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Touchpad Updates - 3 point calibration support +

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Touchpad reads now return coord_t instead of uint16_t
tpTransform function does the calibration transformation instead of
the original functions
This commit is contained in:
Kumar Abhishek 2012-11-09 00:41:22 +05:30
parent 6105b88f89
commit f75a2ae91e
1 changed files with 375 additions and 266 deletions
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191
src/touchpad.c
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@ -54,11 +54,11 @@ static struct cal_t *cal;
/* Driver local functions. */ /* Driver local functions. */
/*===========================================================================*/ /*===========================================================================*/
static uint16_t _tpReadRealX(void) { static coord_t _tpReadRealX(void) {
uint32_t results = 0; int32_t results = 0;
uint16_t i, x; int16_t i;
coord_t x;
/* Median filtering is already done in LLD */
for(i = 0; i < CONVERSIONS; i++) { for(i = 0; i < CONVERSIONS; i++) {
results += tp_lld_read_x(); results += tp_lld_read_x();
} }
@ -69,11 +69,11 @@ static uint16_t _tpReadRealX(void) {
return x; return x;
} }
static uint16_t _tpReadRealY(void) { static coord_t _tpReadRealY(void) {
uint32_t results = 0; int32_t results = 0;
uint16_t i, y; int16_t i;
coord_t y;
/* Median filtering is already done in LLD */
for(i = 0; i < CONVERSIONS; i++) { for(i = 0; i < CONVERSIONS; i++) {
results += tp_lld_read_y(); results += tp_lld_read_y();
} }
@ -103,6 +103,50 @@ static void _tpDrawCross(uint16_t x, uint16_t y) {
gdispDrawLine(x+15, y-15, x+15, y-7, RGB565CONVERT(184,158,131)); gdispDrawLine(x+15, y-15, x+15, y-7, RGB565CONVERT(184,158,131));
} }
static void _tpTransform(coord_t *x, coord_t *y) {
*x = (coord_t) (cal->ax * (*x) + cal->bx * (*y) + cal->cx);
*y = (coord_t) (cal->ay * (*x) + cal->by * (*y) + cal->cy);
}
static void _tpDo3PointCalibration(const coord_t (*cross)[2], coord_t (*points)[2],
cal_t *c)
{
float dx, dx0, dx1, dx2, dy0, dy1, dy2;
/* Compute all the required determinants */
dx = ((float)(points[0][0] - points[2][0])) * ((float)(points[1][1] - points[2][1]))
- ((float)(points[1][0] - points[2][0])) * ((float)(points[0][1] - points[2][1]));
dx0 = ((float)(cross[0][0] - cross[2][0])) * ((float)(points[1][1] - points[2][1]))
- ((float)(cross[1][0] - cross[2][0])) * ((float)(points[0][1] - points[2][1]));
dx1 = ((float)(points[0][0] - points[2][0])) * ((float)(cross[1][0] - cross[2][0]))
- ((float)(points[1][0] - points[2][0])) * ((float)(cross[0][0] - cross[2][0]));
dx2 = cross[0][0] * ((float)points[1][0] * (float)points[2][1] - (float)points[2][0] * (float)points[1][1]) -
cross[1][0] * ((float)points[0][0] * (float)points[2][1] - (float)points[2][0] * (float)points[0][1]) +
cross[2][0] * ((float)points[0][0] * (float)points[1][1] - (float)points[1][0] * (float)points[0][1]);
dy0 = ((float)(cross[0][1] - cross[2][1])) * ((float)(points[1][1] - points[2][1]))
- ((float)(cross[1][1] - cross[2][1])) * ((float)(points[0][1] - points[2][1]));
dy1 = ((float)(points[0][0] - points[2][0])) * ((float)(cross[1][1] - cross[2][1]))
- ((float)(points[1][0] - points[2][0])) * ((float)(cross[0][1] - cross[2][1]));
dy2 = cross[0][1] * ((float)points[1][0] * (float)points[2][1] - (float)points[2][0] * (float)points[1][1]) -
cross[1][1] * ((float)points[0][0] * (float)points[2][1] - (float)points[2][0] * (float)points[0][1]) +
cross[2][1] * ((float)points[0][0] * (float)points[1][1] - (float)points[1][0] * (float)points[0][1]);
/* Now, calculate all the required coefficients */
c->ax = dx0 / dx;
c->bx = dx1 / dx;
c->cx = dx2 / dx;
c->ay = dy0 / dx;
c->by = dy1 / dx;
c->cy = dy2 / dx;
}
/*===========================================================================*/ /*===========================================================================*/
/* Driver exported functions. */ /* Driver exported functions. */
/*===========================================================================*/ /*===========================================================================*/
@ -145,17 +189,19 @@ void tpInit(const TOUCHPADDriver *tp) {
* *
* @api * @api
*/ */
uint16_t tpReadX(void) { coord_t tpReadX(void) {
uint16_t x, y; coord_t x, y;
#if TOUCHPAD_XY_INVERTED == TRUE #if TOUCHPAD_XY_INVERTED == TRUE
x = cal->xm * _tpReadRealY() + cal->xn; x = _tpReadRealY();
y = cal->ym * _tpReadRealX() + cal->yn; y = _tpReadRealX();
#else #else
x = cal->xm * _tpReadRealX() + cal->xn; x = _tpReadRealX();
y = cal->ym * _tpReadRealY() + cal->yn; y = _tpReadRealY();
#endif #endif
_tpTransform(&x, &y);
switch(gdispGetOrientation()) { switch(gdispGetOrientation()) {
case GDISP_ROTATE_0: case GDISP_ROTATE_0:
return x; return x;
@ -177,17 +223,19 @@ uint16_t tpReadX(void) {
* *
* @api * @api
*/ */
uint16_t tpReadY(void) { coord_t tpReadY(void) {
uint16_t x, y; coord_t x, y;
#if TOUCHPAD_XY_INVERTED == TRUE #if TOUCHPAD_XY_INVERTED == TRUE
x = cal->xm * _tpReadRealY() + cal->xn; x = _tpReadRealY();
y = cal->ym * _tpReadRealX() + cal->yn; y = _tpReadRealX();
#else #else
x = cal->xm * _tpReadRealX() + cal->xn; x = _tpReadRealX();
y = cal->ym * _tpReadRealY() + cal->yn; y = _tpReadRealY();
#endif #endif
_tpTransform(&x, &y);
switch(gdispGetOrientation()) { switch(gdispGetOrientation()) {
case GDISP_ROTATE_0: case GDISP_ROTATE_0:
return y; return y;
@ -217,45 +265,106 @@ uint16_t tpReadY(void) {
#endif #endif
/** /**
* @brief returns if touchpad is pressed or not * @brief Returns if touchpad is pressed or not
* *
* @return 1 if pressed, 0 otherwise * @return TRUE if pressed, FALSE otherwise
* *
* @api * @api
*/ */
#if TOUCHPAD_HAS_IRQ || defined(__DOXYGEN__) #if TOUCHPAD_HAS_IRQ || defined(__DOXYGEN__)
uint8_t tpIRQ(void) { bool_t tpIRQ(void) {
return tp_lld_irq(); return tp_lld_irq();
} }
#endif #endif
/* Define maximum no. of times to sample the calibration point */
#define MAX_CAL_SAMPLES 10
/**
* @brief This function interactively performs calibration of the touchscreen
* using 3-point calibration algorithm. Optionally, it also verifies
* the accuracy of the calibration coefficients obtained if the symbol
* TOUCHPAD_VERIFY_CALIBRATION is defined in the configuration.
*
* @api
*/
void tpCalibrate(void) { void tpCalibrate(void) {
const uint16_t h = gdispGetHeight(); const uint16_t height = gdispGetHeight();
const uint16_t w = gdispGetWidth(); const uint16_t width = gdispGetWidth();
const uint16_t cross[2][2] = {{(w/8), (h/8)}, {(w-(w/8)) , (h-(h/8))}}; const coord_t cross[][2] = {{(width / 4), (height / 4)},
uint16_t points[2][2]; {(width - (width / 4)) , (height / 4)},
uint8_t i; {(width - (width / 4)) , (height - (height / 4))},
{(width / 2), (height / 2)}}; /* Check point */
coord_t points[4][2];
int32_t px, py;
uint8_t i, j;
gdispSetOrientation(GDISP_ROTATE_0); gdispSetOrientation(GDISP_ROTATE_0);
gdispClear(Red); gdispClear(Blue);
gdispFillStringBox(0, 10, gdispGetWidth(), 30, "Calibration", &fontUI2Double, White, Red, justifyCenter);
for(i = 0; i < 2; i++) { gdispFillStringBox(0, 5, gdispGetWidth(), 30, "Calibration", &fontUI2Double, White, Blue, justifyCenter);
#if defined(TOUCHPAD_VERIFY_CALIBRATION)
calibrate:
for(i = 0; i < 4; i++) {
#else
for(i = 0; i < 3; i++) {
#endif
_tpDrawCross(cross[i][0], cross[i][1]); _tpDrawCross(cross[i][0], cross[i][1]);
while(!tpIRQ());
points[i][0] = _tpReadRealX(); while(!tpIRQ())
points[i][1] = _tpReadRealY(); chThdSleepMilliseconds(2); /* Be nice to other threads*/
chThdSleepMilliseconds(100);
while(tpIRQ()); chThdSleepMilliseconds(20); /* Allow screen to settle */
gdispFillArea(cross[i][0]-15, cross[i][1]-15, 42, 42, Red);
/* Take a little more samples per point and their average
* for precise calibration */
px = py = 0;
j = 0;
while (j < MAX_CAL_SAMPLES) {
if (tpIRQ()) {
/* We have valid pointer data */
px += _tpReadRealX();
py += _tpReadRealY();
j++;
}
} }
cal->xm = ((float)cross[1][0] - (float)cross[0][0]) / ((float)points[1][0] - (float)points[0][0]); points[i][0] = px / j;
cal->ym = ((float)cross[1][1] - (float)cross[0][1]) / ((float)points[1][1] - (float)points[0][1]); points[i][1] = py / j;
cal->xn = (float)cross[0][0] - cal->xm * (float)points[0][0]; chThdSleepMilliseconds(100);
cal->yn = (float)cross[0][1] - cal->ym * (float)points[0][1];
while(tpIRQ())
chThdSleepMilliseconds(2); /* Be nice to other threads*/
gdispFillArea(cross[i][0] - 15, cross[i][1] - 15, 42, 42, Blue);
}
/* Apply 3 point calibration algorithm */
_tpDo3PointCalibration(cross, points, cal);
#if defined(TOUCHPAD_VERIFY_CALIBRATION)
/* Verification of correctness of calibration (optional) :
* See if the 4th point (Middle of the screen) coincides with the calibrated
* result. If point is with +/- 2 pixel margin, then successful calibration
* Else, start from the beginning.
*/
/* Transform the co-ordinates */
_tpTransform(&points[3][0], &points[3][1]);
/* Calculate the delta */
px = (points[3][0] - cross[3][0]) * (points[3][0] - cross[3][0]) +
(points[3][1] - cross[3][1]) * (points[3][1] - cross[3][1]);
if (px > 4)
goto calibrate;
#endif
/* If enabled, serialize the calibration values for storage */
#if TOUCHPAD_STORE_CALIBRATION #if TOUCHPAD_STORE_CALIBRATION
tp_store_calibration_lld(cal); tp_store_calibration_lld(cal);
#endif #endif