Kerry Martin / RA8875

KSM edits to RA8875

Dependents:   Liz_Test_Code

RA8875_Touch.cpp@81:01da2e34283d, 2014-12-28 (annotated)

Committer:
WiredHome
Date:
Sun Dec 28 21:50:28 2014 +0000
Revision:
81:01da2e34283d
Parent:
79:544eb4964795
Child:
83:7bad0068cca0
Refactored constructor() and init().; Added rect_t as a rectangle type.; Added new rect() methods that use rect_t.; Added touch panel calibration (and some renamed touch* methods).

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 81:01da2e34283d 40 // +----------------------------------------------------+
WiredHome 81:01da2e34283d 41 // | |
WiredHome 81:01da2e34283d 42 // | 1 |
WiredHome 81:01da2e34283d 43 // | |
WiredHome 81:01da2e34283d 44 // | |
WiredHome 81:01da2e34283d 45 // | 2 |
WiredHome 81:01da2e34283d 46 // | |
WiredHome 81:01da2e34283d 47 // | |
WiredHome 81:01da2e34283d 48 // | 3 |
WiredHome 81:01da2e34283d 49 // | |
WiredHome 81:01da2e34283d 50 // +----------------------------------------------------+
WiredHome 81:01da2e34283d 51
WiredHome 81:01da2e34283d 52
WiredHome 81:01da2e34283d 53 RetCode_t RA8875::TouchPanelCalibrate(tpMatrix_t * matrix)
WiredHome 81:01da2e34283d 54 {
WiredHome 81:01da2e34283d 55 return TouchPanelCalibrate(NULL, matrix);
WiredHome 81:01da2e34283d 56 }
WiredHome 81:01da2e34283d 57
WiredHome 81:01da2e34283d 58
WiredHome 81:01da2e34283d 59 RetCode_t RA8875::TouchPanelCalibrate(const char * msg, tpMatrix_t * matrix)
WiredHome 81:01da2e34283d 60 {
WiredHome 81:01da2e34283d 61 point_t pTest[3];
WiredHome 81:01da2e34283d 62 point_t pSample[3];
WiredHome 81:01da2e34283d 63 loc_t x,y;
WiredHome 81:01da2e34283d 64
WiredHome 81:01da2e34283d 65 cls();
WiredHome 81:01da2e34283d 66 if (msg)
WiredHome 81:01da2e34283d 67 puts(msg);
WiredHome 81:01da2e34283d 68 SetTextCursor(0,height()/2);
WiredHome 81:01da2e34283d 69 pTest[0].x = 50; pTest[0].y = 50;
WiredHome 81:01da2e34283d 70 pTest[1].x = width() - 50; pTest[1].y = height()/2;
WiredHome 81:01da2e34283d 71 pTest[2].x = width()/2; pTest[2].y = height() - 50;
WiredHome 81:01da2e34283d 72 for (int i=0; i<3; i++) {
WiredHome 81:01da2e34283d 73 foreground(Blue);
WiredHome 81:01da2e34283d 74 printf(" (%3d,%3d) => ", pTest[i].x, pTest[i].y);
WiredHome 81:01da2e34283d 75 line(pTest[i].x-10, pTest[i].y, pTest[i].x+10, pTest[i].y, White);
WiredHome 81:01da2e34283d 76 line(pTest[i].x, pTest[i].y-10, pTest[i].x, pTest[i].y+10, White);
WiredHome 81:01da2e34283d 77 while (!TouchPanelA2DFiltered(&x, &y))
WiredHome 81:01da2e34283d 78 wait_ms(20);
WiredHome 81:01da2e34283d 79 pSample[i].x = x;
WiredHome 81:01da2e34283d 80 pSample[i].y = y;
WiredHome 81:01da2e34283d 81 line(pTest[i].x-10, pTest[i].y, pTest[i].x+10, pTest[i].y, Black);
WiredHome 81:01da2e34283d 82 line(pTest[i].x, pTest[i].y-10, pTest[i].x, pTest[i].y+10, Black);
WiredHome 81:01da2e34283d 83 foreground(Blue);
WiredHome 81:01da2e34283d 84 printf(" (%4d,%4d)\r\n", x,y);
WiredHome 81:01da2e34283d 85 while (TouchPanelA2DFiltered(&x, &y))
WiredHome 81:01da2e34283d 86 wait_ms(20);
WiredHome 81:01da2e34283d 87 wait(2);
WiredHome 81:01da2e34283d 88 }
WiredHome 81:01da2e34283d 89 return TouchPanelComputeCalibration(pTest, pSample, matrix);
WiredHome 81:01da2e34283d 90 }
WiredHome 81:01da2e34283d 91
WiredHome 81:01da2e34283d 92
WiredHome 81:01da2e34283d 93 /**********************************************************************
WiredHome 81:01da2e34283d 94 *
WiredHome 81:01da2e34283d 95 * Function: getDisplayPoint()
WiredHome 81:01da2e34283d 96 *
WiredHome 81:01da2e34283d 97 * Description: Given a valid set of calibration factors and a point
WiredHome 81:01da2e34283d 98 * value reported by the touch screen, this function
WiredHome 81:01da2e34283d 99 * calculates and returns the true (or closest to true)
WiredHome 81:01da2e34283d 100 * display point below the spot where the touch screen
WiredHome 81:01da2e34283d 101 * was touched.
WiredHome 81:01da2e34283d 102 *
WiredHome 81:01da2e34283d 103 *
WiredHome 81:01da2e34283d 104 *
WiredHome 81:01da2e34283d 105 * Argument(s): displayPtr (output) - Pointer to the calculated
WiredHome 81:01da2e34283d 106 * (true) display point.
WiredHome 81:01da2e34283d 107 * screenPtr (input) - Pointer to the reported touch
WiredHome 81:01da2e34283d 108 * screen point.
WiredHome 81:01da2e34283d 109 * matrixPtr (input) - Pointer to calibration factors
WiredHome 81:01da2e34283d 110 * matrix previously calculated
WiredHome 81:01da2e34283d 111 * from a call to
WiredHome 81:01da2e34283d 112 * setCalibrationMatrix()
WiredHome 81:01da2e34283d 113 *
WiredHome 81:01da2e34283d 114 *
WiredHome 81:01da2e34283d 115 * The function simply solves for Xd and Yd by implementing the
WiredHome 81:01da2e34283d 116 * computations required by the translation matrix.
WiredHome 81:01da2e34283d 117 *
WiredHome 81:01da2e34283d 118 * /- -\
WiredHome 81:01da2e34283d 119 * /- -\ /- -\ | |
WiredHome 81:01da2e34283d 120 * | | | | | Xs |
WiredHome 81:01da2e34283d 121 * | Xd | | A B C | | |
WiredHome 81:01da2e34283d 122 * | | = | | * | Ys |
WiredHome 81:01da2e34283d 123 * | Yd | | D E F | | |
WiredHome 81:01da2e34283d 124 * | | | | | 1 |
WiredHome 81:01da2e34283d 125 * \- -/ \- -/ | |
WiredHome 81:01da2e34283d 126 * \- -/
WiredHome 81:01da2e34283d 127 *
WiredHome 81:01da2e34283d 128 * It must be kept brief to avoid consuming CPU cycles.
WiredHome 81:01da2e34283d 129 *
WiredHome 81:01da2e34283d 130 * Return: OK - the display point was correctly calculated
WiredHome 81:01da2e34283d 131 * and its value is in the output argument.
WiredHome 81:01da2e34283d 132 * NOT_OK - an error was detected and the function
WiredHome 81:01da2e34283d 133 * failed to return a valid point.
WiredHome 81:01da2e34283d 134 *
WiredHome 81:01da2e34283d 135 * NOTE! NOTE! NOTE!
WiredHome 81:01da2e34283d 136 *
WiredHome 81:01da2e34283d 137 * setCalibrationMatrix() and getDisplayPoint() will do fine
WiredHome 81:01da2e34283d 138 * for you as they are, provided that your digitizer
WiredHome 81:01da2e34283d 139 * resolution does not exceed 10 bits (1024 values). Higher
WiredHome 81:01da2e34283d 140 * resolutions may cause the integer operations to overflow
WiredHome 81:01da2e34283d 141 * and return incorrect values. If you wish to use these
WiredHome 81:01da2e34283d 142 * functions with digitizer resolutions of 12 bits (4096
WiredHome 81:01da2e34283d 143 * values) you will either have to a) use 64-bit signed
WiredHome 81:01da2e34283d 144 * integer variables and math, or b) judiciously modify the
WiredHome 81:01da2e34283d 145 * operations to scale results by a factor of 2 or even 4.
WiredHome 81:01da2e34283d 146 *
WiredHome 81:01da2e34283d 147 */
WiredHome 81:01da2e34283d 148 bool RA8875::TouchPanelReadable(point_t * TouchPoint)
WiredHome 81:01da2e34283d 149 {
WiredHome 81:01da2e34283d 150 bool touched = false;
WiredHome 81:01da2e34283d 151 point_t screenpoint = {0, 0};
WiredHome 81:01da2e34283d 152
WiredHome 81:01da2e34283d 153 if (TouchPanelA2DFiltered(&screenpoint.x, &screenpoint.y)) {
WiredHome 81:01da2e34283d 154 touched = true;
WiredHome 81:01da2e34283d 155 if (tpMatrix.Divider != 0 && TouchPoint) {
WiredHome 81:01da2e34283d 156 /* Operation order is important since we are doing integer */
WiredHome 81:01da2e34283d 157 /* math. Make sure you add all terms together before */
WiredHome 81:01da2e34283d 158 /* dividing, so that the remainder is not rounded off */
WiredHome 81:01da2e34283d 159 /* prematurely. */
WiredHome 81:01da2e34283d 160 TouchPoint->x = ( (tpMatrix.An * screenpoint.x) +
WiredHome 81:01da2e34283d 161 (tpMatrix.Bn * screenpoint.y) +
WiredHome 81:01da2e34283d 162 tpMatrix.Cn
WiredHome 81:01da2e34283d 163 ) / tpMatrix.Divider ;
WiredHome 81:01da2e34283d 164
WiredHome 81:01da2e34283d 165 TouchPoint->y = ( (tpMatrix.Dn * screenpoint.x) +
WiredHome 81:01da2e34283d 166 (tpMatrix.En * screenpoint.y) +
WiredHome 81:01da2e34283d 167 tpMatrix.Fn
WiredHome 81:01da2e34283d 168 ) / tpMatrix.Divider ;
WiredHome 81:01da2e34283d 169 } else {
WiredHome 81:01da2e34283d 170 touched = false;
WiredHome 81:01da2e34283d 171 }
WiredHome 81:01da2e34283d 172 }
WiredHome 81:01da2e34283d 173 return touched;
WiredHome 81:01da2e34283d 174 }
WiredHome 81:01da2e34283d 175
WiredHome 81:01da2e34283d 176
WiredHome 81:01da2e34283d 177 RetCode_t RA8875::TouchPanelSetMatrix(tpMatrix_t * matrixPtr)
WiredHome 81:01da2e34283d 178 {
WiredHome 81:01da2e34283d 179 if (matrixPtr == NULL || matrixPtr->Divider == 0)
WiredHome 81:01da2e34283d 180 return bad_parameter;
WiredHome 81:01da2e34283d 181 memcpy(&tpMatrix, matrixPtr, sizeof(tpMatrix_t));
WiredHome 81:01da2e34283d 182 return noerror;
WiredHome 81:01da2e34283d 183 }
WiredHome 81:01da2e34283d 184
WiredHome 81:01da2e34283d 185
WiredHome 79:544eb4964795 186 bool RA8875::TouchPanelA2DFiltered(loc_t *x, loc_t *y)
WiredHome 78:faf49c381591 187 {
WiredHome 78:faf49c381591 188 unsigned char touchready;
WiredHome 78:faf49c381591 189 static int xbuf[TPBUFSIZE], ybuf[TPBUFSIZE], sample = 0;
WiredHome 78:faf49c381591 190 int i, j, temp;
WiredHome 78:faf49c381591 191
WiredHome 78:faf49c381591 192 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
WiredHome 78:faf49c381591 193 // Get the next data samples
WiredHome 78:faf49c381591 194 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 195 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 196 // Check for a complete set
WiredHome 78:faf49c381591 197 if(++sample == TPBUFSIZE) {
WiredHome 78:faf49c381591 198 // Buffers are full, so process them using Finn's method described in Analog Dialogue No. 44, Feb 2010
WiredHome 78:faf49c381591 199 // This requires sorting the samples in order of size, then discarding the top 25% and
WiredHome 78:faf49c381591 200 // bottom 25% as noise spikes. Finally, the middle 50% of the values are averaged to
WiredHome 78:faf49c381591 201 // reduce Gaussian noise.
WiredHome 78:faf49c381591 202
WiredHome 78:faf49c381591 203 // Sort the Y buffer using an Insertion Sort
WiredHome 78:faf49c381591 204 for(i = 1; i <= TPBUFSIZE; i++) {
WiredHome 78:faf49c381591 205 temp = ybuf[i];
WiredHome 78:faf49c381591 206 j = i;
WiredHome 78:faf49c381591 207 while( j && (ybuf[j-1] > temp) ) {
WiredHome 78:faf49c381591 208 ybuf[j] = ybuf[j-1];
WiredHome 78:faf49c381591 209 j = j-1;
WiredHome 78:faf49c381591 210 }
WiredHome 78:faf49c381591 211 ybuf[j] = temp;
WiredHome 78:faf49c381591 212 } // End of Y sort
WiredHome 78:faf49c381591 213 // Sort the X buffer the same way
WiredHome 78:faf49c381591 214 for(i = 1; i <= TPBUFSIZE; i++) {
WiredHome 78:faf49c381591 215 temp = xbuf[i];
WiredHome 78:faf49c381591 216 j = i;
WiredHome 78:faf49c381591 217 while( j && (xbuf[j-1] > temp) ) {
WiredHome 78:faf49c381591 218 xbuf[j] = xbuf[j-1];
WiredHome 78:faf49c381591 219 j = j-1;
WiredHome 78:faf49c381591 220 }
WiredHome 78:faf49c381591 221 xbuf[j] = temp;
WiredHome 78:faf49c381591 222 } // End of X sort
WiredHome 78:faf49c381591 223 // Average the middle half of the Y values and report them
WiredHome 78:faf49c381591 224 j = 0;
WiredHome 78:faf49c381591 225 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
WiredHome 78:faf49c381591 226 j += ybuf[i];
WiredHome 78:faf49c381591 227 }
WiredHome 78:faf49c381591 228 *y = j * (float)2/TPBUFSIZE; // This is the average
WiredHome 78:faf49c381591 229 // Average the middle half of the X values and report them
WiredHome 78:faf49c381591 230 j = 0;
WiredHome 78:faf49c381591 231 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
WiredHome 78:faf49c381591 232 j += xbuf[i];
WiredHome 78:faf49c381591 233 }
WiredHome 78:faf49c381591 234 *x = j * (float)2/TPBUFSIZE; // This is the average
WiredHome 78:faf49c381591 235 // Tidy up and return
WiredHome 78:faf49c381591 236 touchready = 1;
WiredHome 78:faf49c381591 237 sample = 0; // Ready to start on the next set of data samples
WiredHome 78:faf49c381591 238 } else {
WiredHome 78:faf49c381591 239 // Buffer not yet full, so do not return any results yet
WiredHome 78:faf49c381591 240 touchready = 0;
WiredHome 78:faf49c381591 241 }
WiredHome 78:faf49c381591 242 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
WiredHome 78:faf49c381591 243 } // End of initial if -- data has been read and processed
WiredHome 78:faf49c381591 244 else
WiredHome 78:faf49c381591 245 touchready = 0; // Touch Panel "Int" was not set
WiredHome 78:faf49c381591 246 return touchready;
WiredHome 78:faf49c381591 247 }
WiredHome 78:faf49c381591 248
WiredHome 79:544eb4964795 249 bool RA8875::TouchPanelA2DRaw(loc_t *x, loc_t *y)
WiredHome 78:faf49c381591 250 {
WiredHome 78:faf49c381591 251 unsigned char touchready;
WiredHome 78:faf49c381591 252
WiredHome 78:faf49c381591 253 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
WiredHome 78:faf49c381591 254 *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 255 *x = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0]
WiredHome 78:faf49c381591 256 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
WiredHome 78:faf49c381591 257 touchready = 1;
WiredHome 78:faf49c381591 258 } else
WiredHome 78:faf49c381591 259 touchready = 0;
WiredHome 78:faf49c381591 260 return touchready;
WiredHome 78:faf49c381591 261 }
WiredHome 78:faf49c381591 262
WiredHome 78:faf49c381591 263 /* The following section is derived from Carlos E. Vidales.
WiredHome 78:faf49c381591 264 *
WiredHome 78:faf49c381591 265 * Copyright (c) 2001, Carlos E. Vidales. All rights reserved.
WiredHome 78:faf49c381591 266 *
WiredHome 78:faf49c381591 267 * This sample program was written and put in the public domain
WiredHome 78:faf49c381591 268 * by Carlos E. Vidales. The program is provided "as is"
WiredHome 78:faf49c381591 269 * without warranty of any kind, either expressed or implied.
WiredHome 78:faf49c381591 270 * If you choose to use the program within your own products
WiredHome 78:faf49c381591 271 * you do so at your own risk, and assume the responsibility
WiredHome 78:faf49c381591 272 * for servicing, repairing or correcting the program should
WiredHome 78:faf49c381591 273 * it prove defective in any manner.
WiredHome 78:faf49c381591 274 * You may copy and distribute the program's source code in any
WiredHome 78:faf49c381591 275 * medium, provided that you also include in each copy an
WiredHome 78:faf49c381591 276 * appropriate copyright notice and disclaimer of warranty.
WiredHome 78:faf49c381591 277 * You may also modify this program and distribute copies of
WiredHome 78:faf49c381591 278 * it provided that you include prominent notices stating
WiredHome 78:faf49c381591 279 * that you changed the file(s) and the date of any change,
WiredHome 78:faf49c381591 280 * and that you do not charge any royalties or licenses for
WiredHome 78:faf49c381591 281 * its use.
WiredHome 78:faf49c381591 282 *
WiredHome 78:faf49c381591 283 * This file contains functions that implement calculations
WiredHome 78:faf49c381591 284 * necessary to obtain calibration factors for a touch screen
WiredHome 78:faf49c381591 285 * that suffers from multiple distortion effects: namely,
WiredHome 78:faf49c381591 286 * translation, scaling and rotation.
WiredHome 78:faf49c381591 287 *
WiredHome 78:faf49c381591 288 * The following set of equations represent a valid display
WiredHome 78:faf49c381591 289 * point given a corresponding set of touch screen points:
WiredHome 78:faf49c381591 290 *
WiredHome 78:faf49c381591 291 * /- -\
WiredHome 78:faf49c381591 292 * /- -\ /- -\ | |
WiredHome 78:faf49c381591 293 * | | | | | Xs |
WiredHome 78:faf49c381591 294 * | Xd | | A B C | | |
WiredHome 78:faf49c381591 295 * | | = | | * | Ys |
WiredHome 78:faf49c381591 296 * | Yd | | D E F | | |
WiredHome 78:faf49c381591 297 * | | | | | 1 |
WiredHome 78:faf49c381591 298 * \- -/ \- -/ | |
WiredHome 78:faf49c381591 299 * \- -/
WiredHome 78:faf49c381591 300 * where:
WiredHome 78:faf49c381591 301 * (Xd,Yd) represents the desired display point
WiredHome 78:faf49c381591 302 * coordinates,
WiredHome 78:faf49c381591 303 * (Xs,Ys) represents the available touch screen
WiredHome 78:faf49c381591 304 * coordinates, and the matrix
WiredHome 78:faf49c381591 305 * /- -\
WiredHome 78:faf49c381591 306 * |A,B,C|
WiredHome 78:faf49c381591 307 * |D,E,F| represents the factors used to translate
WiredHome 78:faf49c381591 308 * \- -/ the available touch screen point values
WiredHome 78:faf49c381591 309 * into the corresponding display
WiredHome 78:faf49c381591 310 * coordinates.
WiredHome 78:faf49c381591 311 * Note that for practical considerations, the utilities
WiredHome 78:faf49c381591 312 * within this file do not use the matrix coefficients as
WiredHome 78:faf49c381591 313 * defined above, but instead use the following
WiredHome 78:faf49c381591 314 * equivalents, since floating point math is not used:
WiredHome 78:faf49c381591 315 * A = An/Divider
WiredHome 78:faf49c381591 316 * B = Bn/Divider
WiredHome 78:faf49c381591 317 * C = Cn/Divider
WiredHome 78:faf49c381591 318 * D = Dn/Divider
WiredHome 78:faf49c381591 319 * E = En/Divider
WiredHome 78:faf49c381591 320 * F = Fn/Divider
WiredHome 78:faf49c381591 321 * The functions provided within this file are:
WiredHome 78:faf49c381591 322 * setCalibrationMatrix() - calculates the set of factors
WiredHome 78:faf49c381591 323 * in the above equation, given
WiredHome 78:faf49c381591 324 * three sets of test points.
WiredHome 78:faf49c381591 325 * getDisplayPoint() - returns the actual display
WiredHome 78:faf49c381591 326 * coordinates, given a set of
WiredHome 78:faf49c381591 327 * touch screen coordinates.
WiredHome 78:faf49c381591 328 * translateRawScreenCoordinates() - helper function to transform
WiredHome 78:faf49c381591 329 * raw screen points into values
WiredHome 78:faf49c381591 330 * scaled to the desired display
WiredHome 78:faf49c381591 331 * resolution.
WiredHome 78:faf49c381591 332 */
WiredHome 78:faf49c381591 333
WiredHome 78:faf49c381591 334 /**********************************************************************
WiredHome 78:faf49c381591 335 *
WiredHome 78:faf49c381591 336 * Function: setCalibrationMatrix()
WiredHome 78:faf49c381591 337 *
WiredHome 78:faf49c381591 338 * Description: Calling this function with valid input data
WiredHome 78:faf49c381591 339 * in the display and screen input arguments
WiredHome 78:faf49c381591 340 * causes the calibration factors between the
WiredHome 78:faf49c381591 341 * screen and display points to be calculated,
WiredHome 78:faf49c381591 342 * and the output argument - matrixPtr - to be
WiredHome 78:faf49c381591 343 * populated.
WiredHome 78:faf49c381591 344 *
WiredHome 78:faf49c381591 345 * This function needs to be called only when new
WiredHome 78:faf49c381591 346 * calibration factors are desired.
WiredHome 78:faf49c381591 347 *
WiredHome 78:faf49c381591 348 *
WiredHome 78:faf49c381591 349 * Argument(s): displayPtr (input) - Pointer to an array of three
WiredHome 78:faf49c381591 350 * sample, reference points.
WiredHome 78:faf49c381591 351 * screenPtr (input) - Pointer to the array of touch
WiredHome 78:faf49c381591 352 * screen points corresponding
WiredHome 78:faf49c381591 353 * to the reference display points.
WiredHome 78:faf49c381591 354 * matrixPtr (output) - Pointer to the calibration
WiredHome 78:faf49c381591 355 * matrix computed for the set
WiredHome 78:faf49c381591 356 * of points being provided.
WiredHome 78:faf49c381591 357 *
WiredHome 78:faf49c381591 358 *
WiredHome 78:faf49c381591 359 * From the article text, recall that the matrix coefficients are
WiredHome 78:faf49c381591 360 * resolved to be the following:
WiredHome 78:faf49c381591 361 *
WiredHome 78:faf49c381591 362 *
WiredHome 78:faf49c381591 363 * Divider = (Xs0 - Xs2)*(Ys1 - Ys2) - (Xs1 - Xs2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 364 *
WiredHome 78:faf49c381591 365 *
WiredHome 78:faf49c381591 366 *
WiredHome 78:faf49c381591 367 * (Xd0 - Xd2)*(Ys1 - Ys2) - (Xd1 - Xd2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 368 * A = ---------------------------------------------------
WiredHome 78:faf49c381591 369 * Divider
WiredHome 78:faf49c381591 370 *
WiredHome 78:faf49c381591 371 *
WiredHome 78:faf49c381591 372 * (Xs0 - Xs2)*(Xd1 - Xd2) - (Xd0 - Xd2)*(Xs1 - Xs2)
WiredHome 78:faf49c381591 373 * B = ---------------------------------------------------
WiredHome 78:faf49c381591 374 * Divider
WiredHome 78:faf49c381591 375 *
WiredHome 78:faf49c381591 376 *
WiredHome 78:faf49c381591 377 * Ys0*(Xs2*Xd1 - Xs1*Xd2) +
WiredHome 78:faf49c381591 378 * Ys1*(Xs0*Xd2 - Xs2*Xd0) +
WiredHome 78:faf49c381591 379 * Ys2*(Xs1*Xd0 - Xs0*Xd1)
WiredHome 78:faf49c381591 380 * C = ---------------------------------------------------
WiredHome 78:faf49c381591 381 * Divider
WiredHome 78:faf49c381591 382 *
WiredHome 78:faf49c381591 383 *
WiredHome 78:faf49c381591 384 * (Yd0 - Yd2)*(Ys1 - Ys2) - (Yd1 - Yd2)*(Ys0 - Ys2)
WiredHome 78:faf49c381591 385 * D = ---------------------------------------------------
WiredHome 78:faf49c381591 386 * Divider
WiredHome 78:faf49c381591 387 *
WiredHome 78:faf49c381591 388 *
WiredHome 78:faf49c381591 389 * (Xs0 - Xs2)*(Yd1 - Yd2) - (Yd0 - Yd2)*(Xs1 - Xs2)
WiredHome 78:faf49c381591 390 * E = ---------------------------------------------------
WiredHome 78:faf49c381591 391 * Divider
WiredHome 78:faf49c381591 392 *
WiredHome 78:faf49c381591 393 *
WiredHome 78:faf49c381591 394 * Ys0*(Xs2*Yd1 - Xs1*Yd2) +
WiredHome 78:faf49c381591 395 * Ys1*(Xs0*Yd2 - Xs2*Yd0) +
WiredHome 78:faf49c381591 396 * Ys2*(Xs1*Yd0 - Xs0*Yd1)
WiredHome 78:faf49c381591 397 * F = ---------------------------------------------------
WiredHome 78:faf49c381591 398 * Divider
WiredHome 78:faf49c381591 399 *
WiredHome 78:faf49c381591 400 *
WiredHome 78:faf49c381591 401 * Return: OK - the calibration matrix was correctly
WiredHome 78:faf49c381591 402 * calculated and its value is in the
WiredHome 78:faf49c381591 403 * output argument.
WiredHome 78:faf49c381591 404 * NOT_OK - an error was detected and the
WiredHome 78:faf49c381591 405 * function failed to return a valid
WiredHome 78:faf49c381591 406 * set of matrix values.
WiredHome 78:faf49c381591 407 * The only time this sample code returns
WiredHome 78:faf49c381591 408 * NOT_OK is when Divider == 0
WiredHome 78:faf49c381591 409 *
WiredHome 78:faf49c381591 410 *
WiredHome 78:faf49c381591 411 *
WiredHome 78:faf49c381591 412 * NOTE! NOTE! NOTE!
WiredHome 78:faf49c381591 413 *
WiredHome 78:faf49c381591 414 * setCalibrationMatrix() and getDisplayPoint() will do fine
WiredHome 78:faf49c381591 415 * for you as they are, provided that your digitizer
WiredHome 78:faf49c381591 416 * resolution does not exceed 10 bits (1024 values). Higher
WiredHome 78:faf49c381591 417 * resolutions may cause the integer operations to overflow
WiredHome 78:faf49c381591 418 * and return incorrect values. If you wish to use these
WiredHome 78:faf49c381591 419 * functions with digitizer resolutions of 12 bits (4096
WiredHome 78:faf49c381591 420 * values) you will either have to a) use 64-bit signed
WiredHome 78:faf49c381591 421 * integer variables and math, or b) judiciously modify the
WiredHome 78:faf49c381591 422 * operations to scale results by a factor of 2 or even 4.
WiredHome 78:faf49c381591 423 *
WiredHome 78:faf49c381591 424 */
WiredHome 81:01da2e34283d 425 RetCode_t RA8875::TouchPanelComputeCalibration(point_t * displayPtr, point_t * screenPtr, tpMatrix_t * matrixPtr)
WiredHome 78:faf49c381591 426 {
WiredHome 78:faf49c381591 427 RetCode_t retValue = noerror;
WiredHome 78:faf49c381591 428
WiredHome 78:faf49c381591 429 tpMatrix.Divider = ((screenPtr[0].x - screenPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 430 ((screenPtr[1].x - screenPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 431
WiredHome 78:faf49c381591 432 if( tpMatrix.Divider == 0 ) {
WiredHome 78:faf49c381591 433 retValue = bad_parameter;
WiredHome 78:faf49c381591 434 } else {
WiredHome 78:faf49c381591 435 tpMatrix.An = ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 436 ((displayPtr[1].x - displayPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 437
WiredHome 78:faf49c381591 438 tpMatrix.Bn = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].x - displayPtr[2].x)) -
WiredHome 78:faf49c381591 439 ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].x - screenPtr[2].x)) ;
WiredHome 78:faf49c381591 440
WiredHome 78:faf49c381591 441 tpMatrix.Cn = (screenPtr[2].x * displayPtr[1].x - screenPtr[1].x * displayPtr[2].x) * screenPtr[0].y +
WiredHome 78:faf49c381591 442 (screenPtr[0].x * displayPtr[2].x - screenPtr[2].x * displayPtr[0].x) * screenPtr[1].y +
WiredHome 78:faf49c381591 443 (screenPtr[1].x * displayPtr[0].x - screenPtr[0].x * displayPtr[1].x) * screenPtr[2].y ;
WiredHome 78:faf49c381591 444
WiredHome 78:faf49c381591 445 tpMatrix.Dn = ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].y - screenPtr[2].y)) -
WiredHome 78:faf49c381591 446 ((displayPtr[1].y - displayPtr[2].y) * (screenPtr[0].y - screenPtr[2].y)) ;
WiredHome 78:faf49c381591 447
WiredHome 78:faf49c381591 448 tpMatrix.En = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].y - displayPtr[2].y)) -
WiredHome 78:faf49c381591 449 ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].x - screenPtr[2].x)) ;
WiredHome 78:faf49c381591 450
WiredHome 78:faf49c381591 451 tpMatrix.Fn = (screenPtr[2].x * displayPtr[1].y - screenPtr[1].x * displayPtr[2].y) * screenPtr[0].y +
WiredHome 78:faf49c381591 452 (screenPtr[0].x * displayPtr[2].y - screenPtr[2].x * displayPtr[0].y) * screenPtr[1].y +
WiredHome 78:faf49c381591 453 (screenPtr[1].x * displayPtr[0].y - screenPtr[0].x * displayPtr[1].y) * screenPtr[2].y ;
WiredHome 78:faf49c381591 454 if (matrixPtr)
WiredHome 78:faf49c381591 455 memcpy(matrixPtr, &tpMatrix, sizeof(tpMatrix_t));
WiredHome 78:faf49c381591 456 }
WiredHome 78:faf49c381591 457 return( retValue ) ;
WiredHome 78:faf49c381591 458 }
WiredHome 78:faf49c381591 459
WiredHome 78:faf49c381591 460 // #### end of touch panel code additions