r1022 - packages/libtk-png-perl/trunk/libpng
Carlo Segre
segre-guest@costa.debian.org
Mon, 16 May 2005 17:25:54 +0000
Author: segre-guest
Date: 2005-05-16 17:25:54 +0000 (Mon, 16 May 2005)
New Revision: 1022
Removed:
packages/libtk-png-perl/trunk/libpng/example.c.orig
Log:
example.c.orig removed, was interfering with svn-build
Deleted: packages/libtk-png-perl/trunk/libpng/example.c.orig
===================================================================
--- packages/libtk-png-perl/trunk/libpng/example.c.orig 2005-05-16 17:13:30 UTC (rev 1021)
+++ packages/libtk-png-perl/trunk/libpng/example.c.orig 2005-05-16 17:25:54 UTC (rev 1022)
@@ -1,706 +0,0 @@
-
-#if 0 /* in case someone actually tries to compile this */
-
-/* example.c - an example of using libpng */
-
-/* This is an example of how to use libpng to read and write PNG files.
- * The file libpng.txt is much more verbose then this. If you have not
- * read it, do so first. This was designed to be a starting point of an
- * implementation. This is not officially part of libpng, and therefore
- * does not require a copyright notice.
- *
- * This file does not currently compile, because it is missing certain
- * parts, like allocating memory to hold an image. You will have to
- * supply these parts to get it to compile. For an example of a minimal
- * working PNG reader/writer, see pngtest.c, included in this distribution.
- */
-
-#include "png.h"
-
-/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp()
- * returns zero if the image is a PNG and nonzero if it isn't a PNG.
- *
- * The function check_if_png() shown here, but not used, returns nonzero (true)
- * if the file can be opened and is a PNG, 0 (false) otherwise.
- *
- * If this call is successful, and you are going to keep the file open,
- * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
- * you have created the png_ptr, so that libpng knows your application
- * has read that many bytes from the start of the file. Make sure you
- * don't call png_set_sig_bytes() with more than 8 bytes read or give it
- * an incorrect number of bytes read, or you will either have read too
- * many bytes (your fault), or you are telling libpng to read the wrong
- * number of magic bytes (also your fault).
- *
- * Many applications already read the first 2 or 4 bytes from the start
- * of the image to determine the file type, so it would be easiest just
- * to pass the bytes to png_sig_cmp() or even skip that if you know
- * you have a PNG file, and call png_set_sig_bytes().
- */
-#define PNG_BYTES_TO_CHECK 4
-int check_if_png(char *file_name, FILE **fp)
-{
- char buf[PNG_BYTES_TO_CHECK];
-
- /* Open the prospective PNG file. */
- if ((*fp = fopen(file_name, "rb")) != NULL);
- return 0;
-
- /* Read in some of the signature bytes */
- if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
- return 0;
-
- /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
- Return nonzero (true) if they match */
-
- return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
-}
-
-/* Read a PNG file. You may want to return an error code if the read
- * fails (depending upon the failure). There are two "prototypes" given
- * here - one where we are given the filename, and we need to open the
- * file, and the other where we are given an open file (possibly with
- * some or all of the magic bytes read - see comments above).
- */
-#ifdef open_file /* prototype 1 */
-void read_png(char *file_name) /* We need to open the file */
-{
- png_structp png_ptr;
- png_infop info_ptr;
- unsigned int sig_read = 0;
- png_uint_32 width, height;
- int bit_depth, color_type, interlace_type;
- FILE *fp;
-
- if ((fp = fopen(file_name, "rb")) == NULL)
- return;
-#else no_open_file /* prototype 2 */
-void read_png(FILE *fp, unsigned int sig_read) /* file is already open */
-{
- png_structp png_ptr;
- png_infop info_ptr;
- png_uint_32 width, height;
- int bit_depth, color_type, interlace_type;
-#endif no_open_file /* only use one prototype! */
-
- /* Create and initialize the png_struct with the desired error handler
- * functions. If you want to use the default stderr and longjump method,
- * you can supply NULL for the last three parameters. We also supply the
- * the compiler header file version, so that we know if the application
- * was compiled with a compatible version of the library. REQUIRED
- */
- png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
-
- if (png_ptr == NULL)
- {
- fclose(fp);
- return;
- }
-
- /* Allocate/initialize the memory for image information. REQUIRED. */
- info_ptr = png_create_info_struct(png_ptr);
- if (info_ptr == NULL)
- {
- fclose(fp);
- png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
- return;
- }
-
- /* Set error handling if you are using the setjmp/longjmp method (this is
- * the normal method of doing things with libpng). REQUIRED unless you
- * set up your own error handlers in the png_create_read_struct() earlier.
- */
- if (setjmp(png_ptr->jmpbuf))
- {
- /* Free all of the memory associated with the png_ptr and info_ptr */
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
- fclose(fp);
- /* If we get here, we had a problem reading the file */
- return;
- }
-
- /* One of the following I/O initialization methods is REQUIRED */
-#ifdef streams /* PNG file I/O method 1 */
- /* Set up the input control if you are using standard C streams */
- png_init_io(png_ptr, fp);
-
-#else no_streams /* PNG file I/O method 2 */
- /* If you are using replacement read functions, instead of calling
- * png_init_io() here you would call:
- */
- png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn);
- /* where user_io_ptr is a structure you want available to the callbacks */
-#endif no_streams /* Use only one I/O method! */
-
- /* If we have already read some of the signature */
- png_set_sig_bytes(png_ptr, sig_read);
-
- /* The call to png_read_info() gives us all of the information from the
- * PNG file before the first IDAT (image data chunk). REQUIRED
- */
- png_read_info(png_ptr, info_ptr);
-
- png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
- &interlace_type, NULL, NULL);
-
-/**** Set up the data transformations you want. Note that these are all
- **** optional. Only call them if you want/need them. Many of the
- **** transformations only work on specific types of images, and many
- **** are mutually exclusive.
- ****/
-
- /* tell libpng to strip 16 bit/color files down to 8 bits/color */
- png_set_strip_16(png_ptr);
-
- /* Strip alpha bytes from the input data without combining with the
- * background (not recommended).
- */
- png_set_strip_alpha(png_ptr);
-
- /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
- * byte into separate bytes (useful for paletted and grayscale images).
- */
- png_set_packing(png_ptr);
-
- /* Change the order of packed pixels to least significant bit first
- * (not useful if you are using png_set_packing). */
- png_set_packswap(png_ptr);
-
- /* Expand paletted colors into true RGB triplets */
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- png_set_expand(png_ptr);
-
- /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
- if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
- png_set_expand(png_ptr);
-
- /* Expand paletted or RGB images with transparency to full alpha channels
- * so the data will be available as RGBA quartets.
- */
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
- png_set_expand(png_ptr);
-
- /* Set the background color to draw transparent and alpha images over.
- * It is possible to set the red, green, and blue components directly
- * for paletted images instead of supplying a palette index. Note that
- * even if the PNG file supplies a background, you are not required to
- * use it - you should use the (solid) application background if it has one.
- */
-
- png_color_16 my_background, *image_background;
-
- if (png_get_bKGD(png_ptr, info_ptr, &image_background))
- png_set_background(png_ptr, image_background,
- PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
- else
- png_set_background(png_ptr, &my_background,
- PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
-
- /* Some suggestions as to how to get a screen gamma value */
-
- /* Note that screen gamma is the display_exponent, which includes
- * the CRT_exponent and any correction for viewing conditions */
- if (/* We have a user-defined screen gamma value */)
- {
- screen_gamma = user-defined screen_gamma;
- }
- /* This is one way that applications share the same screen gamma value */
- else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
- {
- screen_gamma = atof(gamma_str);
- }
- /* If we don't have another value */
- else
- {
- screen_gamma = 2.2; /* A good guess for a PC monitors in a dimly
- lit room */
- screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
- }
-
- /* Tell libpng to handle the gamma conversion for you. The second call
- * is a good guess for PC generated images, but it should be configurable
- * by the user at run time by the user. It is strongly suggested that
- * your application support gamma correction.
- */
-
- int intent;
-
- if (png_get_sRGB(png_ptr, info_ptr, &intent))
- png_set_sRGB(png_ptr, intent, 0);
- else
- {
- double image_gamma;
- if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
- png_set_gamma(png_ptr, screen_gamma, image_gamma);
- else
- png_set_gamma(png_ptr, screen_gamma, 0.45455);
- }
-
- /* Dither RGB files down to 8 bit palette or reduce palettes
- * to the number of colors available on your screen.
- */
- if (color_type & PNG_COLOR_MASK_COLOR)
- {
- png_uint_32 num_palette;
- png_colorp palette;
-
- /* This reduces the image to the application supplied palette */
- if (/* we have our own palette */)
- {
- /* An array of colors to which the image should be dithered */
- png_color std_color_cube[MAX_SCREEN_COLORS];
-
- png_set_dither(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
- MAX_SCREEN_COLORS, NULL, 0);
- }
- /* This reduces the image to the palette supplied in the file */
- else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
- {
- png_color16p histogram;
-
- png_get_hIST(png_ptr, info_ptr, &histogram);
-
- png_set_dither(png_ptr, palette, num_palette,
- max_screen_colors, histogram, 0);
- }
- }
-
- /* invert monocrome files to have 0 as white and 1 as black */
- png_set_invert_mono(png_ptr);
-
- /* If you want to shift the pixel values from the range [0,255] or
- * [0,65535] to the original [0,7] or [0,31], or whatever range the
- * colors were originally in:
- */
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
- {
- png_color8p sig_bit;
-
- png_get_sBIT(png_ptr, info_ptr, &sig_bit);
- png_set_shift(png_ptr, sig_bit);
- }
-
- /* flip the RGB pixels to BGR (or RGBA to BGRA) */
- png_set_bgr(png_ptr);
-
- /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
- png_set_swap_alpha(png_ptr);
-
- /* swap bytes of 16 bit files to least significant byte first */
- png_set_swap(png_ptr);
-
- /* Add filler (or alpha) byte (before/after each RGB triplet) */
- png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
-
- /* Turn on interlace handling. REQUIRED if you are not using
- * png_read_image(). To see how to handle interlacing passes,
- * see the png_read_row() method below:
- */
- number_passes = png_set_interlace_handling(png_ptr);
-
- /* Optional call to gamma correct and add the background to the palette
- * and update info structure. REQUIRED if you are expecting libpng to
- * update the palette for you (ie you selected such a transform above).
- */
- png_read_update_info(png_ptr, info_ptr);
-
- /* Allocate the memory to hold the image using the fields of info_ptr. */
-
- /* The easiest way to read the image: */
- png_bytep row_pointers[height];
-
- for (row = 0; row < height; row++)
- {
- row_pointers[row] = malloc(png_get_rowbytes(png_ptr, info_ptr));
- }
-
- /* Now it's time to read the image. One of these methods is REQUIRED */
-#ifdef entire /* Read the entire image in one go */
- png_read_image(png_ptr, row_pointers);
-
-#else no_entire /* Read the image one or more scanlines at a time */
- /* The other way to read images - deal with interlacing: */
-
- for (pass = 0; pass < number_passes; pass++)
- {
-#ifdef single /* Read the image a single row at a time */
- for (y = 0; y < height; y++)
- {
- png_read_rows(png_ptr, &row_pointers[y], NULL, 1);
- }
-
-#else no_single /* Read the image several rows at a time */
- for (y = 0; y < height; y += number_of_rows)
- {
-#ifdef sparkle /* Read the image using the "sparkle" effect. */
- png_read_rows(png_ptr, &row_pointers[y], NULL, number_of_rows);
-
- png_read_rows(png_ptr, NULL, row_pointers[y], number_of_rows);
-#else no_sparkle /* Read the image using the "rectangle" effect */
- png_read_rows(png_ptr, NULL, &row_pointers[y], number_of_rows);
-#endif no_sparkle /* use only one of these two methods */
- }
-
- /* if you want to display the image after every pass, do
- so here */
-#endif no_single /* use only one of these two methods */
- }
-#endif no_entire /* use only one of these two methods */
-
- /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
- png_read_end(png_ptr, info_ptr);
-
- /* clean up after the read, and free any memory allocated - REQUIRED */
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
-
- /* close the file */
- fclose(fp);
-
- /* that's it */
- return;
-}
-
-/* progressively read a file */
-
-int
-initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
-{
- /* Create and initialize the png_struct with the desired error handler
- * functions. If you want to use the default stderr and longjump method,
- * you can supply NULL for the last three parameters. We also check that
- * the library version is compatible in case we are using dynamically
- * linked libraries.
- */
- *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
-
- if (*png_ptr == NULL)
- {
- *info_ptr = NULL;
- return ERROR;
- }
-
- *info_ptr = png_create_info_struct(png_ptr);
-
- if (*info_ptr == NULL)
- {
- png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
- return ERROR;
- }
-
- if (setjmp((*png_ptr)->jmpbuf))
- {
- png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
- return ERROR;
- }
-
- /* This one's new. You will need to provide all three
- * function callbacks, even if you aren't using them all.
- * If you aren't using all functions, you can specify NULL
- * parameters. Even when all three functions are NULL,
- * you need to call png_set_progressive_read_fn().
- * These functions shouldn't be dependent on global or
- * static variables if you are decoding several images
- * simultaneously. You should store stream specific data
- * in a separate struct, given as the second parameter,
- * and retrieve the pointer from inside the callbacks using
- * the function png_get_progressive_ptr(png_ptr).
- */
- png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
- info_callback, row_callback, end_callback);
-
- return OK;
-}
-
-int
-process_data(png_structp *png_ptr, png_infop *info_ptr,
- png_bytep buffer, png_uint_32 length)
-{
- if (setjmp((*png_ptr)->jmpbuf))
- {
- /* Free the png_ptr and info_ptr memory on error */
- png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
- return ERROR;
- }
-
- /* This one's new also. Simply give it chunks of data as
- * they arrive from the data stream (in order, of course).
- * On Segmented machines, don't give it any more than 64K.
- * The library seems to run fine with sizes of 4K, although
- * you can give it much less if necessary (I assume you can
- * give it chunks of 1 byte, but I haven't tried with less
- * than 256 bytes yet). When this function returns, you may
- * want to display any rows that were generated in the row
- * callback, if you aren't already displaying them there.
- */
- png_process_data(*png_ptr, *info_ptr, buffer, length);
- return OK;
-}
-
-info_callback(png_structp png_ptr, png_infop info)
-{
-/* do any setup here, including setting any of the transformations
- * mentioned in the Reading PNG files section. For now, you _must_
- * call either png_start_read_image() or png_read_update_info()
- * after all the transformations are set (even if you don't set
- * any). You may start getting rows before png_process_data()
- * returns, so this is your last chance to prepare for that.
- */
-}
-
-row_callback(png_structp png_ptr, png_bytep new_row,
- png_uint_32 row_num, int pass)
-{
-/* this function is called for every row in the image. If the
- * image is interlacing, and you turned on the interlace handler,
- * this function will be called for every row in every pass.
- * Some of these rows will not be changed from the previous pass.
- * When the row is not changed, the new_row variable will be NULL.
- * The rows and passes are called in order, so you don't really
- * need the row_num and pass, but I'm supplying them because it
- * may make your life easier.
- *
- * For the non-NULL rows of interlaced images, you must call
- * png_progressive_combine_row() passing in the row and the
- * old row. You can call this function for NULL rows (it will
- * just return) and for non-interlaced images (it just does the
- * memcpy for you) if it will make the code easier. Thus, you
- * can just do this for all cases:
- */
-
- png_progressive_combine_row(png_ptr, old_row, new_row);
-
-/* where old_row is what was displayed for previous rows. Note
- * that the first pass (pass == 0 really) will completely cover
- * the old row, so the rows do not have to be initialized. After
- * the first pass (and only for interlaced images), you will have
- * to pass the current row, and the function will combine the
- * old row and the new row.
- */
-}
-
-end_callback(png_structp png_ptr, png_infop info)
-{
-/* this function is called when the whole image has been read,
- * including any chunks after the image (up to and including
- * the IEND). You will usually have the same info chunk as you
- * had in the header, although some data may have been added
- * to the comments and time fields.
- *
- * Most people won't do much here, perhaps setting a flag that
- * marks the image as finished.
- */
-}
-
-/* write a png file */
-void write_png(char *file_name /* , ... other image information ... */)
-{
- FILE *fp;
- png_structp png_ptr;
- png_infop info_ptr;
-
- /* open the file */
- fp = fopen(file_name, "wb");
- if (fp == NULL)
- return;
-
- /* Create and initialize the png_struct with the desired error handler
- * functions. If you want to use the default stderr and longjump method,
- * you can supply NULL for the last three parameters. We also check that
- * the library version is compatible with the one used at compile time,
- * in case we are using dynamically linked libraries. REQUIRED.
- */
- png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
-
- if (png_ptr == NULL)
- {
- fclose(fp);
- return;
- }
-
- /* Allocate/initialize the image information data. REQUIRED */
- info_ptr = png_create_info_struct(png_ptr);
- if (info_ptr == NULL)
- {
- fclose(fp);
- png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
- return;
- }
-
- /* Set error handling. REQUIRED if you aren't supplying your own
- * error hadnling functions in the png_create_write_struct() call.
- */
- if (setjmp(png_ptr->jmpbuf))
- {
- /* If we get here, we had a problem reading the file */
- fclose(fp);
- png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
- return;
- }
-
- /* One of the following I/O initialization functions is REQUIRED */
-#ifdef streams /* I/O initialization method 1 */
- /* set up the output control if you are using standard C streams */
- png_init_io(png_ptr, fp);
-#else no_streams /* I/O initialization method 2 */
- /* If you are using replacement read functions, instead of calling
- * png_init_io() here you would call */
- png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
- user_IO_flush_function);
- /* where user_io_ptr is a structure you want available to the callbacks */
-#endif no_streams /* only use one initialization method */
-
- /* Set the image information here. Width and height are up to 2^31,
- * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
- * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
- * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
- * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
- * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
- * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
- */
- png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???,
- PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- /* set the palette if there is one. REQUIRED for indexed-color images */
- palette = (png_colorp)png_malloc(png_ptr, 256 * sizeof (png_color));
- /* ... set palette colors ... */
- png_set_PLTE(png_ptr, info_ptr, palette, 256);
-
- /* optional significant bit chunk */
- /* if we are dealing with a grayscale image then */
- sig_bit.gray = true_bit_depth;
- /* otherwise, if we are dealing with a color image then */
- sig_bit.red = true_red_bit_depth;
- sig_bit.green = true_green_bit_depth;
- sig_bit.blue = true_blue_bit_depth;
- /* if the image has an alpha channel then */
- sig_bit.alpha = true_alpha_bit_depth;
- png_set_sBIT(png_ptr, info_ptr, sig_bit);
-
-
- /* Optional gamma chunk is strongly suggested if you have any guess
- * as to the correct gamma of the image.
- */
- png_set_gAMA(png_ptr, info_ptr, gamma);
-
- /* Optionally write comments into the image */
- text_ptr[0].key = "Title";
- text_ptr[0].text = "Mona Lisa";
- text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[1].key = "Author";
- text_ptr[1].text = "Leonardo DaVinci";
- text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[2].key = "Description";
- text_ptr[2].text = "<long text>";
- text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
- png_set_text(png_ptr, info_ptr, text_ptr, 3);
-
- /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
- /* note that if sRGB is present the cHRM chunk must be ignored
- * on read and must be written in accordance with the sRGB profile */
-
- /* Write the file header information. REQUIRED */
- png_write_info(png_ptr, info_ptr);
-
- /* Once we write out the header, the compression type on the text
- * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
- * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
- * at the end.
- */
-
- /* set up the transformations you want. Note that these are
- * all optional. Only call them if you want them.
- */
-
- /* invert monocrome pixels */
- png_set_invert_mono(png_ptr);
-
- /* Shift the pixels up to a legal bit depth and fill in
- * as appropriate to correctly scale the image.
- */
- png_set_shift(png_ptr, &sig_bit);
-
- /* pack pixels into bytes */
- png_set_packing(png_ptr);
-
- /* swap location of alpha bytes from ARGB to RGBA */
- png_set_swap_alpha(png_ptr);
-
- /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
- * RGB (4 channels -> 3 channels). The second parameter is not used.
- */
- png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
-
- /* flip BGR pixels to RGB */
- png_set_bgr(png_ptr);
-
- /* swap bytes of 16-bit files to most significant byte first */
- png_set_swap(png_ptr);
-
- /* swap bits of 1, 2, 4 bit packed pixel formats */
- png_set_packswap(png_ptr);
-
- /* turn on interlace handling if you are not using png_write_image() */
- if (interlacing)
- number_passes = png_set_interlace_handling(png_ptr);
- else
- number_passes = 1;
-
- /* The easiest way to write the image (you may have a different memory
- * layout, however, so choose what fits your needs best). You need to
- * use the first method if you aren't handling interlacing yourself.
- */
- png_uint_32 k, height, width;
- png_byte image[height][width];
- png_bytep row_pointers[height];
- for (k = 0; k < height; k++)
- row_pointers[k] = image + k*width;
-
- /* One of the following output methods is REQUIRED */
-#ifdef entire /* write out the entire image data in one call */
- png_write_image(png_ptr, row_pointers);
-
- /* the other way to write the image - deal with interlacing */
-
-#else no_entire /* write out the image data by one or more scanlines */
- /* The number of passes is either 1 for non-interlaced images,
- * or 7 for interlaced images.
- */
- for (pass = 0; pass < number_passes; pass++)
- {
- /* Write a few rows at a time. */
- png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows);
-
- /* If you are only writing one row at a time, this works */
- for (y = 0; y < height; y++)
- {
- png_write_rows(png_ptr, &row_pointers[y], 1);
- }
- }
-#endif no_entire /* use only one output method */
-
- /* You can write optional chunks like tEXt, zTXt, and tIME at the end
- * as well.
- */
-
- /* It is REQUIRED to call this to finish writing the rest of the file */
- png_write_end(png_ptr, info_ptr);
-
- /* if you malloced the palette, free it here */
- free(info_ptr->palette);
-
- /* if you allocated any text comments, free them here */
-
- /* clean up after the write, and free any memory allocated */
- png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
-
- /* close the file */
- fclose(fp);
-
- /* that's it */
- return;
-}
-
-#endif /* if 0 */