/* Copyright (c) the JPEG XL Project Authors. All rights reserved.
 *
 * Use of this source code is governed by a BSD-style
 * license that can be found in the LICENSE file.
 */

/** @file butteraugli.h
 * @brief Butteraugli API for JPEG XL.
 */

#ifndef JXL_BUTTERAUGLI_H_
#define JXL_BUTTERAUGLI_H_

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#include "jxl/jxl_export.h"
#include "jxl/memory_manager.h"
#include "jxl/parallel_runner.h"
#include "jxl/types.h"

/**
 * Opaque structure that holds a butteraugli API.
 *
 * Allocated and initialized with JxlButteraugliApiCreate().
 * Cleaned up and deallocated with JxlButteraugliApiDestroy().
 */
typedef struct JxlButteraugliApiStruct JxlButteraugliApi;

/**
 * Opaque structure that holds intermediary butteraugli results.
 *
 * Allocated and initialized with JxlButteraugliCompute().
 * Cleaned up and deallocated with JxlButteraugliResultDestroy().
 */
typedef struct JxlButteraugliResultStruct JxlButteraugliResult;

/**
 * Deinitializes and frees JxlButteraugliResult instance.
 *
 * @param result instance to be cleaned up and deallocated.
 */
JXL_EXPORT void JxlButteraugliResultDestroy(JxlButteraugliResult* result);

/**
 * Creates an instance of JxlButteraugliApi and initializes it.
 *
 * @p memory_manager will be used for all the library dynamic allocations made
 * from this instance. The parameter may be NULL, in which case the default
 * allocator will be used. See jxl/memory_manager.h for details.
 *
 * @param memory_manager custom allocator function. It may be NULL. The memory
 *        manager will be copied internally.
 * @return @c NULL if the instance can not be allocated or initialized
 * @return pointer to initialized JxlEncoder otherwise
 */
JXL_EXPORT JxlButteraugliApi* JxlButteraugliApiCreate(
    const JxlMemoryManager* memory_manager);

/**
 * Set the parallel runner for multithreading.
 *
 * @param api api instance.
 * @param parallel_runner function pointer to runner for multithreading. A
 * multithreaded runner should be set to reach fast performance.
 * @param parallel_runner_opaque opaque pointer for parallel_runner.
 */
JXL_EXPORT void JxlButteraugliApiSetParallelRunner(
    JxlButteraugliApi* api, JxlParallelRunner parallel_runner,
    void* parallel_runner_opaque);

/**
 * Set the hf_asymmetry option for butteraugli.
 *
 * @param api api instance.
 * @param v new hf_asymmetry value.
 */
JXL_EXPORT void JxlButteraugliApiSetHFAsymmetry(JxlButteraugliApi* api,
                                                float v);

/**
 * Set the intensity_target option for butteraugli.
 *
 * @param api api instance.
 * @param v new intensity_target value.
 */
JXL_EXPORT void JxlButteraugliApiSetIntensityTarget(JxlButteraugliApi* api,
                                                    float v);

/**
 * Deinitializes and frees JxlButteraugliApi instance.
 *
 * @param api instance to be cleaned up and deallocated.
 */
JXL_EXPORT void JxlButteraugliApiDestroy(JxlButteraugliApi* api);

/**
 * Computes intermediary butteraugli result between an original image and a
 * distortion.
 *
 * @param api api instance for this computation.
 * @param xsize width of the compared images.
 * @param ysize height of the compared images.
 * @param pixel_format_orig pixel format for original image.
 * @param buffer_orig pixel data for original image.
 * @param size_orig size of buffer_orig in bytes.
 * @param pixel_format_dist pixel format for distortion.
 * @param buffer_dist pixel data for distortion.
 * @param size_dist size of buffer_dist in bytes.
 * @return @c NULL if the results can not be computed or initialized.
 * @return pointer to initialized and computed intermediary result.
 */
JXL_EXPORT JxlButteraugliResult* JxlButteraugliCompute(
    const JxlButteraugliApi* api, uint32_t xsize, uint32_t ysize,
    const JxlPixelFormat* pixel_format_orig, const void* buffer_orig,
    size_t size_orig, const JxlPixelFormat* pixel_format_dist,
    const void* buffer_dist, size_t size_dist);

/**
 * Computes butteraugli max distance based on an intermediary butteraugli
 * result.
 *
 * @param result intermediary result instance.
 * @return max distance.
 */
JXL_EXPORT float JxlButteraugliResultGetMaxDistance(
    const JxlButteraugliResult* result);

/**
 * Computes a butteraugli distance based on an intermediary butteraugli result.
 *
 * @param result intermediary result instance.
 * @param pnorm pnorm to calculate.
 * @return distance using the given pnorm.
 */
JXL_EXPORT float JxlButteraugliResultGetDistance(
    const JxlButteraugliResult* result, float pnorm);

/**
 * Get a pointer to the distmap in the result.
 *
 * @param result intermediary result instance.
 * @param buffer will be set to the distmap. The distance value for (x,y) will
 * be available at buffer + y * row_stride + x.
 * @param row_stride will be set to the row stride of the distmap.
 */
JXL_EXPORT void JxlButteraugliResultGetDistmap(
    const JxlButteraugliResult* result, const float** buffer,
    uint32_t* row_stride);

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#endif /* JXL_BUTTERAUGLI_H_ */