/* sane - Scanner Access Now Easy.
   Copyright (C) 2002 Frank Zago (sane at zago dot net)

   This file is part of the SANE package.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.

   As a special exception, the authors of SANE give permission for
   additional uses of the libraries contained in this release of SANE.

   The exception is that, if you link a SANE library with other files
   to produce an executable, this does not by itself cause the
   resulting executable to be covered by the GNU General Public
   License.  Your use of that executable is in no way restricted on
   account of linking the SANE library code into it.

   This exception does not, however, invalidate any other reasons why
   the executable file might be covered by the GNU General Public
   License.

   If you submit changes to SANE to the maintainers to be included in
   a subsequent release, you agree by submitting the changes that
   those changes may be distributed with this exception intact.

   If you write modifications of your own for SANE, it is your choice
   whether to permit this exception to apply to your modifications.
   If you do not wish that, delete this exception notice.
*/

/* Commands supported by the Sceptre S1200 scanner. */
#define SCSI_TEST_UNIT_READY			0x00
#define SCSI_GET_STATUS					0x02
#define SCSI_INQUIRY					0x12
#define SCSI_MODE_SELECT				0x15
#define SCSI_MODE_SENSE					0x1a
#define SCSI_SCAN						0x1b
#define SCSI_RECEIVE_DIAG				0x1c
#define SCSI_SEND_DIAG					0x1D
#define SCSI_SET_WINDOW					0x24
#define SCSI_READ_10					0x28
#define SCSI_REQUEST_SENSE				0x03
#define SCSI_SEND_10					0x2a
#define SCSI_GET_DATA_BUFFER_STATUS		0x34

typedef struct
{
  unsigned char data[16];
  int len;
}
CDB;


/* Set a specific bit depending on a boolean.
 *   MKSCSI_BIT(TRUE, 3) will generate 0x08. */
#define MKSCSI_BIT(bit, pos) ((bit)? 1<<(pos): 0)

/* Set a value in a range of bits.
 *   MKSCSI_I2B(5, 3, 5) will generate 0x28 */
#define MKSCSI_I2B(bits, pos_b, pos_e) ((bits) << (pos_b) & ((1<<((pos_e)-(pos_b)+1))-1))

/* Store an integer in 2, 3 or 4 byte in an array. */
#define Ito16(val, buf) { \
 ((unsigned char *)buf)[0] = ((val) >> 8) & 0xff; \
 ((unsigned char *)buf)[1] = ((val) >> 0) & 0xff; \
}

#define Ito24(val, buf) { \
 ((unsigned char *)buf)[0] = ((val) >> 16) & 0xff; \
 ((unsigned char *)buf)[1] = ((val) >>  8) & 0xff; \
 ((unsigned char *)buf)[2] = ((val) >>  0) & 0xff; \
}

#define Ito32(val, buf) { \
 ((unsigned char *)buf)[0] = ((val) >> 24) & 0xff; \
 ((unsigned char *)buf)[1] = ((val) >> 16) & 0xff; \
 ((unsigned char *)buf)[2] = ((val) >>  8) & 0xff; \
 ((unsigned char *)buf)[3] = ((val) >>  0) & 0xff; \
}

#define MKSCSI_TEST_UNIT_READY(cdb) \
	cdb.data[0] = SCSI_TEST_UNIT_READY; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = 0; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_GET_STATUS(cdb, buflen) \
	cdb.data[0] = SCSI_GET_STATUS; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = buflen; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_INQUIRY(cdb, buflen) \
	cdb.data[0] = SCSI_INQUIRY; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = buflen; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_MODE_SELECT(cdb, pf, sp, buflen) \
	cdb.data[0] = SCSI_MODE_SELECT; \
	cdb.data[1] = MKSCSI_BIT(pf, 4) | MKSCSI_BIT(sp, 0); \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = buflen; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_MODE_SENSE(cdb, pc, page_code, buflen) \
	cdb.data[0] = SCSI_MODE_SENSE; \
	cdb.data[1] = 0; \
	cdb.data[2] = MKSCSI_I2B(pc, 6, 7) | MKSCSI_I2B(page_code, 0, 5); \
	cdb.data[3] = 0; \
	cdb.data[4] = buflen; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_SCAN(cdb) \
	cdb.data[0] = SCSI_SCAN; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = 0; \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_RECEIVE_DIAG(cdb, pc, buflen) \
	cdb.data[0] = SCSI_RECEIVE_DIAG; \
	cdb.data[1] = 0; \
	cdb.data[2] = pc; \
	cdb.data[3] = (((buflen) >> 8) & 0xff); \
	cdb.data[4] = (((buflen) >> 0) & 0xff); \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_SEND_DIAG(cdb, buflen) \
	cdb.data[0] = SCSI_SEND_DIAG; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = (((buflen) >> 8) & 0xff); \
	cdb.data[4] = (((buflen) >> 0) & 0xff); \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_SET_WINDOW(cdb, buflen) \
	cdb.data[0] = SCSI_SET_WINDOW; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = 0; \
	cdb.data[5] = 0; \
	cdb.data[6] = (((buflen) >> 16) & 0xff); \
	cdb.data[7] = (((buflen) >>  8) & 0xff); \
	cdb.data[8] = (((buflen) >>  0) & 0xff); \
	cdb.data[9] = 0; \
	cdb.len = 10;

#define MKSCSI_READ_10(cdb, dtc, dtq, buflen) \
	cdb.data[0] = SCSI_READ_10; \
	cdb.data[1] = 0; \
	cdb.data[2] = (dtc); \
	cdb.data[3] = 0; \
	cdb.data[4] = (((dtq) >> 8) & 0xff); \
	cdb.data[5] = (((dtq) >> 0) & 0xff); \
	cdb.data[6] = (((buflen) >> 16) & 0xff); \
	cdb.data[7] = (((buflen) >>  8) & 0xff); \
	cdb.data[8] = (((buflen) >>  0) & 0xff); \
	cdb.data[9] = 0; \
	cdb.len = 10;

#define MKSCSI_REQUEST_SENSE(cdb, buflen) \
	cdb.data[0] = SCSI_REQUEST_SENSE; \
	cdb.data[1] = 0; \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = (buflen); \
	cdb.data[5] = 0; \
	cdb.len = 6;

#define MKSCSI_SEND_10(cdb, dtc, dtq, buflen) \
	cdb.data[0] = SCSI_SEND_10; \
	cdb.data[1] = 0; \
	cdb.data[2] = (dtc); \
	cdb.data[3] = 0; \
	cdb.data[4] = (((dtq) >> 8) & 0xff); \
	cdb.data[5] = (((dtq) >> 0) & 0xff); \
	cdb.data[6] = (((buflen) >> 16) & 0xff); \
	cdb.data[7] = (((buflen) >>  8) & 0xff); \
	cdb.data[8] = (((buflen) >>  0) & 0xff); \
	cdb.data[9] = 0; \
	cdb.len = 10;

#define MKSCSI_GET_DATA_BUFFER_STATUS(cdb, wait, buflen) \
	cdb.data[0] = SCSI_GET_DATA_BUFFER_STATUS; \
	cdb.data[1] = MKSCSI_BIT(wait, 0); \
	cdb.data[2] = 0; \
	cdb.data[3] = 0; \
	cdb.data[4] = 0; \
	cdb.data[5] = 0; \
	cdb.data[6] = 0; \
	cdb.data[7] = (((buflen) >>  8) & 0xff); \
	cdb.data[8] = (((buflen) >>  0) & 0xff); \
	cdb.data[9] = 0; \
	cdb.len = 10;

/*--------------------------------------------------------------------------*/

#define length_quant SANE_UNFIX(SANE_FIX(MM_PER_INCH / 600))
#define mmToIlu(mm) ((mm) / length_quant)
#define iluToMm(ilu) ((ilu) * length_quant)

/*--------------------------------------------------------------------------*/

#define GAMMA_LENGTH 0x100	/* number of value per color */

/*--------------------------------------------------------------------------*/

enum Sceptre_Option
{
  OPT_NUM_OPTS = 0,

  OPT_MODE_GROUP,
  OPT_MODE,			/* scanner modes */
  OPT_RESOLUTION,		/* X and Y resolution */

  OPT_GEOMETRY_GROUP,
  OPT_TL_X,			/* upper left X */
  OPT_TL_Y,			/* upper left Y */
  OPT_BR_X,			/* bottom right X */
  OPT_BR_Y,			/* bottom right Y */

  OPT_ENHANCEMENT_GROUP,
  OPT_CUSTOM_GAMMA,		/* Use the custom gamma tables */
  OPT_GAMMA_VECTOR_R,		/* Custom Red gamma table */
  OPT_GAMMA_VECTOR_G,		/* Custom Green Gamma table */
  OPT_GAMMA_VECTOR_B,		/* Custom Blue Gamma table */
  OPT_THRESHOLD,		/* Threshold */
  OPT_HALFTONE_PATTERN,		/* Halftone pattern (1 to 4) */

  OPT_PREVIEW,			/* preview mode */

  /* must come last: */
  OPT_NUM_OPTIONS
};

/*--------------------------------------------------------------------------*/

/*
 * Scanner supported by this backend.
 */
struct scanners_supported
{
  /* From scsi inquiry */
  int scsi_type;
  char scsi_vendor[9];
  char scsi_product[17];

  char *real_vendor;
  char *real_product;
};

/*--------------------------------------------------------------------------*/

#define LINEART_STR			SANE_VALUE_SCAN_MODE_LINEART
#define HALFTONE_STR		        SANE_VALUE_SCAN_MODE_HALFTONE
#define GRAY_STR			SANE_VALUE_SCAN_MODE_GRAY
#define COLOR_STR			SANE_VALUE_SCAN_MODE_COLOR

/*--------------------------------------------------------------------------*/

/* Define a scanner occurrence. */
typedef struct Sceptre_Scanner
{
  struct Sceptre_Scanner *next;
  SANE_Device sane;

  char *devicename;
  int sfd;			/* device handle */

  /* Infos from inquiry. */
  char scsi_type;
  char scsi_vendor[9];
  char scsi_product[17];
  char scsi_version[5];

  /* Scanner infos. */
  SANE_Range x_range;
  SANE_Range y_range;
  SANE_Range resolution_range;
  int scnum;			/* index of that scanner in
				   * scanners_supported */

  /* SCSI handling */
  SANE_Byte *buffer;		/* for SCSI transfer. */
  size_t buffer_size;		/* allocated size of buffer */

  /* Scanning handling. */
  int scanning;			/* TRUE is a scan is running. */
  int resolution;		/* scan resolution */
  int x_tl;			/* X top left */
  int y_tl;			/* Y top left */
  int x_br;			/* X bottom right */
  int y_br;			/* Y bottom right */
  int width;			/* width of the scan area in mm */
  int length;			/* length of the scan area in mm */

  enum
  {
    SCEPTRE_LINEART,
    SCEPTRE_HALFTONE,
    SCEPTRE_GRAYSCALE,
    SCEPTRE_COLOR
  }
  scan_mode;

  int depth;			/* depth per color */
  int halftone_param;		/* haltone number, valid for SCEPTRE_HALFTONE */

  size_t bytes_left;		/* number of bytes left to give to the backend */

  size_t real_bytes_left;	/* number of bytes left the scanner will return. */

  SANE_Byte *image;		/* keep the raw image here */
  size_t image_size;		/* allocated size of image */
  size_t image_begin;		/* first significant byte in image */
  size_t image_end;		/* first free byte in image */

  int color_shift;		/* for color scan: number of lines to
				   * shift the colors. The higher the
				   * resolution, the higher this
				   * number. */

  int raster_size;		/* size of a raster */
  int raster_num;		/* for colour scan, current raster read */
  int raster_real;		/* real number of raster in the
				   * scan. This is necessary since I
				   * don't know how to reliably compute
				   * the number of lines */

  int raster_ahead;		/* max size of the incomplete lines */

  int line;			/* current line of the scan */


  SANE_Parameters params;

  /* Options */
  SANE_Option_Descriptor opt[OPT_NUM_OPTIONS];
  Option_Value val[OPT_NUM_OPTIONS];

  /* Gamma table. 1 array per colour. */
  SANE_Word gamma_R[GAMMA_LENGTH];
  SANE_Word gamma_G[GAMMA_LENGTH];
  SANE_Word gamma_B[GAMMA_LENGTH];

}
Sceptre_Scanner;

/*--------------------------------------------------------------------------*/

/* Debug levels.
 * Should be common to all backends. */

#define DBG_error0  0
#define DBG_error   1
#define DBG_sense   2
#define DBG_warning 3
#define DBG_inquiry 4
#define DBG_info    5
#define DBG_info2   6
#define DBG_proc    7
#define DBG_read    8
#define DBG_sane_init   10
#define DBG_sane_proc   11
#define DBG_sane_info   12
#define DBG_sane_option 13

/*--------------------------------------------------------------------------*/

/* 32 bits from an array to an integer (eg ntohl). */
#define B32TOI(buf) \
	((((unsigned char *)buf)[0] << 24) | \
	 (((unsigned char *)buf)[1] << 16) | \
	 (((unsigned char *)buf)[2] <<  8) |  \
	 (((unsigned char *)buf)[3] <<  0))

/* 16 bits from an array to an integer (eg ntohs). */
#define B16TOI(buf) \
	((((unsigned char *)buf)[0] <<  8) | \
	 (((unsigned char *)buf)[1] <<  0))
