/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "mrpt_jpeglib.h"

/* Note: currently, there is no operating mode in which a full-image buffer
 * is needed at this step.  If there were, that mode could not be used with
 * "raw data" input, since this module is bypassed in that case.  However,
 * we've left the code here for possible use in special applications.
 */
#undef FULL_MAIN_BUFFER_SUPPORTED

/* Private buffer controller object */

typedef struct
{
	struct jpeg_c_main_controller pub; /* public fields */

	JDIMENSION cur_iMCU_row; /* number of current iMCU row */
	JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */
	boolean suspended; /* remember if we suspended output */
	J_BUF_MODE pass_mode; /* current operating mode */

	/* If using just a strip buffer, this points to the entire set of buffers
	 * (we allocate one for each component).  In the full-image case, this
	 * points to the currently accessible strips of the virtual arrays.
	 */
	JSAMPARRAY buffer[MAX_COMPONENTS];

#ifdef FULL_MAIN_BUFFER_SUPPORTED
	/* If using full-image storage, this array holds pointers to virtual-array
	 * control blocks for each component.  Unused if not full-image storage.
	 */
	jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
#endif
} my_main_controller;

typedef my_main_controller* my_main_ptr;

/* Forward declarations */
METHODDEF(void)
process_data_simple_main JPP(
	(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION* in_row_ctr,
	 JDIMENSION in_rows_avail));
#ifdef FULL_MAIN_BUFFER_SUPPORTED
METHODDEF(void)
process_data_buffer_main JPP(
	(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION* in_row_ctr,
	 JDIMENSION in_rows_avail));
#endif

/*
 * Initialize for a processing pass.
 */

METHODDEF(void)
start_pass_main(j_compress_ptr cinfo, J_BUF_MODE pass_mode)
{
	my_main_ptr main = (my_main_ptr)cinfo->main;

	/* Do nothing in raw-data mode. */
	if (cinfo->raw_data_in) return;

	main->cur_iMCU_row = 0; /* initialize counters */
	main->rowgroup_ctr = 0;
	main->suspended = FALSE;
	main->pass_mode = pass_mode; /* save mode for use by process_data */

	switch (pass_mode)
	{
		case JBUF_PASS_THRU:
#ifdef FULL_MAIN_BUFFER_SUPPORTED
			if (main->whole_image[0] != nullptr)
				ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
			main->pub.process_data = process_data_simple_main;
			break;
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		case JBUF_SAVE_SOURCE:
		case JBUF_CRANK_DEST:
		case JBUF_SAVE_AND_PASS:
			if (main->whole_image[0] == nullptr)
				ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
			main->pub.process_data = process_data_buffer_main;
			break;
#endif
		default:
			ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
			break;
	}
}

/*
 * Process some data.
 * This routine handles the simple pass-through mode,
 * where we have only a strip buffer.
 */

METHODDEF(void)
process_data_simple_main(
	j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION* in_row_ctr,
	JDIMENSION in_rows_avail)
{
	my_main_ptr main = (my_main_ptr)cinfo->main;

	while (main->cur_iMCU_row < cinfo->total_iMCU_rows)
	{
		/* Read input data if we haven't filled the main buffer yet */
		if (main->rowgroup_ctr < DCTSIZE)
			(*cinfo->prep->pre_process_data)(
				cinfo, input_buf, in_row_ctr, in_rows_avail, main->buffer,
				&main->rowgroup_ctr, (JDIMENSION)DCTSIZE);

		/* If we don't have a full iMCU row buffered, return to application for
		 * more data.  Note that preprocessor will always pad to fill the iMCU
		 * row
		 * at the bottom of the image.
		 */
		if (main->rowgroup_ctr != DCTSIZE) return;

		/* Send the completed row to the compressor */
		if (!(*cinfo->coef->compress_data)(cinfo, main->buffer))
		{
			/* If compressor did not consume the whole row, then we must need to
			 * suspend processing and return to the application.  In this
			 * situation
			 * we pretend we didn't yet consume the last input row; otherwise,
			 * if
			 * it happened to be the last row of the image, the application
			 * would
			 * think we were done.
			 */
			if (!main->suspended)
			{
				(*in_row_ctr)--;
				main->suspended = TRUE;
			}
			return;
		}
		/* We did finish the row.  Undo our little suspension hack if a previous
		 * call suspended; then mark the main buffer empty.
		 */
		if (main->suspended)
		{
			(*in_row_ctr)++;
			main->suspended = FALSE;
		}
		main->rowgroup_ctr = 0;
		main->cur_iMCU_row++;
	}
}

#ifdef FULL_MAIN_BUFFER_SUPPORTED

/*
 * Process some data.
 * This routine handles all of the modes that use a full-size buffer.
 */

METHODDEF(void)
process_data_buffer_main(
	j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION* in_row_ctr,
	JDIMENSION in_rows_avail)
{
	my_main_ptr main = (my_main_ptr)cinfo->main;
	int ci;
	jpeg_component_info* compptr;
	boolean writing = (main->pass_mode != JBUF_CRANK_DEST);

	while (main->cur_iMCU_row < cinfo->total_iMCU_rows)
	{
		/* Realign the virtual buffers if at the start of an iMCU row. */
		if (main->rowgroup_ctr == 0)
		{
			for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
				 ci++, compptr++)
			{
				main->buffer[ci] = (*cinfo->mem->access_virt_sarray)(
					(j_common_ptr)cinfo, main->whole_image[ci],
					main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
					(JDIMENSION)(compptr->v_samp_factor * DCTSIZE), writing);
			}
			/* In a read pass, pretend we just read some source data. */
			if (!writing)
			{
				*in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
				main->rowgroup_ctr = DCTSIZE;
			}
		}

		/* If a write pass, read input data until the current iMCU row is full.
		 */
		/* Note: preprocessor will pad if necessary to fill the last iMCU row.
		 */
		if (writing)
		{
			(*cinfo->prep->pre_process_data)(
				cinfo, input_buf, in_row_ctr, in_rows_avail, main->buffer,
				&main->rowgroup_ctr, (JDIMENSION)DCTSIZE);
			/* Return to application if we need more data to fill the iMCU row.
			 */
			if (main->rowgroup_ctr < DCTSIZE) return;
		}

		/* Emit data, unless this is a sink-only pass. */
		if (main->pass_mode != JBUF_SAVE_SOURCE)
		{
			if (!(*cinfo->coef->compress_data)(cinfo, main->buffer))
			{
				/* If compressor did not consume the whole row, then we must
				 * need to
				 * suspend processing and return to the application.  In this
				 * situation
				 * we pretend we didn't yet consume the last input row;
				 * otherwise, if
				 * it happened to be the last row of the image, the application
				 * would
				 * think we were done.
				 */
				if (!main->suspended)
				{
					(*in_row_ctr)--;
					main->suspended = TRUE;
				}
				return;
			}
			/* We did finish the row.  Undo our little suspension hack if a
			 * previous
			 * call suspended; then mark the main buffer empty.
			 */
			if (main->suspended)
			{
				(*in_row_ctr)++;
				main->suspended = FALSE;
			}
		}

		/* If get here, we are done with this iMCU row.  Mark buffer empty. */
		main->rowgroup_ctr = 0;
		main->cur_iMCU_row++;
	}
}

#endif /* FULL_MAIN_BUFFER_SUPPORTED */

/*
 * Initialize main buffer controller.
 */

GLOBAL(void)
jinit_c_main_controller(j_compress_ptr cinfo, boolean need_full_buffer)
{
	my_main_ptr main;
	int ci;
	jpeg_component_info* compptr;

	main = (my_main_ptr)(*cinfo->mem->alloc_small)(
		(j_common_ptr)cinfo, JPOOL_IMAGE, SIZEOF(my_main_controller));
	cinfo->main = (struct jpeg_c_main_controller*)main;
	main->pub.start_pass = start_pass_main;

	/* We don't need to create a buffer in raw-data mode. */
	if (cinfo->raw_data_in) return;

	/* Create the buffer.  It holds downsampled data, so each component
	 * may be of a different size.
	 */
	if (need_full_buffer)
	{
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		/* Allocate a full-image virtual array for each component */
		/* Note we pad the bottom to a multiple of the iMCU height */
		for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
			 ci++, compptr++)
		{
			main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)(
				(j_common_ptr)cinfo, JPOOL_IMAGE, FALSE,
				compptr->width_in_blocks * DCTSIZE,
				(JDIMENSION)jround_up(
					(long)compptr->height_in_blocks,
					(long)compptr->v_samp_factor) *
					DCTSIZE,
				(JDIMENSION)(compptr->v_samp_factor * DCTSIZE));
		}
#else
		ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
	}
	else
	{
#ifdef FULL_MAIN_BUFFER_SUPPORTED
		main->whole_image[0] = nullptr; /* flag for no virtual arrays */
#endif
		/* Allocate a strip buffer for each component */
		for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
			 ci++, compptr++)
		{
			main->buffer[ci] = (*cinfo->mem->alloc_sarray)(
				(j_common_ptr)cinfo, JPOOL_IMAGE,
				compptr->width_in_blocks * DCTSIZE,
				(JDIMENSION)(compptr->v_samp_factor * DCTSIZE));
		}
	}
}
