// -*- compile-command: "gcc -o main main.c && ./main 5x5.ppm && eog blackboard.ppm"; -*-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// backslash, semi colon are missing from the font

#define SIZE 5
#define SPACING 1+5

unsigned char *data;

static unsigned char img[400][400][3];

#define CHAR_A data + (95*0) + 0
#define CHAR_B data + (95*0) + 15
#define CHAR_C data + (95*0) + 30
#define CHAR_D data + (95*0) + 45
#define CHAR_E data + (95*0) + 60
#define CHAR_F data + (95*0) + 75
#define CHAR_G data + (95*0) + 90
#define CHAR_H data + (95*0) + 105
#define CHAR_I data + (95*0) + 120
#define CHAR_J data + (95*0) + 135
#define CHAR_K data + (95*0) + 150
#define CHAR_L data + (95*0) + 165
#define CHAR_M data + (95*0) + 180
#define CHAR_N data + (95*0) + 195
#define CHAR_O data + (95*0) + 210
#define CHAR_P data + (95*0) + 225
#define CHAR_Q data + (95*0) + 240
#define CHAR_R data + (95*0) + 255
#define CHAR_S data + (95*0) + 270

#define CHAR_T data + (95*15) + 0
#define CHAR_U data + (95*15) + 15
#define CHAR_V data + (95*15) + 30
#define CHAR_W data + (95*15) + 45
#define CHAR_X data + (95*15) + 60
#define CHAR_Y data + (95*15) + 75
#define CHAR_Z data + (95*15) + 90
#define CHAR_0 data + (95*15) + 105
#define CHAR_1 data + (95*15) + 120
#define CHAR_2 data + (95*15) + 135
#define CHAR_3 data + (95*15) + 150
#define CHAR_4 data + (95*15) + 165
#define CHAR_5 data + (95*15) + 180
#define CHAR_6 data + (95*15) + 195
#define CHAR_7 data + (95*15) + 210
#define CHAR_8 data + (95*15) + 225
#define CHAR_9 data + (95*15) + 240
#define CHAR_CPAR data + (95*15) + 255 /* ) */
#define CHAR_EXC data + (95*15) + 270  /* ! */


#define CHAR_DOLLAR data + (95*30) + 0 /* $ */
#define CHAR_PERCENT data + (95*30) + 15 /* % */
#define CHAR_HAT data + (95*30) + 30     /* ^ */
#define CHAR_AND data + (95*30) + 45     /* & */
#define CHAR_PLUS data + (95*30) + 60    /* + */
#define CHAR_OPAR data + (95*30) + 75    /* ( */
#define CHAR_COMMA data + (95*30) + 90   /* , */
#define CHAR_DOT data + (95*30) + 105    /* . */
#define CHAR_SLASH data + (95*30) + 120  /* / */
#define CHAR_CBRKT data + (95*30) + 135  /* ] */
#define CHAR_APO data + (95*30) + 150    /* ' */
#define CHAR_OBRKT data + (95*30) + 165  /* [ */
#define CHAR_PIPE data + (95*30) + 180   /* | */
#define CHAR_LT data + (95*30) + 195     /* < */
#define CHAR_BT data + (95*30) + 210     /* > */
#define CHAR_QM data + (95*30) + 225     /* ? */
#define CHAR_DQ data + (95*30) + 240     /* " */
#define CHAR_CBC data + (95*30) + 255    /* } */
#define CHAR_CBO data + (95*30) + 270    /* { */

void print_char (int x, int y, unsigned char *pos)
{
  unsigned char *ptr = pos;

  for (int k = 0; k < 5; ++k)
    {
      for (int j = 0; j < 5; ++j)
        {
          // if (ptr[0] != 255 || ptr[1] != 255 || ptr[2] != 255) // same as below
          if (*ptr != 255 || *(ptr+1) != 255 || *(ptr+2) != 255)
            {
              img[y+k][x+j][0] = *ptr++;
              img[y+k][x+j][1] = *ptr++;
              img[y+k][x+j][2] = *ptr++;
            }
          else
            {
              ptr+=3;
            }
        }
      ptr = pos + (3*(k+1))*95;
    }
}

void add_text (int x, int y, char *text)
{
  for (int i = 0; i < strlen (text); ++i)
    {
      // better than if else (dictionary lookup not branching as terry davis says)
      switch (text[i])
        {
        case 'A':
        case 'a':
          {
            print_char (x, y, CHAR_A);
            break;
          }
        case 'B':
        case 'b':
          {
            print_char (x, y, CHAR_B);
            break;
          }
        case 'C':
        case 'c':
          {
            print_char (x, y, CHAR_C);
            break;
          }
        case 'D':
        case 'd':
          {
            print_char (x, y, CHAR_D);
            break;
          }
        case 'E':
        case 'e':
          {
            print_char (x, y, CHAR_E);
            break;
          }
        case 'F':
        case 'f':
          {
            print_char (x, y, CHAR_F);
            break;
          }
        case 'G':
        case 'g':
          {
            print_char (x, y, CHAR_G);
            break;
          }
        case 'H':
        case 'h':
          {
            print_char (x, y, CHAR_H);
            break;
          }
        case 'I':
        case 'i':
          {
            print_char (x, y, CHAR_I);
            break;
          }
        case 'J':
        case 'j':
          {
            print_char (x, y, CHAR_J);
            break;
          }
        case 'K':
        case 'k':
          {
            print_char (x, y, CHAR_K);
            break;
          }
        case 'L':
        case 'l':
          {
            print_char (x, y, CHAR_L);
            break;
          }
        case 'M':
        case 'm':
          {
            print_char (x, y, CHAR_M);
            break;
          }
        case 'N':
        case 'n':
          {
            print_char (x, y, CHAR_N);
            break;
          }
        case 'O':
        case 'o':
          {
            print_char (x, y, CHAR_O);
            break;
          }
        case 'P':
        case 'p':
          {
            print_char (x, y, CHAR_P);
            break;
          }
        case 'Q':
        case 'q':
          {
            print_char (x, y, CHAR_Q);
            break;
          }
        case 'R':
        case 'r':
          {
            print_char (x, y, CHAR_R);
            break;
          }
        case 'S':
        case 's':
          {
            print_char (x, y, CHAR_S);
            break;
          }
        case 'T':
        case 't':
          {
            print_char (x, y, CHAR_T);
            break;
          }
        case 'U':
        case 'u':
          {
            print_char (x, y, CHAR_U);
            break;
          }
        case 'V':
        case 'v':
          {
            print_char (x, y, CHAR_V);
            break;
          }
        case 'W':
        case 'w':
          {
            print_char (x, y, CHAR_W);
            break;
          }
        case 'X':
        case 'x':
          {
            print_char (x, y, CHAR_X);
            break;
          }
        case 'Y':
        case 'y':
          {
            print_char (x, y, CHAR_Y);
            break;
          }
        case 'Z':
        case 'z':
          {
            print_char (x, y, CHAR_Z);
            break;
          }
        case '0':
          {
            print_char (x, y, CHAR_0);
            break;
          }
        case '1':
          {
            print_char (x, y, CHAR_1);
            break;
          }
        case '2':
          {
            print_char (x, y, CHAR_2);
            break;
          }
        case '3':
          {
            print_char (x, y, CHAR_3);
            break;
          }
        case '4':
          {
            print_char (x, y, CHAR_4);
            break;
          }
        case '5':
          {
            print_char (x, y, CHAR_5);
            break;
          }
        case '6':
          {
            print_char (x, y, CHAR_6);
            break;
          }
        case '7':
          {
            print_char (x, y, CHAR_7);
            break;
          }
        case '8':
          {
            print_char (x, y, CHAR_8);
            break;
          }
        case '9':
          {
            print_char (x, y, CHAR_9);
            break;
          }
        case ')':
          {
            print_char (x, y, CHAR_CPAR);
            break;
          }
        case '!':
          {
            print_char (x, y, CHAR_EXC);
            break;
          }
        case '$':
          {
            print_char (x, y, CHAR_DOLLAR);
            break;
          }
        case '%':
          {
            print_char (x, y, CHAR_PERCENT);
            break;
          }
        case '^':
          {
            print_char (x, y, CHAR_HAT);
            break;
          }
        case '&':
          {
            print_char (x, y, CHAR_AND);
            break;
          }
        case '+':
          {
            print_char (x, y, CHAR_PLUS);
            break;
          }
        case '(':
          {
            print_char (x, y, CHAR_OPAR);
            break;
          }
        case ',':
          {
            print_char (x, y, CHAR_COMMA);
            break;
          }
        case '.':
          {
            print_char (x, y, CHAR_DOT);
            break;
          }
        case '/':
          {
            print_char (x, y, CHAR_SLASH);
            break;
          }
        case ']':
          {
            print_char (x, y, CHAR_CBRKT);
            break;
          }
        case '\'':
          {
            print_char (x, y, CHAR_APO);
            break;
          }
        case '[':
          {
            print_char (x, y, CHAR_OBRKT);
            break;
          }
        case '|':
          {
            print_char (x, y, CHAR_PIPE);
            break;
          }
        case '<':
          {
            print_char (x, y, CHAR_LT);
            break;
          }
        case '>':
          {
            print_char (x, y, CHAR_BT);
            break;
          }
        case '?':
          {
            print_char (x, y, CHAR_QM);
            break;
          }
        case '"':
          {
            print_char (x, y, CHAR_DQ);
            break;
          }
        case '}':
          {
            print_char (x, y, CHAR_CBC);
            break;
          }
        case '{':
          {
            print_char (x, y, CHAR_CBO);
            break;
          }

        default:
          break;
        }
      x+=SPACING;
    }
}

int main(int argc, char **argv)
{
  if (argc < 2)
    {
      printf("Usage: %s font.ppm\n", argv[0]);
      exit (0);
    }

  unsigned int w, h, d;
  FILE *fp = fopen(argv[1], "rb");
  char *line = NULL; // initializing it to NULL is very important for memory safty
  size_t len;
  getline (&line, &len, fp);
  if (strcmp ("P6\n", line) != 0)
    { printf("This is not valid P6 ppm file\n"); fclose (fp); exit (1); }
  getline (&line, &len, fp);
  while (strstr(line, "#") != NULL) getline (&line, &len, fp);
  sscanf (line, "%u %u", &w, &h);
  getline (&line, &len, fp);
  sscanf (line, "%u", &d);
  data = malloc (w*h*3);
  fread (data, w*h*3, 1, fp);
  fclose (fp);

  FILE *fpb = fopen("blackboard.ppm", "w+b");
  fprintf(fpb, "P6\n400 400\n255\n");

  for (int i = 0; i < 400; ++i)
    for (int j = 0; j < 400; ++j)
      {img[i][j][0]=i; img[i][j][1]=255; img[i][j][2]=i;}


  add_text (10,10,"Ali sadeq");

  add_text (10,100,"Happy, Hacking!.");

  add_text (10,380,"Donec Suspendisse potenti.  Aliquam erat volutpat.");

  add_text (150, 10, "Join us now and share the software;");
  add_text (150, 20,"You'll be free, hackers, you'll be free.");
  add_text (150, 30,"Join us now and share the software;");
  add_text (150, 40,"You'll be free, hackers, you'll be free.");

  add_text (150, 60,"Hoarders can get piles of money,");
  add_text (150, 70,"That is true, hackers, that is true.");
  add_text (150, 80,"But they cannot help their neighbors;");
  add_text (150, 90,"That's not good, hackers, that's not good.");

  add_text (150, 110,"When we have enough free software");
  add_text (150, 120,"At our call, hackers, at our call,");
  add_text (150, 130,"We'll kick out those dirty licenses");
  add_text (150, 140,"Ever more, hackers, ever more.");

  add_text (150, 160,"Join us now and share the software;");
  add_text (150, 170,"You'll be free, hackers, you'll be free.");
  add_text (150, 180,"Join us now and share the software;");
  add_text (150, 190,"You'll be free, hackers, you'll be free.");

  fwrite (img, 400*400*3, 1, fpb);
  fclose (fpb);

  free (data);
  return 0;
}

...

#define CHAR_A data + (95*0) + 0
#define CHAR_B data + (95*0) + 15
#define CHAR_C data + (95*0) + 30

...

#define CHAR_T data + (95*15) + 0
#define CHAR_U data + (95*15) + 15
#define CHAR_V data + (95*15) + 30

...

for (int k = 0; k < 5; ++k)
  {
    for (int j = 0; j < 5; ++j)
      {
        // if (ptr[0] != 255 || ptr[1] != 255 || ptr[2] != 255) // same as below
        if (*ptr != 255 || *(ptr+1) != 255 || *(ptr+2) != 255)
          {
            img[y+k][x+j][0] = *ptr++;
            img[y+k][x+j][1] = *ptr++;
            img[y+k][x+j][2] = *ptr++;
          }
        else
          {
            ptr+=3;
          }
      }
    ptr = pos + (3*(k+1))*95;
  }