images/images.h

   1 #ifndef _IMAGES_IMAGES_H
   2 #define _IMAGES_IMAGES_H
   3
   4 #include "lib/mempool.h"
   5
   6 /* image.c */
   7
   8 /* error handling */
   9
  10 enum image_error {
  11   IMAGE_ERR_OK = 0,
  12   IMAGE_ERR_UNSPECIFIED,
  13   IMAGE_ERR_NOT_IMPLEMENTED,
  14   IMAGE_ERR_INVALID_DIMENSIONS,
  15   IMAGE_ERR_INVALID_FILE_FORMAT,
  16   IMAGE_ERR_INVALID_PIXEL_FORMAT,
  17   IMAGE_ERR_READ_FAILED,
  18   IMAGE_ERR_WRITE_FAILED,
  19   IMAGE_ERR_MAX
  20 };
  21
  22 struct image_thread {
  23   byte *err_msg;
  24   enum image_error err_code;
  25   struct mempool *pool;
  26 };
  27
  28 void image_thread_init(struct image_thread *thread);
  29 void image_thread_cleanup(struct image_thread *thread);
  30
  31 static inline void
  32 image_thread_flush(struct image_thread *thread)
  33 {
  34   thread->err_code = 0;
  35   thread->err_msg = NULL;
  36   mp_flush(thread->pool);
  37 }
  38
  39 static inline void
  40 image_thread_err(struct image_thread *thread, uns code, char *msg)
  41 {
  42   thread->err_code = code;
  43   thread->err_msg = (byte *)msg;
  44 }
  45
  46 static inline void
  47 image_thread_err_dup(struct image_thread *thread, uns code, char *msg)
  48 {
  49   thread->err_code = code;
  50   thread->err_msg = mp_strdup(thread->pool, msg);
  51 }
  52
  53 void image_thread_err_format(struct image_thread *thread, uns code, char *msg, ...);
  54
  55 /* basic image manupulation */
  56
  57 #define IMAGE_MAX_SIZE          0xffffU /* maximum number of cols/rows, must be <(1<<16) */
  58 #define IMAGE_SSE_ALIGN_SIZE    (MAX(16, sizeof(uns)))
  59
  60 enum color_space {
  61   COLOR_SPACE_UNKNOWN,
  62   COLOR_SPACE_GRAYSCALE,
  63   COLOR_SPACE_RGB,
  64   COLOR_SPACE_MAX
  65 };
  66
  67 enum image_flag {
  68   IMAGE_COLOR_SPACE = 0x7,      /* mask for enum color_space */
  69   IMAGE_ALPHA = 0x8,            /* alpha channel */
  70   IMAGE_PIXELS_ALIGNED = 0x10,  /* align pixel size to the nearest power of two  */
  71   IMAGE_SSE_ALIGNED = 0x20,     /* align scanlines to multiples of 16 bytes (both start and size) */
  72   IMAGE_NEED_DESTROY = 0x40,    /* image is allocated with xmalloc */
  73   IMAGE_GAPS_PROTECTED = 0x80,  /* cannot access gaps between rows */
  74   IMAGE_CHANNELS_FORMAT = IMAGE_COLOR_SPACE | IMAGE_ALPHA,
  75   IMAGE_PIXEL_FORMAT = IMAGE_CHANNELS_FORMAT | IMAGE_PIXELS_ALIGNED,
  76   IMAGE_ALIGNED = IMAGE_PIXELS_ALIGNED | IMAGE_SSE_ALIGNED,
  77   IMAGE_NEW_FLAGS = IMAGE_PIXEL_FORMAT | IMAGE_SSE_ALIGNED,
  78   IMAGE_INTERNAL_FLAGS = IMAGE_NEED_DESTROY | IMAGE_GAPS_PROTECTED,
  79 };
  80
  81 struct image {
  82   byte *pixels;                 /* left top pixel, there are at least sizeof(uns)
  83                                    unsed bytes after the buffer (possible optimizations) */
  84   u32 cols;                     /* number of columns */
  85   u32 rows;                     /* number of rows */
  86   u32 pixel_size;               /* size of pixel (1, 2, 3 or 4) */
  87   u32 row_size;                 /* scanline size in bytes */
  88   u32 image_size;               /* rows * row_size */
  89   u32 flags;                    /* enum image_flag */
  90 };
  91
  92 struct image *image_new(struct image_thread *it, uns cols, uns rows, uns flags, struct mempool *pool);
  93 struct image *image_clone(struct image_thread *it, struct image *src, uns flags, struct mempool *pool);
  94 void image_destroy(struct image *img);
  95 void image_clear(struct image_thread *it, struct image *img);
  96 struct image *image_init_matrix(struct image_thread *it, struct image *img, byte *pixels, uns cols, uns rows, uns row_size, uns flags);
  97 struct image *image_init_subimage(struct image_thread *it, struct image *img, struct image *src, uns left, uns top, uns cols, uns rows);
  98
  99 static inline int
 100 image_dimensions_valid(uns cols, uns rows)
 101 {
 102   return cols && rows && cols <= IMAGE_MAX_SIZE && rows <= IMAGE_MAX_SIZE;
 103 }
 104
 105 byte *color_space_to_name(enum color_space cs);
 106 byte *image_channels_format_to_name(uns format);
 107 uns image_name_to_channels_format(byte *name);
 108
 109 struct color {
 110   byte c[3];
 111   byte color_space;
 112 } PACKED;
 113
 114 /* scale.c */
 115
 116 int image_scale(struct image_thread *thread, struct image *dest, struct image *src);
 117 void image_dimensions_fit_to_box(u32 *cols, u32 *rows, u32 max_cols, u32 max_rows, uns upsample);
 118
 119 /* alpha.c */
 120
 121 int image_apply_background(struct image_thread *thread, struct image *dest, struct image *src, struct color *background);
 122
 123 /* image-io.c */
 124
 125 enum image_format {
 126   IMAGE_FORMAT_UNDEFINED,
 127   IMAGE_FORMAT_JPEG,
 128   IMAGE_FORMAT_PNG,
 129   IMAGE_FORMAT_GIF,
 130   IMAGE_FORMAT_MAX
 131 };
 132
 133 struct image_io {
 134                                         /*  R - read_header input */
 135                                         /*   H - read_header output */
 136                                         /*    I - read_data input */
 137                                         /*     O - read_data output */
 138                                         /*      W - write input */
 139
 140   struct image *image;                  /* [   OW] - image data */
 141   enum image_format format;             /* [R   W] - file format (IMAGE_FORMAT_x) */
 142   struct fastbuf *fastbuf;              /* [R   W] - source/destination stream */
 143   struct mempool *pool;                 /* [  I  ] - parameter to image_new */
 144   u32 cols;                             /* [ HI  ] - number of columns, parameter to image_new */
 145   u32 rows;                             /* [ HI  ] - number of rows, parameter to image_new */
 146   u32 flags;                            /* [ HI  ] - see enum image_io_flags */
 147   u32 jpeg_quality;                     /* [    W] - JPEG compression quality (1..100) */
 148   u32 number_of_colors;                 /* [ H   ] - number of image colors */
 149   struct color background_color;        /* [ HI  ] - background color, zero if undefined */
 150
 151   /* internals */
 152   struct image_thread *thread;
 153   struct mempool *internal_pool;
 154   void *read_data;
 155   void (*read_cancel)(struct image_io *io);
 156 };
 157
 158 enum image_io_flags {
 159   IMAGE_IO_IMAGE_FLAGS = 0xffff,        /* [ HI  ] - mask of parameters to image new, read_header fills IMAGE_CHANNELS_FORMAT */
 160   IMAGE_IO_NEED_DESTROY = 0x10000,      /* [   O ] - enables automatic call of image_destroy */
 161   IMAGE_IO_HAS_PALETTE = 0x20000,       /* [ H   ] - true for image with indexed colors */
 162   IMAGE_IO_USE_BACKGROUND = 0x40000,    /* [  I  ] - merge transparent pixels with background_color */
 163 };
 164
 165 int image_io_init(struct image_thread *it, struct image_io *io);
 166 void image_io_cleanup(struct image_io *io);
 167 void image_io_reset(struct image_io *io);
 168
 169 int image_io_read_header(struct image_io *io);
 170 struct image *image_io_read_data(struct image_io *io, int ref);
 171 struct image *image_io_read(struct image_io *io, int ref);
 172
 173 int image_io_write(struct image_io *io);
 174
 175 byte *image_format_to_extension(enum image_format format);
 176 enum image_format image_extension_to_format(byte *extension);
 177 enum image_format image_file_name_to_format(byte *file_name);
 178
 179 #endif