//*****************************************************************************
//
//! Debounces presses of the touch screen.
//!
//! This function is called when a new X/Y sample pair has been captured in
//! order to perform debouncing of the touch screen.
//!
//! \return None.
//
//*****************************************************************************
static void
TouchScreenDebouncer(void)
{
long lX, lY, lTemp;
//
// Convert the ADC readings into pixel values on the screen.
//
lX = g_sTouchX;
lY = g_sTouchY;
lTemp = (((lX * g_plParmSet[0]) + (lY * g_plParmSet[1]) + g_plParmSet[2]) /
g_plParmSet[6]);
lY = (((lX * g_plParmSet[3]) + (lY * g_plParmSet[4]) + g_plParmSet[5]) /
g_plParmSet[6]);
lX = lTemp;
//
// See if the touch screen is being touched.
//
if((g_sTouchX < g_sTouchMin) || (g_sTouchY < g_sTouchMin))
{
//
// See if the pen is not up right now.
//
if(g_cState != 0x00)
{
//
// Decrement the state count.
//
g_cState--;
//
// See if the pen has been detected as up three times in a row.
//
if(g_cState == 0x80)
{
//
// Indicate that the pen is up.
//
g_cState = 0x00;
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler)
{
//
// Send the pen up message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_UP, g_psSamples[g_cIndex],
g_psSamples[g_cIndex + 1]);
}
}
}
}
else
{
//
// See if the pen is not down right now.
//
if(g_cState != 0x83)
{
//
// Increment the state count.
//
g_cState++;
//
// See if the pen has been detected as down three times in a row.
//
if(g_cState == 0x03)
{
//
// Indicate that the pen is up.
//
g_cState = 0x83;
//
// Set the index to -8, so that the next 3 samples are stored
// into the sample buffer before sending anything back to the
// touch screen event handler.
//
g_cIndex = -8;
//
// Store this sample into the sample buffer.
//
g_psSamples[0] = lX;
g_psSamples[1] = lY;
}
}
else
{
//
// See if the sample buffer pre-fill has completed.
//
if(g_cIndex == -2)
{
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler)
{
//
// Send the pen down message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_DOWN, g_psSamples[0],
g_psSamples[1]);
}
//
// Store this sample into the sample buffer.
//
g_psSamples[0] = lX;
g_psSamples[1] = lY;
//
// Set the index to the next sample to send.
//
g_cIndex = 2;
}
//
// Otherwise, see if the sample buffer pre-fill is in progress.
//
else if(g_cIndex < 0)
{
//
// Store this sample into the sample buffer.
//
g_psSamples[g_cIndex + 10] = lX;
g_psSamples[g_cIndex + 11] = lY;
//
// Increment the index.
//
g_cIndex += 2;
}
//
// Otherwise, the sample buffer is full.
//
else
{
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler)
{
//
// Send the pen move message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_MOVE, g_psSamples[g_cIndex],
g_psSamples[g_cIndex + 1]);
}
//
// Store this sample into the sample buffer.
//
g_psSamples[g_cIndex] = lX;
g_psSamples[g_cIndex + 1] = lY;
//
// Increment the index.
//
g_cIndex = (g_cIndex + 2) & 7;
}
}
}
}
//*****************************************************************************
//
//! Debounces presses of the touch screen.
//!
//! This function is called when a new X/Y sample pair has been captured in
//! order to perform debouncing of the touch screen.
//!
//! \return None.
//
//*****************************************************************************
static void
TouchScreenDebouncer(void)
{
int32_t i32X, i32Y, i32Temp;
//
// Convert the ADC readings into pixel values on the screen.
//
i32X = g_i16TouchX;
i32Y = g_i16TouchY;
i32Temp = (((i32X * g_pi32TouchParameters[0]) +
(i32Y * g_pi32TouchParameters[1]) + g_pi32TouchParameters[2]) /
g_pi32TouchParameters[6]);
i32Y = (((i32X * g_pi32TouchParameters[3]) +
(i32Y * g_pi32TouchParameters[4]) + g_pi32TouchParameters[5]) /
g_pi32TouchParameters[6]);
i32X = i32Temp;
//
// See if the touch screen is being touched.
//
if((g_i16TouchX < g_i16TouchMin) || (g_i16TouchY < g_i16TouchMin)) {
//
// If there are no valid values yet then ignore this state.
//
if((g_ui8State & 0x80) == 0) {
g_ui8State = 0;
}
//
// See if the pen is not up right now.
//
if(g_ui8State != 0x00) {
//
// Decrement the state count.
//
g_ui8State--;
//
// See if the pen has been detected as up three times in a row.
//
if(g_ui8State == 0x80) {
//
// Indicate that the pen is up.
//
g_ui8State = 0x00;
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler) {
//
// If we got caught pre-filling the values, just return the
// first valid value as a press and release. If this is
// not done there is a perceived miss of a press event.
//
if(g_i8Index < 0) {
g_pfnTSHandler(WIDGET_MSG_PTR_DOWN, g_pi16Samples[0],
g_pi16Samples[1]);
g_i8Index = 0;
}
//
// Send the pen up message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_UP, g_pi16Samples[g_i8Index],
g_pi16Samples[g_i8Index + 1]);
}
}
}
} else {
//
// If the state was counting down above then fall back to the idle
// state and start waiting for new values.
//
if((g_ui8State & 0x80) && (g_ui8State != 0x83)) {
//
// Restart the release count down.
//
g_ui8State = 0x83;
}
//
// See if the pen is not down right now.
//
if(g_ui8State != 0x83) {
//
// Increment the state count.
//
g_ui8State++;
//
// See if the pen has been detected as down three times in a row.
//
if(g_ui8State == 0x03) {
//
// Indicate that the pen is down.
//
g_ui8State = 0x83;
//
// Set the index to -8, so that the next 3 samples are stored
// into the sample buffer before sending anything back to the
// touch screen event handler.
//
g_i8Index = -8;
//
// Store this sample into the sample buffer.
//
g_pi16Samples[0] = i32X;
g_pi16Samples[1] = i32Y;
}
} else {
//
// See if the sample buffer pre-fill has completed.
//
if(g_i8Index == -2) {
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler) {
//
// Send the pen down message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_DOWN, g_pi16Samples[0],
g_pi16Samples[1]);
}
//
// Store this sample into the sample buffer.
//
g_pi16Samples[0] = i32X;
g_pi16Samples[1] = i32Y;
//
// Set the index to the next sample to send.
//
g_i8Index = 2;
}
//
// Otherwise, see if the sample buffer pre-fill is in progress.
//
else if(g_i8Index < 0) {
//
// Store this sample into the sample buffer.
//
g_pi16Samples[g_i8Index + 10] = i32X;
g_pi16Samples[g_i8Index + 11] = i32Y;
//
// Increment the index.
//
g_i8Index += 2;
}
//
// Otherwise, the sample buffer is full.
//
else {
//
// See if there is a touch screen event handler.
//
if(g_pfnTSHandler) {
//
// Send the pen move message to the touch screen event
// handler.
//
g_pfnTSHandler(WIDGET_MSG_PTR_MOVE,
g_pi16Samples[g_i8Index],
g_pi16Samples[g_i8Index + 1]);
}
//
// Store this sample into the sample buffer.
//
g_pi16Samples[g_i8Index] = i32X;
g_pi16Samples[g_i8Index + 1] = i32Y;
//
// Increment the index.
//
g_i8Index = (g_i8Index + 2) & 7;
}
}
}
}
