#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "algo.h"
#include "output.h"

#define VIEWPORT_WIDTH   16
#define VIEWPORT_HEIGHT  16

#define FMT_BITMAP 1
#define FMT_TEXT   2

/* Format of the output */
static int fmt = FMT_BITMAP;

static struct _viewport {
  int x;
  int y;
  int width;
  int height;
} viewport = { 0, 0, VIEWPORT_WIDTH, VIEWPORT_HEIGHT };

typedef struct _viewport Viewport;

typedef char pixel;

static pixel **pixarray;

/*****************************************************************
 *
 * Pixel allocation
 *
 *****************************************************************/
void *my_calloc(size_t n, size_t size)
{
  void *ptr = calloc(n, size);
  assert(ptr);
  return ptr;
}

void allocate_pixels()
{
  int i;
  pixarray = my_calloc(viewport.height + 1, sizeof(pixel *));
  for(i = 0; i < viewport.height + 1; i++)
    pixarray[i] = my_calloc(viewport.width + 1, sizeof(pixel));
}


/*****************************************************************
 *
 * Output functions
 *
 *****************************************************************/

void output(int x, int y) {
  x -= viewport.x;
  y -= viewport.y;
  /* Clip */
  if(x>= 0 && y >= 0 && x <= viewport.width && y <= viewport.height)
    pixarray[x][y] = 1u;
}

void output4(int x, int y)
{
  output(x, y);
  output(x, -y);
  output(-x, y);
  output(-x, -y);
}

void output8(int x, int y)
{
  output4(x, y);
  output4(y, x);
}

/*****************************************************************
 *
 * Rendering functions
 *
 *****************************************************************/

void render_bitmap() {
  int x, y;
  for(y = viewport.width; y >= 0; y--) {
    for(x = 0; x < viewport.height; x++) {
      if(pixarray[x][y] != 0u) {
	printf("#");
      } else {
	printf("-");
      }
    }
    puts("");
  }
  
  fflush(stdout);
}

void render_text() {
  int x, y;
  for(x = 0; x < viewport.height; x++)
    for(y = 0; y < viewport.width; y++)
      if(pixarray[x][y] != 0u)
	printf("%d %d\n", x + viewport.x, y + viewport.y);
  fflush(stdout);
}


/*****************************************************************
 *
 * Wrappers for raw algorithms
 *
 *****************************************************************/

void d_line(int argc, char *argv[])
{
  int x0 = 3, y0 = 2, x1 = 10, y1 =7;

  if(argc >= 1) 
    x0 = atoi(argv[0]);

  if(argc >= 2) 
    y0 = atoi(argv[1]);

  if(argc >= 3) 
    x1 = atoi(argv[2]);

  if(argc >= 4) 
    y1 = atoi(argv[3]);

  line(x0, y0, x1, y1);
}

void d_circle(void (*circle)(int), int argc, char *argv[])
{
  int radius = 7;

  if(argc >= 1)
    radius = atoi(argv[0]);

  (*circle)(radius);
}

/*****************************************************************
 *
 * Driver info
 *
 *****************************************************************/
static char* shapes[] = {"line", "circle"};

void list_shapes(FILE *f)
{
  int i;
  for(i = 0; i < sizeof(shapes)/sizeof(char *); i++)
    fprintf(f, "-%s, \n", shapes[i]);
}

void usage(char *progname) {
  fprintf(stderr, "Usage: %s -name arg1 arg2 ...\n", progname);
  list_shapes(stderr);
}


/*****************************************************************
 *
 * main
 *
 *****************************************************************/
int main(int argc, char*argv[])
{
  char *progname = argv[0];

  argv++; argc--;		/* Skip progname */


  /* Parse input line */
  while(argc >= 1) {
    if(!strncmp(*argv, "-text", 5)) {
      fmt = FMT_TEXT;
      argc--; argv++;
    } else if(!strncmp(*argv, "-bitmap", 5)) {
      fmt = FMT_BITMAP;
      argc--; argv++;
    } else if(!strncmp(*argv, "-w", 2)) {
      argc--; argv++;
      if(argc >= 1) {
	viewport.width = atoi(*argv);
	argc--; argv++;
      } else
	continue;
    } else if(!strncmp(*argv, "-h", 2)){
      argc--; argv++;
      if(argc >= 1) {
	viewport.height = atoi(*argv);
	argc--; argv++;
      } else
	continue;
    } else if(!strncmp(*argv, "-x", 2)) {
      argc--; argv++;
      if(argc >= 1) {
	viewport.x = atoi(*argv);
	argc--; argv++;
      } else
	continue;
    } else if(!strncmp(*argv, "-y", 2)) {
      argc--; argv++;
      if(argc >= 1) {
	viewport.y = atoi(*argv);
	argc--; argv++;
      } else
	continue;
    } else
      break;
  }

  allocate_pixels();

  /* Set the shape to be scan-converted */
  if(argc >= 1) {
    if(!strncmp(*argv, "-line", 6))
      d_line(--argc, ++argv);
    else if(!strncmp(*argv, "-circle", 7))
      d_circle(circle, --argc, ++argv);
    else if(!strncmp(*argv, "-circle2", 7))
      d_circle(circle2, --argc, ++argv);
    else {
      usage(progname);
      return 1;
    }
  }

  switch(fmt){
  case FMT_TEXT:
    render_text();
    break;
  case FMT_BITMAP:
    render_bitmap();
    break;
  default:
  }

  return 0;
}