#pragma once

#include <kinc/global.h>

#include <kinc/backend/graphics5/indexbuffer.h>

/*! \file indexbuffer.h
    \brief Provides functions for setting up and using index-buffers.
*/

#ifdef __cplusplus
extern "C" {
#endif

typedef enum kinc_g5_index_buffer_format { KINC_G5_INDEX_BUFFER_FORMAT_32BIT, KINC_G5_INDEX_BUFFER_FORMAT_16BIT } kinc_g5_index_buffer_format_t;

typedef struct kinc_g5_index_buffer {
	IndexBuffer5Impl impl;
} kinc_g5_index_buffer_t;

/// <summary>
/// Initializes an index-buffer.
/// </summary>
/// <param name="buffer">The buffer to initialize</param>
/// <param name="count">The number of indices to allocate for the buffer</param>
/// <param name="gpu_memory">When true, the buffer will be uploaded to gpu-memory which will make it faster to use but slower to change</param>
KINC_FUNC void kinc_g5_index_buffer_init(kinc_g5_index_buffer_t *buffer, int count, kinc_g5_index_buffer_format_t format, bool gpu_memory);

/// <summary>
/// Destroys an index-buffer.
/// </summary>
/// <param name="buffer">The buffer to destroy</param>
KINC_FUNC void kinc_g5_index_buffer_destroy(kinc_g5_index_buffer_t *buffer);

/// <summary>
/// Locks an index-buffer so its contents can be modified.
/// </summary>
/// <param name="buffer">The buffer to lock</param>
/// <returns>The contents of the index-buffer in uint32s or uint16s depending on the format provided when initializing</returns>
KINC_FUNC void *kinc_g5_index_buffer_lock_all(kinc_g5_index_buffer_t *buffer);

/// <summary>
/// Locks part of a vertex-buffer to modify its contents.
/// </summary>
/// <param name="buffer">The buffer to lock</param>
/// <param name="start">The index of the first index to lock</param>
/// <param name="count">The number of indices to lock</param>
/// <returns>The contents of the index-buffer, starting at start, in uint32s or uint16s depending on the format provided when initializing</returns>
KINC_FUNC void *kinc_g5_index_buffer_lock(kinc_g5_index_buffer_t *buffer, int start, int count);

/// <summary>
/// Unlocks an index-buffer after locking it so the changed buffer-contents can be used.
/// </summary>
/// <param name="buffer">The buffer to unlock</param>
KINC_FUNC void kinc_g5_index_buffer_unlock_all(kinc_g5_index_buffer_t *buffer);

/// <summary>
/// Unlocks part of an index-buffer after locking so the changed buffer-contents can be used.
/// </summary>
/// <param name="buffer">The buffer to unlock</param>
/// <param name="count">The number of indices to unlock, starting from the start-index from the previous lock-call</param>
KINC_FUNC void kinc_g5_index_buffer_unlock(kinc_g5_index_buffer_t *buffer, int count);

/// <summary>
/// Returns the number of indices in the buffer.
/// </summary>
/// <param name="buffer">The buffer to query for its number of indices</param>
/// <returns>The number of indices</returns>
KINC_FUNC int kinc_g5_index_buffer_count(kinc_g5_index_buffer_t *buffer);

#ifdef __cplusplus
}
#endif