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Merge pull request #13 from abhishek-kakkar/master 

Touchscreen 3 point calibration support
ugfx_release_2.6
Tectu 2012-11-08 14:35:30 -08:00
parent 9592a87826 f75a2ae91e
commit 3dd0b1a5af
2 changed files with 387 additions and 273 deletions
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19
include/touchpad.h
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@ -49,6 +49,9 @@
/* Include the low level driver information */
#include "touchpad_lld.h"
/* For definitions of coord_t, we require gdisp.h */
#include "gdisp.h"
/*===========================================================================*/
/* Type definitions */
/*===========================================================================*/
@ -57,10 +60,12 @@
* @brief Struct used for calibration
*/
typedef struct cal_t {
float xm;
float ym;
float xn;
float yn;
float ax;
float bx;
float cx;
float ay;
float by;
float cy;
} cal_t;
/*===========================================================================*/
@ -72,12 +77,12 @@ extern "C" {
#endif
void tpInit(const TOUCHPADDriver *tp);
uint16_t tpReadX(void);
uint16_t tpReadY(void);
coord_t tpReadX(void);
coord_t tpReadY(void);
void tpCalibrate(void);
#if TOUCHPAD_HAS_IRQ
uint8_t tpIRQ(void);
bool_t tpIRQ(void);
#endif
#if TOUCHPAD_HAS_PRESSURE

191
src/touchpad.c
View File

@ -54,11 +54,11 @@ static struct cal_t *cal;
/* Driver local functions. */
/*===========================================================================*/
static uint16_t _tpReadRealX(void) {
uint32_t results = 0;
uint16_t i, x;
static coord_t _tpReadRealX(void) {
int32_t results = 0;
int16_t i;
coord_t x;
/* Median filtering is already done in LLD */
for(i = 0; i < CONVERSIONS; i++) {
results += tp_lld_read_x();
}
@ -69,11 +69,11 @@ static uint16_t _tpReadRealX(void) {
return x;
}
static uint16_t _tpReadRealY(void) {
uint32_t results = 0;
uint16_t i, y;
static coord_t _tpReadRealY(void) {
int32_t results = 0;
int16_t i;
coord_t y;
/* Median filtering is already done in LLD */
for(i = 0; i < CONVERSIONS; i++) {
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));
}
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. */
/*===========================================================================*/
@ -145,17 +189,19 @@ void tpInit(const TOUCHPADDriver *tp) {
*
* @api
*/
uint16_t tpReadX(void) {
uint16_t x, y;
coord_t tpReadX(void) {
coord_t x, y;
#if TOUCHPAD_XY_INVERTED == TRUE
x = cal->xm * _tpReadRealY() + cal->xn;
y = cal->ym * _tpReadRealX() + cal->yn;
x = _tpReadRealY();
y = _tpReadRealX();
#else
x = cal->xm * _tpReadRealX() + cal->xn;
y = cal->ym * _tpReadRealY() + cal->yn;
x = _tpReadRealX();
y = _tpReadRealY();
#endif
_tpTransform(&x, &y);
switch(gdispGetOrientation()) {
case GDISP_ROTATE_0:
return x;
@ -177,17 +223,19 @@ uint16_t tpReadX(void) {
*
* @api
*/
uint16_t tpReadY(void) {
uint16_t x, y;
coord_t tpReadY(void) {
coord_t x, y;
#if TOUCHPAD_XY_INVERTED == TRUE
x = cal->xm * _tpReadRealY() + cal->xn;
y = cal->ym * _tpReadRealX() + cal->yn;
x = _tpReadRealY();
y = _tpReadRealX();
#else
x = cal->xm * _tpReadRealX() + cal->xn;
y = cal->ym * _tpReadRealY() + cal->yn;
x = _tpReadRealX();
y = _tpReadRealY();
#endif
_tpTransform(&x, &y);
switch(gdispGetOrientation()) {
case GDISP_ROTATE_0:
return y;
@ -217,45 +265,106 @@ uint16_t tpReadY(void) {
#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
*/
#if TOUCHPAD_HAS_IRQ || defined(__DOXYGEN__)
uint8_t tpIRQ(void) {
bool_t tpIRQ(void) {
return tp_lld_irq();
}
#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) {
const uint16_t h = gdispGetHeight();
const uint16_t w = gdispGetWidth();
const uint16_t cross[2][2] = {{(w/8), (h/8)}, {(w-(w/8)) , (h-(h/8))}};
uint16_t points[2][2];
uint8_t i;
const uint16_t height = gdispGetHeight();
const uint16_t width = gdispGetWidth();
const coord_t cross[][2] = {{(width / 4), (height / 4)},
{(width - (width / 4)) , (height / 4)},
{(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);
gdispClear(Red);
gdispFillStringBox(0, 10, gdispGetWidth(), 30, "Calibration", &fontUI2Double, White, Red, justifyCenter);
gdispClear(Blue);
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]);
while(!tpIRQ());
points[i][0] = _tpReadRealX();
points[i][1] = _tpReadRealY();
chThdSleepMilliseconds(100);
while(tpIRQ());
gdispFillArea(cross[i][0]-15, cross[i][1]-15, 42, 42, Red);
while(!tpIRQ())
chThdSleepMilliseconds(2); /* Be nice to other threads*/
chThdSleepMilliseconds(20); /* Allow screen to settle */
/* 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]);
cal->ym = ((float)cross[1][1] - (float)cross[0][1]) / ((float)points[1][1] - (float)points[0][1]);
points[i][0] = px / j;
points[i][1] = py / j;
cal->xn = (float)cross[0][0] - cal->xm * (float)points[0][0];
cal->yn = (float)cross[0][1] - cal->ym * (float)points[0][1];
chThdSleepMilliseconds(100);
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
tp_store_calibration_lld(cal);
#endif