//
// shoes/image.c
// Loading image formats in Cairo.  I've already tried gdk-pixbuf and imlib2, but 
// the idea here is to cut down dependencies, since I only really need reading of 
// the basics: GIF and JPEG.
//
#include <stdio.h>
#include <setjmp.h>
#include <sys/stat.h>
#include "shoes/app.h"
#include "shoes/canvas.h"
#include "shoes/ruby.h"
#include "shoes/internal.h"
#include "shoes/world.h"
#include "shoes/native.h"
#include "shoes/version.h"
#include "shoes/http.h"
 
#undef HAVE_PROTOTYPES
#undef HAVE_STDLIB_H
#undef EXTERN
#include <jpeglib.h>
#include <jerror.h>
 
#ifndef SHOES_GTK
#ifdef DrawText
#undef DrawText
#endif
#endif
#define DrawText gif_DrawText
#include <gif_lib.h>
 
shoes_image_format shoes_image_detect(VALUE, int *, int *);
 
#define JPEG_LINES 16
#define SIZE_SURFACE ((cairo_surface_t *)1)
 
typedef struct {
  unsigned int state[5];
  unsigned int count[2];
  unsigned char buffer[64];
} SHA1_CTX;
 
void SHA1Transform(unsigned int state[5], unsigned char buffer[64]);
void SHA1Init(SHA1_CTX* context);
void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len);
void SHA1Final(unsigned char digest[20], SHA1_CTX* context);
 
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
/* blk0() and blk() perform the initial expand. */
/* I got the idea of expanding during the round function from SSLeay */
#ifdef LITTLE_ENDIAN
#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
  |(rol(block->l[i],8)&0x00FF00FF))
#else
#define blk0(i) block->l[i]
#endif
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
  ^block->l[(i+2)&15]^block->l[i&15],1))
 
/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
 
/* Hash a single 512-bit block. This is the core of the algorithm. */
void SHA1Transform(unsigned int state[5], unsigned char buffer[64])
{
unsigned int a, b, c, d, e;
typedef union {
  unsigned char c[64];
  unsigned int l[16];
} CHAR64LONG16;
CHAR64LONG16* block;
#ifdef SHA1HANDSOFF
static unsigned char workspace[64];
  block = (CHAR64LONG16*)workspace;
  memcpy(block, buffer, 64);
#else
  block = (CHAR64LONG16*)buffer;
#endif
  /* Copy context->state[] to working vars */
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  /* 4 rounds of 20 operations each. Loop unrolled. */
  R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
  R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
  R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
  R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
  R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
  R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
  R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
  R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
  R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
  R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
  R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
  R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
  R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
  R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
  R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
  R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
  R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
  R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
  R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
  R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;
  /* Wipe variables */
  a = b = c = d = e = 0;
}
 
/* SHA1Init - Initialize new context */
void SHA1Init(SHA1_CTX* context)
{
  /* SHA1 initialization constants */
  context->state[0] = 0x67452301;
  context->state[1] = 0xEFCDAB89;
  context->state[2] = 0x98BADCFE;
  context->state[3] = 0x10325476;
  context->state[4] = 0xC3D2E1F0;
  context->count[0] = context->count[1] = 0;
}
 
/* Run your data through this. */
void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len)
{
unsigned int i, j;
 
  j = (context->count[0] >> 3) & 63;
  if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
  context->count[1] += (len >> 29);
  if ((j + len) > 63) {
    memcpy(&context->buffer[j], data, (i = 64-j));
    SHA1Transform(context->state, context->buffer);
    for ( ; i + 63 < len; i += 64) {
      SHA1Transform(context->state, &data[i]);
    }
    j = 0;
  }
  else i = 0;
  memcpy(&context->buffer[j], &data[i], len - i);
}
 
/* Add padding and return the message digest. */
void SHA1Final(unsigned char digest[20], SHA1_CTX* context)
{
unsigned int i, j;
unsigned char finalcount[8];
 
  for (i = 0; i < 8; i++) {
    finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
     >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
  }
  SHA1Update(context, (unsigned char *)"\200", 1);
  while ((context->count[0] & 504) != 448) {
    SHA1Update(context, (unsigned char *)"\0", 1);
  }
  SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */
  for (i = 0; i < 20; i++) {
    digest[i] = (unsigned char)
     ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
  }
  /* Wipe variables */
  i = j = 0;
  memset(context->buffer, 0, 64);
  memset(context->state, 0, 20);
  memset(context->count, 0, 8);
  memset(&finalcount, 0, 8);
#ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite it's own static vars */
  SHA1Transform(context->state, context->buffer);
#endif
}
 
cairo_surface_t *
shoes_surface_create_from_pixels(PIXEL *pixels, int width, int height)
{
  guchar *cairo_pixels;
  cairo_surface_t *surface;
  cairo_user_data_key_t key;
  int j;
 
  cairo_pixels = (guchar *)g_malloc(4 * width * height);
  surface = cairo_image_surface_create_for_data((unsigned char *)cairo_pixels,
    CAIRO_FORMAT_ARGB32,
    width, height, 4 * width);
  cairo_surface_set_user_data(surface, &key,
    cairo_pixels, (cairo_destroy_func_t)g_free);
 
  for (j = height; j; j--)
  {
    guchar *p = (guchar *)pixels;
    guchar *q = cairo_pixels;
   
    guchar *end = p + 4 * width;
    guint t1,t2,t3;
 
#define MULT(d,c,a,t) G_STMT_START { t = c * a; d = ((t >> 8) + t) >> 8; } G_STMT_END
 
    while (p < end)
    {
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
      MULT(q[2], p[2], p[3], t1);
      MULT(q[1], p[1], p[3], t2);
      MULT(q[0], p[0], p[3], t3);
      q[3] = p[3];
#else
      q[0] = p[3];
      MULT(q[3], p[0], p[3], t1);
      MULT(q[2], p[1], p[3], t2);
      MULT(q[1], p[2], p[3], t3);
#endif
    
      p += 4;
      q += 4;
    }
   
#undef MULT
   
    pixels += width;
    cairo_pixels += 4 * width;
  }
 
  return surface;
}
 
#define PNG_SIG "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"
 
cairo_surface_t *
shoes_png_size(char *filename, int *width, int *height)
{
  unsigned char *sig = SHOE_ALLOC_N(unsigned char, 32);
  cairo_surface_t *surface = NULL;
  FILE *image = fopen(filename, "rb");
  if (image == NULL) return NULL;
 
  if (fread(sig, 1, 32, image) < 8)
    goto done; 
  if (memcmp(sig, PNG_SIG, 8) != 0)
    goto done;
 
  *width = *((int *)(sig + 0x10));
  BE_CPU(*width);
  *height = *((int *)(sig + 0x14));
  BE_CPU(*height);
 
  surface = SIZE_SURFACE;
done:
  fclose(image);
  return surface;
}
 
cairo_surface_t *
shoes_surface_create_from_gif(char *filename, int *width, int *height, unsigned char load)
{
  cairo_surface_t *surface = NULL;
  GifFileType *gif;
  PIXEL *ptr = NULL, *pixels = NULL;
  GifPixelType **rows = NULL;
  GifRecordType rec;
  ColorMapObject *cmap;
  int i, j, bg, r, g, b, w = 0, h = 0, done = 0, transp = -1;
  float per = 0.0, per_inc;
  int intoffset[] = { 0, 4, 2, 1 };
  int intjump[] = { 8, 8, 4, 2 };
 
  transp = -1;
  gif = DGifOpenFileName(filename);
  if (gif == NULL)
    goto done;
 
  do
  {
    if (DGifGetRecordType(gif, &rec) == GIF_ERROR)
      rec = TERMINATE_RECORD_TYPE;
    if ((rec == IMAGE_DESC_RECORD_TYPE) && (!done))
    {
      if (DGifGetImageDesc(gif) == GIF_ERROR)
        {
           /* PrintGifError(); */
           rec = TERMINATE_RECORD_TYPE;
        }
      w = gif->Image.Width;
      if (width != NULL) *width = w;
      h = gif->Image.Height;
      if (height != NULL) *height = h;
      if ((w < 1) || (h < 1) || (w > 8192) || (h > 8192))
        goto done;
 
      if (!load)
      {
        surface = SIZE_SURFACE;
        goto done;
      }
 
      rows = SHOE_ALLOC_N(GifPixelType *, h);
      if (rows == NULL)
        goto done;
 
      SHOE_MEMZERO(