Add scroll direction field

4 files changed, 75 insertions, 27 deletions

diff --git a/pugl/detail/mac.m b/pugl/detail/mac.m
index 3e5a018..50c52c5 100644
--- a/pugl/detail/mac.m
+++ b/pugl/detail/mac.m
@@ -460,19 +460,32 @@ handleCrossing(PuglWrapperView* view, NSEvent* event, const PuglEventType type)
 
 - (void) scrollWheel:(NSEvent*)event
 {
-	const NSPoint         wloc = [self eventLocation:event];
-	const NSPoint         rloc = [NSEvent mouseLocation];
-	const PuglEventScroll ev   = {
-		PUGL_SCROLL,
-		0,
-		[event timestamp],
-		wloc.x,
-		wloc.y,
-		rloc.x,
-		[[NSScreen mainScreen] frame].size.height - rloc.y,
-		getModifiers(event),
-		[event scrollingDeltaX],
-		[event scrollingDeltaY],
+	const NSPoint             wloc = [self eventLocation:event];
+	const NSPoint             rloc = [NSEvent mouseLocation];
+	const double              dx   = [event scrollingDeltaX];
+	const double              dy   = [event scrollingDeltaY];
+	const PuglScrollDirection dir =
+	    ((dx == 0.0 && dy > 0.0)
+	         ? PUGL_SCROLL_UP
+	         : ((dx == 0.0 && dy < 0.0)
+	                ? PUGL_SCROLL_DOWN
+	                : ((dy == 0.0 && dx > 0.0)
+	                       ? PUGL_SCROLL_RIGHT
+	                       : ((dy == 0.0 && dx < 0.0) ? PUGL_SCROLL_LEFT
+	                                                  : PUGL_SCROLL_SMOOTH))));
+
+	const PuglEventScroll ev = {
+	    PUGL_SCROLL,
+	    0,
+	    [event timestamp],
+	    wloc.x,
+	    wloc.y,
+	    rloc.x,
+	    [[NSScreen mainScreen] frame].size.height - rloc.y,
+	    getModifiers(event),
+	    [event hasPreciseScrollingDeltas] ? PUGL_SCROLL_SMOOTH : dir,
+	    dx,
+	    dy,
 	};
 
 	puglDispatchEvent(puglview, (const PuglEvent*)&ev);
diff --git a/pugl/detail/win.c b/pugl/detail/win.c
index 38f2615..ee690c4 100644
--- a/pugl/detail/win.c
+++ b/pugl/detail/win.c
@@ -668,10 +668,16 @@ handleMessage(PuglView* view, UINT message, WPARAM wParam, LPARAM lParam)
 	case WM_MOUSEWHEEL:
 		initScrollEvent(&event, view, lParam);
 		event.scroll.dy = GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+		event.scroll.direction = (event.scroll.dy > 0
+		                          ? PUGL_SCROLL_UP
+		                          : PUGL_SCROLL_DOWN);
 		break;
 	case WM_MOUSEHWHEEL:
 		initScrollEvent(&event, view, lParam);
 		event.scroll.dx = GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+		event.scroll.direction = (event.scroll.dx > 0
+		                          ? PUGL_SCROLL_RIGHT
+		                          : PUGL_SCROLL_LEFT);
 		break;
 	case WM_KEYDOWN:
 		if (!ignoreKeyEvent(view, lParam)) {
diff --git a/pugl/detail/x11.c b/pugl/detail/x11.c
index 1cd76f7..b06f940 100644
--- a/pugl/detail/x11.c
+++ b/pugl/detail/x11.c
@@ -587,10 +587,22 @@ translateEvent(PuglView* view, XEvent xevent)
 			event.scroll.dx      = 0.0;
 			event.scroll.dy      = 0.0;
 			switch (xevent.xbutton.button) {
-			case 4: event.scroll.dy =  1.0; break;
-			case 5: event.scroll.dy = -1.0; break;
-			case 6: event.scroll.dx = -1.0; break;
-			case 7: event.scroll.dx =  1.0; break;
+			case 4:
+				event.scroll.dy        = 1.0;
+				event.scroll.direction = PUGL_SCROLL_UP;
+				break;
+			case 5:
+				event.scroll.dy        = -1.0;
+				event.scroll.direction = PUGL_SCROLL_DOWN;
+				break;
+			case 6:
+				event.scroll.dx        = -1.0;
+				event.scroll.direction = PUGL_SCROLL_LEFT;
+				break;
+			case 7:
+				event.scroll.dx        = 1.0;
+				event.scroll.direction = PUGL_SCROLL_RIGHT;
+				break;
 			}
 			// fallthru
 		}
diff --git a/pugl/pugl.h b/pugl/pugl.h
index 137e6d1..8c0bd6d 100644
--- a/pugl/pugl.h
+++ b/pugl/pugl.h
@@ -239,6 +239,22 @@ typedef enum {
 } PuglCrossingMode;
 
 /**
+   Scroll direction.
+
+   Describes the direction of a #PuglEventScroll along with whether the scroll
+   is a "smooth" scroll.  The discrete directions are for devices like mouse
+   wheels with constrained axes, while a smooth scroll is for those with
+   arbitrary scroll direction freedom, like some touchpads.
+*/
+typedef enum {
+	PUGL_SCROLL_UP,    ///< Scroll up
+	PUGL_SCROLL_DOWN,  ///< Scroll down
+	PUGL_SCROLL_LEFT,  ///< Scroll left
+	PUGL_SCROLL_RIGHT, ///< Scroll right
+	PUGL_SCROLL_SMOOTH ///< Smooth scroll in any direction
+} PuglScrollDirection;
+
+/**
    Common header for all event structs.
 */
 typedef struct {
@@ -471,16 +487,17 @@ typedef struct {
    gracefully.
 */
 typedef struct {
-	PuglEventType  type;  ///< #PUGL_SCROLL
-	PuglEventFlags flags; ///< Bitwise OR of #PuglEventFlag values
-	double         time;  ///< Time in seconds
-	double         x;     ///< View-relative X coordinate
-	double         y;     ///< View-relative Y coordinate
-	double         xRoot; ///< Root-relative X coordinate
-	double         yRoot; ///< Root-relative Y coordinate
-	PuglMods       state; ///< Bitwise OR of #PuglMod flags
-	double         dx;    ///< Scroll X distance in lines
-	double         dy;    ///< Scroll Y distance in lines
+	PuglEventType       type;      ///< #PUGL_SCROLL
+	PuglEventFlags      flags;     ///< Bitwise OR of #PuglEventFlag values
+	double              time;      ///< Time in seconds
+	double              x;         ///< View-relative X coordinate
+	double              y;         ///< View-relative Y coordinate
+	double              xRoot;     ///< Root-relative X coordinate
+	double              yRoot;     ///< Root-relative Y coordinate
+	PuglMods            state;     ///< Bitwise OR of #PuglMod flags
+	PuglScrollDirection direction; ///< Scroll direction
+	double              dx;        ///< Scroll X distance in lines
+	double              dy;        ///< Scroll Y distance in lines
 } PuglEventScroll;
 
 /**