Author: manolo
Date: 2011-01-17 12:51:12 -0800 (Mon, 17 Jan 2011)
New Revision: 8287
Log:
Fix 2nd part of STR #2520: added Fl_PNG_Image in-memory constructor.
This constructor has a 3rd argument, the size of the array holding the
in-memory PNG image.
This allows the constructor to check for errors in the image.
Modified:
branches/branch-1.3/FL/Fl_PNG_Image.H
branches/branch-1.3/src/Fl_PNG_Image.cxx
Modified: branches/branch-1.3/FL/Fl_PNG_Image.H
===================================================================
--- branches/branch-1.3/FL/Fl_PNG_Image.H 2011-01-17 09:39:14 UTC (rev
8286)
+++ branches/branch-1.3/FL/Fl_PNG_Image.H 2011-01-17 20:51:12 UTC (rev
8287)
@@ -40,9 +40,12 @@
*/
class FL_EXPORT Fl_PNG_Image : public Fl_RGB_Image {
- public:
+public:
Fl_PNG_Image(const char* filename);
+ Fl_PNG_Image (const char *name_png, const unsigned char *buffer, int
datasize);
+private:
+ void load_png_(const char *name_png, const unsigned char *buffer_png, int
datasize);
};
#endif
Modified: branches/branch-1.3/src/Fl_PNG_Image.cxx
===================================================================
--- branches/branch-1.3/src/Fl_PNG_Image.cxx 2011-01-17 09:39:14 UTC (rev
8286)
+++ branches/branch-1.3/src/Fl_PNG_Image.cxx 2011-01-17 20:51:12 UTC (rev
8287)
@@ -42,50 +42,96 @@
#include <stdlib.h>
#include <FL/fl_utf8.h>
+#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
extern "C"
{
-#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
# include <zlib.h>
# ifdef HAVE_PNG_H
# include <png.h>
# else
# include <libpng/png.h>
# endif // HAVE_PNG_H
-#endif // HAVE_LIBPNG && HAVE_LIBZ
}
+typedef struct {
+ png_structp pp;
+ const unsigned char *current;
+ const unsigned char *last;
+} fl_png_memory;
+static void png_read_data_from_mem( png_structp png_ptr, //pointer to our data
+ png_bytep data, // where to copy the image
data for libpng computing
+ png_size_t length) // length of data to copy
+{
+ fl_png_memory *png_mem_data = (fl_png_memory*)png_get_io_ptr(png_ptr); //
get the pointer to our struct
+ if (png_mem_data->current + length > png_mem_data->last) {
+ png_error(png_mem_data->pp, "Invalid attempt to read row data");
+ return;
+ }
+ /* copy data from image buffer */
+ memcpy (data, png_mem_data->current, length);
+ /* advance in the memory data */
+ png_mem_data->current += length;
+}
+#endif // HAVE_LIBPNG && HAVE_LIBZ
+
+
/**
The constructor loads the named PNG image from the given png filename.
- <P>The destructor free all memory and server resources that are used by
+ <P>The destructor frees all memory and server resources that are used by
the image.
*/
-Fl_PNG_Image::Fl_PNG_Image(const char *png) // I - File to read
- : Fl_RGB_Image(0,0,0) {
+Fl_PNG_Image::Fl_PNG_Image (const char *filename): Fl_RGB_Image(0,0,0)
+{
+ load_png_(filename, NULL, 0);
+}
+
+/** Constructor that reads a PNG image from memory.
+ \param name_png A name given to this image
+ \param buffer Pointer to the start of the PNG image in memory
+ \param maxsize Size in bytes of the memory buffer containing the PNG image
+ */
+Fl_PNG_Image::Fl_PNG_Image (
+ const char *name_png, const unsigned char *buffer, int maxsize):
Fl_RGB_Image(0,0,0)
+{
+ load_png_(name_png, buffer, maxsize);
+}
+
+void Fl_PNG_Image::load_png_(const char *name_png, const unsigned char
*buffer_png, int maxsize)
+{
#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
- int i; // Looping var
- FILE *fp; // File pointer
- int channels; // Number of color channels
- png_structp pp; // PNG read pointer
- png_infop info; // PNG info pointers
- png_bytep *rows; // PNG row pointers
+ int i; // Looping var
+ FILE *fp; // File pointer
+ int channels; // Number of color channels
+ png_structp pp; // PNG read pointer
+ png_infop info; // PNG info pointers
+ png_bytep *rows;// PNG row pointers
+ fl_png_memory png_mem_data;
+ int from_memory = (buffer_png != NULL); // true iff reading image from memory
+ if (!from_memory) {
+ if ((fp = fl_fopen(name_png, "rb")) == NULL) return;
+ }
- // Open the PNG file...
- if ((fp = fl_fopen(png, "rb")) == NULL) return;
-
// Setup the PNG data structures...
pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(pp);
if (setjmp(png_jmpbuf(pp)))
{
- Fl::warning("PNG file \"%s\" contains errors!\n", png);
+ Fl::warning("PNG file \"%s\" contains errors!\n", name_png);
return;
}
- // Initialize the PNG read "engine"...
- png_init_io(pp, fp);
+ if (from_memory) {
+ png_mem_data.current = buffer_png;
+ png_mem_data.last = buffer_png + maxsize;
+ png_mem_data.pp = pp;
+ // Initialize the function pointer to the PNG read "engine"...
+ png_set_read_fn (pp, (png_voidp) &png_mem_data, png_read_data_from_mem);
+ } else {
+ png_init_io(pp, fp); // Initialize the PNG file read "engine"...
+ }
// Get the image dimensions and convert to grayscale or RGB...
png_read_info(pp, info);
@@ -101,7 +147,7 @@
int num_trans = 0;
png_get_tRNS(pp, info, 0, &num_trans, 0);
if ((png_get_color_type(pp, info) & PNG_COLOR_MASK_ALPHA) || (num_trans !=
0))
- channels ++;
+ channels ++;
w((int)(png_get_image_width(pp, info)));
h((int)(png_get_image_height(pp, info)));
@@ -150,7 +196,7 @@
png_read_end(pp, info);
png_destroy_read_struct(&pp, &info, NULL);
- fclose(fp);
+ if (!from_memory) fclose(fp);
#endif // HAVE_LIBPNG && HAVE_LIBZ
}
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