// Copyright 2014 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// GIF decode.

#ifndef WEBP_EXAMPLES_GIFDEC_H_

#define WEBP_EXAMPLES_GIFDEC_H_

#include <stdio.h>

#include "webp/types.h"

#ifdef HAVE_CONFIG_H

#include "webp/config.h"

#endif

#ifdef WEBP_HAVE_GIF

#include <gif_lib.h>

#endif

#ifdef __cplusplus

extern "C" {

#endif

// GIFLIB_MAJOR is only defined in libgif >= 4.2.0.

#if defined(GIFLIB_MAJOR) && defined(GIFLIB_MINOR)

# define LOCAL_GIF_VERSION ((GIFLIB_MAJOR << 8) | GIFLIB_MINOR)

# define LOCAL_GIF_PREREQ(maj, min) \

    (LOCAL_GIF_VERSION >= (((maj) << 8) | (min)))

#else

# define LOCAL_GIF_VERSION 0

# define LOCAL_GIF_PREREQ(maj, min) 0

#endif

#define GIF_INDEX_INVALID (-1)

typedef enum GIFDisposeMethod {

  GIF_DISPOSE_NONE,

  GIF_DISPOSE_BACKGROUND,

  GIF_DISPOSE_RESTORE_PREVIOUS

} GIFDisposeMethod;

typedef struct {

  int x_offset, y_offset, width, height;

} GIFFrameRect;

struct WebPData;

struct WebPPicture;

#ifndef WEBP_HAVE_GIF

struct ColorMapObject;

struct GifFileType;

typedef unsigned char GifByteType;

#endif

// Given the index of background color and transparent color, returns the

// corresponding background color (in BGRA format) in 'bgcolor'.

void GIFGetBackgroundColor(const struct ColorMapObject* const color_map,

                           int bgcolor_index, int transparent_index,

                           uint32_t* const bgcolor);

// Parses the given graphics extension data to get frame duration (in 1ms

// units), dispose method and transparent color index.

// Returns true on success.

int GIFReadGraphicsExtension(const GifByteType* const buf, int* const duration,

                             GIFDisposeMethod* const dispose,

                             int* const transparent_index);

// Reads the next GIF frame from 'gif' into 'picture'. Also, returns the GIF

// frame dimensions and offsets in 'rect'.

// Returns true on success.

int GIFReadFrame(struct GifFileType* const gif, int transparent_index,

                 GIFFrameRect* const gif_rect,

                 struct WebPPicture* const picture);

// Parses loop count from the given Netscape extension data.

int GIFReadLoopCount(struct GifFileType* const gif, GifByteType** const buf,

                     int* const loop_count);

// Parses the given ICC or XMP extension data and stores it into 'metadata'.

// Returns true on success.

int GIFReadMetadata(struct GifFileType* const gif, GifByteType** const buf,

                    struct WebPData* const metadata);

// Dispose the pixels within 'rect' of 'curr_canvas' based on 'dispose' method

// and 'prev_canvas'.

void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,

                     const struct WebPPicture* const prev_canvas,

                     struct WebPPicture* const curr_canvas);

// Given 'src' picture and its frame rectangle 'rect', blend it into 'dst'.

void GIFBlendFrames(const struct WebPPicture* const src,

                    const GIFFrameRect* const rect,

                    struct WebPPicture* const dst);

// Prints an error string based on 'gif_error'.

void GIFDisplayError(const struct GifFileType* const gif, int gif_error);

// In the given 'pic', clear the pixels in 'rect' to transparent color.

void GIFClearPic(struct WebPPicture* const pic, const GIFFrameRect* const rect);

// Copy pixels from 'src' to 'dst' honoring strides. 'src' and 'dst' are assumed

// to be already allocated.

void GIFCopyPixels(const struct WebPPicture* const src,

                   struct WebPPicture* const dst);

#ifdef __cplusplus

}    // extern "C"

#endif

#endif  // WEBP_EXAMPLES_GIFDEC_H_