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#ifndef PNGTILE_PNG_H

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#define PNGTILE_PNG_H

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/**

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 * @file

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 * PNG-specific handling

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 */

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#include <png.h>

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#include <stdint.h>

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/**

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 * Handle sparse data at this granularity (pixels)

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 */

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#define PT_IMG_BLOCK_SIZE 64

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/**

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 * PNG img state

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 */

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struct pt_png_img {

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    /** libpng state */

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    png_struct *png;

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    png_info *info;

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    /** Possible opened I/O file */

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    FILE *fh;

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};

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/**

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 * Cache header layout for PNG-format images

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 */

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struct pt_png_header {

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    /** Pixel dimensions of image */

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    uint32_t width, height;

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    /** Pixel format */

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    uint8_t bit_depth, color_type;

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    /** Number of png_color entries that follow */

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    uint16_t num_palette;

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    /** Number of bytes per row */

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    uint32_t row_bytes;

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    /** Number of bytes per pixel */

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    uint8_t col_bytes;

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    /** Palette entries, up to 256 entries used */

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    png_color palette[PNG_MAX_PALETTE_LENGTH];

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};

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#include "image.h"

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#include "tile.h"

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/**

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 * Check if the given path looks like a .png file.

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 *

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 * Returns 0 if ok, 1 if non-png file, -1 on error

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 */

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int pt_png_check (const char *path);

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/**

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 * Open the given .png image, and read info

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 */

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int pt_png_open (struct pt_image *image, struct pt_png_img *img);

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/**

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 * Fill in the PNG header and return the size of the pixel data

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 */

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int pt_png_read_header (struct pt_png_img *img, struct pt_png_header *header, size_t *data_size);

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/**

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 * Decode the PNG data into the given data segment, using the header as decoded by pt_png_read_header

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 */

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int pt_png_decode (struct pt_png_img *img, const struct pt_png_header *header, const struct pt_image_params *params, uint8_t *out);

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/**

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 * Fill in img_* fields of pt_image_info from header

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 */

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int pt_png_info (struct pt_png_header *header, struct pt_image_info *info);

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/**

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 * Render out a tile

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 */

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int pt_png_tile (const struct pt_png_header *header, const uint8_t *data, struct pt_tile *tile);

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/**

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 * Release pt_png_ctx resources as allocated by pt_png_open

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 */

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void pt_png_release_read (struct pt_png_img *img);

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/**

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 * Release pt_png_ctx resources as allocated by pt_png_...

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 */

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void pt_png_release_write (struct pt_png_img *img);

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#endif