[pulseview.git] / pv / data / logicsnapshot.cpp

/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <extdef.h>

#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

#include <boost/foreach.hpp>

#include "config.h"
#include "logicsnapshot.h"

using boost::lock_guard;
using boost::recursive_mutex;
using std::max;
using std::min;
using std::pair;

namespace pv {
namespace data {

const int LogicSnapshot::MipMapScalePower = 4;
const int LogicSnapshot::MipMapScaleFactor = 1 << MipMapScalePower;
const float LogicSnapshot::LogMipMapScaleFactor = logf(MipMapScaleFactor);
const uint64_t LogicSnapshot::MipMapDataUnit = 64*1024;	// bytes

LogicSnapshot::LogicSnapshot(const sr_datafeed_logic &logic,
                             const uint64_t expected_num_samples) :
	Snapshot(logic.unitsize),
	_last_append_sample(0)
{
	set_capacity(expected_num_samples);

	lock_guard<recursive_mutex> lock(_mutex);
	memset(_mip_map, 0, sizeof(_mip_map));
	append_payload(logic);
}

LogicSnapshot::~LogicSnapshot()
{
	lock_guard<recursive_mutex> lock(_mutex);
	BOOST_FOREACH(MipMapLevel &l, _mip_map)
		free(l.data);
}

uint64_t LogicSnapshot::unpack_sample(const uint8_t *ptr) const
{
#ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
	return *(uint64_t*)ptr;
#else
	uint64_t value = 0;
	switch(_unit_size) {
	default:
		value |= ((uint64_t)ptr[7]) << 56;
		/* FALLTHRU */
	case 7:
		value |= ((uint64_t)ptr[6]) << 48;
		/* FALLTHRU */
	case 6:
		value |= ((uint64_t)ptr[5]) << 40;
		/* FALLTHRU */
	case 5:
		value |= ((uint64_t)ptr[4]) << 32;
		/* FALLTHRU */
	case 4:
		value |= ((uint32_t)ptr[3]) << 24;
		/* FALLTHRU */
	case 3:
		value |= ((uint32_t)ptr[2]) << 16;
		/* FALLTHRU */
	case 2:
		value |= ptr[1] << 8;
		/* FALLTHRU */
	case 1:
		value |= ptr[0];
		/* FALLTHRU */
	case 0:
		break;
	}
	return value;
#endif
}

void LogicSnapshot::pack_sample(uint8_t *ptr, uint64_t value)
{
#ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
	*(uint64_t*)ptr = value;
#else
	switch(_unit_size) {
	default:
		ptr[7] = value >> 56;
		/* FALLTHRU */
	case 7:
		ptr[6] = value >> 48;
		/* FALLTHRU */
	case 6:
		ptr[5] = value >> 40;
		/* FALLTHRU */
	case 5:
		ptr[4] = value >> 32;
		/* FALLTHRU */
	case 4:
		ptr[3] = value >> 24;
		/* FALLTHRU */
	case 3:
		ptr[2] = value >> 16;
		/* FALLTHRU */
	case 2:
		ptr[1] = value >> 8;
		/* FALLTHRU */
	case 1:
		ptr[0] = value;
		/* FALLTHRU */
	case 0:
		break;
	}
#endif
}

void LogicSnapshot::append_payload(
	const sr_datafeed_logic &logic)
{
	assert(_unit_size == logic.unitsize);
	assert((logic.length % _unit_size) == 0);

	lock_guard<recursive_mutex> lock(_mutex);

	append_data(logic.data, logic.length / _unit_size);

	// Generate the first mip-map from the data
	append_payload_to_mipmap();
}

void LogicSnapshot::get_samples(uint8_t *const data,
	int64_t start_sample, int64_t end_sample) const
{
	assert(data);
	assert(start_sample >= 0);
	assert(start_sample <= (int64_t)_sample_count);
	assert(end_sample >= 0);
	assert(end_sample <= (int64_t)_sample_count);
	assert(start_sample <= end_sample);

	lock_guard<recursive_mutex> lock(_mutex);

	const size_t size = (end_sample - start_sample) * _unit_size;
	memcpy(data, (const uint8_t*)_data + start_sample, size);
}

void LogicSnapshot::reallocate_mipmap_level(MipMapLevel &m)
{
	const uint64_t new_data_length = ((m.length + MipMapDataUnit - 1) /
		MipMapDataUnit) * MipMapDataUnit;
	if (new_data_length > m.data_length)
	{
		m.data_length = new_data_length;

		// Padding is added to allow for the uint64_t write word
		m.data = realloc(m.data, new_data_length * _unit_size +
			sizeof(uint64_t));
	}
}

void LogicSnapshot::append_payload_to_mipmap()
{
	MipMapLevel &m0 = _mip_map[0];
	uint64_t prev_length;
	const uint8_t *src_ptr;
	uint8_t *dest_ptr;
	uint64_t accumulator;
	unsigned int diff_counter;

	// Expand the data buffer to fit the new samples
	prev_length = m0.length;
	m0.length = _sample_count / MipMapScaleFactor;

	// Break off if there are no new samples to compute
	if (m0.length == prev_length)
		return;

	reallocate_mipmap_level(m0);

	dest_ptr = (uint8_t*)m0.data + prev_length * _unit_size;

	// Iterate through the samples to populate the first level mipmap
	const uint8_t *const end_src_ptr = (uint8_t*)_data +
		m0.length * _unit_size * MipMapScaleFactor;
	for (src_ptr = (uint8_t*)_data +
		prev_length * _unit_size * MipMapScaleFactor;
		src_ptr < end_src_ptr;)
	{
		// Accumulate transitions which have occurred in this sample
		accumulator = 0;
		diff_counter = MipMapScaleFactor;
		while (diff_counter-- > 0)
		{
			const uint64_t sample = unpack_sample(src_ptr);
			accumulator |= _last_append_sample ^ sample;
			_last_append_sample = sample;
			src_ptr += _unit_size;
		}

		pack_sample(dest_ptr, accumulator);
		dest_ptr += _unit_size;
	}

	// Compute higher level mipmaps
	for (unsigned int level = 1; level < ScaleStepCount; level++)
	{
		MipMapLevel &m = _mip_map[level];
		const MipMapLevel &ml = _mip_map[level-1];

		// Expand the data buffer to fit the new samples
		prev_length = m.length;
		m.length = ml.length / MipMapScaleFactor;

		// Break off if there are no more samples to computed
		if (m.length == prev_length)
			break;

		reallocate_mipmap_level(m);

		// Subsample the level lower level
		src_ptr = (uint8_t*)ml.data +
			_unit_size * prev_length * MipMapScaleFactor;
		const uint8_t *const end_dest_ptr =
			(uint8_t*)m.data + _unit_size * m.length;
		for (dest_ptr = (uint8_t*)m.data +
			_unit_size * prev_length;
			dest_ptr < end_dest_ptr;
			dest_ptr += _unit_size)
		{
			accumulator = 0;
			diff_counter = MipMapScaleFactor;
			while (diff_counter-- > 0)
			{
				accumulator |= unpack_sample(src_ptr);
				src_ptr += _unit_size;
			}

			pack_sample(dest_ptr, accumulator);
		}
	}
}

uint64_t LogicSnapshot::get_sample(uint64_t index) const
{
	assert(_data);
	assert(index < _sample_count);

	return unpack_sample((uint8_t*)_data + index * _unit_size);
}

void LogicSnapshot::get_subsampled_edges(
	std::vector<EdgePair> &edges,
	uint64_t start, uint64_t end,
	float min_length, int sig_index)
{
	uint64_t index = start;
	unsigned int level;
	bool last_sample;
	bool fast_forward;

	assert(end <= get_sample_count());
	assert(start <= end);
	assert(min_length > 0);
	assert(sig_index >= 0);
	assert(sig_index < 64);

	lock_guard<recursive_mutex> lock(_mutex);

	const uint64_t block_length = (uint64_t)max(min_length, 1.0f);
	const unsigned int min_level = max((int)floorf(logf(min_length) /
		LogMipMapScaleFactor) - 1, 0);
	const uint64_t sig_mask = 1ULL << sig_index;

	// Store the initial state
	last_sample = (get_sample(start) & sig_mask) != 0;
	edges.push_back(pair<int64_t, bool>(index++, last_sample));

	while (index + block_length <= end)
	{
		//----- Continue to search -----//
		level = min_level;

		// We cannot fast-forward if there is no mip-map data at
		// at the minimum level.
		fast_forward = (_mip_map[level].data != NULL);

		if (min_length < MipMapScaleFactor)
		{
			// Search individual samples up to the beginning of
			// the next first level mip map block
			const uint64_t final_index = min(end,
				pow2_ceil(index, MipMapScalePower));

			for (; index < final_index &&
				(index & ~(~0 << MipMapScalePower)) != 0;
				index++)
			{
				const bool sample =
					(get_sample(index) & sig_mask) != 0;

				// If there was a change we cannot fast forward
				if (sample != last_sample) {
					fast_forward = false;
					break;
				}
			}
		}
		else
		{
			// If resolution is less than a mip map block,
			// round up to the beginning of the mip-map block
			// for this level of detail
			const int min_level_scale_power =
				(level + 1) * MipMapScalePower;
			index = pow2_ceil(index, min_level_scale_power);
			if (index >= end)
				break;

			// We can fast forward only if there was no change
			const bool sample =
				(get_sample(index) & sig_mask) != 0;
			if (last_sample != sample)
				fast_forward = false;
		}

		if (fast_forward) {

			// Fast forward: This involves zooming out to higher
			// levels of the mip map searching for changes, then
			// zooming in on them to find the point where the edge
			// begins.

			// Slide right and zoom out at the beginnings of mip-map
			// blocks until we encounter a change
			while (1) {
				const int level_scale_power =
					(level + 1) * MipMapScalePower;
				const uint64_t offset =
					index >> level_scale_power;

				// Check if we reached the last block at this
				// level, or if there was a change in this block
				if (offset >= _mip_map[level].length ||
					(get_subsample(level, offset) &
						sig_mask))
					break;

				if ((offset & ~(~0 << MipMapScalePower)) == 0) {
					// If we are now at the beginning of a
					// higher level mip-map block ascend one
					// level
					if (level + 1 >= ScaleStepCount ||
						!_mip_map[level + 1].data)
						break;

					level++;
				} else {
					// Slide right to the beginning of the
					// next mip map block
					index = pow2_ceil(index + 1,
						level_scale_power);
				}
			}

			// Zoom in, and slide right until we encounter a change,
			// and repeat until we reach min_level
			while (1) {
				assert(_mip_map[level].data);

				const int level_scale_power =
					(level + 1) * MipMapScalePower;
				const uint64_t offset =
					index >> level_scale_power;

				// Check if we reached the last block at this
				// level, or if there was a change in this block
				if (offset >= _mip_map[level].length ||
					(get_subsample(level, offset) &
						sig_mask)) {
					// Zoom in unless we reached the minimum
					// zoom
					if (level == min_level)
						break;

					level--;
				} else {
					// Slide right to the beginning of the
					// next mip map block
					index = pow2_ceil(index + 1,
						level_scale_power);
				}
			}

			// If individual samples within the limit of resolution,
			// do a linear search for the next transition within the
			// block
			if (min_length < MipMapScaleFactor) {
				for (; index < end; index++) {
					const bool sample = (get_sample(index) &
						sig_mask) != 0;
					if (sample != last_sample)
						break;
				}
			}
		}

		//----- Store the edge -----//

		// Take the last sample of the quanization block
		const int64_t final_index = index + block_length;
		if (index + block_length > end)
			break;

		// Store the final state
		const bool final_sample =
			(get_sample(final_index - 1) & sig_mask) != 0;
		edges.push_back(pair<int64_t, bool>(index, final_sample));

		index = final_index;
		last_sample = final_sample;
	}

	// Add the final state
	const bool end_sample = get_sample(end) & sig_mask;
	if (last_sample != end_sample)
		edges.push_back(pair<int64_t, bool>(end, end_sample));
	edges.push_back(pair<int64_t, bool>(end + 1, end_sample));
}

uint64_t LogicSnapshot::get_subsample(int level, uint64_t offset) const
{
	assert(level >= 0);
	assert(_mip_map[level].data);
	return unpack_sample((uint8_t*)_mip_map[level].data +
		_unit_size * offset);
}

uint64_t LogicSnapshot::pow2_ceil(uint64_t x, unsigned int power)
{
	const uint64_t p = 1 << power;
	return (x + p - 1) / p * p;
}

} // namespace data
} // namespace pv
Commit	Line	Data
28a4c9c5	1	/*
b3f22de0	2	* This file is part of the PulseView project.
28a4c9c5 JH	3	*
	4	* Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
cef18fc6	21	#include <extdef.h>
28a4c9c5	22
f556bc6a	23	#include <assert.h>
4ceab49a	24	#include <string.h>
b36d8550	25	#include <stdlib.h>
4ceab49a JH	26	#include <math.h>
	27
	28	#include <boost/foreach.hpp>
	29
9df8453f	30	#include "config.h"
1b1ec774	31	#include "logicsnapshot.h"
f556bc6a	32
819f4c25 JH	33	using boost::lock_guard;
	34	using boost::recursive_mutex;
	35	using std::max;
	36	using std::min;
	37	using std::pair;
28a4c9c5	38
51e77110	39	namespace pv {
1b1ec774	40	namespace data {
51e77110	41
1b1ec774 JH	42	const int LogicSnapshot::MipMapScalePower = 4;
	43	const int LogicSnapshot::MipMapScaleFactor = 1 << MipMapScalePower;
	44	const float LogicSnapshot::LogMipMapScaleFactor = logf(MipMapScaleFactor);
	45	const uint64_t LogicSnapshot::MipMapDataUnit = 64*1024; // bytes
4ceab49a	46
27d7c96b DK	47	LogicSnapshot::LogicSnapshot(const sr_datafeed_logic &logic,
27d7c96b DK	48	const uint64_t expected_num_samples) :
1b1ec774	49	Snapshot(logic.unitsize),
4ceab49a	50	_last_append_sample(0)
f556bc6a	51	{
27d7c96b DK	52	set_capacity(expected_num_samples);
27d7c96b DK	53
7d29656f	54	lock_guard<recursive_mutex> lock(_mutex);
4ceab49a	55	memset(_mip_map, 0, sizeof(_mip_map));
f556bc6a JH	56	append_payload(logic);
	57	}
	58
1b1ec774	59	LogicSnapshot::~LogicSnapshot()
4ceab49a	60	{
7d29656f	61	lock_guard<recursive_mutex> lock(_mutex);
4ceab49a JH	62	BOOST_FOREACH(MipMapLevel &l, _mip_map)
	63	free(l.data);
	64	}
	65
8cb71705 MC	66	uint64_t LogicSnapshot::unpack_sample(const uint8_t *ptr) const
8cb71705 MC	67	{
9df8453f MC	68	#ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
	69	return (uint64_t)ptr;
	70	#else
8cb71705 MC	71	uint64_t value = 0;
	72	switch(_unit_size) {
	73	default:
	74	value \|= ((uint64_t)ptr[7]) << 56;
	75	/* FALLTHRU */
	76	case 7:
	77	value \|= ((uint64_t)ptr[6]) << 48;
	78	/* FALLTHRU */
	79	case 6:
	80	value \|= ((uint64_t)ptr[5]) << 40;
	81	/* FALLTHRU */
	82	case 5:
	83	value \|= ((uint64_t)ptr[4]) << 32;
	84	/* FALLTHRU */
	85	case 4:
	86	value \|= ((uint32_t)ptr[3]) << 24;
	87	/* FALLTHRU */
	88	case 3:
	89	value \|= ((uint32_t)ptr[2]) << 16;
	90	/* FALLTHRU */
	91	case 2:
	92	value \|= ptr[1] << 8;
	93	/* FALLTHRU */
	94	case 1:
	95	value \|= ptr[0];
	96	/* FALLTHRU */
	97	case 0:
	98	break;
	99	}
	100	return value;
9df8453f	101	#endif
8cb71705 MC	102	}
	103
	104	void LogicSnapshot::pack_sample(uint8_t *ptr, uint64_t value)
	105	{
9df8453f MC	106	#ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
	107	(uint64_t)ptr = value;
	108	#else
8cb71705 MC	109	switch(_unit_size) {
	110	default:
	111	ptr[7] = value >> 56;
	112	/* FALLTHRU */
	113	case 7:
	114	ptr[6] = value >> 48;
	115	/* FALLTHRU */
	116	case 6:
	117	ptr[5] = value >> 40;
	118	/* FALLTHRU */
	119	case 5:
	120	ptr[4] = value >> 32;
	121	/* FALLTHRU */
	122	case 4:
	123	ptr[3] = value >> 24;
	124	/* FALLTHRU */
	125	case 3:
	126	ptr[2] = value >> 16;
	127	/* FALLTHRU */
	128	case 2:
	129	ptr[1] = value >> 8;
	130	/* FALLTHRU */
	131	case 1:
	132	ptr[0] = value;
	133	/* FALLTHRU */
	134	case 0:
	135	break;
	136	}
9df8453f	137	#endif
8cb71705 MC	138	}
8cb71705 MC	139
1b1ec774	140	void LogicSnapshot::append_payload(
28a4c9c5 JH	141	const sr_datafeed_logic &logic)
28a4c9c5 JH	142	{
f556bc6a	143	assert(_unit_size == logic.unitsize);
5cef1ea3	144	assert((logic.length % _unit_size) == 0);
f556bc6a	145
7d29656f JH	146	lock_guard<recursive_mutex> lock(_mutex);
7d29656f JH	147
5cef1ea3	148	append_data(logic.data, logic.length / _unit_size);
4ceab49a JH	149
	150	// Generate the first mip-map from the data
	151	append_payload_to_mipmap();
	152	}
	153
ed990f11 JH	154	void LogicSnapshot::get_samples(uint8_t *const data,
	155	int64_t start_sample, int64_t end_sample) const
	156	{
	157	assert(data);
	158	assert(start_sample >= 0);
0fbda3c2	159	assert(start_sample <= (int64_t)_sample_count);
ed990f11	160	assert(end_sample >= 0);
0fbda3c2	161	assert(end_sample <= (int64_t)_sample_count);
ed990f11 JH	162	assert(start_sample <= end_sample);
	163
	164	lock_guard<recursive_mutex> lock(_mutex);
	165
	166	const size_t size = (end_sample - start_sample) * _unit_size;
	167	memcpy(data, (const uint8_t*)_data + start_sample, size);
	168	}
	169
023887ca	170	void LogicSnapshot::reallocate_mipmap_level(MipMapLevel &m)
4ceab49a JH	171	{
	172	const uint64_t new_data_length = ((m.length + MipMapDataUnit - 1) /
	173	MipMapDataUnit) * MipMapDataUnit;
333d5bbc	174	if (new_data_length > m.data_length)
4ceab49a JH	175	{
4ceab49a JH	176	m.data_length = new_data_length;
8fe60279 JH	177
	178	// Padding is added to allow for the uint64_t write word
	179	m.data = realloc(m.data, new_data_length * _unit_size +
	180	sizeof(uint64_t));
4ceab49a JH	181	}
	182	}
	183
1b1ec774	184	void LogicSnapshot::append_payload_to_mipmap()
4ceab49a JH	185	{
	186	MipMapLevel &m0 = _mip_map[0];
	187	uint64_t prev_length;
	188	const uint8_t *src_ptr;
	189	uint8_t *dest_ptr;
	190	uint64_t accumulator;
	191	unsigned int diff_counter;
	192
	193	// Expand the data buffer to fit the new samples
	194	prev_length = m0.length;
77bff0b1	195	m0.length = _sample_count / MipMapScaleFactor;
4ceab49a JH	196
4ceab49a JH	197	// Break off if there are no new samples to compute
333d5bbc	198	if (m0.length == prev_length)
4ceab49a JH	199	return;
4ceab49a JH	200
023887ca	201	reallocate_mipmap_level(m0);
4ceab49a JH	202
	203	dest_ptr = (uint8_t)m0.data + prev_length _unit_size;
	204
	205	// Iterate through the samples to populate the first level mipmap
023887ca	206	const uint8_t const end_src_ptr = (uint8_t)_data +
4ceab49a	207	m0.length * _unit_size * MipMapScaleFactor;
333d5bbc	208	for (src_ptr = (uint8_t*)_data +
4ceab49a JH	209	prev_length * _unit_size * MipMapScaleFactor;
	210	src_ptr < end_src_ptr;)
	211	{
	212	// Accumulate transitions which have occurred in this sample
	213	accumulator = 0;
	214	diff_counter = MipMapScaleFactor;
333d5bbc	215	while (diff_counter-- > 0)
4ceab49a	216	{
8cb71705	217	const uint64_t sample = unpack_sample(src_ptr);
4ceab49a JH	218	accumulator \|= _last_append_sample ^ sample;
	219	_last_append_sample = sample;
	220	src_ptr += _unit_size;
	221	}
	222
8cb71705	223	pack_sample(dest_ptr, accumulator);
4ceab49a JH	224	dest_ptr += _unit_size;
	225	}
	226
	227	// Compute higher level mipmaps
333d5bbc	228	for (unsigned int level = 1; level < ScaleStepCount; level++)
4ceab49a JH	229	{
	230	MipMapLevel &m = _mip_map[level];
	231	const MipMapLevel &ml = _mip_map[level-1];
	232
	233	// Expand the data buffer to fit the new samples
	234	prev_length = m.length;
	235	m.length = ml.length / MipMapScaleFactor;
	236
	237	// Break off if there are no more samples to computed
333d5bbc	238	if (m.length == prev_length)
4ceab49a JH	239	break;
4ceab49a JH	240
023887ca	241	reallocate_mipmap_level(m);
4ceab49a JH	242
	243	// Subsample the level lower level
	244	src_ptr = (uint8_t*)ml.data +
	245	_unit_size * prev_length * MipMapScaleFactor;
023887ca	246	const uint8_t *const end_dest_ptr =
4ceab49a	247	(uint8_t)m.data + _unit_size m.length;
333d5bbc	248	for (dest_ptr = (uint8_t*)m.data +
4ceab49a JH	249	_unit_size * prev_length;
	250	dest_ptr < end_dest_ptr;
	251	dest_ptr += _unit_size)
	252	{
	253	accumulator = 0;
	254	diff_counter = MipMapScaleFactor;
333d5bbc	255	while (diff_counter-- > 0)
4ceab49a	256	{
8cb71705	257	accumulator \|= unpack_sample(src_ptr);
4ceab49a JH	258	src_ptr += _unit_size;
	259	}
	260
8cb71705	261	pack_sample(dest_ptr, accumulator);
4ceab49a JH	262	}
4ceab49a JH	263	}
28a4c9c5	264	}
2858b391	265
1b1ec774	266	uint64_t LogicSnapshot::get_sample(uint64_t index) const
2858b391 JH	267	{
2858b391 JH	268	assert(_data);
3f96c34a	269	assert(index < _sample_count);
2858b391	270
8cb71705	271	return unpack_sample((uint8_t)_data + index _unit_size);
2858b391 JH	272	}
2858b391 JH	273
1b1ec774	274	void LogicSnapshot::get_subsampled_edges(
2858b391	275	std::vector<EdgePair> &edges,
60b0c2da	276	uint64_t start, uint64_t end,
0b02e057	277	float min_length, int sig_index)
2858b391	278	{
60b0c2da JH	279	uint64_t index = start;
60b0c2da JH	280	unsigned int level;
7d0d64f9 JH	281	bool last_sample;
7d0d64f9 JH	282	bool fast_forward;
0b02e057	283
0b02e057	284	assert(end <= get_sample_count());
2858b391	285	assert(start <= end);
0b02e057	286	assert(min_length > 0);
2858b391	287	assert(sig_index >= 0);
80d50141	288	assert(sig_index < 64);
2858b391	289
7d29656f JH	290	lock_guard<recursive_mutex> lock(_mutex);
7d29656f JH	291
60b0c2da JH	292	const uint64_t block_length = (uint64_t)max(min_length, 1.0f);
60b0c2da JH	293	const unsigned int min_level = max((int)floorf(logf(min_length) /
0b02e057	294	LogMipMapScaleFactor) - 1, 0);
7d0d64f9	295	const uint64_t sig_mask = 1ULL << sig_index;
2858b391	296
7d0d64f9 JH	297	// Store the initial state
	298	last_sample = (get_sample(start) & sig_mask) != 0;
	299	edges.push_back(pair<int64_t, bool>(index++, last_sample));
2858b391	300
333d5bbc	301	while (index + block_length <= end)
2858b391	302	{
7d0d64f9	303	//----- Continue to search -----//
0b02e057	304	level = min_level;
f06ab143 JH	305
	306	// We cannot fast-forward if there is no mip-map data at
	307	// at the minimum level.
	308	fast_forward = (_mip_map[level].data != NULL);
2858b391	309
333d5bbc	310	if (min_length < MipMapScaleFactor)
0b02e057 JH	311	{
	312	// Search individual samples up to the beginning of
	313	// the next first level mip map block
7d0d64f9	314	const uint64_t final_index = min(end,
0b02e057 JH	315	pow2_ceil(index, MipMapScalePower));
0b02e057 JH	316
333d5bbc	317	for (; index < final_index &&
0b02e057 JH	318	(index & ~(~0 << MipMapScalePower)) != 0;
	319	index++)
	320	{
	321	const bool sample =
	322	(get_sample(index) & sig_mask) != 0;
7d0d64f9 JH	323
7d0d64f9 JH	324	// If there was a change we cannot fast forward
333d5bbc	325	if (sample != last_sample) {
7d0d64f9	326	fast_forward = false;
0b02e057	327	break;
7d0d64f9	328	}
0b02e057 JH	329	}
	330	}
	331	else
	332	{
	333	// If resolution is less than a mip map block,
	334	// round up to the beginning of the mip-map block
	335	// for this level of detail
	336	const int min_level_scale_power =
	337	(level + 1) * MipMapScalePower;
	338	index = pow2_ceil(index, min_level_scale_power);
333d5bbc	339	if (index >= end)
0b02e057 JH	340	break;
0b02e057 JH	341
7d0d64f9 JH	342	// We can fast forward only if there was no change
	343	const bool sample =
	344	(get_sample(index) & sig_mask) != 0;
f06ab143 JH	345	if (last_sample != sample)
f06ab143 JH	346	fast_forward = false;
0b02e057 JH	347	}
0b02e057 JH	348
333d5bbc	349	if (fast_forward) {
7d0d64f9 JH	350
	351	// Fast forward: This involves zooming out to higher
	352	// levels of the mip map searching for changes, then
	353	// zooming in on them to find the point where the edge
	354	// begins.
	355
	356	// Slide right and zoom out at the beginnings of mip-map
	357	// blocks until we encounter a change
333d5bbc	358	while (1) {
7d0d64f9 JH	359	const int level_scale_power =
	360	(level + 1) * MipMapScalePower;
	361	const uint64_t offset =
	362	index >> level_scale_power;
7d0d64f9 JH	363
	364	// Check if we reached the last block at this
	365	// level, or if there was a change in this block
333d5bbc	366	if (offset >= _mip_map[level].length \|\|
7d0d64f9 JH	367	(get_subsample(level, offset) &
7d0d64f9 JH	368	sig_mask))
0b02e057 JH	369	break;
0b02e057 JH	370
333d5bbc	371	if ((offset & ~(~0 << MipMapScalePower)) == 0) {
7d0d64f9 JH	372	// If we are now at the beginning of a
	373	// higher level mip-map block ascend one
	374	// level
333d5bbc	375	if (level + 1 >= ScaleStepCount \|\|
7d0d64f9 JH	376	!_mip_map[level + 1].data)
	377	break;
	378
	379	level++;
	380	} else {
	381	// Slide right to the beginning of the
	382	// next mip map block
	383	index = pow2_ceil(index + 1,
	384	level_scale_power);
	385	}
0b02e057	386	}
7d0d64f9 JH	387
	388	// Zoom in, and slide right until we encounter a change,
	389	// and repeat until we reach min_level
333d5bbc	390	while (1) {
7d0d64f9 JH	391	assert(_mip_map[level].data);
	392
	393	const int level_scale_power =
	394	(level + 1) * MipMapScalePower;
	395	const uint64_t offset =
	396	index >> level_scale_power;
7d0d64f9 JH	397
	398	// Check if we reached the last block at this
	399	// level, or if there was a change in this block
333d5bbc	400	if (offset >= _mip_map[level].length \|\|
7d0d64f9 JH	401	(get_subsample(level, offset) &
	402	sig_mask)) {
	403	// Zoom in unless we reached the minimum
	404	// zoom
333d5bbc	405	if (level == min_level)
7d0d64f9 JH	406	break;
	407
	408	level--;
	409	} else {
	410	// Slide right to the beginning of the
	411	// next mip map block
	412	index = pow2_ceil(index + 1,
	413	level_scale_power);
	414	}
0b02e057	415	}
0b02e057	416
7d0d64f9 JH	417	// If individual samples within the limit of resolution,
	418	// do a linear search for the next transition within the
	419	// block
333d5bbc UH	420	if (min_length < MipMapScaleFactor) {
333d5bbc UH	421	for (; index < end; index++) {
7d0d64f9 JH	422	const bool sample = (get_sample(index) &
7d0d64f9 JH	423	sig_mask) != 0;
333d5bbc	424	if (sample != last_sample)
7d0d64f9 JH	425	break;
7d0d64f9 JH	426	}
0b02e057 JH	427	}
	428	}
	429
7d0d64f9 JH	430	//----- Store the edge -----//
	431
	432	// Take the last sample of the quanization block
	433	const int64_t final_index = index + block_length;
333d5bbc	434	if (index + block_length > end)
7d0d64f9 JH	435	break;
	436
	437	// Store the final state
	438	const bool final_sample =
	439	(get_sample(final_index - 1) & sig_mask) != 0;
	440	edges.push_back(pair<int64_t, bool>(index, final_sample));
	441
	442	index = final_index;
	443	last_sample = final_sample;
2858b391 JH	444	}
	445
	446	// Add the final state
175d6573 JH	447	const bool end_sample = get_sample(end) & sig_mask;
	448	if (last_sample != end_sample)
	449	edges.push_back(pair<int64_t, bool>(end, end_sample));
	450	edges.push_back(pair<int64_t, bool>(end + 1, end_sample));
2858b391	451	}
0b02e057	452
1b1ec774	453	uint64_t LogicSnapshot::get_subsample(int level, uint64_t offset) const
b2bcbe51 JH	454	{
	455	assert(level >= 0);
	456	assert(_mip_map[level].data);
8cb71705	457	return unpack_sample((uint8_t*)_mip_map[level].data +
b2bcbe51 JH	458	_unit_size * offset);
	459	}
	460
1b1ec774	461	uint64_t LogicSnapshot::pow2_ceil(uint64_t x, unsigned int power)
0b02e057	462	{
60b0c2da JH	463	const uint64_t p = 1 << power;
60b0c2da JH	464	return (x + p - 1) / p * p;
0b02e057	465	}
51e77110	466
1b1ec774	467	} // namespace data
51e77110	468	} // namespace pv