root / lab4 / state_machine.c @ 78
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| 1 | 78 | up20180655 | #include <lcom/lcf.h> |
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| 2 | |||
| 3 | #include "state_machine.h" |
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| 4 | #include "mouse_macros.h" |
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| 5 | #include "mouse.h" |
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| 6 | #include "errors.h" |
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| 7 | |||
| 8 | struct mouse_ev* mouse_get_event(struct packet *pp) { |
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| 9 | |||
| 10 | static struct mouse_ev event; |
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| 11 | static struct packet last; // compare consecutive events |
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| 12 | static int aux = 1; // first iteration |
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| 13 | |||
| 14 | if (pp == NULL) |
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| 15 | return &event;
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| 16 | |||
| 17 | // current packet
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| 18 | uint8_t lb_press = pp->bytes[0] & LEFT_BUTTON;
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| 19 | uint8_t rb_press = pp->bytes[0] & RIGHT_BUTTON;
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| 20 | uint8_t mb_press = pp->bytes[0] & MIDDLE_BUTTON;
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| 21 | int16_t delta_x = sign_extend_byte(pp->bytes[0] & MSB_X_DELTA, pp->bytes[1]); |
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| 22 | int16_t delta_y = sign_extend_byte(pp->bytes[0] & MSB_Y_DELTA, pp->bytes[2]); |
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| 23 | |||
| 24 | if (aux) { // first event detected |
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| 25 | if (lb_press && (rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0) |
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| 26 | event.type = LB_PRESSED; |
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| 27 | else if (rb_press && (lb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0) |
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| 28 | event.type = RB_PRESSED; |
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| 29 | else if ((delta_x || delta_y) && (lb_press | rb_press | mb_press) == 0) { |
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| 30 | event.type = MOUSE_MOV; |
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| 31 | event.delta_x = delta_x; |
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| 32 | event.delta_y = delta_y; |
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| 33 | } else
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| 34 | event.type = BUTTON_EV; |
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| 35 | aux = 0;
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| 36 | } else {
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| 37 | // last packet
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| 38 | uint8_t last_lb_press = last.bytes[0] & LEFT_BUTTON;
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| 39 | uint8_t last_rb_press = last.bytes[0] & RIGHT_BUTTON;
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| 40 | uint8_t last_mb_press = last.bytes[0] & MIDDLE_BUTTON;
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| 41 | |||
| 42 | if (lb_press && (rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_lb_press == 0) |
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| 43 | event.type = LB_PRESSED; |
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| 44 | else if (rb_press && (lb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_rb_press == 0) |
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| 45 | event.type = RB_PRESSED; |
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| 46 | else if ((lb_press | rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_lb_press) |
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| 47 | event.type = LB_RELEASED; |
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| 48 | else if ((lb_press | rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_rb_press) |
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| 49 | event.type = RB_RELEASED; |
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| 50 | else if ((delta_x || delta_y) && (lb_press | rb_press | mb_press) == (last_lb_press | last_rb_press | last_mb_press)) { |
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| 51 | event.type = MOUSE_MOV; |
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| 52 | event.delta_x = delta_x; |
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| 53 | event.delta_y = delta_y; |
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| 54 | } else
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| 55 | event.type = BUTTON_EV; |
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| 56 | } |
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| 57 | |||
| 58 | // update last packet for comparison
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| 59 | last = *pp; |
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| 60 | |||
| 61 | return &event;
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| 62 | } |
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| 63 | |||
| 64 | int state_machine(struct mouse_ev* event, uint8_t x_len, uint8_t tolerance) { |
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| 65 | |||
| 66 | static enum states state = INITIAL; |
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| 67 | static int response = OTHER_ERROR; |
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| 68 | static int x_length = 0; |
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| 69 | static int y_length = 0; |
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| 70 | |||
| 71 | if (event == NULL) |
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| 72 | return response;
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| 73 | |||
| 74 | switch (state) {
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| 75 | case INITIAL:
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| 76 | if (event->type == LB_PRESSED)
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| 77 | state = DRAG_UP; |
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| 78 | break;
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| 79 | case DRAG_UP:
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| 80 | if (event->type == MOUSE_MOV) {
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| 81 | if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance) {
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| 82 | state = INITIAL; |
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| 83 | x_length = 0;
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| 84 | y_length = 0;
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| 85 | break;
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| 86 | } |
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| 87 | |||
| 88 | x_length += event->delta_x; |
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| 89 | y_length += event->delta_y; |
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| 90 | } else if (event->type == LB_RELEASED) { |
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| 91 | if (x_length == 0 || y_length == 0) { |
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| 92 | state = INITIAL; |
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| 93 | break;
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| 94 | } |
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| 95 | |||
| 96 | int slope = y_length / x_length;
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| 97 | |||
| 98 | if (slope <= 1 || x_length < x_len) { |
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| 99 | state = INITIAL; |
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| 100 | x_length = 0;
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| 101 | y_length = 0;
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| 102 | break;
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| 103 | } |
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| 104 | |||
| 105 | state = VERTEX; |
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| 106 | x_length = 0;
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| 107 | y_length = 0;
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| 108 | } else {
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| 109 | state = INITIAL; |
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| 110 | x_length = 0;
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| 111 | y_length = 0;
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| 112 | } |
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| 113 | break;
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| 114 | case VERTEX:
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| 115 | if (event->type == MOUSE_MOV) {
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| 116 | if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance)
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| 117 | state = INITIAL; |
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| 118 | } else if (event->type == RB_PRESSED) { |
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| 119 | state = DRAG_DOWN; |
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| 120 | } else if (event->type == LB_PRESSED) { |
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| 121 | state = DRAG_UP; |
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| 122 | } else
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| 123 | state = INITIAL; |
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| 124 | break;
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| 125 | case DRAG_DOWN:
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| 126 | if (event->type == MOUSE_MOV) {
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| 127 | if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance) {
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| 128 | state = INITIAL; |
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| 129 | x_length = 0;
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| 130 | y_length = 0;
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| 131 | break;
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| 132 | } |
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| 133 | |||
| 134 | x_length += event->delta_x; |
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| 135 | y_length += event->delta_y; |
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| 136 | } else if (event->type == RB_RELEASED) { |
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| 137 | if (x_length == 0 || y_length == 0) { |
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| 138 | state = INITIAL; |
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| 139 | break;
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| 140 | } |
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| 141 | |||
| 142 | int slope = y_length / x_length;
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| 143 | |||
| 144 | if (slope >= -1 || x_length < x_len) { |
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| 145 | state = INITIAL; |
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| 146 | x_length = 0;
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| 147 | y_length = 0;
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| 148 | break;
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| 149 | } |
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| 150 | |||
| 151 | state = FINAL; |
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| 152 | x_length = 0;
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| 153 | y_length = 0;
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| 154 | } else {
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| 155 | state = INITIAL; |
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| 156 | x_length = 0;
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| 157 | y_length = 0;
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| 158 | } |
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| 159 | break;
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| 160 | case FINAL: // acception state |
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| 161 | response = SUCCESS; |
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| 162 | default: // invalid state / dead state |
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| 163 | response = INVALID_STATE; |
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| 164 | } |
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| 165 | return response;
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| 166 | } |