MultiTouch

a cross platform MultiTouch library that aims to provide a unified MultiTouch API

now includes DiligentLog for stand-alone compilation

USAGE

Mac OS

to add MultiTouch support to your application, adapt your source to the following

inside NSView that subclasses a NSResponder, for example, NSOpenGLView

implementation (.mm)

- (void)updateTrackingAreas {
    [self initTrackingArea];
}

-(void) initTrackingArea {
    NSTrackingAreaOptions options = (
        NSTrackingActiveAlways |
        NSTrackingInVisibleRect |
        NSTrackingMouseMoved
     );

    NSTrackingArea *area = [
        [NSTrackingArea alloc]
        initWithRect:[self bounds]
        options:options
        owner:self
        userInfo:nil
    ];
    [self addTrackingArea:area];
}

- (BOOL)acceptsFirstResponder {
    return YES;
}

// https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/EventOverview/HandlingTouchEvents/HandlingTouchEvents.html#//apple_ref/doc/uid/10000060i-CH13-SW21

- (NSPoint) getMouse {
    NSPoint x = [[self window] mouseLocationOutsideOfEventStream];
    // bottom is 0, top is height
    // we need top is 0, bottom is height
    x.y = [self bounds].size.height - x.y;
    return x;
}

- (void)touchesBeganWithEvent:(NSEvent *)event {
    NSSet * touches = [event touchesMatchingPhase:NSTouchPhaseBegan inView:self];
    NSArray *array = [touches allObjects];
    NSUInteger numberOfTouches = [array count];
    for (unsigned long i = 0; i < numberOfTouches; i++) {
        NSTouch *touch = [array objectAtIndex:i];
        [_renderer touchesBeganWithTouch:touch AndPoint:[self getMouse]];
    }
}

- (void)touchesMovedWithEvent:(NSEvent *)event {
    NSSet * touches = [event touchesMatchingPhase:NSTouchPhaseMoved inView:self];
    NSArray *array = [touches allObjects];
    NSUInteger numberOfTouches = [array count];
    for (unsigned long i = 0; i < numberOfTouches; i++) {
        NSTouch *touch = [array objectAtIndex:i];
        [_renderer touchesMovedWithTouch:touch AndPoint:[self getMouse]];
    }
}

- (void)touchesEndedWithEvent:(NSEvent *)event {
    NSSet * touches = [event touchesMatchingPhase:NSTouchPhaseEnded inView:self];
    NSArray *array = [touches allObjects];
    NSUInteger numberOfTouches = [array count];
    for (unsigned long i = 0; i < numberOfTouches; i++) {
        NSTouch *touch = [array objectAtIndex:i];
        [_renderer touchesEndedWithTouch:touch AndPoint:[self getMouse]];
    }
}

- (void)touchesCancelledWithEvent:(NSEvent *)event {
    NSSet * touches = [event touchesMatchingPhase:NSTouchPhaseCancelled inView:self];
    NSArray *array = [touches allObjects];
    NSUInteger numberOfTouches = [array count];
    for (unsigned long i = 0; i < numberOfTouches; i++) {
        NSTouch *touch = [array objectAtIndex:i];
        [_renderer touchesCancelledWithTouch:touch AndPoint:[self getMouse]];
    }
}

- (void) awakeFromNib

{
    [self setAcceptsTouchEvents:YES];
    // ...
}

// ...

inside a callback class, eg _renderer

interface (.h)

// include path/to/MultiTouch.h here

@interface OpenGLRenderer : NSObject
{
    MultiTouch multiTouch;

    // something that consumes MultiTouch objects
    AppInstance appInstance;
}

- (instancetype) init;

- (void) touchesBeganWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point;
- (void) touchesMovedWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point;
- (void) touchesEndedWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point;
- (void) touchesCancelledWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point;

// ...

@end

implementation (.mm)

@implementation OpenGLRenderer

- (instancetype) init {
    multiTouch.setMaxSupportedTouches(10);
    return self;
}

- (void)touchesBeganWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point {
    multiTouch.addTouch(
        ((NSInteger) touch.identity),
        point.x,
        point.y
    );
    appInstance.onTouchEvent(multiTouch);
}

- (void)touchesMovedWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point {
    multiTouch.moveTouch(
        ((NSInteger) touch.identity),
        point.x,
        point.y
    );
    appInstance.onTouchEvent(multiTouch);
}

- (void)touchesEndedWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point {
    multiTouch.removeTouch(
        ((NSInteger) touch.identity),
        point.x,
        point.y
    );
    appInstance.onTouchEvent(multiTouch);
}

- (void)touchesCancelledWithTouch:(NSTouch *)touch AndPoint:(NSPoint)point {
    multiTouch.cancelTouch(
        ((NSInteger) touch.identity),
        point.x,
        point.y
    );
    appInstance.onTouchEvent(multiTouch);
}
// ...

Android

to add MultiTouch support to android, adapt your views OnTouchEvent to the following

@Override
public boolean onTouchEvent(MotionEvent event) {
    int action = event.getActionMasked();
    int actionIndex = event.getActionIndex();
    int id = 0;
    boolean isUpDown = false;
    switch (action) {
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_POINTER_DOWN:
        case MotionEvent.ACTION_POINTER_UP:
            id = event.getPointerId(actionIndex);
            isUpDown = true;
            break;
    }

    int c = event.getPointerCount();
    for (int i = 0; i < c; i++) {
        int pid = event.getPointerId(i);
        if (isUpDown) {
            if (actionIndex == i) {
                switch (action) {
                    case MotionEvent.ACTION_DOWN:
                    case MotionEvent.ACTION_POINTER_DOWN:
                        renderer.addTouch(
                                id,
                                event.getX(actionIndex),
                                event.getY(actionIndex),
                                event.getSize(actionIndex),
                                event.getPressure(actionIndex)
                        );
                        break;
                    case MotionEvent.ACTION_UP:
                    case MotionEvent.ACTION_POINTER_UP:
                        renderer.removeTouch(
                                id,
                                event.getX(actionIndex),
                                event.getY(actionIndex),
                                event.getSize(actionIndex),
                                event.getPressure(actionIndex)
                        );
                        break;
                }
            }
        }

        if (actionIndex != i || !isUpDown) {
            renderer.moveTouch(
                    pid,
                    event.getX(i),
                    event.getY(i),
                    event.getSize(i),
                    event.getPressure(i)
            );
        }
    }
    return renderer.onTouchEvent(renderer.nativeInstance);
}

and add the following native calls

native void addTouch(long identity, float x, float y);
native void addTouch(long identity, float x, float y, float size);
native void addTouch(long identity, float x, float y, float size, float pressure);
native void moveTouch(long identity, float x, float y);
native void moveTouch(long identity, float x, float y, float size);
native void moveTouch(long identity, float x, float y, float size, float pressure);
native void removeTouch(long identity, float x, float y);
native void removeTouch(long identity, float x, float y, float size);
native void removeTouch(long identity, float x, float y, float size, float pressure);
native void cancelTouch(long identity, float x, float y);
native void cancelTouch(long identity, float x, float y, float size);
native void cancelTouch(long identity, float x, float y, float size, float pressure);
native boolean onTouchEvent(long instance);

finally, add the native implementation

#include <MultiTouch.h>
MultiTouch multiTouch;

#define APP(jlong) reinterpret_cast<YourNativeClassInstance*>(jlong)

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_addTouch__JFF(
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y
)
{
    multiTouch.addTouch(identifier, x, y);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_addTouch__JFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size
)
{
    multiTouch.addTouch(identifier, x, y, size);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_addTouch__JFFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size, jfloat pressure
)
{
    multiTouch.addTouch(identifier, x, y, size, pressure);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_moveTouch__JFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y
)
{
    multiTouch.moveTouch(identifier, x, y);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_moveTouch__JFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size
)
{
    multiTouch.moveTouch(identifier, x, y, size);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_moveTouch__JFFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size, jfloat pressure
)
{
    multiTouch.moveTouch(identifier, x, y, size, pressure);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_removeTouch__JFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y
)
{
    multiTouch.removeTouch(identifier, x, y);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_removeTouch__JFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size
)
{
    multiTouch.removeTouch(identifier, x, y, size);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_removeTouch__JFFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size, jfloat pressure
)
{
    multiTouch.removeTouch(identifier, x, y, size, pressure);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_cancelTouch__JFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y
)
{
    multiTouch.cancelTouch(identifier, x, y);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_cancelTouch__JFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size
)
{
    multiTouch.cancelTouch(identifier, x, y, size);
}

extern "C" JNIEXPORT void JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_cancelTouch__JFFFF (
        JNIEnv * env, jobject thiz,
        jlong identifier, jfloat x, jfloat y, jfloat size, jfloat pressure
)
{
    multiTouch.cancelTouch(identifier, x, y, size, pressure);
}

extern "C" JNIEXPORT jboolean JNICALL
Java_smallville7123_graphical_tool_kit_DiligentEngineView_00024DiligentEngineRenderer_onTouchEvent (
        JNIEnv * env, jobject thiz, jlong instance
)
{
    return APP(instance)->onTouchEvent(multiTouch);
}