Files
raylib/src/gestures.c
2016-02-02 17:59:13 +01:00

389 lines
13 KiB
C

/**********************************************************************************************
*
* raylib Gestures System - Gestures Detection and Usage Functions (Android and HTML5)
*
* Copyright (c) 2015 Marc Palau and Ramon Santamaria
*
* This software is provided "as-is", without any express or implied warranty. In no event
* will the authors be held liable for any damages arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose, including commercial
* applications, and to alter it and redistribute it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not claim that you
* wrote the original software. If you use this software in a product, an acknowledgment
* in the product documentation would be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be misrepresented
* as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*
**********************************************************************************************/
//#define GESTURES_STANDALONE // NOTE: To use the gestures module as standalone lib, just uncomment this line
#if defined(GESTURES_STANDALONE)
#include "gestures.h"
#else
#include "raylib.h" // Required for typedef(s): Vector2, Gestures
#endif
#include <stdlib.h> // malloc(), free()
#include <stdio.h> // printf(), fprintf()
#include <math.h> // Used for ...
#include <stdint.h> // Defines int32_t, int64_t
#if defined(_WIN32)
// Functions required to query time on Windows
int __stdcall QueryPerformanceCounter(unsigned long long int *lpPerformanceCount);
int __stdcall QueryPerformanceFrequency(unsigned long long int *lpFrequency);
#elif defined(__linux)
#include <time.h> // Used for clock functions
#endif
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
#define FORCE_TO_SWIPE 20
#define FORCE_TO_DRAG 20
#define FORCE_TO_PINCH 5
#define TAP_TIMEOUT 300 // Time in milliseconds
#define PINCH_TIMEOUT 300 // Time in milliseconds
#define DOUBLETAP_RANGE 30
//#define MAX_TOUCH_POINTS 4
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
typedef enum {
TYPE_MOTIONLESS,
TYPE_DRAG,
TYPE_DUAL_INPUT
} GestureType;
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
// Drag gesture variables
static Vector2 dragVector = { 0, 0 };
// Touch gesture variables
static Vector2 touchDownPosition = { 0, 0 };
static Vector2 touchDownPosition2 = { 0, 0 };
static Vector2 touchUpPosition = { 0, 0 };
static Vector2 moveDownPosition = { 0, 0 };
static Vector2 moveDownPosition2 = { 0, 0 };
static int numTap = 0;
static int numHold = 0;
static int pointCount = 0;
static int touchId = -1;
static double eventTime = 0;
static float magnitude = 0; // Distance traveled dragging
static float angle = 0; // Angle direction of the drag
static float intensity = 0; // How fast we did the drag (pixels per frame)
static int draggingTimeCounter = 0; // Time that have passed while dragging
// Pinch gesture variables
static float pinchDelta = 0; // Pinch delta displacement
// Detected gestures
static int previousGesture = GESTURE_NONE;
static int currentGesture = GESTURE_NONE;
// Enabled gestures flags, all gestures enabled by default
static unsigned int enabledGestures = 0b0000001111111111;
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static float CalculateAngle(Vector2 initialPosition, Vector2 actualPosition, float magnitude);
static float Vector2Distance(Vector2 v1, Vector2 v2);
static double GetCurrentTime();
//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
// Process gesture event and translate it into gestures
void ProcessGestureEvent(GestureEvent event)
{
// Resets
dragVector = (Vector2){ 0, 0 };
pinchDelta = 0;
previousGesture = currentGesture;
pointCount = event.pointCount; // Required on UpdateGestures()
if (pointCount < 2)
{
touchId = event.pointerId[0];
if (event.touchAction == TOUCH_DOWN)
{
numTap++; // Tap counter
// Detect GESTURE_DOUBLE_TAP
if ((currentGesture == GESTURE_NONE) && (numTap >= 2) && ((GetCurrentTime() - eventTime) < TAP_TIMEOUT) && (Vector2Distance(touchDownPosition, event.position[0]) < DOUBLETAP_RANGE))
{
currentGesture = GESTURE_DOUBLETAP;
numTap = 0;
}
else // Detect GESTURE_TAP
{
numTap = 1;
currentGesture = GESTURE_TAP;
}
touchDownPosition = event.position[0];
touchUpPosition = touchDownPosition;
eventTime = GetCurrentTime();
}
else if (event.touchAction == TOUCH_UP)
{
if (currentGesture == GESTURE_DRAG) touchUpPosition = event.position[0];
// Calculate for swipe
magnitude = Vector2Distance(touchDownPosition, touchUpPosition);
intensity = magnitude / (float)draggingTimeCounter;
// Detect GESTURE_SWIPE
if ((intensity > FORCE_TO_SWIPE) && (touchId == 0))
{
angle = CalculateAngle(touchDownPosition, touchUpPosition, magnitude);
if ((angle < 30) || (angle > 330)) currentGesture = GESTURE_SWIPE_RIGHT; // Right
else if ((angle > 30) && (angle < 120)) currentGesture = GESTURE_SWIPE_UP; // Up
else if ((angle > 120) && (angle < 210)) currentGesture = GESTURE_SWIPE_LEFT; // Left
else if ((angle > 210) && (angle < 300)) currentGesture = GESTURE_SWIPE_DOWN; // Down
else currentGesture = GESTURE_NONE;
}
else
{
magnitude = 0;
angle = 0;
intensity = 0;
currentGesture = GESTURE_NONE;
}
draggingTimeCounter = 0;
}
else if (event.touchAction == TOUCH_MOVE)
{
if (Vector2Distance(moveDownPosition, event.position[0]) > 5) eventTime = GetCurrentTime();
moveDownPosition = event.position[0];
if (currentGesture == GESTURE_HOLD)
{
if (numHold == 1) touchDownPosition = event.position[0];
numHold = 2;
magnitude = Vector2Distance(touchDownPosition, moveDownPosition);
// Detect GESTURE_DRAG
if (magnitude >= FORCE_TO_DRAG) currentGesture = GESTURE_DRAG;
}
draggingTimeCounter++;
}
}
else // Two touch points
{
if (event.touchAction == TOUCH_DOWN)
{
touchDownPosition = event.position[0];
touchDownPosition2 = event.position[1];
currentGesture = GESTURE_HOLD;
}
else if (event.touchAction == TOUCH_MOVE)
{
magnitude = Vector2Distance(moveDownPosition, moveDownPosition2);
touchDownPosition = moveDownPosition;
touchDownPosition2 = moveDownPosition2;
moveDownPosition = event.position[0];
moveDownPosition2 = event.position[1];
if ((Vector2Distance(touchDownPosition, moveDownPosition) > FORCE_TO_PINCH) || (Vector2Distance(touchDownPosition2, moveDownPosition2) > FORCE_TO_PINCH))
{
if ((Vector2Distance(moveDownPosition, moveDownPosition2) - magnitude) < 0) currentGesture = GESTURE_PINCH_IN;
else currentGesture = GESTURE_PINCH_OUT;
}
else
{
currentGesture = GESTURE_HOLD;
}
}
else if (event.touchAction == TOUCH_UP)
{
currentGesture = GESTURE_NONE;
}
}
}
// Update gestures detected (must be called every frame)
void UpdateGestures(void)
{
// NOTE: Gestures are processed through system callbacks on touch events
// Detect GESTURE_HOLD
if (((currentGesture == GESTURE_TAP) || (currentGesture == GESTURE_DOUBLETAP)) && pointCount < 2) currentGesture = GESTURE_HOLD;
if ((GetCurrentTime() - eventTime) > TAP_TIMEOUT && (currentGesture == GESTURE_DRAG) && pointCount < 2)
{
currentGesture = GESTURE_HOLD;
numHold = 1;
}
// Detect GESTURE_NONE
if ((currentGesture == GESTURE_SWIPE_RIGHT) || (currentGesture == GESTURE_SWIPE_UP) || (currentGesture == GESTURE_SWIPE_LEFT) || (currentGesture == GESTURE_SWIPE_DOWN))
{
currentGesture = GESTURE_NONE;
}
}
// Check if a gesture have been detected
bool IsGestureDetected(void)
{
if ((enabledGestures & currentGesture) != GESTURE_NONE) return true;
else return false;
}
// Check gesture type
int GetGestureType(void)
{
// Get current gesture only if enabled
return (enabledGestures & currentGesture);
}
void SetGesturesEnabled(unsigned int gestureFlags)
{
enabledGestures = gestureFlags;
}
// Get drag intensity (pixels per frame)
float GetGestureDragIntensity(void)
{
return intensity;
}
// Get drag angle
// NOTE: Angle in degrees, horizontal-right is 0, counterclock-wise
float GetGestureDragAngle(void)
{
return angle;
}
// Get drag vector (between initial and final position)
Vector2 GetGestureDragVector(void)
{
return dragVector;
}
// Hold time measured in frames
int GetGestureHoldDuration(void)
{
return 0;
}
// Get magnitude between two pinch points
float GetGesturePinchDelta(void)
{
return pinchDelta;
}
// Get angle beween two pinch points
// NOTE: Angle in degrees, horizontal-right is 0, counterclock-wise
float GetGesturePinchAngle(void)
{
return 0;
}
//----------------------------------------------------------------------------------
// Module specific Functions Definition
//----------------------------------------------------------------------------------
static float CalculateAngle(Vector2 initialPosition, Vector2 finalPosition, float magnitude)
{
float angle;
// Calculate arcsinus of the movement
angle = asin((finalPosition.y - initialPosition.y)/magnitude);
angle *= RAD2DEG;
// Calculate angle depending on the sector
if ((finalPosition.x - initialPosition.x) >= 0)
{
// Sector 4
if ((finalPosition.y - initialPosition.y) >= 0)
{
angle *= -1;
angle += 360;
}
// Sector 1
else angle *= -1;
}
else
{
// Sector 3
if ((finalPosition.y - initialPosition.y) >= 0) angle += 180;
// Sector 2
else
{
angle *= -1;
angle = 180 - angle;
}
}
return angle;
}
static float Vector2Distance(Vector2 v1, Vector2 v2)
{
float result;
float dx = v2.x - v1.x;
float dy = v2.y - v1.y;
result = sqrt(dx*dx + dy*dy);
return result;
}
// Time measure returned are milliseconds
static double GetCurrentTime()
{
double time = 0;
#if defined(_WIN32)
unsigned long long int clockFrequency, currentTime;
QueryPerformanceFrequency(&clockFrequency);
QueryPerformanceCounter(&currentTime);
time = (double)currentTime/clockFrequency*1000.0f; // time in miliseconds
#endif
#if defined(__linux)
// NOTE: Only for Linux-based systems
struct timespec now;
clock_gettime(CLOCK_MONOTONIC, &now);
uint64_t nowTime = (uint64_t)now.tv_sec*1000000000LLU + (uint64_t)now.tv_nsec; // Time provided in nanoseconds
time = ((double)nowTime/1000000.0); // time in miliseconds
#endif
return time;
}