imagequant/libimagequant.h

/*
 * https://pngquant.org
 */

#ifndef LIBIMAGEQUANT_H
#define LIBIMAGEQUANT_H

#ifdef IMAGEQUANT_EXPORTS
#define LIQ_EXPORT __declspec(dllexport)
#endif

#ifndef LIQ_EXPORT
#define LIQ_EXPORT extern
#endif

#define LIQ_VERSION 21200
#define LIQ_VERSION_STRING "2.12.2"

#ifndef LIQ_PRIVATE
#if defined(__GNUC__) || defined (__llvm__)
#define LIQ_PRIVATE __attribute__((visibility("hidden")))
#define LIQ_NONNULL __attribute__((nonnull))
#define LIQ_USERESULT __attribute__((warn_unused_result))
#else
#define LIQ_PRIVATE
#define LIQ_NONNULL
#define LIQ_USERESULT
#endif
#endif

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>

typedef struct liq_attr liq_attr;
typedef struct liq_image liq_image;
typedef struct liq_result liq_result;
typedef struct liq_histogram liq_histogram;

typedef struct liq_color {
    unsigned char r, g, b, a;
} liq_color;

typedef struct liq_palette {
    unsigned int count;
    liq_color entries[256];
} liq_palette;

typedef enum liq_error {
    LIQ_OK = 0,
    LIQ_QUALITY_TOO_LOW = 99,
    LIQ_VALUE_OUT_OF_RANGE = 100,
    LIQ_OUT_OF_MEMORY,
    LIQ_ABORTED,
    LIQ_BITMAP_NOT_AVAILABLE,
    LIQ_BUFFER_TOO_SMALL,
    LIQ_INVALID_POINTER,
    LIQ_UNSUPPORTED,
} liq_error;

enum liq_ownership {
    LIQ_OWN_ROWS=4,
    LIQ_OWN_PIXELS=8,
    LIQ_COPY_PIXELS=16,
};

typedef struct liq_histogram_entry {
    liq_color color;
    unsigned int count;
} liq_histogram_entry;

LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create(void);
LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create_with_allocator(void* (*malloc)(size_t), void (*free)(void*));
LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_copy(const liq_attr *orig) LIQ_NONNULL;
LIQ_EXPORT void liq_attr_destroy(liq_attr *attr) LIQ_NONNULL;

LIQ_EXPORT LIQ_USERESULT liq_histogram* liq_histogram_create(const liq_attr* attr);
LIQ_EXPORT liq_error liq_histogram_add_image(liq_histogram *hist, const liq_attr *attr, liq_image* image) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_histogram_add_colors(liq_histogram *hist, const liq_attr *attr, const liq_histogram_entry entries[], int num_entries, double gamma) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_histogram_add_fixed_color(liq_histogram *hist, liq_color color, double gamma) LIQ_NONNULL;
LIQ_EXPORT void liq_histogram_destroy(liq_histogram *hist) LIQ_NONNULL;

LIQ_EXPORT liq_error liq_set_max_colors(liq_attr* attr, int colors) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_max_colors(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_speed(liq_attr* attr, int speed) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_speed(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_min_opacity(liq_attr* attr, int min) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_opacity(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_min_posterization(liq_attr* attr, int bits) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_posterization(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_quality(liq_attr* attr, int minimum, int maximum) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_quality(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_max_quality(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT void liq_set_last_index_transparent(liq_attr* attr, int is_last) LIQ_NONNULL;

typedef void liq_log_callback_function(const liq_attr*, const char *message, void* user_info);
typedef void liq_log_flush_callback_function(const liq_attr*, void* user_info);
LIQ_EXPORT void liq_set_log_callback(liq_attr*, liq_log_callback_function*, void* user_info);
LIQ_EXPORT void liq_set_log_flush_callback(liq_attr*, liq_log_flush_callback_function*, void* user_info);

typedef int liq_progress_callback_function(float progress_percent, void* user_info);
LIQ_EXPORT void liq_attr_set_progress_callback(liq_attr*, liq_progress_callback_function*, void* user_info);
LIQ_EXPORT void liq_result_set_progress_callback(liq_result*, liq_progress_callback_function*, void* user_info);

// The rows and their data are not modified. The type of `rows` is non-const only due to a bug in C's typesystem design.
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba_rows(const liq_attr *attr, void *const rows[], int width, int height, double gamma) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba(const liq_attr *attr, const void *bitmap, int width, int height, double gamma) LIQ_NONNULL;

typedef void liq_image_get_rgba_row_callback(liq_color row_out[], int row, int width, void* user_info);
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_custom(const liq_attr *attr, liq_image_get_rgba_row_callback *row_callback, void* user_info, int width, int height, double gamma);

LIQ_EXPORT liq_error liq_image_set_memory_ownership(liq_image *image, int ownership_flags) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_set_background(liq_image *img, liq_image *background_image) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_set_importance_map(liq_image *img, unsigned char buffer[], size_t buffer_size, enum liq_ownership memory_handling) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_add_fixed_color(liq_image *img, liq_color color) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_image_get_width(const liq_image *img) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_image_get_height(const liq_image *img) LIQ_NONNULL;
LIQ_EXPORT void liq_image_destroy(liq_image *img) LIQ_NONNULL;

LIQ_EXPORT LIQ_USERESULT liq_error liq_histogram_quantize(liq_histogram *const input_hist, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_error liq_image_quantize(liq_image *const input_image, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;

LIQ_EXPORT liq_error liq_set_dithering_level(liq_result *res, float dither_level) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_output_gamma(liq_result* res, double gamma) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT double liq_get_output_gamma(const liq_result *result) LIQ_NONNULL;

LIQ_EXPORT LIQ_USERESULT const liq_palette *liq_get_palette(liq_result *result) LIQ_NONNULL;

LIQ_EXPORT liq_error liq_write_remapped_image(liq_result *result, liq_image *input_image, void *buffer, size_t buffer_size) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_write_remapped_image_rows(liq_result *result, liq_image *input_image, unsigned char **row_pointers) LIQ_NONNULL;

LIQ_EXPORT double liq_get_quantization_error(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT int liq_get_quantization_quality(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT double liq_get_remapping_error(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT int liq_get_remapping_quality(const liq_result *result) LIQ_NONNULL;

LIQ_EXPORT void liq_result_destroy(liq_result *) LIQ_NONNULL;

LIQ_EXPORT int liq_version(void);


// Deprecated
LIQ_EXPORT LIQ_USERESULT liq_result *liq_quantize_image(liq_attr *options, liq_image *input_image) LIQ_NONNULL;

#ifdef __cplusplus
}
#endif

#endif