project for a (works on my devices) demo

sources/input/touch/touch_controller_L3.c

@@ -0,0 +1,145 @@
+#define _GNU_SOURCE
+#include <stdlib.h>
+
+/* a single printf */
+#include <stdio.h>
+
+#include "../../../headers/input/touch/touch_controller_L2.h"
+#include "../../../headers/input/touch/touch_controller_L3.h"
+#include "../../../headers/input/touch/touch_controller_L3_deltas_compute.h"
+
+
+
+/*
+
+	WHAT POINTER IS THE THIRD???
+
+*/
+static int cmp_uint64(const void *p1, const void *p2)
+{
+	uint64_t a = *(const uint64_t*) p1;
+	uint64_t b = *(const uint64_t*) p2;
+//printf("comparison between %ld and %ld\n", a, b);
+	if( a < b ){
+		return 1;
+	}
+	else if( a > b){
+		return -1;
+	}
+	else{
+		return 0;
+	}
+}
+
+
+/* returns the sorted tracking_ids of a touch_coordinates array */
+void touch_events_to_sorted_ids( uint64_t **sortedIds, touch_event **full, uint8_t full_count){
+//printf("sorting an array of ids long %d\n", full_count);
+	*sortedIds = malloc( full_count * sizeof( uint64_t));
+//printf("populate\n");
+	for( uint8_t i = 0; i < full_count; i++){
+		// could crash here...
+		( *sortedIds)[i] = full[i]->tracking_id;
+	}
+//printf("begin of actual sorting\n");
+	/* this NULL arg could bite */
+	/* qsort_r */
+	qsort( sortedIds, full_count, sizeof( uint64_t), cmp_uint64);
+}
+
+void TC_L3_get_position_deltas( 
+	touch_event **previous, uint8_t previous_count, 
+	touch_event **current, uint8_t current_count, 
+	touch_coordinates **deltas, uint8_t *count
+){
+	if( previous && current){
+		uint64_t *sorted_previous_ids = NULL;
+		uint64_t *sorted_current_ids = NULL;
+		tracked_delta *id_deltas;
+		/*	the number of total id_deltas, being a sum of sets, can be greater than the single sorted_ids list
+			but the output count, being their intersections, cannot
+		*/
+		uint16_t id_deltas_count;
+		
+		printf("mannaggia all'abaco mostrami sti id\n");
+		printf("previous\n");
+		for( uint8_t i = 0; i < previous_count; i++){
+			printf( "%ld\n", previous[i]->tracking_id);
+		}
+
+		printf("current\n");
+		for( uint8_t i = 0; i < current_count; i++){
+			printf( "%ld\n", current[i]->tracking_id);
+		}
+		
+		printf("sort ids 1\n");
+
+		touch_events_to_sorted_ids( &sorted_previous_ids, previous, previous_count);
+
+		printf("sort ids 2\n");
+
+		touch_events_to_sorted_ids( &sorted_current_ids, current, current_count);
+
+		printf("sorted ids\n");
+
+		printf("get id_deltas\n");
+		touch_events_sorted_ids_deltas( 
+			&id_deltas, &id_deltas_count, 
+			sorted_previous_ids, previous_count, 
+			sorted_current_ids, current_count
+		);
+		printf("got id_deltas\n");
+		
+		free( sorted_previous_ids);
+		free( sorted_current_ids);
+
+		uint8_t endcount = 0;
+
+		for( uint16_t i = 0; i < id_deltas_count; i++){
+			if( TRACKED_DELTA_UNCHANGED == id_deltas[i].state){
+				endcount++;
+			}
+		}
+
+		*count = endcount;
+
+		*deltas = new_touch_coordinates_buffer( endcount);
+
+		for( uint16_t i = 0; i < id_deltas_count; i++){
+			tracked_delta current_id_delta = id_deltas[i];
+			if( TRACKED_DELTA_UNCHANGED == current_id_delta.state){
+				touch_event *prev_evt = previous[ current_id_delta.old_index];
+				touch_event *next_evt = current[ current_id_delta.new_index];
+				deltas[i]->x =  next_evt->position.x - prev_evt->position.x;
+				deltas[i]->y =  next_evt->position.y - prev_evt->position.y;
+			}
+		}
+		free( id_deltas);
+	}
+	else{
+		printf( "previous or current are empty!\n");
+		*deltas = NULL;
+		*count = 0;
+	}
+}
+
+float TC_L3_get_angle_delta( float previous_angle, float current_angle){
+	float dAngle = 0;
+	dAngle = current_angle - previous_angle;
+	if( dAngle > 180){
+		dAngle -= 360;
+	}
+	else if( dAngle < -180){
+		dAngle += 360;
+	}
+	return dAngle;
+}
+
+touch_coordinates* TC_L3_get_midpoint_delta( touch_coordinates previous, touch_coordinates current){
+	touch_coordinates* delta = malloc( sizeof( touch_coordinates));
+
+	delta->x = current.x - previous.x;
+	delta->y = current.y - previous.y;
+
+	return delta;
+}