uikit: Initial Apple Pencil support.

Reference Issue libsdl-org#9911.
Reference Issue libsdl-org#10516.

src/video/uikit/SDL_uikitpen.h

@@ -0,0 +1,37 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <[email protected]>
+
+  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.
+*/
+
+#ifndef SDL_uikitpen_h_
+#define SDL_uikitpen_h_
+
+#include "SDL_uikitvideo.h"
+#include "SDL_uikitwindow.h"
+
+extern bool UIKit_InitPen(SDL_VideoDevice *_this);
+extern void UIKit_HandlePenEnter();
+extern void UIKit_HandlePenLeave();
+extern void UIKit_HandlePenHover(SDL_uikitview *view, CGPoint point);
+extern void UIKit_HandlePenMotion(SDL_uikitview *view, UITouch *pencil);
+extern void UIKit_HandlePenPress(SDL_uikitview *view, UITouch *pencil);
+extern void UIKit_HandlePenRelease(SDL_uikitview *view, UITouch *pencil);
+extern void UIKit_QuitPen(SDL_VideoDevice *_this);
+
+#endif // SDL_uikitpen_h_

src/video/uikit/SDL_uikitpen.m

@@ -0,0 +1,93 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <[email protected]>
+
+  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.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_VIDEO_DRIVER_UIKIT
+
+#include "SDL_uikitevents.h"
+#include "SDL_uikitpen.h"
+#include "SDL_uikitwindow.h"
+
+#include "../../events/SDL_pen_c.h"
+
+SDL_PenID penId;
+
+typedef struct UIKit_PenHandle
+{
+    SDL_PenID pen;
+} UIKit_PenHandle;
+
+bool UIKit_InitPen(SDL_VideoDevice *_this)
+{
+    return true;
+}
+
+void UIKit_HandlePenEnter()
+{
+    SDL_PenInfo penInfo;
+    SDL_zero(penInfo);
+    penInfo.capabilities = SDL_PEN_CAPABILITY_PRESSURE | SDL_PEN_CAPABILITY_ROTATION | SDL_PEN_CAPABILITY_XTILT | SDL_PEN_CAPABILITY_YTILT | SDL_PEN_CAPABILITY_TANGENTIAL_PRESSURE;
+    penInfo.max_tilt = 90.0f;
+    penInfo.num_buttons = 0;
+    penInfo.subtype = SDL_PEN_TYPE_PENCIL;
+
+    // probably make this better
+    penId = SDL_AddPenDevice(0, [@"Apple Pencil" UTF8String], &penInfo, calloc(1, sizeof(UIKit_PenHandle)));
+}
+
+void UIKit_HandlePenHover(SDL_uikitview *view, CGPoint point)
+{
+    SDL_SendPenMotion(0, penId, [view getSDLWindow], point.x, point.y);
+}
+
+void UIKit_HandlePenMotion(SDL_uikitview *view, UITouch *pencil)
+{
+    CGPoint point = [pencil locationInView:view];
+    SDL_SendPenMotion(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], point.x, point.y);
+    SDL_SendPenAxis(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], SDL_PEN_AXIS_PRESSURE, [pencil force] / [pencil maximumPossibleForce]);
+    NSLog(@"ALTITUDE: %f", [pencil altitudeAngle]);
+    NSLog(@"AZIMUTH VECTOR: %@", [NSValue valueWithCGVector: [pencil azimuthUnitVectorInView:view]]);
+    NSLog(@"AZIMUTH ANGLE: %f", [pencil azimuthAngleInView:view]);
+    // hold it
+    //    SDL_SendPenAxis(0, penId, [view getSDLWindow], SDL_PEN_AXIS_XTILT, [pencil altitudeAngle] / M_PI);
+}
+
+void UIKit_HandlePenPress(SDL_uikitview *view, UITouch *pencil)
+{
+    SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], false, true);
+}
+
+void UIKit_HandlePenRelease(SDL_uikitview *view, UITouch *pencil)
+{
+    SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], false, false);
+}
+
+void UIKit_HandlePenLeave()
+{
+    SDL_RemovePenDevice(0, penId);
+    penId = 0;
+}
+
+void UIKit_QuitPen(SDL_VideoDevice *_this)
+{
+}
+
+#endif // SDL_VIDEO_DRIVER_UIKIT

src/video/uikit/SDL_uikitview.h

@@ -34,9 +34,16 @@
 - (void)setSDLWindow:(SDL_Window *)window;
 - (SDL_Window *)getSDLWindow;
 
+#if defined(__IPHONE_13_0)
+- (void)pencilHovering:(UIHoverGestureRecognizer *)recognizer API_AVAILABLE(ios(13.0));
+#endif
+
 #if !defined(SDL_PLATFORM_TVOS) && defined(__IPHONE_13_4)
 - (UIPointerRegion *)pointerInteraction:(UIPointerInteraction *)interaction regionForRequest:(UIPointerRegionRequest *)request defaultRegion:(UIPointerRegion *)defaultRegion API_AVAILABLE(ios(13.4));
 - (UIPointerStyle *)pointerInteraction:(UIPointerInteraction *)interaction styleForRegion:(UIPointerRegion *)region API_AVAILABLE(ios(13.4));
+- (void)indirectPointerHovering:(UIHoverGestureRecognizer *)recognizer API_AVAILABLE(ios(13.4));
+- (void)updateIndirectPointerFromTouch:(UITouch *)touch;
+- (void)updateIndirectPointerButtonState:(UITouch *)touch fromEvent:(UIEvent *)event;
 #endif
 
 - (CGPoint)touchLocation:(UITouch *)touch shouldNormalize:(BOOL)normalize;