From b975babfa5312b9a11800708f354ff9c4d4288df Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sun, 11 Aug 2024 17:56:49 -0400
Subject: [PATCH] pen: Emscripten support!
Reference Issue #10516.
---
src/video/emscripten/SDL_emscriptenevents.c | 168 ++++++++++++++++++++
1 file changed, 168 insertions(+)
diff --git a/src/video/emscripten/SDL_emscriptenevents.c b/src/video/emscripten/SDL_emscriptenevents.c
index 6cfeeaed2cba2..591ba3cfa7753 100644
--- a/src/video/emscripten/SDL_emscriptenevents.c
+++ b/src/video/emscripten/SDL_emscriptenevents.c
@@ -641,6 +641,166 @@ static const char *Emscripten_HandleBeforeUnload(int eventType, const void *rese
return ""; /* don't trigger confirmation dialog */
}
+// IF YOU CHANGE THIS STRUCTURE, YOU NEED TO UPDATE THE JAVASCRIPT THAT FILLS IT IN: makePointerEventCStruct, below.
+typedef struct Emscripten_PointerEvent
+{
+ int pointerid;
+ int button;
+ int buttons;
+ float movementX;
+ float movementY;
+ float targetX;
+ float targetY;
+ float pressure;
+ float tangential_pressure;
+ float tiltx;
+ float tilty;
+ float rotation;
+} Emscripten_PointerEvent;
+
+static void Emscripten_UpdatePointerFromEvent(SDL_WindowData *window_data, const Emscripten_PointerEvent *event)
+{
+ const SDL_PenID pen = SDL_FindPenByHandle((void *) (size_t) event->pointerid);
+ if (pen) {
+ /* rescale (in case canvas is being scaled)*/
+ double client_w, client_h;
+ emscripten_get_element_css_size(window_data->canvas_id, &client_w, &client_h);
+ const double xscale = window_data->window->w / client_w;
+ const double yscale = window_data->window->h / client_h;
+
+ const SDL_bool isPointerLocked = window_data->has_pointer_lock;
+ float mx, my;
+ if (isPointerLocked) {
+ mx = (float)(event->movementX * xscale);
+ my = (float)(event->movementY * yscale);
+ } else {
+ mx = (float)(event->targetX * xscale);
+ my = (float)(event->targetY * yscale);
+ }
+
+ SDL_SendPenMotion(0, pen, window_data->window, mx, my);
+
+ if (event->button == 0) { // pen touch
+ SDL_SendPenTouch(0, pen, window_data->window, (event->buttons & 1) ? SDL_PRESSED : SDL_RELEASED, 0);
+ } else if (event->button == 5) { // eraser touch...? Not sure if this is right...
+ SDL_SendPenTouch(0, pen, window_data->window, (event->buttons & 32) ? SDL_PRESSED : SDL_RELEASED, 1);
+ } else if (event->button == 1) {
+ SDL_SendPenButton(0, pen, window_data->window, (event->buttons & 4) ? SDL_PRESSED : SDL_RELEASED, 2);
+ } else if (event->button == 2) {
+ SDL_SendPenButton(0, pen, window_data->window, (event->buttons & 2) ? SDL_PRESSED : SDL_RELEASED, 1);
+ }
+
+ SDL_SendPenAxis(0, pen, window_data->window, SDL_PEN_AXIS_PRESSURE, event->pressure);
+ SDL_SendPenAxis(0, pen, window_data->window, SDL_PEN_AXIS_TANGENTIAL_PRESSURE, event->tangential_pressure);
+ SDL_SendPenAxis(0, pen, window_data->window, SDL_PEN_AXIS_XTILT, event->tiltx);
+ SDL_SendPenAxis(0, pen, window_data->window, SDL_PEN_AXIS_YTILT, event->tilty);
+ SDL_SendPenAxis(0, pen, window_data->window, SDL_PEN_AXIS_ROTATION, event->rotation);
+ }
+}
+
+EMSCRIPTEN_KEEPALIVE void Emscripten_HandlePointerEnter(SDL_WindowData *window_data, const Emscripten_PointerEvent *event)
+{
+ // Emscripten 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 | SDL_PEN_CAPABILITY_TANGENTIAL_PRESSURE | SDL_PEN_CAPABILITY_ERASER;
+ peninfo.max_tilt = 90.0f;
+ peninfo.num_buttons = 2;
+ peninfo.subtype = SDL_PEN_TYPE_PEN;
+ SDL_AddPenDevice(0, NULL, &peninfo, (void *) (size_t) event->pointerid);
+ Emscripten_UpdatePointerFromEvent(window_data, event);
+}
+
+EMSCRIPTEN_KEEPALIVE void Emscripten_HandlePointerLeave(SDL_WindowData *window_data, const Emscripten_PointerEvent *event)
+{
+ const SDL_PenID pen = SDL_FindPenByHandle((void *) (size_t) event->pointerid);
+ if (pen) {
+ Emscripten_UpdatePointerFromEvent(window_data, event); // last data updates?
+ SDL_RemovePenDevice(0, pen);
+ }
+}
+
+EMSCRIPTEN_KEEPALIVE void Emscripten_HandlePointerGeneric(SDL_WindowData *window_data, const Emscripten_PointerEvent *event)
+{
+ Emscripten_UpdatePointerFromEvent(window_data, event);
+}
+
+static void Emscripten_set_pointer_event_callbacks(SDL_WindowData *data)
+{
+ MAIN_THREAD_EM_ASM({
+ var target = document.querySelector(UTF8ToString($1));
+ if (target) {
+ var data = $0;
+
+ if (typeof(Module['SDL3']) === 'undefined') {
+ Module['SDL3'] = {};
+ }
+ var SDL3 = Module['SDL3'];
+
+ var makePointerEventCStruct = function(event) {
+ var ptr = 0;
+ if (event.pointerType == "pen") {
+ ptr = _malloc($2);
+ if (ptr != 0) {
+ var rect = target.getBoundingClientRect();
+ var idx = ptr >> 2;
+ HEAP32[idx++] = event.pointerId;
+ HEAP32[idx++] = (typeof(event.button) !== "undefined") ? event.button : -1;
+ HEAP32[idx++] = event.buttons;
+ HEAPF32[idx++] = event.movementX;
+ HEAPF32[idx++] = event.movementY;
+ HEAPF32[idx++] = event.clientX - rect.left;
+ HEAPF32[idx++] = event.clientY - rect.top;
+ HEAPF32[idx++] = event.pressure;
+ HEAPF32[idx++] = event.tangentialPressure;
+ HEAPF32[idx++] = event.tiltX;
+ HEAPF32[idx++] = event.tiltY;
+ HEAPF32[idx++] = event.twist;
+ }
+ }
+ return ptr;
+ };
+
+ SDL3.eventHandlerPointerEnter = function(event) {
+ var d = makePointerEventCStruct(event); if (d != 0) { _Emscripten_HandlePointerEnter(data, d); _free(d); }
+ };
+ target.addEventListener("pointerenter", SDL3.eventHandlerPointerEnter);
+
+ SDL3.eventHandlerPointerLeave = function(event) {
+ var d = makePointerEventCStruct(event); if (d != 0) { _Emscripten_HandlePointerLeave(data, d); _free(d); }
+ };
+ target.addEventListener("pointerleave", SDL3.eventHandlerPointerLeave);
+ target.addEventListener("pointercancel", SDL3.eventHandlerPointerLeave); /* catch this, just in case. */
+
+ SDL3.eventHandlerPointerGeneric = function(event) {
+ var d = makePointerEventCStruct(event); if (d != 0) { _Emscripten_HandlePointerGeneric(data, d); _free(d); }
+ };
+ target.addEventListener("pointerdown", SDL3.eventHandlerPointerGeneric);
+ target.addEventListener("pointerup", SDL3.eventHandlerPointerGeneric);
+ target.addEventListener("pointermove", SDL3.eventHandlerPointerGeneric);
+ }
+ }, data, data->canvas_id, sizeof (Emscripten_PointerEvent));
+}
+
+static void Emscripten_unset_pointer_event_callbacks(SDL_WindowData *data)
+{
+ MAIN_THREAD_EM_ASM({
+ var target = document.querySelector(UTF8ToString($0));
+ if (target) {
+ var SDL3 = Module['SDL3'];
+ target.removeEventListener("pointerenter", SDL3.eventHandlerPointerEnter);
+ target.removeEventListener("pointerleave", SDL3.eventHandlerPointerLeave);
+ target.removeEventListener("pointercancel", SDL3.eventHandlerPointerLeave);
+ target.removeEventListener("pointerdown", SDL3.eventHandlerPointerGeneric);
+ target.removeEventListener("pointerup", SDL3.eventHandlerPointerGeneric);
+ target.removeEventListener("pointermove", SDL3.eventHandlerPointerGeneric);
+ SDL3.eventHandlerPointerEnter = undefined;
+ SDL3.eventHandlerPointerLeave = undefined;
+ SDL3.eventHandlerPointerGeneric = undefined;
+ }
+ }, data->canvas_id);
+}
+
void Emscripten_RegisterEventHandlers(SDL_WindowData *data)
{
const char *keyElement;
@@ -683,12 +843,20 @@ void Emscripten_RegisterEventHandlers(SDL_WindowData *data)
emscripten_set_visibilitychange_callback(data, 0, Emscripten_HandleVisibilityChange);
emscripten_set_beforeunload_callback(data, Emscripten_HandleBeforeUnload);
+
+ // !!! FIXME: currently Emscripten doesn't have a Pointer Events functions like emscripten_set_*_callback, but we should use those when they do:
+ // !!! FIXME: https://github.com/emscripten-core/emscripten/issues/7278#issuecomment-2280024621
+ Emscripten_set_pointer_event_callbacks(data);
}
void Emscripten_UnregisterEventHandlers(SDL_WindowData *data)
{
const char *target;
+ // !!! FIXME: currently Emscripten doesn't have a Pointer Events functions like emscripten_set_*_callback, but we should use those when they do:
+ // !!! FIXME: https://github.com/emscripten-core/emscripten/issues/7278#issuecomment-2280024621
+ Emscripten_unset_pointer_event_callbacks(data);
+
/* only works due to having one window */
emscripten_set_mousemove_callback(data->canvas_id, NULL, 0, NULL);