root / lab4 / state_machine.c @ 78
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#include <lcom/lcf.h> |
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#include "state_machine.h" |
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#include "mouse_macros.h" |
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#include "mouse.h" |
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#include "errors.h" |
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struct mouse_ev* mouse_get_event(struct packet *pp) { |
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static struct mouse_ev event; |
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static struct packet last; // compare consecutive events |
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static int aux = 1; // first iteration |
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if (pp == NULL) |
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return &event;
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// current packet
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uint8_t lb_press = pp->bytes[0] & LEFT_BUTTON;
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uint8_t rb_press = pp->bytes[0] & RIGHT_BUTTON;
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uint8_t mb_press = pp->bytes[0] & MIDDLE_BUTTON;
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int16_t delta_x = sign_extend_byte(pp->bytes[0] & MSB_X_DELTA, pp->bytes[1]); |
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int16_t delta_y = sign_extend_byte(pp->bytes[0] & MSB_Y_DELTA, pp->bytes[2]); |
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if (aux) { // first event detected |
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if (lb_press && (rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0) |
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event.type = LB_PRESSED; |
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else if (rb_press && (lb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0) |
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event.type = RB_PRESSED; |
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else if ((delta_x || delta_y) && (lb_press | rb_press | mb_press) == 0) { |
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event.type = MOUSE_MOV; |
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event.delta_x = delta_x; |
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event.delta_y = delta_y; |
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} else
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event.type = BUTTON_EV; |
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aux = 0;
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} else {
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// last packet
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uint8_t last_lb_press = last.bytes[0] & LEFT_BUTTON;
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uint8_t last_rb_press = last.bytes[0] & RIGHT_BUTTON;
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uint8_t last_mb_press = last.bytes[0] & MIDDLE_BUTTON;
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if (lb_press && (rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_lb_press == 0) |
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event.type = LB_PRESSED; |
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else if (rb_press && (lb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_rb_press == 0) |
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event.type = RB_PRESSED; |
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else if ((lb_press | rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_lb_press) |
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event.type = LB_RELEASED; |
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else if ((lb_press | rb_press | mb_press) == 0 && delta_x == 0 && delta_y == 0 && last_rb_press) |
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event.type = RB_RELEASED; |
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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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event.type = MOUSE_MOV; |
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event.delta_x = delta_x; |
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event.delta_y = delta_y; |
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} else
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event.type = BUTTON_EV; |
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} |
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// update last packet for comparison
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last = *pp; |
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return &event;
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} |
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int state_machine(struct mouse_ev* event, uint8_t x_len, uint8_t tolerance) { |
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static enum states state = INITIAL; |
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static int response = OTHER_ERROR; |
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static int x_length = 0; |
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static int y_length = 0; |
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if (event == NULL) |
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return response;
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switch (state) {
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case INITIAL:
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if (event->type == LB_PRESSED)
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state = DRAG_UP; |
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break;
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case DRAG_UP:
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if (event->type == MOUSE_MOV) {
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if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance) {
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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break;
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} |
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x_length += event->delta_x; |
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y_length += event->delta_y; |
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} else if (event->type == LB_RELEASED) { |
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if (x_length == 0 || y_length == 0) { |
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state = INITIAL; |
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break;
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} |
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int slope = y_length / x_length;
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if (slope <= 1 || x_length < x_len) { |
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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break;
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} |
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state = VERTEX; |
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x_length = 0;
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y_length = 0;
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} else {
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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} |
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break;
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case VERTEX:
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if (event->type == MOUSE_MOV) {
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if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance)
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state = INITIAL; |
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} else if (event->type == RB_PRESSED) { |
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state = DRAG_DOWN; |
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} else if (event->type == LB_PRESSED) { |
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state = DRAG_UP; |
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} else
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state = INITIAL; |
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break;
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case DRAG_DOWN:
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if (event->type == MOUSE_MOV) {
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if (abs(event->delta_x) > tolerance || abs(event->delta_y) > tolerance) {
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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break;
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} |
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x_length += event->delta_x; |
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y_length += event->delta_y; |
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} else if (event->type == RB_RELEASED) { |
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if (x_length == 0 || y_length == 0) { |
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state = INITIAL; |
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break;
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} |
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int slope = y_length / x_length;
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if (slope >= -1 || x_length < x_len) { |
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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break;
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} |
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state = FINAL; |
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x_length = 0;
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y_length = 0;
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} else {
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state = INITIAL; |
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x_length = 0;
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y_length = 0;
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} |
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break;
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case FINAL: // acception state |
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response = SUCCESS; |
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default: // invalid state / dead state |
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response = INVALID_STATE; |
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} |
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return response;
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} |