fix potential memory leaks for failing mixing scaling on very large images

[imager.git] / imdatatypes.h

diff --git a/imdatatypes.h b/imdatatypes.h
index 8e9cdd36e5d517611550b1aaafdaf085094c206a..8a194908b9c8a0520a475a3aeaf8e6d9d897bc9d 100644 (file)
--- a/imdatatypes.h
+++ b/imdatatypes.h
@@ -1,11 +1,34 @@
 #ifndef _DATATYPES_H_
 #define _DATATYPES_H_
 
 #ifndef _DATATYPES_H_
 #define _DATATYPES_H_
 

+#include <stddef.h>

 #include "imconfig.h"
 #include "imconfig.h"

-#include "imio.h"

 
 #define MAXCHANNELS 4
 
 
 #define MAXCHANNELS 4
 

+/*
+=item im_context_t
+=category Data Types
+
+Imager's per-thread context.
+
+=cut
+*/
+
+typedef struct im_context_tag *im_context_t;
+
+/*
+=item im_slot_t
+=category Data Types
+
+Represents a slot in the context object.
+
+=cut
+*/
+
+typedef ptrdiff_t im_slot_t;
+typedef void (*im_slot_destroy_t)(void *);
+

 /* used for palette indices in some internal code (which might be 
    exposed at some point
 */
 /* used for palette indices in some internal code (which might be 
    exposed at some point
 */


@@ -22,6 +45,79 @@ typedef struct { i_sample_t c,m,y,k; } cmyk_color;
 
 typedef int undef_int; /* special value to put in typemaps to retun undef on 0 and 1 on 1 */
 
 
 typedef int undef_int; /* special value to put in typemaps to retun undef on 0 and 1 on 1 */
 

+/*
+=item i_img_dim
+=category Data Types
+=synopsis i_img_dim x, y;
+=order 90
+
+A signed integer type that represents an image dimension or ordinate.
+
+May be larger than int on some platforms.
+
+=cut
+*/
+
+typedef ptrdiff_t i_img_dim;
+
+/*
+=item i_img_dim_u
+=category Data Types
+=synopsis i_img_dim_u limit;
+=order 90
+
+An unsigned variant of L</i_img_dim>.
+
+=cut
+*/
+
+typedef size_t i_img_dim_u;
+
+#define i_img_dim_MAX ((i_img_dim)(~(i_img_dim_u)0 >> 1))
+
+/*
+=item i_color
+=category Data Types
+=synopsis i_color black;
+=synopsis black.rgba.r = black.rgba.g = black.rgba.b = black.rgba.a = 0;
+
+Type for 8-bit/sample color.
+
+Samples as per;
+
+  i_color c;
+
+i_color is a union of:
+
+=over
+
+=item *
+
+gray - contains a single element gray_color, eg. C<c.gray.gray_color>
+
+=item *
+
+C<rgb> - contains three elements C<r>, C<g>, C<b>, eg. C<c.rgb.r>
+
+=item *
+
+C<rgba> - contains four elements C<r>, C<g>, C<b>, C<a>, eg. C<c.rgba.a>
+
+=item *
+
+C<cmyk> - contains four elements C<c>, C<m>, C<y>, C<k>,
+eg. C<c.cmyk.y>.  Note that Imager never uses CMYK colors except when
+reading/writing files.
+
+=item *
+
+channels - an array of four channels, eg C<c.channels[2]>.
+
+=back
+
+=cut
+*/
+

 typedef union {
   gray_color gray;
   rgb_color rgb;
 typedef union {
   gray_color gray;
   rgb_color rgb;


@@ -40,6 +136,17 @@ typedef struct { i_fsample_t r, g, b; } i_frgb_color_t;
 typedef struct { i_fsample_t r, g, b, a; } i_frgba_color_t;
 typedef struct { i_fsample_t c, m, y, k; } i_fcmyk_color_t;
 
 typedef struct { i_fsample_t r, g, b, a; } i_frgba_color_t;
 typedef struct { i_fsample_t c, m, y, k; } i_fcmyk_color_t;
 

+/*
+=item i_fcolor
+=category Data Types
+
+This is the double/sample color type.
+
+Its layout exactly corresponds to i_color.
+
+=cut
+*/
+

 typedef union {
   i_fgray_color_t gray;
   i_frgb_color_t rgb;
 typedef union {
   i_fgray_color_t gray;
   i_frgb_color_t rgb;


@@ -76,22 +183,22 @@ typedef struct {
 } i_img_tags;
 
 typedef struct i_img_ i_img;
 } i_img_tags;
 
 typedef struct i_img_ i_img;

-typedef int (*i_f_ppix_t)(i_img *im, int x, int y, const i_color *pix);
-typedef int (*i_f_ppixf_t)(i_img *im, int x, int y, const i_fcolor *pix);
-typedef int (*i_f_plin_t)(i_img *im, int x, int r, int y, const i_color *vals);
-typedef int (*i_f_plinf_t)(i_img *im, int x, int r, int y, const i_fcolor *vals);
-typedef int (*i_f_gpix_t)(i_img *im, int x, int y, i_color *pix);
-typedef int (*i_f_gpixf_t)(i_img *im, int x, int y, i_fcolor *pix);
-typedef int (*i_f_glin_t)(i_img *im, int x, int r, int y, i_color *vals);
-typedef int (*i_f_glinf_t)(i_img *im, int x, int r, int y, i_fcolor *vals);
-
-typedef int (*i_f_gsamp_t)(i_img *im, int x, int r, int y, i_sample_t *samp,
+typedef int (*i_f_ppix_t)(i_img *im, i_img_dim x, i_img_dim y, const i_color *pix);
+typedef int (*i_f_ppixf_t)(i_img *im, i_img_dim x, i_img_dim y, const i_fcolor *pix);
+typedef i_img_dim (*i_f_plin_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, const i_color *vals);
+typedef i_img_dim (*i_f_plinf_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, const i_fcolor *vals);
+typedef int (*i_f_gpix_t)(i_img *im, i_img_dim x, i_img_dim y, i_color *pix);
+typedef int (*i_f_gpixf_t)(i_img *im, i_img_dim x, i_img_dim y, i_fcolor *pix);
+typedef i_img_dim (*i_f_glin_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, i_color *vals);
+typedef i_img_dim (*i_f_glinf_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, i_fcolor *vals);
+
+typedef i_img_dim (*i_f_gsamp_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, i_sample_t *samp,

                            const int *chans, int chan_count);
                            const int *chans, int chan_count);

-typedef int (*i_f_gsampf_t)(i_img *im, int x, int r, int y, i_fsample_t *samp,
+typedef i_img_dim (*i_f_gsampf_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, i_fsample_t *samp,

                             const int *chan, int chan_count);
 
                             const int *chan, int chan_count);
 

-typedef int (*i_f_gpal_t)(i_img *im, int x, int r, int y, i_palidx *vals);
-typedef int (*i_f_ppal_t)(i_img *im, int x, int r, int y, const i_palidx *vals);
+typedef i_img_dim (*i_f_gpal_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, i_palidx *vals);
+typedef i_img_dim (*i_f_ppal_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, const i_palidx *vals);

 typedef int (*i_f_addcolors_t)(i_img *im, const i_color *colors, int count);
 typedef int (*i_f_getcolors_t)(i_img *im, int i, i_color *, int count);
 typedef int (*i_f_colorcount_t)(i_img *im);
 typedef int (*i_f_addcolors_t)(i_img *im, const i_color *colors, int count);
 typedef int (*i_f_getcolors_t)(i_img *im, int i, i_color *, int count);
 typedef int (*i_f_colorcount_t)(i_img *im);


@@ -102,17 +209,22 @@ typedef int (*i_f_setcolors_t)(i_img *im, int index, const i_color *colors,
 
 typedef void (*i_f_destroy_t)(i_img *im);
 
 
 typedef void (*i_f_destroy_t)(i_img *im);
 

-typedef int (*i_f_gsamp_bits_t)(i_img *im, int x, int r, int y, unsigned *samp,
+typedef i_img_dim (*i_f_gsamp_bits_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, unsigned *samp,

                            const int *chans, int chan_count, int bits);
                            const int *chans, int chan_count, int bits);

-typedef int (*i_f_psamp_bits_t)(i_img *im, int x, int r, int y, unsigned const *samp,
+typedef i_img_dim (*i_f_psamp_bits_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, unsigned const *samp,

                                 const int *chans, int chan_count, int bits);
                                 const int *chans, int chan_count, int bits);

-
-typedef int i_img_dim;
+typedef i_img_dim
+(*i_f_psamp_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y, 
+               const i_sample_t *samp, const int *chan, int chan_count);
+typedef i_img_dim
+(*i_f_psampf_t)(i_img *im, i_img_dim x, i_img_dim r, i_img_dim y,
+               const i_fsample_t *samp, const int *chan, int chan_count);

 
 /*
 =item i_img
 =category Data Types
 =synopsis i_img *img;
 
 /*
 =item i_img
 =category Data Types
 =synopsis i_img *img;

+=order 10

 
 This is Imager's image type.
 
 
 This is Imager's image type.
 


@@ -122,57 +234,57 @@ It contains the following members:
 
 =item *
 
 
 =item *
 

-channels - the number of channels in the image
+C<channels> - the number of channels in the image

 
 =item *
 
 
 =item *
 

-xsize, ysize - the width and height of the image in pixels
+C<xsize>, C<ysize> - the width and height of the image in pixels

 
 =item *
 
 
 =item *
 

-bytes - the number of bytes used to store the image data.  Undefined
+C<bytes> - the number of bytes used to store the image data.  Undefined

 where virtual is non-zero.
 
 =item *
 
 where virtual is non-zero.
 
 =item *
 

-ch_mask - a mask of writable channels.  eg. if this is 6 then only
+C<ch_mask> - a mask of writable channels.  eg. if this is 6 then only

 channels 1 and 2 are writable.  There may be bits set for which there
 are no channels in the image.
 
 =item *
 
 channels 1 and 2 are writable.  There may be bits set for which there
 are no channels in the image.
 
 =item *
 

-bits - the number of bits stored per sample.  Should be one of
+C<bits> - the number of bits stored per sample.  Should be one of

 i_8_bits, i_16_bits, i_double_bits.
 
 =item *
 
 i_8_bits, i_16_bits, i_double_bits.
 
 =item *
 

-type - either i_direct_type for direct color images, or i_palette_type
+C<type> - either i_direct_type for direct color images, or i_palette_type

 for paletted images.
 
 =item *
 
 for paletted images.
 
 =item *
 

-virtual - if zero then this image is-self contained.  If non-zero then
-this image could be an interface to some other implementation.
+C<virtual> - if zero then this image is-self contained.  If non-zero
+then this image could be an interface to some other implementation.

 
 =item *
 
 
 =item *
 

-idata - the image data.  This should not be directly accessed.  A new
+C<idata> - the image data.  This should not be directly accessed.  A new

 image implementation can use this to store its image data.
 i_img_destroy() will myfree() this pointer if it's non-null.
 
 =item *
 
 image implementation can use this to store its image data.
 i_img_destroy() will myfree() this pointer if it's non-null.
 
 =item *
 

-tags - a structure storing the image's tags.  This should only be
+C<tags> - a structure storing the image's tags.  This should only be

 accessed via the i_tags_*() functions.
 
 =item *
 
 accessed via the i_tags_*() functions.
 
 =item *
 

-ext_data - a pointer for use internal to an image implementation.
+C<ext_data> - a pointer for use internal to an image implementation.

 This should be freed by the image's destroy handler.
 
 =item *
 
 This should be freed by the image's destroy handler.
 
 =item *
 

-im_data - data internal to Imager.  This is initialized by
+C<im_data> - data internal to Imager.  This is initialized by

 i_img_init().
 
 =item *
 i_img_init().
 
 =item *


@@ -201,6 +313,22 @@ i_f_gsamp_bits - implements i_gsamp_bits() for this image.
 
 i_f_psamp_bits - implements i_psamp_bits() for this image.
 
 
 i_f_psamp_bits - implements i_psamp_bits() for this image.
 

+=item *
+
+i_f_psamp - implements psamp() for this image.
+
+=item *
+
+i_f_psampf - implements psamp() for this image.
+
+=item *
+
+C<im_data> - image specific data internal to Imager.
+
+=item *
+
+C<context> - the Imager API context this image belongs to.
+

 =back
 
 =cut
 =back
 
 =cut


@@ -248,7 +376,14 @@ struct i_img_ {
   i_f_gsamp_bits_t i_f_gsamp_bits;
   i_f_psamp_bits_t i_f_psamp_bits;
 
   i_f_gsamp_bits_t i_f_gsamp_bits;
   i_f_psamp_bits_t i_f_psamp_bits;
 

+  /* as of 0.88 */
+  i_f_psamp_t i_f_psamp;
+  i_f_psampf_t i_f_psampf;
+

   void *im_data;
   void *im_data;

+
+  /* 0.91 */
+  im_context_t context;

 };
 
 /* ext_data for paletted images
 };
 
 /* ext_data for paletted images


@@ -270,27 +405,17 @@ typedef struct {
 
 */
 
 
 */
 

-
-
-
-

 /* bitmap mask */
 
 struct i_bitmap {
 /* bitmap mask */
 
 struct i_bitmap {

-  int xsize,ysize;
+  i_img_dim xsize,ysize;

   char *data;
 };
 
   char *data;
 };
 

-struct i_bitmap* btm_new(int xsize,int ysize);
+struct i_bitmap* btm_new(i_img_dim xsize,i_img_dim ysize);

 void btm_destroy(struct i_bitmap *btm);
 void btm_destroy(struct i_bitmap *btm);

-int btm_test(struct i_bitmap *btm,int x,int y);
-void btm_set(struct i_bitmap *btm,int x,int y);
-
-
-
-
-
-
+int btm_test(struct i_bitmap *btm,i_img_dim x,i_img_dim y);
+void btm_set(struct i_bitmap *btm,i_img_dim x,i_img_dim y);

 
 
 /* Stack/Linked list */
 
 
 /* Stack/Linked list */


@@ -304,21 +429,16 @@ struct llink {
 struct llist {
   struct llink *h,*t;
   int multip;          /* # of copies in a single chain  */
 struct llist {
   struct llink *h,*t;
   int multip;          /* # of copies in a single chain  */

-  int ssize;           /* size of each small element     */
+  size_t ssize;                /* size of each small element     */

   int count;           /* number of elements on the list */
 };
 
 
   int count;           /* number of elements on the list */
 };
 
 

-/* Links */
-
-struct llink *llink_new( struct llink* p,int size );
-int  llist_llink_push( struct llist *lst, struct llink *lnk, void *data );
-

 /* Lists */
 
 /* Lists */
 

-struct llist *llist_new( int multip, int ssize );
+struct llist *llist_new( int multip, size_t ssize );

 void llist_destroy( struct llist *l );
 void llist_destroy( struct llist *l );

-void llist_push( struct llist *l, void *data );
+void llist_push( struct llist *l, const void *data );

 void llist_dump( struct llist *l );
 int llist_pop( struct llist *l,void *data );
 
 void llist_dump( struct llist *l );
 int llist_pop( struct llist *l,void *data );
 


@@ -352,20 +472,83 @@ enum bounding_box_index_t {
   BOUNDING_BOX_COUNT
 };
 
   BOUNDING_BOX_COUNT
 };
 

+/*
+=item i_polygon_t
+=category Data Types
+
+Represents a polygon.  Has the following members:
+
+=over
+
+=item *
+
+C<x>, C<y> - arrays of x and y locations of vertices.
+
+=item *
+
+C<count> - the number of entries in the C<x> and C<y> arrays.
+
+=back
+
+=cut
+*/
+
+typedef struct i_polygon_tag {
+  const double *x;
+  const double *y;
+  size_t count;
+} i_polygon_t;
+
+/*
+=item i_poly_fill_mode_t
+=category Data Types
+
+Control how polygons are filled.  Has the following values:
+
+=over
+
+=item *
+
+C<i_pfm_evenodd> - simple even-odd fills.
+
+=item *
+
+C<i_pfm_nonzero> - non-zero winding rule fills.
+
+=back
+
+=cut
+*/
+
+typedef enum i_poly_fill_mode_tag {
+  i_pfm_evenodd,
+  i_pfm_nonzero
+} i_poly_fill_mode_t;
+

 /* Generic fills */
 struct i_fill_tag;
 
 typedef void (*i_fill_with_color_f)
 /* Generic fills */
 struct i_fill_tag;
 
 typedef void (*i_fill_with_color_f)

-     (struct i_fill_tag *fill, int x, int y, int width, int channels, 
+(struct i_fill_tag *fill, i_img_dim x, i_img_dim y, i_img_dim width, int channels, 

       i_color *data);
 typedef void (*i_fill_with_fcolor_f)
       i_color *data);
 typedef void (*i_fill_with_fcolor_f)

-     (struct i_fill_tag *fill, int x, int y, int width, int channels,
+     (struct i_fill_tag *fill, i_img_dim x, i_img_dim y, i_img_dim width, int channels,

       i_fcolor *data);
 typedef void (*i_fill_destroy_f)(struct i_fill_tag *fill);
       i_fcolor *data);
 typedef void (*i_fill_destroy_f)(struct i_fill_tag *fill);

+
+/* combine functions modify their target and are permitted to modify
+   the source to prevent having to perform extra copying/memory
+   allocations, etc
+   The out array has I<channels> channels.
+
+   The in array has I<channels> channels + an alpha channel if one
+   isn't included in I<channels>.
+*/
+

 typedef void (*i_fill_combine_f)(i_color *out, i_color *in, int channels, 
 typedef void (*i_fill_combine_f)(i_color *out, i_color *in, int channels, 

-                                 int count);
+                                 i_img_dim count);

 typedef void (*i_fill_combinef_f)(i_fcolor *out, i_fcolor *in, int channels,
 typedef void (*i_fill_combinef_f)(i_fcolor *out, i_fcolor *in, int channels,

-                                  int count);
+                                  i_img_dim count);

 
 /* fountain fill types */
 typedef enum {
 
 /* fountain fill types */
 typedef enum {


@@ -411,16 +594,28 @@ typedef enum {
   i_fts_circle
 } i_ft_supersample;
 
   i_fts_circle
 } i_ft_supersample;
 

+/*
+=item i_fill_t
+=category Data Types
+=synopsis i_fill_t *fill;
+
+This is the "abstract" base type for Imager's fill types.
+
+Unless you're implementing a new fill type you'll typically treat this
+as an opaque type.
+
+=cut
+*/

 
 typedef struct i_fill_tag
 {
   /* called for 8-bit/sample image (and maybe lower) */
   /* this may be NULL, if so call fill_with_fcolor */
 
 typedef struct i_fill_tag
 {
   /* called for 8-bit/sample image (and maybe lower) */
   /* this may be NULL, if so call fill_with_fcolor */

-  i_fill_with_color_f fill_with_color;
+  i_fill_with_color_f f_fill_with_color;

 
   /* called for other sample sizes */
   /* this must be non-NULL */
 
   /* called for other sample sizes */
   /* this must be non-NULL */

-  i_fill_with_fcolor_f fill_with_fcolor;
+  i_fill_with_fcolor_f f_fill_with_fcolor;

 
   /* called if non-NULL to release any extra resources */
   i_fill_destroy_f destroy;
 
   /* called if non-NULL to release any extra resources */
   i_fill_destroy_f destroy;


@@ -447,6 +642,18 @@ typedef enum {
   ic_color
 } i_combine_t;
 
   ic_color
 } i_combine_t;
 

+/*
+=item i_mutex_t
+X<i_mutex>
+=category mutex
+=synopsis i_mutex_t mutex;
+
+Opaque type for Imager's mutex API.
+
+=cut
+ */
+typedef struct i_mutex_tag *i_mutex_t;
+

 /*
    describes an axis of a MM font.
    Modelled on FT2's FT_MM_Axis.
 /*
    describes an axis of a MM font.
    Modelled on FT2's FT_MM_Axis.


@@ -479,11 +686,39 @@ typedef struct TT_Fonthandle_ TT_Fonthandle;
 
 #endif
 
 
 #endif
 

-#ifdef HAVE_FT2
+/*
+=item i_transp
+=category Data Types
+
+An enumerated type for controlling how transparency is handled during
+quantization.

 
 

-typedef struct FT2_Fonthandle FT2_Fonthandle;
+This has the following possible values:

 
 

-#endif
+=over
+
+=item *
+
+C<tr_none> - ignore the alpha channel
+
+=item *
+
+C<tr_threshold> - simple transparency thresholding.
+
+=item *
+
+C<tr_errdiff> - use error diffusion to control which pixels are
+transparent.
+
+=item *
+
+C<tr_ordered> - use ordered dithering to control which pixels are
+transparent.
+
+=back
+
+=cut
+*/

 
 /* transparency handling for quantized output */
 typedef enum i_transp_tag {
 
 /* transparency handling for quantized output */
 typedef enum i_transp_tag {


@@ -493,16 +728,92 @@ typedef enum i_transp_tag {
   tr_ordered /* an ordered dither */
 } i_transp;
 
   tr_ordered /* an ordered dither */
 } i_transp;
 

-/* controls how we build the colour map */
+/*
+=item i_make_colors
+=category Data Types
+
+An enumerated type used to control the method used for produce the
+color map:
+
+=over
+
+=item *
+
+C<mc_none> - the user supplied map is used.
+
+=item *
+
+C<mc_web_map> - use the classic web map.  Any existing fixed colors
+are ignored.
+
+=item *
+
+C<mc_median_cut> - use median cut
+
+=item *
+
+C<mono> - use a fixed black and white map.
+
+=item *
+
+C<gray> - 256 step gray map.
+
+=item *
+
+C<gray4> - 4 step gray map.
+
+=item *
+
+C<gray16> - 16 step gray map.
+
+=back
+
+=cut
+*/
+

 typedef enum i_make_colors_tag {
   mc_none, /* user supplied colour map only */
   mc_web_map, /* Use the 216 colour web colour map */
   mc_addi, /* Addi's algorithm */
   mc_median_cut, /* median cut - similar to giflib, hopefully */
   mc_mono, /* fixed mono color map */
 typedef enum i_make_colors_tag {
   mc_none, /* user supplied colour map only */
   mc_web_map, /* Use the 216 colour web colour map */
   mc_addi, /* Addi's algorithm */
   mc_median_cut, /* median cut - similar to giflib, hopefully */
   mc_mono, /* fixed mono color map */

+  mc_gray, /* 256 gray map */
+  mc_gray4, /* four step gray map */
+  mc_gray16, /* sixteen step gray map */

   mc_mask = 0xFF /* (mask for generator) */
 } i_make_colors;
 
   mc_mask = 0xFF /* (mask for generator) */
 } i_make_colors;
 

+/*
+=item i_translate
+=category Data Types
+
+An enumerated type that controls how colors are translated:
+
+=over
+
+=item *
+
+C<pt_giflib> - obsolete, forces C<make_colors> to use median cut and
+acts like C<pt_closest>.
+
+=item *
+
+C<pt_closest> - always use the closest color.
+
+=item *
+
+C<pt_perturb> - add random values to each sample and find the closest
+color.
+
+=item *
+
+C<pt_errdiff> - error diffusion dither.
+
+=back
+
+=cut
+*/
+

 /* controls how we translate the colours */
 typedef enum i_translate_tag {
   pt_giflib, /* get gif lib to do it (ignores make_colours) */
 /* controls how we translate the colours */
 typedef enum i_translate_tag {
   pt_giflib, /* get gif lib to do it (ignores make_colours) */


@@ -511,6 +822,41 @@ typedef enum i_translate_tag {
   pt_errdiff /* error diffusion dither - uses errdiff */
 } i_translate;
 
   pt_errdiff /* error diffusion dither - uses errdiff */
 } i_translate;
 

+/*
+=item i_errdiff
+=category Data Types
+
+Controls the type of error diffusion to use:
+
+=over
+
+=item *
+
+C<ed_floyd> - floyd-steinberg
+
+=item *
+
+C<ed_jarvis> - Jarvis, Judice and Ninke 
+
+=item *
+
+C<ed_stucki> - Stucki
+
+=item *
+
+C<ed_custom> - not usable for transparency dithering, allows a custom
+error diffusion map to be used.
+
+=item *
+
+C<ed_bidir> - or with the error diffusion type to use alternate
+directions on each line of the dither.
+
+=back
+
+=cut
+*/
+

 /* Which error diffusion map to use */
 typedef enum i_errdiff_tag {
   ed_floyd, /* floyd-steinberg */
 /* Which error diffusion map to use */
 typedef enum i_errdiff_tag {
   ed_floyd, /* floyd-steinberg */


@@ -521,8 +867,55 @@ typedef enum i_errdiff_tag {
   ed_bidir = 0x100 /* change direction for each row */
 } i_errdiff;
 
   ed_bidir = 0x100 /* change direction for each row */
 } i_errdiff;
 

-/* which ordered dither map to use
-   currently only available for transparency
+/*
+=item i_ord_dith
+=category Data Types
+
+Which ordered dither map to use, currently only available for
+transparency.  Values are:
+
+=over
+
+=item *
+
+C<od_random> - a pre-generated random map.
+
+=item *
+
+C<od_dot8> - large dot dither.
+
+=item *
+
+C<od_dot4> - smaller dot dither
+
+=item *
+
+C<od_hline> - horizontal line dither.
+
+=item *
+
+C<od_vline> - vertical line dither.
+
+=item *
+
+C<od_slashline> - C</> line dither.
+
+=item *
+
+C<od_backline> - C<\> line dither.
+
+=item *
+
+C<od_tiny> - small checkbox dither
+
+=item *
+
+C<od_custom> - custom dither map.
+
+=back
+
+=cut
+

    I don't know of a way to do ordered dither of an image against some 
    general palette
  */
    I don't know of a way to do ordered dither of an image against some 
    general palette
  */


@@ -539,12 +932,92 @@ typedef enum i_ord_dith_tag
   od_custom /* custom 8x8 map */
 } i_ord_dith;
 
   od_custom /* custom 8x8 map */
 } i_ord_dith;
 

-typedef struct i_gif_pos_tag {
-  int x, y;
-} i_gif_pos;
+/*
+=item i_quantize
+=category Data Types
+
+A structure type used to supply image quantization, ie. when
+converting a direct color image to a paletted image.
+
+This has the following members:
+
+=over
+
+=item *
+
+C<transp> - how to handle transparency, see L</i_transp>.
+
+=item *
+
+C<threshold> - when C<transp> is C<tr_threshold>, this is the alpha
+level at which pixels become transparent.
+
+=item *
+
+C<tr_errdiff> - when C<transp> is C<tr_errdiff> this controls the type
+of error diffusion to be done.  This may not be C<ed_custom> for this
+member.

 
 

-/* passed into i_writegif_gen() to control quantization */
+=item *
+
+C<tr_orddith> - when C<transp> is C<tr_ordered> this controls the
+patten used for dithering transparency.
+
+=item *
+
+C<tr_custom> - when C<tr_orddith> is C<tr_custom> this is the ordered
+dither mask.
+
+=item *
+
+C<make_colors> - the method used to generate the color palette, see
+L</i_make_colors>.
+
+=item *
+
+C<mc_colors> - an array of C<mc_size> L</i_color> entries used to
+define the fixed colors (controlled by C<mc_count> and to return the
+generated color list.
+
+=item *
+
+C<mc_size> - the size of the buffer allocated to C<mc_colors> in
+C<sizeof(i_color)> units.
+
+=item *
+
+C<mc_count> - the number of initialized colors in C<mc_colors>.
+
+=item *
+
+C<translate> - how RGB colors are translated to palette indexes, see
+L</i_translate>.
+
+=item *
+
+C<errdiff> - when C<translate> is C<pt_errdiff> this controls the type
+of error diffusion to be done.
+
+=item *
+
+C<ed_map>, C<ed_width>, C<ed_height>, C<ed_orig> - when C<errdiff> is
+C<ed_custom> this controls the error diffusion map.  C<ed_map> is an
+array of C<ed_width * ed_height> integers.  C<ed_orig> is the position
+of the current pixel in the error diffusion map, always on the top
+row.
+
+=item *
+
+C<perturb> - the amount to perturb pixels when C<translate> is
+C<mc_perturb>.
+
+=back
+
+=cut
+*/

 typedef struct i_quantize_tag {
 typedef struct i_quantize_tag {

+  int version;
+

   /* how to handle transparency */
   i_transp transp;
   /* the threshold at which to make pixels opaque */
   /* how to handle transparency */
   i_transp transp;
   /* the threshold at which to make pixels opaque */


@@ -580,58 +1053,136 @@ typedef struct i_quantize_tag {
 
   /* the amount of perturbation to use for translate is mc_perturb */
   int perturb;
 
   /* the amount of perturbation to use for translate is mc_perturb */
   int perturb;

+  /* version 2 members after here */

 } i_quantize;
 
 } i_quantize;
 

-typedef struct i_gif_opts {
-  /* each image has a local color map */
-  int each_palette;
+/* distance measures used by some filters */
+enum {
+  i_dmeasure_euclidean = 0,
+  i_dmeasure_euclidean_squared = 1,
+  i_dmeasure_manhatten = 2,
+  i_dmeasure_limit = 2,
+};

 
 

-  /* images are interlaced */
-  int interlace;
+#include "iolayert.h"

 
 

-  /* time for which image is displayed 
-   (in 1/100 seconds)
-   default: 0
-  */
-  int delay_count;
-  int *delays;
+/* error message information returned by im_errors() */

 
 

-  /* user input flags 
-     default: 0
-   */
-  int user_input_count;
-  char *user_input_flags;
+typedef struct {
+  char *msg;
+  int code;
+} i_errmsg;

 
 

-  /* disposal
-     default: 0 */
-  int disposal_count;
-  char *disposal;
+typedef struct i_render_tag i_render;

 
 

-  /* this is added to the color table when we make an image transparent */
-  i_color tran_color;
+/*
+=item i_color_model_t
+=category Data Types
+=order 95

 
 

-  /* image positions */
-  int position_count;
-  i_gif_pos *positions;
+Returned by L</i_img_color_model(im)> to indicate the color model of
+the image.

 
 

-  /* Netscape loop extension - number of loops */
-  int loop_count;
+An enumerated type with the following possible values:

 
 

-  /* should be eliminate unused colors? */
-  int eliminate_unused;
-} i_gif_opts;
+=over

 
 

-/* distance measures used by some filters */
-enum {
-  i_dmeasure_euclidean = 0,
-  i_dmeasure_euclidean_squared = 1,
-  i_dmeasure_manhatten = 2,
-  i_dmeasure_limit = 2,
-};
+=item *

 
 

-#include "iolayert.h"
+C<icm_unknown> - the image has no usable color data.  In future
+versions of Imager this will be returned in a few limited cases,
+eg. when the source image is CMYK and the user has requested no color
+translation is done.
+
+=item *
+
+C<icm_gray> - gray scale with no alpha channel.
+
+=item *
+
+C<icm_gray_alpha> - gray scale with an alpha channel.
+
+=item *
+
+C<icm_rgb> - RGB
+
+=item *
+
+C<icm_rgb_alpha> - RGB with an alpha channel.
+
+=back
+
+=cut
+*/
+
+typedef enum {
+  icm_unknown,
+  icm_gray,
+  icm_gray_alpha,
+  icm_rgb,
+  icm_rgb_alpha
+} i_color_model_t;
+
+#ifdef IMAGER_FORMAT_ATTR
+#define I_FORMAT_ATTR(format_index, va_index) \
+  __attribute ((format (printf, format_index, va_index)))
+#else
+#define I_FORMAT_ATTR(format_index, va_index)
+#endif
+
+#ifdef _MSC_VER
+#  ifndef vsnprintf
+#  define vsnprintf _vsnprintf
+#  endif
+#  ifndef snprintf
+#  define snprintf _snprintf
+#  endif
+#endif
+
+/*
+=item i_DF
+=category Data Types
+=synopsis printf("left %" i_DF "\n", i_DFc(x));
+=order 95
+
+This is a constant string that can be used with functions like
+printf() to format i_img_dim values after they're been cast with i_DFc().
+
+Does not include the leading C<%>.
+
+=cut
+
+=item i_DFc
+=category Data Types
+=order 95
+
+Cast an C<i_img_dim> value to a type for use with the i_DF format
+string.
+
+=cut
+
+=item i_DFp
+=category Data Types
+=synopsis printf("point (" i_DFp ")\n", i_DFcp(x, y));
+=order 95
+
+Format a pair of C<i_img_dim> values.  This format string I<does>
+include the leading C<%>.
+
+=cut
+
+=item i_DFcp
+=category Data Types
+=order 95
+
+Casts two C<i_img_dim> values for use with the i_DF (or i_DFp) format.
+
+=cut
+ */

 
 

-#include "rendert.h"
+#define i_DFc(x) ((i_dim_format_t)(x))
+#define i_DFcp(x, y) i_DFc(x), i_DFc(y)
+#define i_DFp "%" i_DF ", %" i_DF

 
 #endif
 
 
 #endif