/*
 * negative.c - Does a simple negative in Imagemaster
 */

#include <stdio.h>

struct jackinbuff
  {
    unsigned char *red;
    unsigned char *green;
    unsigned char *blue;
    unsigned char *mask;
    unsigned short x;
    unsigned short y;
  };

struct jackina
  {
    struct jackinbuff *primary;
    struct jackinbuff *secondary;
    struct jackinbuff *undo;
    struct jackinbuff *blend;
    struct jackinbuff *brush;
    unsigned char     *mask;
    char              jack[4];
  };

static struct jackina *jackins;
static struct jackinbuff *primary_jack;
static struct jackinbuff *secondary_jack;
static struct jackinbuff *undo_jack;
static struct jackinbuff *blend_jack;
static struct jackinbuff *brush_jack;


main(argc,argv)
int    argc;
char   *argv[];
  {
  unsigned int tpoint,x,y,xw,yw,offset,yoffset;
  unsigned char rr,gg,bb;
  
  unsigned char *rbu;
  unsigned char *gbu;
  unsigned char *bbu;
  
    printf("NEGATIVE <pointer to IM jackin structure>\n");
    printf("A simple Imagemaster Public Interface operation.\n");
  
    if (argc <= 1)
      {
        printf("NEGATIVE : No argument supplied!\n");
        return(1);
      }
    else
      {
        sscanf(argv[1],"%X",&tpoint);
      }
    if (tpoint == 0)
      {
        printf("NEGATIVE : Argument is ZERO!\n");
        return(1);
      }
      
    jackins = (struct jackina *)tpoint;
      
    if (jackins->jack[0] != 'J' ||
        jackins->jack[1] != 'A' ||
        jackins->jack[2] != 'C' ||
        jackins->jack[3] != 'K' )
      {
        printf("NEGATIVE : Problem in information passed from Imagemaster!\n");
        return(1);
      }
    if (jackins->primary == NULL)
      {
        printf("NEGATIVE : Primary buffer is NULL!\n");
        return(1);
      }
    xw = jackins->primary->x;
    yw = jackins->primary->y;
    if (xw == 0 || yw == 0)
      {
        printf("NEGATIVE : Primary buffer is Empty!\n");
        return(1);
      }
    rbu = jackins->primary->red;
    gbu = jackins->primary->green;
    bbu = jackins->primary->blue;
    if (rbu == NULL || gbu == NULL || bbu == NULL)
      {
        printf("NEGATIVE : Primary buffer is corrupted!\n");
        return(1);
      }
    /* Run through the image */
    for (y=0; y<yw; y++)
      {
        printf(".");
        yoffset = y * xw;
        for (x=0; x<=xw; x++)
          {
            offset = yoffset + x;
            rr = *(rbu+offset);
            gg = *(gbu+offset);
            bb = *(bbu+offset);
            *(rbu+offset) = 255 - rr;  /* This is a color negative */
            *(gbu+offset) = 255 - gg;
            *(bbu+offset) = 255 - bb;
          }
      }
    printf("\n");
    return(0);
  }