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@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