
else
    vstepx = -64;

    vstepy =  64 * _tan[ang_vis];
do
{
  vposmapx = vposx / 64;
  vposmapy = vposy / 64;
  if (mapa[vposmapx][vposmapy] != 1)
  {
   wall_found = 1;
  }
  vposx += vstepx;
  vposy += vstepy;
}
while (!wall_found);
}



void yray(double x, double y, int ang_vis)
{
double hposx;
double hposy;
double hstepx;
double hstepy;
double hdisty;
int    hposmapx;
int    hposmapy;
int    wall_found=0;


if ((ang_vis > angulo_180) || (ang_vis < angulo_360)) // up
   hposy = ((y/64) * 64) - 1;
else
   hposy = ((y/64) * 64) + 64;

   hposx = (x + (hposy - y)) / _tan[ang_vis];
//calc step
if ((ang_vis > angulo_180) || (ang_vis < angulo_360))// up
   hstepy = -64;
else
   hstepy =  64;

   hstepx =  64/_tan[ang_vis];

   do
   {
    hposmapx = hposx/64;
    hposmapy = hposy/64;
    if (mapa[hposmapx][hposmapy] !=0)
    {
      wall_found = 1;

    }
    hposx += hstepx;
    hposy += hstepx;

   }
   while (!wall_found);


}