firmware/drivers/touchscreen.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Maurus Cuelenaere
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "config.h"
  23 #include "button.h"
  24 #include "button-target.h"
  25 #include "touchscreen.h"
  26 #include "string.h"
  27 #include "logf.h"
  28
  29 /* Size of the 'dead zone' around each 3x3 button */
  30 #define BUTTON_MARGIN_X (int)(LCD_WIDTH * 0.03)
  31 #define BUTTON_MARGIN_Y (int)(LCD_HEIGHT * 0.03)
  32
  33 static enum touchscreen_mode current_mode = TOUCHSCREEN_POINT;
  34 static const int touchscreen_buttons[3][3] =
  35 {
  36     {BUTTON_TOPLEFT,    BUTTON_TOPMIDDLE,    BUTTON_TOPRIGHT},
  37     {BUTTON_MIDLEFT,    BUTTON_CENTER,       BUTTON_MIDRIGHT},
  38     {BUTTON_BOTTOMLEFT, BUTTON_BOTTOMMIDDLE, BUTTON_BOTTOMRIGHT}
  39 };
  40
  41 #ifndef DEFAULT_TOUCHSCREEN_CALIBRATION
  42 #define DEFAULT_TOUCHSCREEN_CALIBRATION { .A=1, .B=0, .C=0, \
  43                                           .D=0, .E=1, .F=0, \
  44                                           .divider=1 }
  45 #endif
  46
  47 struct touchscreen_parameter calibration_parameters
  48                                               = DEFAULT_TOUCHSCREEN_CALIBRATION;
  49 const struct touchscreen_parameter default_calibration_parameters
  50                                               = DEFAULT_TOUCHSCREEN_CALIBRATION;
  51
  52 void touchscreen_disable_mapping(void)
  53 {
  54 #define C(x) calibration_parameters.x
  55     C(A) = C(E) = 1;
  56     C(B) = C(C) = C(D) = C(F) = 0;
  57     C(divider) = 1;
  58 #undef C
  59 }
  60
  61 void touchscreen_reset_mapping(void)
  62 {
  63     memcpy(&calibration_parameters, &default_calibration_parameters,
  64            sizeof(struct touchscreen_parameter));
  65 }
  66
  67 int touchscreen_calibrate(struct touchscreen_calibration *cal)
  68 {
  69 #define C(x)   calibration_parameters.x /* Calibration */
  70 #define S(i,j) cal->i[j][0]             /* Screen */
  71 #define D(i,j) cal->i[j][1]             /* Display */
  72     long divider = (S(x,0) - S(x,2)) * (S(y,1) - S(y,2)) -
  73                    (S(x,1) - S(x,2)) * (S(y,0) - S(y,2));
  74
  75     if(divider == 0)
  76         return -1;
  77     else
  78         C(divider) = divider;
  79
  80     C(A) = (D(x,0) - D(x,2)) * (S(y,1) - S(y,2)) -
  81            (D(x,1) - D(x,2)) * (S(y,0) - S(y,2));
  82
  83     C(B) = (S(x,0) - S(x,2)) * (D(x,1) - D(x,2)) -
  84            (D(x,0) - D(x,2)) * (S(x,1) - S(x,2));
  85
  86     C(C) = S(y,0) * (S(x,2) * D(x,1) - S(x,1) * D(x,2)) +
  87            S(y,1) * (S(x,0) * D(x,2) - S(x,2) * D(x,0)) +
  88            S(y,2) * (S(x,1) * D(x,0) - S(x,0) * D(x,1));
  89
  90     C(D) = (D(y,0) - D(y,2)) * (S(y,1) - S(y,2)) -
  91            (D(y,1) - D(y,2)) * (S(y,0) - S(y,2));
  92
  93     C(E) = (S(x,0) - S(x,2)) * (D(y,1) - D(y,2)) -
  94            (D(y,0) - D(y,2)) * (S(x,1) - S(x,2));
  95
  96     C(F) = S(y,0) * (S(x,2) * D(y,1) - S(x,1) * D(y,2)) +
  97            S(y,1) * (S(x,0) * D(y,2) - S(x,2) * D(y,0)) +
  98            S(y,2) * (S(x,1) * D(y,0) - S(x,0) * D(y,1));
  99
 100     logf("A: %lX B: %lX C: %lX", C(A), C(B), C(C));
 101     logf("D: %lX E: %lX F: %lX", C(D), C(E), C(F));
 102     logf("divider: %lX", C(divider));
 103
 104     return 0;
 105 #undef C
 106 #undef S
 107 #undef D
 108 }
 109
 110 static void map_pixels(int *x, int *y)
 111 {
 112 #define C(x) calibration_parameters.x
 113     int _x = *x, _y = *y;
 114
 115     *x = (C(A) * _x + C(B) * _y + C(C)) / C(divider);
 116     *y = (C(D) * _x + C(E) * _y + C(F)) / C(divider);
 117 #undef C
 118 }
 119
 120 /* TODO: add jitter (and others) filter */
 121 int touchscreen_to_pixels(int x, int y, int *data)
 122 {
 123     x &= 0xFFFF;
 124     y &= 0xFFFF;
 125
 126     map_pixels(&x, &y);
 127
 128     if (current_mode == TOUCHSCREEN_BUTTON)
 129     {
 130         int column = 0, row = 0;
 131
 132         if (x < LCD_WIDTH/3 - BUTTON_MARGIN_X)
 133            column = 0;
 134         else if (x > LCD_WIDTH/3 + BUTTON_MARGIN_X &&
 135                  x < 2*LCD_WIDTH/3 - BUTTON_MARGIN_X)
 136            column = 1;
 137         else if (x > 2*LCD_WIDTH/3 + BUTTON_MARGIN_X)
 138            column = 2;
 139         else
 140            return BUTTON_NONE;
 141
 142         if (y < LCD_HEIGHT/3 - BUTTON_MARGIN_Y)
 143            row = 0;
 144         else if (y > LCD_HEIGHT/3 + BUTTON_MARGIN_Y &&
 145                  y < 2*LCD_HEIGHT/3 - BUTTON_MARGIN_Y)
 146            row = 1;
 147         else if (y > 2*LCD_HEIGHT/3 + BUTTON_MARGIN_Y)
 148            row = 2;
 149         else
 150             return BUTTON_NONE;
 151
 152         return touchscreen_buttons[row][column];
 153     }
 154     else
 155     {
 156         *data = (x << 16 | y);
 157         return BUTTON_TOUCHSCREEN;
 158     }
 159 }
 160
 161 void touchscreen_set_mode(enum touchscreen_mode mode)
 162 {
 163     current_mode = mode;
 164 }
 165
 166 enum touchscreen_mode touchscreen_get_mode(void)
 167 {
 168     return current_mode;
 169 }