nuclear@2: /*
nuclear@2: libimago - a multi-format image file input/output library.
nuclear@2: Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@2: 
nuclear@2: This program is free software: you can redistribute it and/or modify
nuclear@2: it under the terms of the GNU Lesser General Public License as published
nuclear@2: by the Free Software Foundation, either version 3 of the License, or
nuclear@2: (at your option) any later version.
nuclear@2: 
nuclear@2: This program is distributed in the hope that it will be useful,
nuclear@2: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@2: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@2: GNU Lesser General Public License for more details.
nuclear@2: 
nuclear@2: You should have received a copy of the GNU Lesser General Public License
nuclear@2: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@2: */
nuclear@2: 
nuclear@2: #ifndef IMAGO2_H_
nuclear@2: #define IMAGO2_H_
nuclear@2: 
nuclear@2: #include <stdio.h>
nuclear@2: 
nuclear@2: #ifdef __cplusplus
nuclear@2: #define IMG_OPTARG(arg, val)	arg = val
nuclear@2: #else
nuclear@2: #define IMG_OPTARG(arg, val)	arg
nuclear@2: #endif
nuclear@2: 
nuclear@2: /* XXX if you change this make sure to also change pack/unpack arrays in conv.c */
nuclear@2: enum img_fmt {
nuclear@2: 	IMG_FMT_GREY8,
nuclear@2: 	IMG_FMT_RGB24,
nuclear@2: 	IMG_FMT_RGBA32,
nuclear@2: 	IMG_FMT_GREYF,
nuclear@2: 	IMG_FMT_RGBF,
nuclear@2: 	IMG_FMT_RGBAF,
nuclear@2: 
nuclear@2: 	NUM_IMG_FMT
nuclear@2: };
nuclear@2: 
nuclear@2: struct img_pixmap {
nuclear@2: 	void *pixels;
nuclear@2: 	int width, height;
nuclear@2: 	enum img_fmt fmt;
nuclear@2: 	int pixelsz;
nuclear@2: 	char *name;
nuclear@2: };
nuclear@2: 
nuclear@2: struct img_io {
nuclear@2: 	void *uptr;	/* user-data */
nuclear@2: 
nuclear@2: 	size_t (*read)(void *buf, size_t bytes, void *uptr);
nuclear@2: 	size_t (*write)(void *buf, size_t bytes, void *uptr);
nuclear@2: 	long (*seek)(long offs, int whence, void *uptr);
nuclear@2: };
nuclear@2: 
nuclear@2: #ifdef __cplusplus
nuclear@2: extern "C" {
nuclear@2: #endif
nuclear@2: 
nuclear@2: /* initialize the img_pixmap structure */
nuclear@2: void img_init(struct img_pixmap *img);
nuclear@2: /* destroys the img_pixmap structure, freeing the pixel buffer (if available)
nuclear@2:  * and any other memory held by the pixmap.
nuclear@2:  */
nuclear@2: void img_destroy(struct img_pixmap *img);
nuclear@2: 
nuclear@2: /* convenience function that allocates an img_pixmap struct and then initializes it.
nuclear@2:  * returns null if the malloc fails.
nuclear@2:  */
nuclear@2: struct img_pixmap *img_create(void);
nuclear@2: /* frees a pixmap previously allocated with img_create (free followed by img_destroy) */
nuclear@2: void img_free(struct img_pixmap *img);
nuclear@2: 
nuclear@2: int img_set_name(struct img_pixmap *img, const char *name);
nuclear@2: 
nuclear@2: /* set the image pixel format */
nuclear@2: int img_set_format(struct img_pixmap *img, enum img_fmt fmt);
nuclear@2: 
nuclear@2: /* copies one pixmap to another.
nuclear@2:  * equivalent to: img_set_pixels(dest, src->width, src->height, src->fmt, src->pixels)
nuclear@2:  */
nuclear@2: int img_copy(struct img_pixmap *dest, struct img_pixmap *src);
nuclear@2: 
nuclear@2: /* allocates a pixel buffer of the specified dimensions and format, and copies the
nuclear@2:  * pixels given through the pix pointer into it.
nuclear@2:  * the pix pointer can be null, in which case there's no copy, just allocation.
nuclear@2:  *
nuclear@2:  * C++: fmt and pix have default parameters IMG_FMT_RGBA32 and null respectively.
nuclear@2:  */
nuclear@2: int img_set_pixels(struct img_pixmap *img, int w, int h, IMG_OPTARG(enum img_fmt fmt, IMG_FMT_RGBA32), IMG_OPTARG(void *pix, 0));
nuclear@2: 
nuclear@2: /* Simplified image loading
nuclear@2:  * Loads the specified file, and returns a pointer to an array of pixels of the
nuclear@2:  * requested pixel format. The width and height of the image are returned through
nuclear@2:  * the xsz and ysz pointers.
nuclear@2:  * If the image cannot be loaded, the function returns null.
nuclear@2:  *
nuclear@2:  * C++: the format argument is optional and defaults to IMG_FMT_RGBA32
nuclear@2:  */
nuclear@2: void *img_load_pixels(const char *fname, int *xsz, int *ysz, IMG_OPTARG(enum img_fmt fmt, IMG_FMT_RGBA32));
nuclear@2: 
nuclear@2: /* Simplified image saving
nuclear@2:  * Reads an array of pixels supplied through the pix pointer, of dimensions xsz
nuclear@2:  * and ysz, and pixel-format fmt, and saves it to a file.
nuclear@2:  * The output filetype is guessed by the filename suffix.
nuclear@2:  *
nuclear@2:  * C++: the format argument is optional and defaults to IMG_FMT_RGBA32
nuclear@2:  */
nuclear@2: int img_save_pixels(const char *fname, void *pix, int xsz, int ysz, IMG_OPTARG(enum img_fmt fmt, IMG_FMT_RGBA32));
nuclear@2: 
nuclear@2: /* Frees the memory allocated by img_load_pixels */
nuclear@2: void img_free_pixels(void *pix);
nuclear@2: 
nuclear@2: /* Loads an image file into the supplied pixmap */
nuclear@2: int img_load(struct img_pixmap *img, const char *fname);
nuclear@2: /* Saves the supplied pixmap to a file. The output filetype is guessed by the filename suffix */
nuclear@2: int img_save(struct img_pixmap *img, const char *fname);
nuclear@2: 
nuclear@2: /* Reads an image from an open FILE* into the supplied pixmap */
nuclear@2: int img_read_file(struct img_pixmap *img, FILE *fp);
nuclear@2: /* Writes the supplied pixmap to an open FILE* */
nuclear@2: int img_write_file(struct img_pixmap *img, FILE *fp);
nuclear@2: 
nuclear@2: /* Reads an image using user-defined file-i/o functions (see img_io_set_*) */
nuclear@2: int img_read(struct img_pixmap *img, struct img_io *io);
nuclear@2: /* Writes an image using user-defined file-i/o functions (see img_io_set_*) */
nuclear@2: int img_write(struct img_pixmap *img, struct img_io *io);
nuclear@2: 
nuclear@2: /* Converts an image to the specified pixel format */
nuclear@2: int img_convert(struct img_pixmap *img, enum img_fmt tofmt);
nuclear@2: 
nuclear@2: /* Converts an image from an integer pixel format to the corresponding floating point one */
nuclear@2: int img_to_float(struct img_pixmap *img);
nuclear@2: /* Converts an image from a floating point pixel format to the corresponding integer one */
nuclear@2: int img_to_integer(struct img_pixmap *img);
nuclear@2: 
nuclear@2: /* Returns non-zero (true) if the supplied image is in a floating point pixel format */
nuclear@2: int img_is_float(struct img_pixmap *img);
nuclear@2: /* Returns non-zero (true) if the supplied image has an alpha channel */
nuclear@2: int img_has_alpha(struct img_pixmap *img);
nuclear@2: 
nuclear@2: 
nuclear@2: /* These functions can be used to fill an img_io struct before it's passed to
nuclear@2:  * one of the user-defined i/o image reading/writing functions (img_read/img_write).
nuclear@2:  *
nuclear@2:  * User-defined i/o functions:
nuclear@2:  *
nuclear@2:  * - size_t read_func(void *buffer, size_t bytes, void *user_ptr)
nuclear@2:  * Must try to fill the buffer with the specified number of bytes, and return
nuclear@2:  * the number of bytes actually read.
nuclear@2:  *
nuclear@2:  * - size_t write_func(void *buffer, size_t bytes, void *user_ptr)
nuclear@2:  * Must write the specified number of bytes from the supplied buffer and return
nuclear@2:  * the number of bytes actually written.
nuclear@2:  *
nuclear@2:  * - long seek_func(long offset, int whence, void *user_ptr)
nuclear@2:  * Must seek offset bytes from: the beginning of the file if whence is SEEK_SET,
nuclear@2:  * the current position if whence is SEEK_CUR, or the end of the file if whence is
nuclear@2:  * SEEK_END, and return the resulting file offset from the beginning of the file.
nuclear@2:  * (i.e. seek_func(0, SEEK_CUR, user_ptr); must be equivalent to an ftell).
nuclear@2:  *
nuclear@2:  * All three functions get the user-data pointer set through img_io_set_user_data
nuclear@2:  * as their last argument.
nuclear@2:  *
nuclear@2:  * Note: obviously you don't need to set a write function if you're only going
nuclear@2:  * to call img_read, or the read and seek function if you're only going to call
nuclear@2:  * img_write.
nuclear@2:  *
nuclear@2:  * Note: if the user-supplied write function is buffered, make sure to flush
nuclear@2:  * (or close the file) after img_write returns.
nuclear@2:  */
nuclear@2: void img_io_set_user_data(struct img_io *io, void *uptr);
nuclear@2: void img_io_set_read_func(struct img_io *io, size_t (*read)(void*, size_t, void*));
nuclear@2: void img_io_set_write_func(struct img_io *io, size_t (*write)(void*, size_t, void*));
nuclear@2: void img_io_set_seek_func(struct img_io *io, long (*seek)(long, int, void*));
nuclear@2: 
nuclear@2: 
nuclear@2: #ifdef __cplusplus
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: 
nuclear@2: #endif	/* IMAGO_H_ */