David Smart / RA8875 Featured

Library to control a Graphics TFT connected to 4-wire SPI - revised for the Raio RA8875 Display Controller.

Dependents:   FRDM_RA8875_mPaint RA8875_Demo RA8875_KeyPadDemo SignalGenerator ... more

Fork of SPI_TFT by Peter Drescher

See Components - RA8875 Based Display

Enhanced touch-screen support - where it previous supported both the Resistive Touch and Capacitive Touch based on the FT5206 Touch Controller, now it also has support for the GSL1680 Touch Controller.

Offline Help Manual (Windows chm)

/media/uploads/WiredHome/ra8875.zip.bin (download, rename to .zip and unzip)

RA8875_Touch.cpp@78:faf49c381591, 2014-12-28 (annotated)

Committer:
WiredHome
Date:
Sun Dec 28 03:14:35 2014 +0000
Revision:
78:faf49c381591
Child:
79:544eb4964795
Continue work on touch screen, and some file refactoring for easier maintenance.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WiredHome 78:faf49c381591 1 /// This file contains the RA8875 Touch panel methods.
WiredHome 78:faf49c381591 2 ///
WiredHome 78:faf49c381591 3
WiredHome 78:faf49c381591 4 #include "RA8875.h"
WiredHome 78:faf49c381591 5
WiredHome 78:faf49c381591 6 // ### Touch Panel support code additions begin here
WiredHome 78:faf49c381591 7
WiredHome 78:faf49c381591 8 RetCode_t RA8875::TouchPanelInit(void)
WiredHome 78:faf49c381591 9 {
WiredHome 78:faf49c381591 10 //TPCR0: Set enable bit, default sample time, wakeup, and ADC clock
WiredHome 78:faf49c381591 11 WriteCommand(TPCR0, TP_ENABLE | TP_ADC_SAMPLE_DEFAULT_CLKS | TP_ADC_CLKDIV_DEFAULT);
WiredHome 78:faf49c381591 12 // TPCR1: Set auto/manual, Ref voltage, debounce, manual mode params
WiredHome 78:faf49c381591 13 WriteCommand(TPCR1, TP_MODE_DEFAULT | TP_DEBOUNCE_DEFAULT);
WiredHome 78:faf49c381591 14 WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1)
WiredHome 78:faf49c381591 15 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag
WiredHome 78:faf49c381591 16 return noerror;
WiredHome 78:faf49c381591 17 }
WiredHome 78:faf49c381591 18
WiredHome 78:faf49c381591 19 RetCode_t RA8875::TouchPanelInit(uint8_t bTpEnable, uint8_t bTpAutoManual, uint8_t bTpDebounce, uint8_t bTpManualMode, uint8_t bTpAdcClkDiv, uint8_t bTpAdcSampleTime)
WiredHome 78:faf49c381591 20 {
WiredHome 78:faf49c381591 21 // Parameter bounds check
WiredHome 78:faf49c381591 22 if( \
WiredHome 78:faf49c381591 23 !(bTpEnable == TP_ENABLE || bTpEnable == TP_ENABLE) || \
WiredHome 78:faf49c381591 24 !(bTpAutoManual == TP_MODE_AUTO || bTpAutoManual == TP_MODE_MANUAL) || \
WiredHome 78:faf49c381591 25 !(bTpDebounce == TP_DEBOUNCE_OFF || bTpDebounce == TP_DEBOUNCE_ON) || \
WiredHome 78:faf49c381591 26 !(bTpManualMode <= TP_MANUAL_LATCH_Y) || \
WiredHome 78:faf49c381591 27 !(bTpAdcClkDiv <= TP_ADC_CLKDIV_128) || \
WiredHome 78:faf49c381591 28 !(bTpAdcSampleTime <= TP_ADC_SAMPLE_65536_CLKS) \
WiredHome 78:faf49c381591 29 ) return bad_parameter;
WiredHome 78:faf49c381591 30 // Construct the config byte for TPCR0 and write them
WiredHome 78:faf49c381591 31 WriteCommand(TPCR0, bTpEnable | bTpAdcClkDiv | bTpAdcSampleTime); // Note: Wakeup is never enabled
WiredHome 78:faf49c381591 32 // Construct the config byte for TPCR1 and write them
WiredHome 78:faf49c381591 33 WriteCommand(TPCR1, bTpManualMode | bTpDebounce | bTpManualMode); // Note: Always uses internal Vref.
WiredHome 78:faf49c381591 34 // Set up the interrupt flag and enable bits
WiredHome 78:faf49c381591 35 WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1)
WiredHome 78:faf49c381591 36 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag
WiredHome 78:faf49c381591 37 return noerror;
WiredHome 78:faf49c381591 38 }
WiredHome 78:faf49c381591 39
WiredHome 78:faf49c381591 40 unsigned char RA8875::TouchPanelRead(loc_t *x, loc_t *y)
WiredHome 78:faf49c381591 41 {
WiredHome 78:faf49c381591 42 unsigned char touchready;
WiredHome 78:faf49c381591 43 static int xbuf[TPBUFSIZE], ybuf[TPBUFSIZE], sample = 0;
WiredHome 78:faf49c381591 44 int i, j, temp;
WiredHome 78:faf49c381591 45
WiredHome 78:faf49c381591 46 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
WiredHome 78:faf49c381591 47 // Get the next data samples
WiredHome 78:faf49c381591 48 ybuf[sample] = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2]
WiredHome 78:faf49c381591 49 xbuf[sample] = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0]
WiredHome 78:faf49c381591 50 // Check for a complete set
WiredHome 78:faf49c381591 51 if(++sample == TPBUFSIZE) {
WiredHome 78:faf49c381591 52 // Buffers are full, so process them using Finn's method described in Analog Dialogue No. 44, Feb 2010
WiredHome 78:faf49c381591 53 // This requires sorting the samples in order of size, then discarding the top 25% and
WiredHome 78:faf49c381591 54 // bottom 25% as noise spikes. Finally, the middle 50% of the values are averaged to
WiredHome 78:faf49c381591 55 // reduce Gaussian noise.
WiredHome 78:faf49c381591 56
WiredHome 78:faf49c381591 57 // Sort the Y buffer using an Insertion Sort
WiredHome 78:faf49c381591 58 for(i = 1; i <= TPBUFSIZE; i++) {
WiredHome 78:faf49c381591 59 temp = ybuf[i];
WiredHome 78:faf49c381591 60 j = i;
WiredHome 78:faf49c381591 61 while( j && (ybuf[j-1] > temp) ) {
WiredHome 78:faf49c381591 62 ybuf[j] = ybuf[j-1];
WiredHome 78:faf49c381591 63 j = j-1;
WiredHome 78:faf49c381591 64 }
WiredHome 78:faf49c381591 65 ybuf[j] = temp;
WiredHome 78:faf49c381591 66 } // End of Y sort
WiredHome 78:faf49c381591 67 // Sort the X buffer the same way
WiredHome 78:faf49c381591 68 for(i = 1; i <= TPBUFSIZE; i++) {
WiredHome 78:faf49c381591 69 temp = xbuf[i];
WiredHome 78:faf49c381591 70 j = i;
WiredHome 78:faf49c381591 71 while( j && (xbuf[j-1] > temp) ) {
WiredHome 78:faf49c381591 72 xbuf[j] = xbuf[j-1];
WiredHome 78:faf49c381591 73 j = j-1;
WiredHome 78:faf49c381591 74 }
WiredHome 78:faf49c381591 75 xbuf[j] = temp;
WiredHome 78:faf49c381591 76 } // End of X sort
WiredHome 78:faf49c381591 77 // Average the middle half of the Y values and report them
WiredHome 78:faf49c381591 78 j = 0;
WiredHome 78:faf49c381591 79 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
WiredHome 78:faf49c381591 80 j += ybuf[i];
WiredHome 78:faf49c381591 81 }
WiredHome 78:faf49c381591 82 *y = j * (float)2/TPBUFSIZE; // This is the average
WiredHome 78:faf49c381591 83 // Average the middle half of the X values and report them
WiredHome 78:faf49c381591 84 j = 0;
WiredHome 78:faf49c381591 85 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
WiredHome 78:faf49c381591 86 j += xbuf[i];
WiredHome 78:faf49c381591 87 }
WiredHome 78:faf49c381591 88 *x = j * (float)2/TPBUFSIZE; // This is the average
WiredHome 78:faf49c381591 89 // Tidy up and return
WiredHome 78:faf49c381591 90 touchready = 1;
WiredHome 78:faf49c381591 91 sample = 0; // Ready to start on the next set of data samples
WiredHome 78:faf49c381591 92 } else {
WiredHome 78:faf49c381591 93 // Buffer not yet full, so do not return any results yet
WiredHome 78:faf49c381591 94 touchready = 0;
WiredHome 78:faf49c381591 95 }
WiredHome 78:faf49c381591 96 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
WiredHome 78:faf49c381591 97 } // End of initial if -- data has been read and processed
WiredHome 78:faf49c381591 98 else
WiredHome 78:faf49c381591 99 touchready = 0; // Touch Panel "Int" was not set
WiredHome 78:faf49c381591 100 return touchready;
WiredHome 78:faf49c381591 101 }
WiredHome 78:faf49c381591 102
WiredHome 78:faf49c381591 103 unsigned char RA8875::TouchPanelReadRaw(loc_t *x, loc_t *y)
WiredHome 78:faf49c381591 104 {
WiredHome 78:faf49c381591 105 unsigned char touchready;
WiredHome 78:faf49c381591 106
WiredHome 78:faf49c381591 107 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
WiredHome 78:faf49c381591 108 *y = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2]
WiredHome 78:faf49c381591 109 *x = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0]
WiredHome 78:faf49c381591 110 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
WiredHome 78:faf49c381591 111 touchready = 1;
WiredHome 78:faf49c381591 112 } else
WiredHome 78:faf49c381591 113 touchready = 0;
WiredHome 78:faf49c381591 114 return touchready;
WiredHome 78:faf49c381591 115 }
WiredHome 78:faf49c381591 116
WiredHome 78:faf49c381591 117 /* The following section is derived from Carlos E. Vidales.
WiredHome 78:faf49c381591 118 *
WiredHome 78:faf49c381591 119 * Copyright (c) 2001, Carlos E. Vidales. All rights reserved.
WiredHome 78:faf49c381591 120 *
WiredHome 78:faf49c381591 121 * This sample program was written and put in the public domain
WiredHome 78:faf49c381591 122 * by Carlos E. Vidales. The program is provided "as is"
WiredHome 78:faf49c381591 123 * without warranty of any kind, either expressed or implied.
WiredHome 78:faf49c381591 124 * If you choose to use the program within your own products
WiredHome 78:faf49c381591 125 * you do so at your own risk, and assume the responsibility
WiredHome 78:faf49c381591 126 * for servicing, repairing or correcting the program should
WiredHome 78:faf49c381591 127 * it prove defective in any manner.
WiredHome 78:faf49c381591 128 * You may copy and distribute the program's source code in any
WiredHome 78:faf49c381591 129 * medium, provided that you also include in each copy an
WiredHome 78:faf49c381591 130 * appropriate copyright notice and disclaimer of warranty.
WiredHome 78:faf49c381591 131 * You may also modify this program and distribute copies of
WiredHome 78:faf49c381591 132 * it provided that you include prominent notices stating
WiredHome 78:faf49c381591 133 * that you changed the file(s) and the date of any change,
WiredHome 78:faf49c381591 134 * and that you do not charge any royalties or licenses for
WiredHome 78:faf49c381591 135 * its use.
WiredHome 78:faf49c381591 136 *
WiredHome 78:faf49c381591 137 * This file contains functions that implement calculations
WiredHome 78:faf49c381591 138 * necessary to obtain calibration factors for a touch screen
WiredHome 78:faf49c381591 139 * that suffers from multiple distortion effects: namely,
WiredHome 78:faf49c381591 140 * translation, scaling and rotation.
WiredHome 78:faf49c381591 141 *
WiredHome 78:faf49c381591 142 * The following set of equations represent a valid display
WiredHome 78:faf49c381591 143 * point given a corresponding set of touch screen points:
WiredHome 78:faf49c381591 144 *
WiredHome 78:faf49c381591 145 * /- -\
WiredHome 78:faf49c381591 146 * /- -\ /- -\ | |
WiredHome 78:faf49c381591 147 * | | | | | Xs |
WiredHome 78:faf49c381591 148 * | Xd | | A B C | | |
WiredHome 78:faf49c381591 149 * | | = | | * | Ys |
WiredHome 78:faf49c381591 150 * | Yd | | D E F | | |
WiredHome 78:faf49c381591 151 * | | | | | 1 |
WiredHome 78:faf49c381591 152 * \- -/ \- -/ | |
WiredHome 78:faf49c381591 153 * \- -/
WiredHome 78:faf49c381591 154 * where:
WiredHome 78:faf49c381591 155 * (Xd,Yd) represents the desired display point
WiredHome 78:faf49c381591 156 * coordinates,
WiredHome 78:faf49c381591 157 * (Xs,Ys) represents the available touch screen
WiredHome 78:faf49c381591 158 * coordinates, and the matrix
WiredHome 78:faf49c381591 159 * /- -\
WiredHome 78:faf49c381591 160 * |A,B,C|
WiredHome 78:faf49c381591 161 * |D,E,F| represents the factors used to translate
WiredHome 78:faf49c381591 162 * \- -/ the available touch screen point values
WiredHome 78:faf49c381591 163 * into the corresponding display
WiredHome 78:faf49c381591 164 * coordinates.
WiredHome 78:faf49c381591 165 * Note that for practical considerations, the utilities
WiredHome 78:faf49c381591 166 * within this file do not use the matrix coefficients as
WiredHome 78:faf49c381591 167 * defined above, but instead use the following
WiredHome 78:faf49c381591 168 * equivalents, since floating point math is not used:
WiredHome 78:faf49c381591 169 * A = An/Divider
WiredHome 78:faf49c381591 170 * B = Bn/Divider
WiredHome 78:faf49c381591 171 * C = Cn/Divider
WiredHome 78:faf49c381591 172 * D = Dn/Divider
WiredHome 78:faf49c381591 173 * E = En/Divider
WiredHome 78:faf49c381591 174 * F = Fn/Divider
WiredHome 78:faf49c381591 175 * The functions provided within this file are:
WiredHome 78:faf49c381591 176 * setCalibrationMatrix() - calculates the set of factors
WiredHome 78:faf49c381591 177 * in the above equation, given
WiredHome 78:faf49c381591 178 * three sets of test points.
WiredHome 78:faf49c381591 179 * getDisplayPoint() - returns the actual display
WiredHome 78:faf49c381591 180 * coordinates, given a set of
WiredHome 78:faf49c381591 181 * touch screen coordinates.
WiredHome 78:faf49c381591 182 * translateRawScreenCoordinates() - helper function to transform
WiredHome 78:faf49c381591 183 * raw screen points into values
WiredHome 78:faf49c381591 184 * scaled to the desired display
WiredHome 78:faf49c381591 185 * resolution.
WiredHome 78:faf49c381591 186 */
WiredHome 78:faf49c381591 187
WiredHome 78:faf49c381591 188 /**********************************************************************
WiredHome 78:faf49c381591 189 *
WiredHome 78:faf49c381591 190 * Function: setCalibrationMatrix()
WiredHome 78:faf49c381591 191 *
WiredHome 78:faf49c381591 192 * Description: Calling this function with valid input data
WiredHome 78:faf49c381591 193 * in the display and screen input arguments
WiredHome 78:faf49c381591 194 * causes the calibration factors between the
WiredHome 78:faf49c381591 195 * screen and display points to be calculated,
WiredHome 78:faf49c381591 196 * and the output argument - matrixPtr - to be
WiredHome 78:faf49c381591 197 * populated.
WiredHome 78:faf49c381591 198 *
WiredHome 78:faf49c381591 199 * This function needs to be called only when new
WiredHome 78:faf49c381591 200 * calibration factors are desired.
WiredHome 78:faf49c381591 201 *
WiredHome 78:faf49c381591 202 *
WiredHome 78:faf49c381591 203 * Argument(s): displayPtr (input) - Pointer to an array of three
WiredHome 78:faf49c381591 204 * sample, reference points.
WiredHome 78:faf49c381591 205 * screenPtr (input) - Pointer to the array of touch
WiredHome 78:faf49c381591 206 * screen points corresponding
WiredHome 78:faf49c381591 207 * to the reference display points.
WiredHome 78:faf49c381591 208 * matrixPtr (output) - Pointer to the calibration
WiredHome 78:faf49c381591 209 * matrix computed for the set
WiredHome 78:faf49c381591 210 * of points being provided.
WiredHome 78:faf49c381591 211 *
WiredHome 78:faf49c381591 212 *
WiredHome 78:faf49c381591 213 * From the article text, recall that the matrix coefficients are
WiredHome 78:faf49c381591 214 * resolved to be the following:
WiredHome 78:faf49c381591 215 *
WiredHome 78:faf49c381591 216 *
WiredHome 78:faf49c381591 217 * Divider = (Xs0 - Xs2)*(Ys1 - Ys2) - (Xs1 - Xs2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 218 *
WiredHome 78:faf49c381591 219 *
WiredHome 78:faf49c381591 220 *
WiredHome 78:faf49c381591 221 * (Xd0 - Xd2)*(Ys1 - Ys2) - (Xd1 - Xd2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 222 * A = ---------------------------------------------------
WiredHome 78:faf49c381591 223 * Divider
WiredHome 78:faf49c381591 224 *
WiredHome 78:faf49c381591 225 *
WiredHome 78:faf49c381591 226 * (Xs0 - Xs2)*(Xd1 - Xd2) - (Xd0 - Xd2)*(Xs1 - Xs2)
WiredHome 78:faf49c381591 227 * B = ---------------------------------------------------
WiredHome 78:faf49c381591 228 * Divider
WiredHome 78:faf49c381591 229 *
WiredHome 78:faf49c381591 230 *
WiredHome 78:faf49c381591 231 * Ys0*(Xs2*Xd1 - Xs1*Xd2) +
WiredHome 78:faf49c381591 232 * Ys1*(Xs0*Xd2 - Xs2*Xd0) +
WiredHome 78:faf49c381591 233 * Ys2*(Xs1*Xd0 - Xs0*Xd1)
WiredHome 78:faf49c381591 234 * C = ---------------------------------------------------
WiredHome 78:faf49c381591 235 * Divider
WiredHome 78:faf49c381591 236 *
WiredHome 78:faf49c381591 237 *
WiredHome 78:faf49c381591 238 * (Yd0 - Yd2)*(Ys1 - Ys2) - (Yd1 - Yd2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 239 * D = ---------------------------------------------------
WiredHome 78:faf49c381591 240 * Divider
WiredHome 78:faf49c381591 241 *
WiredHome 78:faf49c381591 242 *
WiredHome 78:faf49c381591 243 * (Xs0 - Xs2)*(Yd1 - Yd2) - (Yd0 - Yd2)*(Xs1 - Xs2)
WiredHome 78:faf49c381591 244 * E = ---------------------------------------------------
WiredHome 78:faf49c381591 245 * Divider
WiredHome 78:faf49c381591 246 *
WiredHome 78:faf49c381591 247 *
WiredHome 78:faf49c381591 248 * Ys0*(Xs2*Yd1 - Xs1*Yd2) +
WiredHome 78:faf49c381591 249 * Ys1*(Xs0*Yd2 - Xs2*Yd0) +
WiredHome 78:faf49c381591 250 * Ys2*(Xs1*Yd0 - Xs0*Yd1)
WiredHome 78:faf49c381591 251 * F = ---------------------------------------------------
WiredHome 78:faf49c381591 252 * Divider
WiredHome 78:faf49c381591 253 *
WiredHome 78:faf49c381591 254 *
WiredHome 78:faf49c381591 255 * Return: OK - the calibration matrix was correctly
WiredHome 78:faf49c381591 256 * calculated and its value is in the
WiredHome 78:faf49c381591 257 * output argument.
WiredHome 78:faf49c381591 258 * NOT_OK - an error was detected and the
WiredHome 78:faf49c381591 259 * function failed to return a valid
WiredHome 78:faf49c381591 260 * set of matrix values.
WiredHome 78:faf49c381591 261 * The only time this sample code returns
WiredHome 78:faf49c381591 262 * NOT_OK is when Divider == 0
WiredHome 78:faf49c381591 263 *
WiredHome 78:faf49c381591 264 *
WiredHome 78:faf49c381591 265 *
WiredHome 78:faf49c381591 266 * NOTE! NOTE! NOTE!
WiredHome 78:faf49c381591 267 *
WiredHome 78:faf49c381591 268 * setCalibrationMatrix() and getDisplayPoint() will do fine
WiredHome 78:faf49c381591 269 * for you as they are, provided that your digitizer
WiredHome 78:faf49c381591 270 * resolution does not exceed 10 bits (1024 values). Higher
WiredHome 78:faf49c381591 271 * resolutions may cause the integer operations to overflow
WiredHome 78:faf49c381591 272 * and return incorrect values. If you wish to use these
WiredHome 78:faf49c381591 273 * functions with digitizer resolutions of 12 bits (4096
WiredHome 78:faf49c381591 274 * values) you will either have to a) use 64-bit signed
WiredHome 78:faf49c381591 275 * integer variables and math, or b) judiciously modify the
WiredHome 78:faf49c381591 276 * operations to scale results by a factor of 2 or even 4.
WiredHome 78:faf49c381591 277 *
WiredHome 78:faf49c381591 278 */
WiredHome 78:faf49c381591 279 RetCode_t RA8875::TouchPanelCalibrate(point_t * displayPtr, point_t * screenPtr, tpMatrix_t * matrixPtr)
WiredHome 78:faf49c381591 280 {
WiredHome 78:faf49c381591 281 RetCode_t retValue = noerror;
WiredHome 78:faf49c381591 282
WiredHome 78:faf49c381591 283 tpMatrix.Divider = ((screenPtr[0].x - screenPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 284 ((screenPtr[1].x - screenPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 285
WiredHome 78:faf49c381591 286 if( tpMatrix.Divider == 0 ) {
WiredHome 78:faf49c381591 287 retValue = bad_parameter;
WiredHome 78:faf49c381591 288 } else {
WiredHome 78:faf49c381591 289 tpMatrix.An = ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 290 ((displayPtr[1].x - displayPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 291
WiredHome 78:faf49c381591 292 tpMatrix.Bn = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].x - displayPtr[2].x)) -
WiredHome 78:faf49c381591 293 ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].x - screenPtr[2].x)) ;
WiredHome 78:faf49c381591 294
WiredHome 78:faf49c381591 295 tpMatrix.Cn = (screenPtr[2].x * displayPtr[1].x - screenPtr[1].x * displayPtr[2].x) * screenPtr[0].y +
WiredHome 78:faf49c381591 296 (screenPtr[0].x * displayPtr[2].x - screenPtr[2].x * displayPtr[0].x) * screenPtr[1].y +
WiredHome 78:faf49c381591 297 (screenPtr[1].x * displayPtr[0].x - screenPtr[0].x * displayPtr[1].x) * screenPtr[2].y ;
WiredHome 78:faf49c381591 298
WiredHome 78:faf49c381591 299 tpMatrix.Dn = ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 300 ((displayPtr[1].y - displayPtr[2].y) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 301
WiredHome 78:faf49c381591 302 tpMatrix.En = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].y - displayPtr[2].y)) -
WiredHome 78:faf49c381591 303 ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].x - screenPtr[2].x)) ;
WiredHome 78:faf49c381591 304
WiredHome 78:faf49c381591 305 tpMatrix.Fn = (screenPtr[2].x * displayPtr[1].y - screenPtr[1].x * displayPtr[2].y) * screenPtr[0].y +
WiredHome 78:faf49c381591 306 (screenPtr[0].x * displayPtr[2].y - screenPtr[2].x * displayPtr[0].y) * screenPtr[1].y +
WiredHome 78:faf49c381591 307 (screenPtr[1].x * displayPtr[0].y - screenPtr[0].x * displayPtr[1].y) * screenPtr[2].y ;
WiredHome 78:faf49c381591 308 if (matrixPtr)
WiredHome 78:faf49c381591 309 memcpy(matrixPtr, &tpMatrix, sizeof(tpMatrix_t));
WiredHome 78:faf49c381591 310 }
WiredHome 78:faf49c381591 311 return( retValue ) ;
WiredHome 78:faf49c381591 312 }
WiredHome 78:faf49c381591 313
WiredHome 78:faf49c381591 314 /**********************************************************************
WiredHome 78:faf49c381591 315 *
WiredHome 78:faf49c381591 316 * Function: getDisplayPoint()
WiredHome 78:faf49c381591 317 *
WiredHome 78:faf49c381591 318 * Description: Given a valid set of calibration factors and a point
WiredHome 78:faf49c381591 319 * value reported by the touch screen, this function
WiredHome 78:faf49c381591 320 * calculates and returns the true (or closest to true)
WiredHome 78:faf49c381591 321 * display point below the spot where the touch screen
WiredHome 78:faf49c381591 322 * was touched.
WiredHome 78:faf49c381591 323 *
WiredHome 78:faf49c381591 324 *
WiredHome 78:faf49c381591 325 *
WiredHome 78:faf49c381591 326 * Argument(s): displayPtr (output) - Pointer to the calculated
WiredHome 78:faf49c381591 327 * (true) display point.
WiredHome 78:faf49c381591 328 * screenPtr (input) - Pointer to the reported touch
WiredHome 78:faf49c381591 329 * screen point.
WiredHome 78:faf49c381591 330 * matrixPtr (input) - Pointer to calibration factors
WiredHome 78:faf49c381591 331 * matrix previously calculated
WiredHome 78:faf49c381591 332 * from a call to
WiredHome 78:faf49c381591 333 * setCalibrationMatrix()
WiredHome 78:faf49c381591 334 *
WiredHome 78:faf49c381591 335 *
WiredHome 78:faf49c381591 336 * The function simply solves for Xd and Yd by implementing the
WiredHome 78:faf49c381591 337 * computations required by the translation matrix.
WiredHome 78:faf49c381591 338 *
WiredHome 78:faf49c381591 339 * /- -\
WiredHome 78:faf49c381591 340 * /- -\ /- -\ | |
WiredHome 78:faf49c381591 341 * | | | | | Xs |
WiredHome 78:faf49c381591 342 * | Xd | | A B C | | |
WiredHome 78:faf49c381591 343 * | | = | | * | Ys |
WiredHome 78:faf49c381591 344 * | Yd | | D E F | | |
WiredHome 78:faf49c381591 345 * | | | | | 1 |
WiredHome 78:faf49c381591 346 * \- -/ \- -/ | |
WiredHome 78:faf49c381591 347 * \- -/
WiredHome 78:faf49c381591 348 *
WiredHome 78:faf49c381591 349 * It must be kept brief to avoid consuming CPU cycles.
WiredHome 78:faf49c381591 350 *
WiredHome 78:faf49c381591 351 * Return: OK - the display point was correctly calculated
WiredHome 78:faf49c381591 352 * and its value is in the output argument.
WiredHome 78:faf49c381591 353 * NOT_OK - an error was detected and the function
WiredHome 78:faf49c381591 354 * failed to return a valid point.
WiredHome 78:faf49c381591 355 *
WiredHome 78:faf49c381591 356 * NOTE! NOTE! NOTE!
WiredHome 78:faf49c381591 357 *
WiredHome 78:faf49c381591 358 * setCalibrationMatrix() and getDisplayPoint() will do fine
WiredHome 78:faf49c381591 359 * for you as they are, provided that your digitizer
WiredHome 78:faf49c381591 360 * resolution does not exceed 10 bits (1024 values). Higher
WiredHome 78:faf49c381591 361 * resolutions may cause the integer operations to overflow
WiredHome 78:faf49c381591 362 * and return incorrect values. If you wish to use these
WiredHome 78:faf49c381591 363 * functions with digitizer resolutions of 12 bits (4096
WiredHome 78:faf49c381591 364 * values) you will either have to a) use 64-bit signed
WiredHome 78:faf49c381591 365 * integer variables and math, or b) judiciously modify the
WiredHome 78:faf49c381591 366 * operations to scale results by a factor of 2 or even 4.
WiredHome 78:faf49c381591 367 *
WiredHome 78:faf49c381591 368 */
WiredHome 78:faf49c381591 369 RetCode_t RA8875::TouchPanelPoint(point_t * TouchPoint)
WiredHome 78:faf49c381591 370 {
WiredHome 78:faf49c381591 371 RetCode_t retValue = no_touch;
WiredHome 78:faf49c381591 372 point_t screenpoint = {0, 0};
WiredHome 78:faf49c381591 373
WiredHome 78:faf49c381591 374 if (TouchPanelRead(&screenpoint.x, &screenpoint.y)) {
WiredHome 78:faf49c381591 375 retValue = touch;
WiredHome 78:faf49c381591 376 if (tpMatrix.Divider != 0 ) {
WiredHome 78:faf49c381591 377 /* Operation order is important since we are doing integer */
WiredHome 78:faf49c381591 378 /* math. Make sure you add all terms together before */
WiredHome 78:faf49c381591 379 /* dividing, so that the remainder is not rounded off */
WiredHome 78:faf49c381591 380 /* prematurely. */
WiredHome 78:faf49c381591 381 TouchPoint->x = ( (tpMatrix.An * screenpoint.x) +
WiredHome 78:faf49c381591 382 (tpMatrix.Bn * screenpoint.y) +
WiredHome 78:faf49c381591 383 tpMatrix.Cn
WiredHome 78:faf49c381591 384 ) / tpMatrix.Divider ;
WiredHome 78:faf49c381591 385
WiredHome 78:faf49c381591 386 TouchPoint->y = ( (tpMatrix.Dn * screenpoint.x) +
WiredHome 78:faf49c381591 387 (tpMatrix.En * screenpoint.y) +
WiredHome 78:faf49c381591 388 tpMatrix.Fn
WiredHome 78:faf49c381591 389 ) / tpMatrix.Divider ;
WiredHome 78:faf49c381591 390 } else {
WiredHome 78:faf49c381591 391 retValue = bad_parameter ;
WiredHome 78:faf49c381591 392 }
WiredHome 78:faf49c381591 393 }
WiredHome 78:faf49c381591 394 return( retValue );
WiredHome 78:faf49c381591 395 }
WiredHome 78:faf49c381591 396
WiredHome 78:faf49c381591 397
WiredHome 78:faf49c381591 398 RetCode_t RA8875::TouchPanelSetMatrix(tpMatrix_t * matrixPtr)
WiredHome 78:faf49c381591 399 {
WiredHome 78:faf49c381591 400 if (matrixPtr == NULL || matrixPtr->Divider == 0)
WiredHome 78:faf49c381591 401 return bad_parameter;
WiredHome 78:faf49c381591 402 memcpy(&tpMatrix, matrixPtr, sizeof(tpMatrix_t));
WiredHome 78:faf49c381591 403 return noerror;
WiredHome 78:faf49c381591 404 }
WiredHome 78:faf49c381591 405
WiredHome 78:faf49c381591 406 // #### end of touch panel code additions