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#include "image.h"
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static int pt_image_new (struct pt_image **img_ptr, struct pt_ctx *ctx, const char *png_path)
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{
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struct pt_image *img;
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// alloc
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if ((img = calloc(1, sizeof(*img))) == NULL)
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return -1;
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if ((img->png_path = strdup(png_path)) == NULL)
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goto error;
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// init
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img->ctx = ctx;
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// ok
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*img_ptr = img;
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return 0;
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error:
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pt_image_destroy(img);
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return -1;
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}
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/**
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* Open the image's FILE
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*/
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static int pt_image_open_file (struct pt_image *img, FILE **file_ptr)
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{
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FILE *fp;
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// open
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if (fopen(img->png_path, "rb") < 0)
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return -1;
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// ok
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*file_ptr = fp;
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return 0;
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}
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/**
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* Open the PNG image, setting up the I/O and returning the png_structp and png_infop
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*/
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static int pt_image_open_png (struct pt_image *img, png_structp *png_ptr, png_infop *info_ptr)
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{
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FILE *fp = NULL;
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png_structp png = NULL;
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png_infop info = NULL;
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// open I/O
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if (pt_image_open_file(img, &fp))
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goto error;
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// create the struct
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if ((png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL)) == NULL)
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goto error;
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// create the info
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if ((info = png_create_info_struct(png)) == NULL)
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goto error;
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// setup error trap for the I/O
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if (setjmp(png_jmpbuf(png)))
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goto error;
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// setup I/O to FILE
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png_init_io(png, fp);
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// ok
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*png_ptr = png;
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*info_ptr = info;
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return 0;
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error:
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// cleanup file
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if (fp) fclose(fp);
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// cleanup PNG state
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png_destroy_read_struct(&png, &info, NULL);
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return -1;
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}
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/**
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* Open the PNG image, and write out to the cache
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*/
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static int pt_image_update_cache (struct pt_image *img)
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{
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png_structp png;
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png_infop info;
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// open .png
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if (pt_image_open_png(img, &png, &info))
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return -1;
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// setup error trap
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if (setjmp(png_jmpbuf(png)))
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goto error;
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// read meta-info
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png_read_info(png, info);
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// pass to cache object
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if (pt_cache_update_png(img->cache, png, info))
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goto error;
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// finish off, ignore trailing data
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png_read_end(png, NULL);
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// clean up
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png_destroy_read_struct(&png, &info);
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return 0;
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error:
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// clean up
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png_destroy_read_struct(&png, &info);
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return -1;
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}
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int pt_image_open (struct pt_image **img_ptr, struct pt_ctx *ctx, const char *png_path, int cache_mode)
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{
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struct pt_image *img;
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// XXX: verify that the png_path exists and looks like a PNG file
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// alloc
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if (pt_image_new(&img, ctx, png_path))
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return -1;
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// open the cache object for this image
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if (pt_cache_open(&img->cache, img, mode))
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goto error;
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// update if not fresh
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if (!pt_cache_fresh(img->cache))
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pt_image_update_cache(img);
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// ok, ready for access
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*img_ptr = img;
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return 0;
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error:
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pt_image_destroy(img);
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}
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