macOS: Improved scrolling using mouse wheel

This required further SDL hacking. The macOS SDL .diff was updated.

IssueID #26

1 files changed, 36 insertions, 0 deletions

diff --git a/sdl2-macos-mouse-scrolling.diff b/sdl2-macos-mouse-scrolling.diff
new file mode 100644
index 00000000..e2f30c24
--- /dev/null
+++ b/sdl2-macos-mouse-scrolling.diff
@@ -0,0 +1,36 @@
+diff -r 4f06c06b6d19 src/events/SDL_mouse.c
+--- a/src/events/SDL_mouse.c    Wed Aug 05 15:28:51 2020 +0200
++++ b/src/events/SDL_mouse.c    Tue Nov 10 12:16:06 2020 +0200
+@@ -642,8 +642,8 @@
+         event.wheel.preciseX = x;
+         event.wheel.preciseY = y;
+ #endif
+-        event.wheel.x = integral_x;
+-        event.wheel.y = integral_y;
++        event.wheel.x = x; //integral_x;
++        event.wheel.y = y; //integral_y;
+         event.wheel.direction = (Uint32)direction;
+         posted = (SDL_PushEvent(&event) > 0);
+     }
+diff -r 4f06c06b6d19 src/video/cocoa/SDL_cocoamouse.m
+--- a/src/video/cocoa/SDL_cocoamouse.m  Wed Aug 05 15:28:51 2020 +0200
++++ b/src/video/cocoa/SDL_cocoamouse.m  Tue Nov 10 12:16:06 2020 +0200
+@@ -424,10 +424,16 @@
+     }
+ 
+     SDL_MouseID mouseID = mouse->mouseID;
+-    CGFloat x = -[event deltaX];
+-    CGFloat y = [event deltaY];
++    CGFloat x = -[event scrollingDeltaX];
++    CGFloat y = [event scrollingDeltaY];
+     SDL_MouseWheelDirection direction = SDL_MOUSEWHEEL_NORMAL;
+ 
++    /* HACK: Make a distinction between precise and imprecise scrolling.
++       Trackpad seems to be mouseID 0. */
++    if (![event hasPreciseScrollingDeltas]) {
++        mouseID = 1;
++    }
++
+     if ([event respondsToSelector:@selector(isDirectionInvertedFromDevice)]) {
+         if ([event isDirectionInvertedFromDevice] == YES) {
+             direction = SDL_MOUSEWHEEL_FLIPPED;