From bec701dd042827ed7561a5be3353ced8d35ef18f Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sun, 11 Aug 2024 17:55:20 -0400
Subject: [PATCH] pen: Add support for tangential pressure axis.
---
include/SDL3/SDL_pen.h | 1 +
src/events/SDL_events.c | 2 +-
src/events/SDL_pen_c.h | 3 ++-
src/video/cocoa/SDL_cocoapen.m | 5 +++--
4 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/include/SDL3/SDL_pen.h b/include/SDL3/SDL_pen.h
index f195d8db0c0ef..cda4f0fd74d91 100644
--- a/include/SDL3/SDL_pen.h
+++ b/include/SDL3/SDL_pen.h
@@ -99,6 +99,7 @@ typedef enum SDL_PenAxis
SDL_PEN_AXIS_DISTANCE, /**< Pen distance to drawing surface. Unidirectional: 0.0 to 1.0 */
SDL_PEN_AXIS_ROTATION, /**< Pen barrel rotation. Bidirectional: -180 to 179.9 (clockwise, 0 is facing up, -180.0 is facing down). */
SDL_PEN_AXIS_SLIDER, /**< Pen finger wheel or slider (e.g., Airbrush Pen). Unidirectional: 0 to 1.0 */
+ SDL_PEN_AXIS_TANGENTIAL_PRESSURE, /**< Pressure from squeezing the pen ("barrel pressure"). */
SDL_PEN_NUM_AXES /**< Total known pen axis types in this version of SDL. This number may grow in future releases! */
} SDL_PenAxis;
diff --git a/src/events/SDL_events.c b/src/events/SDL_events.c
index d4793653adaef..62fda0867b1b0 100644
--- a/src/events/SDL_events.c
+++ b/src/events/SDL_events.c
@@ -378,7 +378,7 @@ static void SDLCALL SDL_EventLoggingChanged(void *userdata, const char *name, co
static void SDL_LogEvent(const SDL_Event *event)
{
- static const char *pen_axisnames[] = { "PRESSURE", "XTILT", "YTILT", "DISTANCE", "ROTATION", "SLIDER" };
+ static const char *pen_axisnames[] = { "PRESSURE", "XTILT", "YTILT", "DISTANCE", "ROTATION", "SLIDER", "TANGENTIAL_PRESSURE" };
SDL_COMPILE_TIME_ASSERT(pen_axisnames_array_matches, SDL_arraysize(pen_axisnames) == SDL_PEN_NUM_AXES);
char name[64];
diff --git a/src/events/SDL_pen_c.h b/src/events/SDL_pen_c.h
index 50f5e9b30fa52..366176a985fce 100644
--- a/src/events/SDL_pen_c.h
+++ b/src/events/SDL_pen_c.h
@@ -34,7 +34,8 @@ typedef Uint32 SDL_PenCapabilityFlags;
#define SDL_PEN_CAPABILITY_DISTANCE (1u << 3) /**< Provides distance to drawing tablet on SDL_PEN_AXIS_DISTANCE. */
#define SDL_PEN_CAPABILITY_ROTATION (1u << 4) /**< Provides barrel rotation info on SDL_PEN_AXIS_ROTATION. */
#define SDL_PEN_CAPABILITY_SLIDER (1u << 5) /**< Provides slider/finger wheel/etc on SDL_PEN_AXIS_SLIDER. */
-#define SDL_PEN_CAPABILITY_ERASER (1u << 6) /**< Pen also has an eraser tip. */
+#define SDL_PEN_CAPABILITY_TANGENTIAL_PRESSURE (1u << 6) /**< Provides barrel pressure on SDL_PEN_AXIS_TANGENTIAL_PRESSURE. */
+#define SDL_PEN_CAPABILITY_ERASER (1u << 7) /**< Pen also has an eraser tip. */
typedef enum SDL_PenSubtype
{
diff --git a/src/video/cocoa/SDL_cocoapen.m b/src/video/cocoa/SDL_cocoapen.m
index 24f5f5104bbda..e22fa5aaea363 100644
--- a/src/video/cocoa/SDL_cocoapen.m
+++ b/src/video/cocoa/SDL_cocoapen.m
@@ -89,10 +89,10 @@ static void Cocoa_HandlePenProximityEvent(SDL_CocoaWindowData *_data, NSEvent *e
return; // oh well.
}
- // Cocoa offers almost none of this information.
+ // Cocoa offers almost none of this information as specifics, but can without warning offer any of these specific things.
SDL_PenInfo peninfo;
SDL_zero(peninfo);
- peninfo.capabilities = SDL_PEN_CAPABILITY_PRESSURE | SDL_PEN_CAPABILITY_ROTATION | SDL_PEN_CAPABILITY_XTILT | SDL_PEN_CAPABILITY_YTILT | (is_eraser ? SDL_PEN_CAPABILITY_ERASER : 0);
+ peninfo.capabilities = SDL_PEN_CAPABILITY_PRESSURE | SDL_PEN_CAPABILITY_ROTATION | SDL_PEN_CAPABILITY_XTILT | SDL_PEN_CAPABILITY_YTILT | SDL_PEN_CAPABILITY_TANGENTIAL_PRESSURE | (is_eraser ? SDL_PEN_CAPABILITY_ERASER : 0);
peninfo.max_tilt = 90.0f;
peninfo.num_buttons = 2;
peninfo.subtype = is_eraser ? SDL_PEN_TYPE_ERASER : SDL_PEN_TYPE_PEN;
@@ -136,6 +136,7 @@ static void Cocoa_HandlePenPointEvent(SDL_CocoaWindowData *_data, NSEvent *event
SDL_SendPenAxis(timestamp, pen, window, SDL_PEN_AXIS_ROTATION, [event rotation]);
SDL_SendPenAxis(timestamp, pen, window, SDL_PEN_AXIS_XTILT, ((float) tilt.x) * 90.0f);
SDL_SendPenAxis(timestamp, pen, window, SDL_PEN_AXIS_YTILT, ((float) tilt.y) * 90.0f);
+ SDL_SendPenAxis(timestamp, pen, window, SDL_PEN_AXIS_TANGENTIAL_PRESSURE, event.tangentialPressure);
}
SDL_bool Cocoa_HandlePenEvent(SDL_CocoaWindowData *_data, NSEvent *event)