/* FILE:    pkout.c
 *
 * PURPOSE: implementation of PK output functions
 *
 * COMMENT: functions are derived from `The GFtoPK processor' but
 *          presented in a modular fashion so they can be used in other
 *          programs. 
 *          (Porting `top-down' WEB code into modular readable C-code is
 *          not a trivial exercise.)
 *
 * VERSION: Febr. 1992
 *          Dec. 1993
 *
 * AUTHOR:  Piet Tutelaers (rcpt@urc.tue.nl)
 */

#ifdef MSDOS
#define WB "wb"
#else
#define WB "w"
#endif

/* Some constants */
#define PK_ID	 89
#define PK_SPC1	240		/* All we need, max length always < 255 */
#define PK_NUMSPC 244
#define PK_NOOP	246
#define PK_PRE	247
#define PK_POST	245

#define DPI	72.27
#define MIN(a,b) ( (a<b)? (a): (b))

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include "pkout.h"

extern int testing;
static int pk_len = 0;
static FILE *pkfile;

void pk_open(char *pkname)
{
   pkfile = fopen(pkname, WB);
   if (pkfile == NULL) fatal("Can not open %s\n", pkname);
}

void pk_close()
{
   fclose(pkfile);
}

/* Portable Big Endian output functions */

/* Nybble buffer */
static int pk_output_byte, bitweight;
static void pk1(int);

static void pk_nybble(int x)
{
   if (bitweight == 16) {
      bitweight = 1; pk_output_byte = x*16;
   }
   else {
      bitweight = 16; pk1(pk_output_byte + x);
   }
}

static void pk1(int x)
{
   if (x < 0) x += 256; 
   putc(x & 0x00ff, pkfile); 
   pk_len++;
}

static void pk2(int x)
{
   if (x < 0) x += 65536; 
   pk1((x & 0x00ff00) >> 8);
   pk1(x & 0x0000ff);
}

static void pk3(INT32 x)
{
   pk1((x & 0x00ff0000) >> 16);
   pk1((x & 0x0000ff00) >> 8);
   pk1(x & 0x000000ff);
}

static void pk4(INT32 x)
{
   /* Eliminate compiler warnings from first mask and shift. This code */
   /* is close to procedure pk_word in gftopk.web and will be 64-bit safe */
   /* old version used (2 << 31) ; meaningless in a 32-bit environment */
   if (x < 0) {x += 2<<29; x += 2<<29; pk1(((x & 0x7f000000) >> 24)+ 128);}
   else pk1((x & 0x7f000000) >> 24); 
   pk1((x & 0x00ff0000) >> 16);
   pk1((x & 0x0000ff00) >> 8);
   pk1(x & 0x000000ff);
}

static int MAX_COUNTS; /* length of array to hold runlengths */

void pk_preamble(char *comment, 	/* source of the font */
		 float pointsize,	/* pointsize in points */
		 INT32 checksum,        /* should equal to tfm-value */
		 unsigned int h_res,    /* horizontal resolution (dpi) */
		 unsigned int v_res)	/* vertical resolution (dpi) */
{ 
   int i, len;

   /* compute MAX_COUNTS based upon pointsize, h_res and v_res */
   MAX_COUNTS = pointsize / DPI * h_res * (pointsize / DPI * v_res + 1);
   
   pk1(PK_PRE);
   pk1(PK_ID);
   len = strlen(comment);
   len = len>255? 255: len;
   pk1(len);
   for (i=0; i<len; i++) pk1(*comment++);

   pk4(pointsize * (1<<20) + 0.5);
   pk4(checksum);
   pk4(h_res / DPI * (1<<16)); pk4(v_res / DPI * (1<<16));
}

/* From `The GFtoPK processor', pp. 231 */

int optimal_size(int W, int H, int cnt, int count[], int *dyn_f)
{  int comp_size = 0, b_comp_size, deriv[14], i, j, k;

   i = (count[0] == 0? 1: 0); /* skip first empty runlength */
   /* compute comp_size and deriv[1..13] */
   for (j=1; j<14; j++) deriv[j] = 0;
   while (i<cnt) {
      j = count[i++];
      if (j == -1) { comp_size++; continue; }
      if (j < 0) { j = -j; comp_size++; }
      if (j < 209) comp_size += 2;
      else {
      	 k = j - 193;
      	 while (k >= 16) { k=k/16; comp_size += 2; }
      	 comp_size++;
      }
      if (j < 14) deriv[j]--;
      else {
      	 if (j < 209) deriv[(223 - j) / 15]++;
      	 else {
      	    k = 16;
      	    while (k*16 < j+3) k *= 16;
      	    if (j-k <= 192) deriv[(207-j+k)/15] += 2;
      	 }
      }
   }
   /* find minimal value */
   b_comp_size = comp_size; *dyn_f = 0;
   for (i=1; i<14; i++) {
      comp_size += deriv[i];
      if (comp_size <= b_comp_size) {
      	 b_comp_size = comp_size; *dyn_f = i;
      }
   }
   comp_size = (b_comp_size + 1) / 2;
   if (H*W == 0 || (comp_size > (H*W + 7) / 8)) {
      comp_size = (H*W + 7) / 8; *dyn_f = 14;
   }
   return comp_size;
}

/* Next array contains the runlengths */
static int *count = NULL;

/* Global variables (interface between pk_runlengths() and pk_char() */
static int dyn_f, comp_size, cnt;

static void pk_runlengths(int W, int H, int (*next_pixel)())
{  int current_value, pixel, i, j, max_counts, first_count;
   int total_pixels, rc, row, col, runlength;
   int color1, color2, total_pixels2, /* counting equal rows variables */
       pixels, i1, i2, newrow;

   first_count = H; max_counts = first_count + H * W;
   if (count == NULL) {
      count = malloc(MAX_COUNTS * sizeof(int));
      if (count == NULL) fatal("Out of memory\n");
   }
   
   if (max_counts > MAX_COUNTS) {
      free(count);
      count = malloc(max_counts * sizeof(int));
      if (count == NULL) fatal("Out of memory\n");
      MAX_COUNTS = max_counts;
   }

   /* 1: compute transitions BLACK<->WHITE */

   cnt = first_count;
   runlength = 0; current_value = BLACK;
   for (row=0; row < H; row++) {
      for (col=0; col<W; col++) {
      	 pixel = (*next_pixel)();
         if (pixel == current_value) runlength++;
         else if (pixel == OTHER(current_value)) {
            count[cnt++] = runlength;
            current_value = OTHER(current_value);
            runlength = 1;
         }
      }
   }
   if (runlength>0)
      count[cnt++] = runlength;

   if (testing) { current_value = BLACK;
      for (i=first_count; i<cnt; i++)
	 if (count[i] < 0) printf("[%d]", -count[i]);
	 else {
	    if (current_value == BLACK) printf("%d", count[i]);
	    else printf("(%d)", count[i]);
	    current_value = OTHER(current_value);
	 }
      putchar('\n');
   }

   /* 2: Now remove equal lines and add a repeat count at the first
         transition of a row */

   i = first_count; j = 0;
   total_pixels = 0; row = -1;
   current_value = BLACK;
   if (count[i] == 0) {
      count[j++] = count[i++];
      current_value = WHITE;
   }
   while (i < cnt) {
      if (j >= i) fatal("Program error: report to author!\n");
      count[j++] = count[i];
      total_pixels += count[i++];
      current_value = OTHER(current_value);
      newrow = total_pixels / W; col = total_pixels % W;
      /* if transition starts in column zero or in a previous row 
         then continue */
      if (newrow == row || row == H-1 || col == 0) continue;
      row = newrow;

      /* count equal rows */

         /* 1: goto first transition of next row */
      color2 = current_value;
      total_pixels2 = total_pixels; i2 = i;
      while (i2 < cnt && total_pixels2 / W == row) {
	 total_pixels2 += count[i2++];
	 color2 = OTHER(color2);
      }

         /* 2: do we need to compute a repeat count? */
      if (color2 != current_value 
          || total_pixels2 - total_pixels != W) continue;

	 /* 3: count them */
      rc = 0; i1 = i;
      while (i2 < cnt && count[i1] == count[i2]) {
         if (testing) printf("%d (%d)", count[i1], count[i2]);
	 total_pixels2 += count[i2++]; i1++; 
      }
      rc = total_pixels2 / W - row;  /* enclosed rows */
      if (MIN(count[i1], count[i2]) + total_pixels2 % W < W)
            rc--;
      if (testing) printf(" row %d: rc = %d\n", row, rc);

	/* 3: now remove the equal rows and finish last row */      
      if (rc > 0) {
      	 /* insert a repeat count */
         if (j >= i) fatal("Program error: report to author\n");
         count[j++] = -rc;

         /* finish runlengths of current row */
         while (total_pixels + count[i] < row*W+W) {
            if (j >= i) fatal("Program error: increase FIRST_COUNT!\n");
            count[j++] = count[i];
            total_pixels += count[i++];
            current_value = OTHER(current_value);
         }

        /* skip runlengths of equal rows */
         while (total_pixels + count[i] < (row+rc+1)*W) {
            total_pixels += count[i++];
            current_value = OTHER(current_value);
         }
         row += rc;
      }
   }
   cnt = j; /* that is what we have now */

   /* 3: compute optimal packing size */

   comp_size = optimal_size(H, W, cnt, count, &dyn_f);
   if (testing) { current_value = BLACK;
      for (i=0; i<cnt; i++)
	 if (count[i] < 0) printf("[%d]", -count[i]);
	 else {
	    if (current_value == BLACK) printf("%d", count[i]);
	    else printf("(%d)", count[i]);
	    current_value = OTHER(current_value);
	 }
      printf("\nOptimal packing with dyn_f = %d total size %d\n", 
      dyn_f, comp_size);
   }
}

#define MAX_TWOBYTE_NYBBLE (208 - 15*dyn_f)

static void pk_number(int x)
{  int k;

   if (x < 0) { /* repeat count */
      if (x == -1) pk_nybble(0xF);
      else { pk_nybble(0xE);
         pk_number(-x);
      }
   } 
   else if (x <= dyn_f) pk_nybble(x);
   else if (x <= MAX_TWOBYTE_NYBBLE) { /* two nybble values */
      x-= dyn_f+1;
      pk_nybble(dyn_f + 1 + x / 16);
      pk_nybble(x % 16);
   }
   else { /* huge counts */
      x = x - MAX_TWOBYTE_NYBBLE + 15; k = 16;
      while (k <= x) { k *= 16; pk_nybble(0x0); }
      while (k > 1) { k = k / 16; pk_nybble(x / k); x = x % k; }
   } 
}

/* in case runlength encoding is not optimal we send a compressed 
   bitmap in stead of the packed runlengths
   See GFtoPK processor, pp. 235 */
static void pk_bitmap(int width, int cnt, int runlength[])
{  int count,		/* number of bits in the current state to send */
       buff,		/* byte buffer */
       h_bit,		/* horizontal bit count for each runlength */
       p_bit,   	/* what bit are we about to send out? */
       r_on, s_on,	/* state saving variables */
       r_count, s_count,/* dito */
       r_i, s_i,	/* dito */
       rc,		/* repeat count */
       state,		/* state variable (what state?) */
       on,		/* starting with black? */
       i;		/* points to next runlength */
   static int power[9] = {1, 2, 4, 8, 16, 32, 64, 128, 256};

   buff = 0; p_bit = 8; h_bit = width; 
   state = 0; rc = 0;
   on = 1; count = runlength[0]; i = 1;
   while (i < cnt || state || count>0) {
      if (state) { 
         count = r_count; i = r_i; on = r_on; rc--; 
      }
      else { 
         r_count = count; r_i = i; r_on = on; 
      }

      /* send one row of width bits */
      do {
      	 if (count == 0) {
      	    if (runlength[i] < 0) {
	       if (!state) rc = - runlength[i];
	       i++;
      	    }
      	    count = runlength[i]; i++; on = !on;
      	 }
      	 if (count >= p_bit && p_bit < h_bit) {
      	    /* we end a byte, we don't end a runlength */
      	    if (on) buff += power[p_bit] - 1;
      	    pk1(buff); 
      	    buff = 0; h_bit -= p_bit; 
      	    count -= p_bit; p_bit = 8;
      	 }
      	 else {
      	    if (count < p_bit && count < h_bit) {
	       /* we neither end the row nor the byte */
	       if (on) buff += power[p_bit] - power[p_bit-count];
	       p_bit -= count; h_bit -= count; count = 0;
      	    }
      	    else { /* we end a row and maybe a byte */
	       if (on) buff += power[p_bit] - power[p_bit-h_bit];
	       count -= h_bit; p_bit -= h_bit; h_bit = width;
	       if (p_bit == 0) {
	          pk1(buff); buff = 0; p_bit = 8;
	       }
      	    }
      	 }
      } while (h_bit != width);

      if (state && rc == 0) { 
         count = s_count; i = s_i; on = s_on; state = 0;
      }
      else if (!state && rc >0) {
      	 s_count = count; s_i = i; s_on = on; state = 1;
      }
   }
   if (p_bit != 8) pk1(buff);
}

/* For packing a character */
void pk_char(int char_code, 	/* character code 0..255 */
        INT32 tfm_width,        /* TFM width of character */
        int h_escapement,       /* horizontal escapement in pixels */
   	unsigned int width, 	/* width of bounding box */
   	unsigned int height, 	/* height of bounding box */
   	int h_offset, 		/* horizontal offset to reference point */
   	int v_offset, 		/* vertical offset to reference point */
        int (*next_pixel)())	/* user's next pixel generator */
{  int i, pl, current_value;
   short two_byte;	/* two_byte quantities? */
   unsigned short flag_byte;

   pk_runlengths(width, height, next_pixel);

   /* write a character preamble */

   flag_byte = dyn_f * 16;
   if (count[0] > 0) flag_byte += 8; /* starting in BLACK */
   if (tfm_width > 0XFFFFFF || width > 65535 || height > 65535
       || h_offset > 32767 || v_offset > 32767
       || h_offset < -32768 || v_offset < -32768
       || comp_size > 196594) 
   { /* write long format */
      fatal("Can't handle long format yet!\n");
   }
   else if (h_escapement > 255 || width > 255 || height > 255
            || h_offset > 127 || v_offset > 127
            || h_offset < -128 || v_offset < -128 
            || comp_size > 1015)
   { /* write two-byte short character preamble */
      comp_size += 13; flag_byte += comp_size / 65535 + 4; 
      pk1(flag_byte);
      pk2(comp_size % 65535);
      pk1(char_code);
      pk3(tfm_width);
      pk2(h_escapement); /* pixels ! */
      pk2(width);
      pk2(height);
      pk2(h_offset);
      pk2(v_offset);
   }
   else { /* write one-byte short character preamble */
      comp_size += 8;  flag_byte += comp_size / 256; 
      pk1(flag_byte);
      pk1(comp_size % 256);
      pk1(char_code);
      pk3(tfm_width);
      pk1(h_escapement); /* pixels ! */
      pk1(width);
      pk1(height);
      pk1(h_offset);
      pk1(v_offset);
   }

   /* and now the character itself */
   if (dyn_f != 14) { /* send compressed format */ 
      if (count[0] == 0) i = 1; else i = 0;
      bitweight = 16;
      for (i=i; i<cnt; i++) pk_number(count[i]);
      if (bitweight != 16) pk1(pk_output_byte);
   }
   else /* send bitmap */
      if (height > 0) pk_bitmap(width, cnt, count);

}
/*
 * Set specials for "fontid", "codingscheme", "fontfacebyte",
 *                  "mag", "mode", "pixels_per_inch" and "aspect_ratio".
 */
void pk_postamble(char *fontname, /* The real FontName from the afm */
		  char *encname,  /* The actual name, not the filename */
		  char *modename, /* If supplied---default "Unknown". */
		  int base_res,   /* Default 300. */
		  int h_res,	  /* Match against base_res for mag */
		  int v_res,	  /* Match against h_res for aspect_ratio */
		  float pointsize)/* Used for fontfacebyte calculation */
{ 	
   int i;
   char *key, mag_string[80], *magstring = mag_string;
   float mag;

   key = "fontid=";
   pk1(PK_SPC1);
   pk1(strlen(fontname) + strlen(key));
   i = 0; while(*(key +i)) pk1(*(key + i++));
   i = 0; while(*(fontname +i)) pk1(*(fontname + i++));
   key = "codingscheme=";
   pk1(PK_SPC1);
   pk1(strlen(encname) + strlen(key));
   i = 0; while(*(key +i)) pk1(*(key + i++));
   i = 0; while(*(encname +i)) pk1(*(encname + i++));
   key = "fontfacebyte";
   pk1(PK_SPC1);
   pk1(strlen(key));
   i = 0; while(*(key +i)) pk1(*(key + i++));
   pk1(PK_NUMSPC);
   i = (pointsize < 127.0) ?
     ((254 - (int)((2 * pointsize)+0.5)) * (1 << 16)) : 0;
   pk4(i);
   if ( h_res == base_res ) sprintf(magstring, "mag=1");
   else {
     mag = (h_res * 1.0) / (base_res * 1.0); 
     if (mag < 1.0) sprintf(magstring, "mag=%4.3f", mag);
     else {
       if ( (mag > 1.045) && (mag < 1.048) ) {
	 sprintf(magstring, "mag=magstep(0.25)");
       } else {
	 if ( (mag > 1.093) && (mag < 1.098) ) {
	   sprintf(magstring, "mag=magstep(0.5)");
	 } else {
	   if ( (mag > 1.145) && (mag < 1.149) ) {
	     sprintf(magstring, "mag=magstep(0.75)");
	   } else {
	     if ( (mag > 1.190) && (mag < 1.210) ) {
	       sprintf(magstring, "mag=magstep(1.0)");
	     } else {
	       if ( (mag > 1.314) && (mag < 1.317) ) {
		 sprintf(magstring, "mag=magstep(1.5)");
	       } else {
		 if ( (mag > 1.43) && (mag < 1.45) ) {
		   sprintf(magstring, "mag=magstep(2.0)");
		 } else {
		   if ( (mag > 1.72) && (mag < 1.73) ) {
		     sprintf(magstring, "mag=magstep(3.0)");
		   } else {
		     if ( (mag > 2.07) && (mag < 2.08) ) {
		       sprintf(magstring, "mag=magstep(4.0)");
		     } else {
		       if ( (mag > 2.47) && (mag < 2.49) ) {
			 sprintf(magstring, "mag=magstep(5.0)");
		       } else {
			 sprintf(magstring, "mag=%4.3f", mag);
		       }
		     }
		   }
		 }
	       }
	     }
	   }
	 }
       }
     }
   }
   pk1(PK_SPC1);
   pk1(strlen(magstring));
   i = 0; while(*(magstring +i)) pk1(*(magstring + i++));
   key = "mode=(ps2pk)";
   pk1(PK_SPC1);
   pk1(strlen(modename) + strlen(key));
   i = 0; while(*(key +i)) pk1(*(key + i++));
   i = 0; while(*(modename +i)) pk1(*(modename + i++));
   key = "pixels_per_inch=";
   sprintf(magstring, "%d", base_res );
   pk1(PK_SPC1);
   pk1(strlen(magstring) + strlen(key));
   i = 0; while(*(key +i)) pk1(*(key + i++));
   i = 0; while(*(magstring +i)) pk1(*(magstring + i++));
   if (h_res != v_res) {
     mag = (v_res * 1.0) / (h_res * 1.0);
     sprintf(magstring, "%d / %d", 
	     (int)((mag * base_res) + 0.5), base_res);
     key = "aspect ratio=";
     pk1(PK_SPC1);
     pk1(strlen(magstring) + strlen(key));
     i = 0; while(*(key +i)) pk1(*(key + i++));
     i = 0; while(*(magstring +i)) pk1(*(magstring + i++));
   }
   pk1(PK_POST);
   while (pk_len % 4 != 0) pk1(PK_NOOP);
}

/* Give up ... */
void fatal(char *fmt, ...)
{  va_list args;

   va_start(args, fmt);
   vfprintf(stderr, fmt, args);
   va_end(args);
   exit(1);
}
