-#include "iolayer.h"
-#include "imageri.h"
-#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().
- */
-
-/* this is a way to get number of channels from color space
- * Color code to channel number */
-
-static int CC2C[PNG_COLOR_MASK_PALETTE|PNG_COLOR_MASK_COLOR|PNG_COLOR_MASK_ALPHA];
-
-#define PNG_BYTES_TO_CHECK 4
-
-
-
-static void
-wiol_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
- io_glue *ig = (io_glue *)png_ptr->io_ptr;
- int rc = ig->readcb(ig, data, length);
- if (rc != length) png_error(png_ptr, "Read overflow error on an iolayer source.");
-}
-
-static void
-wiol_write_data(png_structp png_ptr, png_bytep data, png_size_t length) {
- int rc;
- io_glue *ig = (io_glue *)png_ptr->io_ptr;
- rc = ig->writecb(ig, data, length);
- if (rc != length) png_error(png_ptr, "Write error on an iolayer source.");
-}
-
-static void
-wiol_flush_data(png_structp png_ptr) {
- /* XXX : This needs to be added to the io layer */
-}
-
-
-/* Check function demo
-
-int
-check_if_png(char *file_name, FILE **fp) {
- char buf[PNG_BYTES_TO_CHECK];
- if ((*fp = fopen(file_name, "rb")) != NULL) return 0;
- if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK) return 0;
- return(!png_sig_cmp((png_bytep)buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
-}
-*/
-
-undef_int
-i_writepng_wiol(i_img *im, io_glue *ig) {
- png_structp png_ptr;
- png_infop info_ptr = NULL;
- int width,height,y;
- volatile int cspace,channels;
- double xres, yres;
- int aspect_only, have_res;
-
- io_glue_commit_types(ig);
- mm_log((1,"i_writepng(im %p ,ig %p)\n", im, ig));
-
- height = im->ysize;
- width = im->xsize;
-
- channels=im->channels;
-
- if (channels > 2) { cspace = PNG_COLOR_TYPE_RGB; channels-=3; }
- else { cspace=PNG_COLOR_TYPE_GRAY; channels--; }
-
- if (channels) cspace|=PNG_COLOR_MASK_ALPHA;
- mm_log((1,"cspace=%d\n",cspace));
-
- channels = im->channels;
-
- /* 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,NULL,NULL,NULL);
-
- if (png_ptr == NULL) return 0;
-
-
- /* Allocate/initialize the image information data. REQUIRED */
- info_ptr = png_create_info_struct(png_ptr);
-
- if (info_ptr == NULL) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return 0;
- }
-
- /* 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)) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return(0);
- }
-
- png_set_write_fn(png_ptr, (png_voidp) (ig), wiol_write_data, wiol_flush_data);
- png_ptr->io_ptr = (png_voidp) ig;
-
- /* 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, 8, cspace,
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- have_res = 1;
- if (i_tags_get_float(&im->tags, "i_xres", 0, &xres)) {
- if (i_tags_get_float(&im->tags, "i_yres", 0, &yres))
- ; /* nothing to do */
- else
- yres = xres;
- }
- else {
- if (i_tags_get_float(&im->tags, "i_yres", 0, &yres))
- xres = yres;
- else
- have_res = 0;
- }
- if (have_res) {
- aspect_only = 0;
- i_tags_get_int(&im->tags, "i_aspect_only", 0, &aspect_only);
- xres /= 0.0254;
- yres /= 0.0254;
- png_set_pHYs(png_ptr, info_ptr, xres + 0.5, yres + 0.5,
- aspect_only ? PNG_RESOLUTION_UNKNOWN : PNG_RESOLUTION_METER);
- }
-
- png_write_info(png_ptr, info_ptr);
-
- if (!im->virtual && im->type == i_direct_type && im->bits == i_8_bits) {
- for (y = 0; y < height; y++)
- png_write_row(png_ptr, (png_bytep) &(im->idata[channels*width*y]));
- }
- else {
- unsigned char *data = mymalloc(im->xsize * im->channels);
- for (y = 0; y < height; y++) {
- i_gsamp(im, 0, im->xsize, y, data, NULL, im->channels);
- png_write_row(png_ptr, (png_bytep)data);
- }
- myfree(data);
- }
-
- png_write_end(png_ptr, info_ptr);
-
- png_destroy_write_struct(&png_ptr, &info_ptr);
-
- ig->closecb(ig);
-
- return(1);
-}
-
-
-
-static void get_png_tags(i_img *im, png_structp png_ptr, png_infop info_ptr);
-
-i_img*
-i_readpng_wiol(io_glue *ig, int length) {
- i_img *im = NULL;
- png_structp png_ptr;
- png_infop info_ptr;
- png_uint_32 width, height;
- int bit_depth, color_type, interlace_type;
- int number_passes,y;
- int channels,pass;
- unsigned int sig_read;
-
- sig_read = 0;
-
- io_glue_commit_types(ig);
- mm_log((1,"i_readpng_wiol(ig %p, length %d)\n", ig, length));
-
- png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
- png_set_read_fn(png_ptr, (png_voidp) (ig), wiol_read_data);
-
- info_ptr = png_create_info_struct(png_ptr);
- if (info_ptr == NULL) {
- png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
- return NULL;
- }
-
- if (setjmp(png_ptr->jmpbuf)) {
- if (im) i_img_destroy(im);
- mm_log((1,"i_readpng_wiol: error.\n"));
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
- return NULL;
- }
-
- png_ptr->io_ptr = (png_voidp) ig;
- png_set_sig_bytes(png_ptr, sig_read);
- png_read_info(png_ptr, info_ptr);
- png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, NULL, NULL);
-
- mm_log((1,
- "png_get_IHDR results: width %d, height %d, bit_depth %d, color_type %d, interlace_type %d\n",
- width,height,bit_depth,color_type,interlace_type));
-
- CC2C[PNG_COLOR_TYPE_GRAY]=1;
- CC2C[PNG_COLOR_TYPE_PALETTE]=3;
- CC2C[PNG_COLOR_TYPE_RGB]=3;
- CC2C[PNG_COLOR_TYPE_RGB_ALPHA]=4;
- CC2C[PNG_COLOR_TYPE_GRAY_ALPHA]=2;
- channels = CC2C[color_type];
-
- mm_log((1,"i_readpng_wiol: channels %d\n",channels));
-
- if (!i_int_check_image_file_limits(width, height, channels, sizeof(i_sample_t))) {
- mm_log((1, "i_readpnm: image size exceeds limits\n"));
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
- return NULL;
- }
-
- png_set_strip_16(png_ptr);
- png_set_packing(png_ptr);
- if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_expand(png_ptr);
- if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) png_set_expand(png_ptr);
-
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
- channels++;
- mm_log((1, "image has transparency, adding alpha: channels = %d\n", channels));
- png_set_expand(png_ptr);
- }
-
- number_passes = png_set_interlace_handling(png_ptr);
- mm_log((1,"number of passes=%d\n",number_passes));
- png_read_update_info(png_ptr, info_ptr);
-
- im = i_img_empty_ch(NULL,width,height,channels);
- if (!im) {
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
- return NULL;
- }
-
- for (pass = 0; pass < number_passes; pass++)
- for (y = 0; y < height; y++) { png_read_row(png_ptr,(png_bytep) &(im->idata[channels*width*y]), NULL); }
-
- png_read_end(png_ptr, info_ptr);
-
- get_png_tags(im, png_ptr, info_ptr);
-
- png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
-
- mm_log((1,"(0x%08X) <- i_readpng_scalar\n", im));
-
- return im;
-}
-
-static void get_png_tags(i_img *im, png_structp png_ptr, png_infop info_ptr) {
- png_uint_32 xres, yres;
- int unit_type;
-
- i_tags_add(&im->tags, "i_format", 0, "png", -1, 0);
- if (png_get_pHYs(png_ptr, info_ptr, &xres, &yres, &unit_type)) {
- mm_log((1,"pHYs (%d, %d) %d\n", xres, yres, unit_type));
- if (unit_type == PNG_RESOLUTION_METER) {
- i_tags_set_float2(&im->tags, "i_xres", 0, xres * 0.0254, 5);
- i_tags_set_float2(&im->tags, "i_yres", 0, yres * 0.0254, 5);
- }
- else {
- i_tags_addn(&im->tags, "i_xres", 0, xres);
- i_tags_addn(&im->tags, "i_yres", 0, yres);
- i_tags_addn(&im->tags, "i_aspect_only", 0, 1);
- }
- }
-}
projects / imager.git / commitdiff
