Added jpeg loading from memory. Added jpeg Fl_Widget->image() support for Fluid - but linking to fltk_images is required if this feature is used!

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7092 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 201 insertions, 26 deletions

diff --git a/src/Fl_JPEG_Image.cxx b/src/Fl_JPEG_Image.cxx
index 050847a92..c4e450c64 100644
--- a/src/Fl_JPEG_Image.cxx
+++ b/src/Fl_JPEG_Image.cxx
@@ -89,40 +89,47 @@ extern "C" {
 
 
 /**
-  The constructor loads the JPEG image from the given jpeg filename.
-  <P>The inherited destructor free all memory and server resources that are used by  the image.
-*/
-Fl_JPEG_Image::Fl_JPEG_Image(const char *jpeg)	// I - File to load
-  : Fl_RGB_Image(0,0,0) {
+ \brief The constructor loads the JPEG image from the given jpeg filename.
+ 
+ The inherited destructor frees all memory and server resources that are used 
+ by the image.
+ 
+ There is no error function in this class. If the image has loaded correctly, 
+ w(), h(), and d() should return values greater zero.
+ 
+ \param filename a full path and name pointing to a valid jpeg file.
+ */
+Fl_JPEG_Image::Fl_JPEG_Image(const char *filename)	// I - File to load
+: Fl_RGB_Image(0,0,0) {
 #ifdef HAVE_LIBJPEG
   FILE				*fp;	// File pointer
   jpeg_decompress_struct	dinfo;	// Decompressor info
   fl_jpeg_error_mgr		jerr;	// Error handler info
   JSAMPROW			row;	// Sample row pointer
-
+  
   // the following variables are pointers allocating some private space that
   // is not reset by 'setjmp()'
   char* max_finish_decompress_err;      // count errors and give up afer a while
   char* max_destroy_decompress_err;     // to avoid recusion and deadlock
-
+  
   // Clear data...
   alloc_array = 0;
   array = (uchar *)0;
-
+  
   // Open the image file...
-  if ((fp = fopen(jpeg, "rb")) == NULL) return;
-
+  if ((fp = fopen(filename, "rb")) == NULL) return;
+  
   // Setup the decompressor info and read the header...
   dinfo.err                = jpeg_std_error((jpeg_error_mgr *)&jerr);
   jerr.pub_.error_exit     = fl_jpeg_error_handler;
   jerr.pub_.output_message = fl_jpeg_output_handler;
-
+  
   // Setup error loop variables
   max_finish_decompress_err = (char*)malloc(1);   // allocate space on the frame for error counters
   max_destroy_decompress_err = (char*)malloc(1);  // otherwise, the variables are reset on the longjmp
   *max_finish_decompress_err=10;
   *max_destroy_decompress_err=10;
-
+  
   if (setjmp(jerr.errhand_))
   {
     // JPEG error handling...
@@ -132,62 +139,230 @@ Fl_JPEG_Image::Fl_JPEG_Image(const char *jpeg)	// I - File to load
       jpeg_finish_decompress(&dinfo);
     if ( (*max_destroy_decompress_err)-- > 0)
       jpeg_destroy_decompress(&dinfo);
-
+    
     fclose(fp);
-
+    
     w(0);
     h(0);
     d(0);
-
+    
     if (array) {
       delete[] (uchar *)array;
       array = 0;
       alloc_array = 0;
     }
-
+    
     free(max_destroy_decompress_err);
     free(max_finish_decompress_err);
     
     return;
   }
-
+  
   jpeg_create_decompress(&dinfo);
   jpeg_stdio_src(&dinfo, fp);
   jpeg_read_header(&dinfo, 1);
-
+  
   dinfo.quantize_colors      = (boolean)FALSE;
   dinfo.out_color_space      = JCS_RGB;
   dinfo.out_color_components = 3;
   dinfo.output_components    = 3;
-
+  
   jpeg_calc_output_dimensions(&dinfo);
-
+  
   w(dinfo.output_width); 
   h(dinfo.output_height);
   d(dinfo.output_components);
-
+  
   array = new uchar[w() * h() * d()];
   alloc_array = 1;
-
+  
   jpeg_start_decompress(&dinfo);
-
+  
   while (dinfo.output_scanline < dinfo.output_height) {
     row = (JSAMPROW)(array +
                      dinfo.output_scanline * dinfo.output_width *
                      dinfo.output_components);
     jpeg_read_scanlines(&dinfo, &row, (JDIMENSION)1);
   }
-
+  
   jpeg_finish_decompress(&dinfo);
   jpeg_destroy_decompress(&dinfo);
-
+  
   free(max_destroy_decompress_err);
   free(max_finish_decompress_err);
-
+  
   fclose(fp);
 #endif // HAVE_LIBJPEG
 }
 
+
+// data source manager for reading jpegs from memory
+// init_source (j_decompress_ptr cinfo)
+// fill_input_buffer (j_decompress_ptr cinfo)
+// skip_input_data (j_decompress_ptr cinfo, long num_bytes)
+// resync_to_restart (j_decompress_ptr cinfo, int desired)
+// term_source (j_decompress_ptr cinfo)
+//         JOCTET * next_output_byte;  /* => next byte to write in buffer */
+//         size_t free_in_buffer;      /* # of byte spaces remaining in buffer */
+
+
+typedef struct {
+  struct jpeg_source_mgr pub;
+  const unsigned char *data, *s;
+  // JOCTET * buffer;              /* start of buffer */
+  // boolean start_of_file;        /* have we gotten any data yet? */
+} my_source_mgr;
+
+typedef my_source_mgr *my_src_ptr;
+
+
+void init_source (j_decompress_ptr cinfo) {
+  my_src_ptr src = (my_src_ptr)cinfo->src;
+  src->s = src->data;
+}
+
+boolean fill_input_buffer(j_decompress_ptr cinfo) {
+  my_src_ptr src = (my_src_ptr)cinfo->src;
+  size_t nbytes = 4096;
+  src->pub.next_input_byte = src->s;
+  src->pub.bytes_in_buffer = nbytes;
+  src->s += nbytes;
+  return TRUE;
+}
+
+void term_source(j_decompress_ptr cinfo)
+{
+}
+
+void skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
+  my_src_ptr src = (my_src_ptr)cinfo->src;
+  if (num_bytes > 0) {
+    while (num_bytes > (long)src->pub.bytes_in_buffer) {
+      num_bytes -= (long)src->pub.bytes_in_buffer;
+      fill_input_buffer(cinfo);
+    }
+    src->pub.next_input_byte += (size_t) num_bytes;
+    src->pub.bytes_in_buffer -= (size_t) num_bytes;
+  }
+}
+
+static void jpeg_mem_src(j_decompress_ptr cinfo, const unsigned char *data)
+{
+  my_src_ptr src;
+  cinfo->src = (struct jpeg_source_mgr *)malloc(sizeof(my_source_mgr));
+  src = (my_src_ptr)cinfo->src;
+  src->pub.init_source = init_source;
+  src->pub.fill_input_buffer = fill_input_buffer;
+  src->pub.skip_input_data = skip_input_data;
+  src->pub.resync_to_restart = jpeg_resync_to_restart;
+  src->pub.term_source = term_source;
+  src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
+  src->pub.next_input_byte = NULL; /* until buffer loaded */
+  src->data = data;
+  src->s = data;
+}
+
+
+/**
+ \brief The constructor loads the JPEG image from memory.
+ 
+ The inherited destructor frees all memory and server resources that are used 
+ by the image.
+ 
+ There is no error function in this class. If the image has loaded correctly, 
+ w(), h(), and d() should return values greater zero.
+ 
+ \param name developer shoud provide a unique name for this image
+ \param data a pointer to the memorry location of the jpeg image
+ */
+Fl_JPEG_Image::Fl_JPEG_Image(const char *name, const unsigned char *data)
+: Fl_RGB_Image(0,0,0) {
+#ifdef HAVE_LIBJPEG
+  jpeg_decompress_struct	dinfo;	// Decompressor info
+  fl_jpeg_error_mgr		jerr;	// Error handler info
+  JSAMPROW			row;	// Sample row pointer
+  
+  // the following variables are pointers allocating some private space that
+  // is not reset by 'setjmp()'
+  char* max_finish_decompress_err;      // count errors and give up afer a while
+  char* max_destroy_decompress_err;     // to avoid recusion and deadlock
+  
+  // Clear data...
+  alloc_array = 0;
+  array = (uchar *)0;
+  
+  // Setup the decompressor info and read the header...
+  dinfo.err                = jpeg_std_error((jpeg_error_mgr *)&jerr);
+  jerr.pub_.error_exit     = fl_jpeg_error_handler;
+  jerr.pub_.output_message = fl_jpeg_output_handler;
+  
+  // Setup error loop variables
+  max_finish_decompress_err = (char*)malloc(1);   // allocate space on the frame for error counters
+  max_destroy_decompress_err = (char*)malloc(1);  // otherwise, the variables are reset on the longjmp
+  *max_finish_decompress_err=10;
+  *max_destroy_decompress_err=10;
+  
+  if (setjmp(jerr.errhand_))
+  {
+    // JPEG error handling...
+    // if any of the cleanup routines hits another error, we would end up 
+    // in a loop. So instead, we decrement max_err for some upper cleanup limit.
+    if ( ((*max_finish_decompress_err)-- > 0) && array)
+      jpeg_finish_decompress(&dinfo);
+    if ( (*max_destroy_decompress_err)-- > 0)
+      jpeg_destroy_decompress(&dinfo);
+    
+    w(0);
+    h(0);
+    d(0);
+    
+    if (array) {
+      delete[] (uchar *)array;
+      array = 0;
+      alloc_array = 0;
+    }
+    
+    free(max_destroy_decompress_err);
+    free(max_finish_decompress_err);
+    
+    return;
+  }
+  
+  jpeg_create_decompress(&dinfo);
+  jpeg_mem_src(&dinfo, data);
+  jpeg_read_header(&dinfo, 1);
+  
+  dinfo.quantize_colors      = (boolean)FALSE;
+  dinfo.out_color_space      = JCS_RGB;
+  dinfo.out_color_components = 3;
+  dinfo.output_components    = 3;
+  
+  jpeg_calc_output_dimensions(&dinfo);
+  
+  w(dinfo.output_width); 
+  h(dinfo.output_height);
+  d(dinfo.output_components);
+  
+  array = new uchar[w() * h() * d()];
+  alloc_array = 1;
+  
+  jpeg_start_decompress(&dinfo);
+  
+  while (dinfo.output_scanline < dinfo.output_height) {
+    row = (JSAMPROW)(array +
+                     dinfo.output_scanline * dinfo.output_width *
+                     dinfo.output_components);
+    jpeg_read_scanlines(&dinfo, &row, (JDIMENSION)1);
+  }
+  
+  jpeg_finish_decompress(&dinfo);
+  jpeg_destroy_decompress(&dinfo);
+  
+  free(max_destroy_decompress_err);
+  free(max_finish_decompress_err);
+#endif // HAVE_LIBJPEG
+}
+
 //
 // End of "$Id$".
 //