WebSVN – libIgnTiming – Blame – /trunk/src/timing.cpp

Rev	Author	Line No.	Line
2	mjames	1	#include <cstdint>
		2	#include <assert.h>
		3	#include "libIgnTiming/timing.h"
12	mjames	4	#include "libIgnTiming/basemap.h"
11	mjames	5
		6
7	mjames	7	#if defined __cplusplus
		8	extern "C"
2	mjames	9	{
7	mjames	10	#endif
2	mjames	11
7	mjames	12	namespace
		13	{
11	mjames	14	int8_t timingAdjust = 0 * TIMING_SCALE; // in TIMING_SCALE
12	mjames	15	// local copy of the data structure
		16	timingTable_t timingMap = baseTimingMap;
2	mjames	17
11	mjames	18	int16_t constexpr MAX_ADVANCE = 50 * TIMING_SCALE;
		19	int16_t constexpr MIN_ADVANCE = 7 * TIMING_SCALE;
2	mjames	20
12	mjames	21
7	mjames	22	}
6	mjames	23
7	mjames	24	uint8_t getTimingAdjust() { return timingAdjust; };
6	mjames	25
7	mjames	26	void setTimingAdjust(int8_t adjust) { timingAdjust = adjust; }
6	mjames	27
7	mjames	28	int16_t getRpmMap(unsigned int i)
		29	{
		30	if (i >= 0 && i < MAX_RPM_POINTS)
12	mjames	31	return timingMap.rpmMap[i];
7	mjames	32	else
		33	return 0;
		34	}
6	mjames	35
12	mjames	36
		37	void setBaseMap(timingTable_t * map)
		38	{
		39	timingMap = *map;
		40	}
		41
		42
		43
7	mjames	44	void setRpmMap(unsigned int i, uint16_t val)
		45	{
11	mjames	46	#if WRITABLE_TABLE
7	mjames	47	if (i >= 0 && i < MAX_RPM_POINTS)
12	mjames	48	timingMap.rpmMap[i] = val;
11	mjames	49	#endif
7	mjames	50	}
6	mjames	51
7	mjames	52	uint16_t getVacuumMap(unsigned int i)
		53	{
		54	if (i >= 0 && i < MAX_VACUUM_POINTS)
12	mjames	55	return timingMap.vacuumMap[i];
7	mjames	56	else
		57	return 0;
		58	}
6	mjames	59
7	mjames	60	void setVacuumMap(unsigned int i, uint16_t val)
		61	{
11	mjames	62	#if WRITABLE_TABLE
7	mjames	63	if (i >= 0 && i < MAX_VACUUM_POINTS)
12	mjames	64	timingMap.vacuumMap[i] = val;
11	mjames	65	#endif
7	mjames	66	}
6	mjames	67
7	mjames	68	void setTiming(unsigned int vacuumIndex, unsigned int rpmIndex, uint8_t value)
2	mjames	69	{
11	mjames	70
		71	#if WRITABLE_TABLE
7	mjames	72	if (vacuumIndex < 0 && vacuumIndex >= MAX_VACUUM_POINTS)
		73	return;
		74	if (rpmIndex < 0 && rpmIndex >= MAX_RPM_POINTS)
		75	return;
12	mjames	76	timingMap.mapping[vacuumIndex][rpmIndex] = value;
11	mjames	77	#endif
2	mjames	78	}
		79
7	mjames	80	uint8_t getTiming(unsigned int vacuumIndex, unsigned int rpmIndex)
2	mjames	81	{
7	mjames	82	if (vacuumIndex < 0 && vacuumIndex >= MAX_VACUUM_POINTS)
		83	return 0;
		84	if (rpmIndex < 0 && rpmIndex >= MAX_RPM_POINTS)
		85	return 0;
12	mjames	86	return timingMap.mapping[vacuumIndex][rpmIndex];
2	mjames	87	}
7	mjames	88
11	mjames	89	/// @brief Lookup a point in a 1 dimensional array -
		90	/// @param point Value to lookup
		91	/// @param curve Lookup table
		92	/// @param size Size of lookup table
		93	/// @param [out] frac fraction of distance from first point in array
		94	/// @return index in array or NO_DATA if operations fail
7	mjames	95	int lookup(int point, int16_t const curve[], int size, int16_t *frac)
2	mjames	96	{
7	mjames	97	// check lower bounds
		98	if (point < curve[0])
2	mjames	99	{
7	mjames	100	*frac = 0;
		101	return 0;
		102	}
		103	// check upper bounds
		104	// find the upper boundary by looking for non -1 points
		105	int upper = size - 1;
8	mjames	106	while (upper != 0 && curve[upper] == NO_DATA)
7	mjames	107	upper--;
2	mjames	108
7	mjames	109	if (point >= curve[upper])
		110	{
		111	*frac = 0;
		112	return upper;
		113	}
		114	for (int pt = 1; pt <= upper; pt++)
		115	{
		116	if ((point >= curve[pt - 1]) && (point < curve[pt]))
		117	{
2	mjames	118
7	mjames	119	int range1 = curve[pt] - curve[pt - 1];
2	mjames	120
7	mjames	121	if (range1 == 0)
		122	{
		123	*frac = 0;
		124	return pt - 1;
		125	}
		126
		127	// how far along axis ?
		128	int offset = point - curve[pt - 1];
		129
		130	int range2 = INTERP_SCALE;
		131
		132	frac = ((offset range2) / range1);
		133	return pt - 1;
		134	}
2	mjames	135	}
7	mjames	136	*frac = 0;
11	mjames	137	return NO_DATA; // give up.
7	mjames	138	};
2	mjames	139
7	mjames	140	extern "C"
2	mjames	141	{
		142
7	mjames	143	int mapTiming(int rpm, int vacuumMb)
		144	{
		145	int angle = 0;
		146	/* lookup the interpolated RPM point */
		147	int16_t rpm_frac = 0;
12	mjames	148	int rpm_index = lookup(rpm, timingMap.rpmMap, MAX_RPM_POINTS, &rpm_frac);
7	mjames	149	if (rpm_index == NO_DATA)
		150	return timingAdjust + MIN_ADVANCE;
2	mjames	151
7	mjames	152	/* lookup the interpolated vacuum point */
		153	int16_t vacuum_frac = 0;
12	mjames	154	int vacuum_index = lookup(vacuumMb, timingMap.vacuumMap, MAX_VACUUM_POINTS, &vacuum_frac);
7	mjames	155	/* if there is a problem, bail out */
		156	if (vacuum_index == NO_DATA)
		157	return timingAdjust + MIN_ADVANCE;
2	mjames	158
7	mjames	159	/* perform a bilinear mapping */
		160	int top_advance;
		161	// we now have a position between two points in X and Y
		162	if (rpm_frac == 0)
12	mjames	163	top_advance = timingMap.mapping[vacuum_index][rpm_index] * INTERP_SCALE;
7	mjames	164	// if fractional part then interpolate points off the map
		165	else
12	mjames	166	top_advance = timingMap.mapping[vacuum_index][rpm_index] * (INTERP_SCALE - rpm_frac) +
		167	timingMap.mapping[vacuum_index][rpm_index + 1] * rpm_frac;
7	mjames	168
		169	int bottom_advance;
		170	// if no fractional part, then the top and bottom advance point is the same
		171	if (vacuum_frac == 0)
		172	{
12	mjames	173	angle = top_advance * TIMING_SCALE / INTERP_SCALE;
7	mjames	174	}
		175	else
		176	{
12	mjames	177	bottom_advance = timingMap.mapping[vacuum_index + 1][rpm_index] * (INTERP_SCALE - rpm_frac) +
		178	timingMap.mapping[vacuum_index + 1][rpm_index + 1] * rpm_frac;
7	mjames	179	/* interpolate down Y axis this time */
		180	int advance = top_advance * (INTERP_SCALE - vacuum_frac) + bottom_advance * vacuum_frac;
		181	/* point is scaled by two multiplications */
12	mjames	182	angle = advance * TIMING_SCALE / (INTERP_SCALE * INTERP_SCALE);
7	mjames	183	}
		184
		185	if (angle < MIN_ADVANCE)
		186	angle = MIN_ADVANCE;
		187	if (angle > MAX_ADVANCE)
		188	angle = MAX_ADVANCE;
		189
		190	return angle + timingAdjust;
2	mjames	191	}
		192	}
7	mjames	193	#if defined __cplusplus
2	mjames	194	}
7	mjames	195	#endif

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(root)/trunk/src/timing.cpp – Rev 12