/* GdkPixbuf library - JPEG image loader * * Copyright (C) 1999 Mark Crichton * Copyright (C) 1999 The Free Software Foundation * * Authors: Mark Crichton * Federico Mena-Quintero * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include #include #include "gdk-pixbuf.h" #include "gdk-pixbuf-io.h" static void setup_png_transformations(png_structp png_read_ptr, png_infop png_info_ptr, gboolean *fatal_error_occurred, png_uint_32* width_p, png_uint_32* height_p, int* color_type_p) { png_uint_32 width, height; int bit_depth, color_type, interlace_type, compression_type, filter_type; int channels; /* Get the image info */ png_get_IHDR (png_read_ptr, png_info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, &compression_type, &filter_type); /* set_expand() basically needs to be called unless we are already in RGB/RGBA mode */ if (color_type == PNG_COLOR_TYPE_PALETTE && bit_depth <= 8) { /* Convert indexed images to RGB */ png_set_expand (png_read_ptr); } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) { /* Convert grayscale to RGB */ png_set_expand (png_read_ptr); } else if (png_get_valid (png_read_ptr, png_info_ptr, PNG_INFO_tRNS)) { /* If we have transparency header, convert it to alpha channel */ png_set_expand(png_read_ptr); } else if (bit_depth < 8) { /* If we have < 8 scale it up to 8 */ png_set_expand(png_read_ptr); /* Conceivably, png_set_packing() is a better idea; * God only knows how libpng works */ } /* If we are 16-bit, convert to 8-bit */ if (bit_depth == 16) { png_set_strip_16(png_read_ptr); } /* If gray scale, convert to RGB */ if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { png_set_gray_to_rgb(png_read_ptr); } /* If interlaced, handle that */ if (interlace_type != PNG_INTERLACE_NONE) { png_set_interlace_handling(png_read_ptr); } /* Update the info the reflect our transformations */ png_read_update_info(png_read_ptr, png_info_ptr); png_get_IHDR (png_read_ptr, png_info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, &compression_type, &filter_type); *width_p = width; *height_p = height; *color_type_p = color_type; #ifndef G_DISABLE_CHECKS /* Check that the new info is what we want */ if (bit_depth != 8) { g_warning("Bits per channel of transformed PNG is %d, not 8.", bit_depth); *fatal_error_occurred = TRUE; return; } if ( ! (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) ) { g_warning("Transformed PNG not RGB or RGBA."); *fatal_error_occurred = TRUE; return; } channels = png_get_channels(png_read_ptr, png_info_ptr); if ( ! (channels == 3 || channels == 4) ) { g_warning("Transformed PNG has %d channels, must be 3 or 4.", channels); *fatal_error_occurred = TRUE; return; } #endif } /* Destroy notification function for the libart pixbuf */ static void free_buffer (gpointer user_data, gpointer data) { free (data); } /* Shared library entry point */ GdkPixbuf * image_load (FILE *f) { png_structp png_ptr; png_infop info_ptr, end_info; gboolean failed = FALSE; gint i, ctype, bpp; png_uint_32 w, h; png_bytepp rows; guchar *pixels; png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) return NULL; info_ptr = png_create_info_struct (png_ptr); if (!info_ptr) { png_destroy_read_struct (&png_ptr, NULL, NULL); return NULL; } end_info = png_create_info_struct (png_ptr); if (!end_info) { png_destroy_read_struct (&png_ptr, &info_ptr, NULL); return NULL; } if (setjmp (png_ptr->jmpbuf)) { png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } png_init_io (png_ptr, f); png_read_info (png_ptr, info_ptr); setup_png_transformations(png_ptr, info_ptr, &failed, &w, &h, &ctype); if (failed) { png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } if (ctype & PNG_COLOR_MASK_ALPHA) bpp = 4; else bpp = 3; pixels = malloc (w * h * bpp); if (!pixels) { png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } rows = g_new (png_bytep, h); for (i = 0; i < h; i++) rows[i] = pixels + i * w * bpp; png_read_image (png_ptr, rows); png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); g_free (rows); if (ctype & PNG_COLOR_MASK_ALPHA) return gdk_pixbuf_new_from_data (pixels, ART_PIX_RGB, TRUE, w, h, w * 4, free_buffer, NULL); else return gdk_pixbuf_new_from_data (pixels, ART_PIX_RGB, FALSE, w, h, w * 3, free_buffer, NULL); } /* These avoid the setjmp()/longjmp() crap in libpng */ static void png_error_callback (png_structp png_read_ptr, png_const_charp error_msg); static void png_warning_callback(png_structp png_read_ptr, png_const_charp warning_msg); /* Called at the start of the progressive load */ static void png_info_callback (png_structp png_read_ptr, png_infop png_info_ptr); /* Called for each row; note that you will get duplicate row numbers for interlaced PNGs */ static void png_row_callback (png_structp png_read_ptr, png_bytep new_row, png_uint_32 row_num, int pass_num); /* Called after reading the entire image */ static void png_end_callback (png_structp png_read_ptr, png_infop png_info_ptr); typedef struct _LoadContext LoadContext; struct _LoadContext { png_structp png_read_ptr; png_infop png_info_ptr; ModulePreparedNotifyFunc notify_func; gpointer notify_user_data; GdkPixbuf* pixbuf; guint fatal_error_occurred : 1; }; gpointer image_begin_load (ModulePreparedNotifyFunc prepare_func, ModuleUpdatedNotifyFunc update_func, gpointer user_data) { LoadContext* lc; lc = g_new0(LoadContext, 1); lc->fatal_error_occurred = FALSE; lc->notify_func = prepare_func; lc->notify_user_data = user_data; /* Create the main PNG context struct */ lc->png_read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, lc, /* error/warning callback data */ png_error_callback, png_warning_callback); if (lc->png_read_ptr == NULL) { g_free(lc); return NULL; } /* Create the auxiliary context struct */ lc->png_info_ptr = png_create_info_struct(lc->png_read_ptr); if (lc->png_info_ptr == NULL) { png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL); g_free(lc); return NULL; } png_set_progressive_read_fn(lc->png_read_ptr, lc, /* callback data */ png_info_callback, png_row_callback, png_end_callback); return lc; } void image_stop_load (gpointer context) { LoadContext* lc = context; g_return_if_fail(lc != NULL); gdk_pixbuf_unref(lc->pixbuf); png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL); g_free(lc); } gboolean image_load_increment(gpointer context, guchar *buf, guint size) { LoadContext* lc = context; g_return_val_if_fail(lc != NULL, FALSE); /* Invokes our callbacks as needed */ png_process_data(lc->png_read_ptr, lc->png_info_ptr, buf, size); if (lc->fatal_error_occurred) return FALSE; else return TRUE; } /* Called at the start of the progressive load, once we have image info */ static void png_info_callback (png_structp png_read_ptr, png_infop png_info_ptr) { LoadContext* lc; png_uint_32 width, height; int color_type; gboolean have_alpha = FALSE; gboolean failed = FALSE; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; setup_png_transformations(lc->png_read_ptr, lc->png_info_ptr, &failed, &width, &height, &color_type); if (failed) { lc->fatal_error_occurred = TRUE; return; } /* If we have alpha, set a flag */ if (color_type & PNG_COLOR_MASK_ALPHA) have_alpha = TRUE; lc->pixbuf = gdk_pixbuf_new(ART_PIX_RGB, have_alpha, 8, width, height); if (lc->pixbuf == NULL) { /* Failed to allocate memory */ lc->fatal_error_occurred = TRUE; return; } /* Notify the client that we are ready to go */ if (lc->notify_func) (* lc->notify_func) (lc->pixbuf, lc->notify_user_data); return; } /* Called for each row; note that you will get duplicate row numbers for interlaced PNGs */ static void png_row_callback (png_structp png_read_ptr, png_bytep new_row, png_uint_32 row_num, int pass_num) { LoadContext* lc; guchar* old_row = NULL; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; old_row = lc->pixbuf->art_pixbuf->pixels + (row_num * lc->pixbuf->art_pixbuf->rowstride); png_progressive_combine_row(lc->png_read_ptr, old_row, new_row); } /* Called after reading the entire image */ static void png_end_callback (png_structp png_read_ptr, png_infop png_info_ptr) { LoadContext* lc; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; /* Doesn't do anything for now */ } static void png_error_callback(png_structp png_read_ptr, png_const_charp error_msg) { LoadContext* lc; lc = png_get_error_ptr(png_read_ptr); lc->fatal_error_occurred = TRUE; fprintf(stderr, "Fatal error loading PNG: %s\n", error_msg); } static void png_warning_callback(png_structp png_read_ptr, png_const_charp warning_msg) { LoadContext* lc; lc = png_get_error_ptr(png_read_ptr); fprintf(stderr, "Warning loading PNG: %s\n", warning_msg); }