diff options
Diffstat (limited to 'src/png.c')
| -rw-r--r-- | src/png.c | 138 |
1 files changed, 72 insertions, 66 deletions
@@ -4,6 +4,7 @@ * * Geoff Lane nov 1999 zzassgl@twirl.mcc.ac.uk * Luca Rota, Jorge Arellano Cid, Eric Gaudet 2000 + * Jorge Arellano Cid 2009 * * "PNG: The Definitive Guide" by Greg Roelofs, O'Reilly * ISBN 1-56592-542-4 @@ -67,19 +68,19 @@ typedef struct _DilloPng { DilloImage *Image; /* Image meta data */ DilloUrl *url; /* Primary Key for the dicache */ - int version; /* Secondary Key for the dicache */ + int version; /* Secondary Key for the dicache */ double display_exponent; /* gamma correction */ - ulong_t width; /* png image width */ - ulong_t height; /* png image height */ + ulong_t width; /* png image width */ + ulong_t height; /* png image height */ png_structp png_ptr; /* libpng private data */ png_infop info_ptr; /* libpng private info */ - uchar_t *image_data; /* decoded image data */ - uchar_t **row_pointers; /* pntr to row starts */ + uchar_t *image_data; /* decoded image data */ + uchar_t **row_pointers; /* pntr to row starts */ jmp_buf jmpbuf; /* png error processing */ - int error; /* error flag */ + int error; /* error flag */ png_uint_32 previous_row; - int rowbytes; /* No. bytes in image row */ + int rowbytes; /* No. bytes in image row */ short passes; short channels; /* No. image channels */ @@ -92,13 +93,13 @@ struct _DilloPng { * ipbuf ipbufstart ipbufsize */ - uchar_t *ipbuf; /* image data in buffer */ - int ipbufstart; /* first valid image byte */ - int ipbufsize; /* size of valid data in */ + uchar_t *ipbuf; /* image data in buffer */ + int ipbufstart; /* first valid image byte */ + int ipbufsize; /* size of valid data in */ enum prog_state state; /* FSM current state */ - uchar_t *linebuf; /* o/p raster data */ + uchar_t *linebuf; /* o/p raster data */ } DilloPng; @@ -297,57 +298,37 @@ static void png->state = IS_finished; } - /* - * Op: Operation to perform. - * If (Op == 0) - * start or continue processing an image if image data exists. - * else - * terminate processing, cleanup any allocated memory, - * close down the decoding process. - * - * Client->CbData : pointer to previously allocated DilloPng work area. - * This holds the current state of the image processing and is saved - * across calls to this routine. - * Client->Buf : Pointer to data start. - * Client->BufSize : the size of the data buffer. - * - * You have to keep track of where you are in the image data and - * how much has been processed. - * - * It's entirely possible that you will not see the end of the data. The - * user may terminate transfer via a Stop button or there may be a network - * failure. This means that you can't just wait for all the data to be - * presented before starting conversion and display. + * Finish the decoding process (and free the memory) */ -static void Png_callback(int Op, CacheClient_t *Client) +static void Png_close(DilloPng *png, CacheClient_t *Client) { - DilloPng *png = Client->CbData; - - if (Op) { - /* finished - free up the resources for this image */ - a_Dicache_close(png->url, png->version, Client); - dFree(png->image_data); - dFree(png->row_pointers); - dFree(png->linebuf); - - if (setjmp(png->jmpbuf)) - MSG_WARN("PNG: can't destroy read structure\n"); - else if (png->png_ptr) - png_destroy_read_struct(&png->png_ptr, &png->info_ptr, NULL); - dFree(png); - return; - } + /* Free up the resources for this image */ + a_Dicache_close(png->url, png->version, Client); + dFree(png->image_data); + dFree(png->row_pointers); + dFree(png->linebuf); + + if (setjmp(png->jmpbuf)) + MSG_WARN("PNG: can't destroy read structure\n"); + else if (png->png_ptr) + png_destroy_read_struct(&png->png_ptr, &png->info_ptr, NULL); + dFree(png); +} - /* Let's make some sound if we have been called with no data */ - dReturn_if_fail ( Client->Buf != NULL && Client->BufSize > 0 ); +/* + * Receive and process new chunks of PNG image data + */ +static void Png_write(DilloPng *png, void *Buf, uint_t BufSize) +{ + dReturn_if_fail ( Buf != NULL && BufSize > 0 ); - _MSG("Png_callback BufSize = %d\n", Client->BufSize); + _MSG("Png_callback BufSize = %d\n", BufSize); /* Keep local copies so we don't have to pass multiple args to * a number of functions. */ - png->ipbuf = Client->Buf; - png->ipbufsize = Client->BufSize; + png->ipbuf = Buf; + png->ipbufsize = BufSize; /* start/resume the FSM here */ while (png->state != IS_finished && DATASIZE) { @@ -408,6 +389,37 @@ static void Png_callback(int Op, CacheClient_t *Client) } /* + * Op: Operation to perform. + * If (Op == 0) + * start or continue processing an image if image data exists. + * else + * terminate processing, cleanup any allocated memory, + * close down the decoding process. + * + * Client->CbData : pointer to previously allocated DilloPng work area. + * This holds the current state of the image processing and is kept + * across calls to this routine. + * Client->Buf : Pointer to data start. + * Client->BufSize : the size of the data buffer. + * + * You have to keep track of where you are in the image data and + * how much has been processed. + * + * It's entirely possible that you will not see the end of the data. The + * user may terminate transfer via a Stop button or there may be a network + * failure. This means that you can't just wait for all the data to be + * presented before starting conversion and display. + */ +static void Png_callback(int Op, CacheClient_t *Client) +{ + if (Op) { /* EOF */ + Png_close(Client->CbData, Client); + } else { + Png_write(Client->CbData, Client->Buf, Client->BufSize); + } +} + +/* * Create the image state data that must be kept between calls */ static DilloPng *Png_new(DilloImage *Image, DilloUrl *url, int version) @@ -433,25 +445,19 @@ static DilloPng *Png_new(DilloImage *Image, DilloUrl *url, int version) /* * MIME handler for "image/png" type * (Sets Png_callback or a_Dicache_callback as the cache-client) + * + * Parameters: + * Type: MIME type + * Ptr: points to a Web structure + * Call: Dillo calls this with more data/eod + * Data: Decoding data structure */ void *a_Png_image(const char *Type, void *Ptr, CA_Callback_t *Call, void **Data) { -/* - * Type: MIME type - * Ptr: points to a Web structure - * Call: Dillo calls this with more data/eod - * Data: raw image data - */ - DilloWeb *web = Ptr; DICacheEntry *DicEntry; - _MSG("a_Png_image: Type = %s\n" - "a_Png_image: libpng - Compiled %s; using %s.\n" - "a_Png_image: zlib - Compiled %s; using %s.\n", - Type, PNG_LIBPNG_VER_STRING, png_libpng_ver,ZLIB_VERSION,zlib_version); - if (!web->Image) web->Image = a_Image_new(0, 0, NULL, prefs.bg_color); |