From e612ce511b0d5a46f40cc414f4963b560d233f3f Mon Sep 17 00:00:00 2001
From: Frank Praznik <[EMAIL REDACTED]>
Date: Tue, 6 Aug 2024 10:18:39 -0400
Subject: [PATCH] wayland: Add support for high-DPI custom cursors
Add a cursor caching system and viewport support, to allow for high-DPI, fractionally-scaled, custom cursors.
---
src/video/wayland/SDL_waylandmouse.c | 163 +++++++++++++++++++++------
1 file changed, 128 insertions(+), 35 deletions(-)
diff --git a/src/video/wayland/SDL_waylandmouse.c b/src/video/wayland/SDL_waylandmouse.c
index 156e8a7ac0011..69af379e7745e 100644
--- a/src/video/wayland/SDL_waylandmouse.c
+++ b/src/video/wayland/SDL_waylandmouse.c
@@ -37,6 +37,7 @@
#include "cursor-shape-v1-client-protocol.h"
#include "pointer-constraints-unstable-v1-client-protocol.h"
+#include "viewporter-client-protocol.h"
#include "../../SDL_hints_c.h"
@@ -47,6 +48,18 @@ static int Wayland_SetRelativeMouseMode(SDL_bool enabled);
typedef struct
{
struct Wayland_SHMBuffer shmBuffer;
+
+ int dst_width;
+ int dst_height;
+ float scale;
+
+ struct wl_list node;
+} Wayland_CachedCustomCursor;
+
+typedef struct
+{
+ SDL_Surface *sdl_cursor_surface;
+ struct wl_list cursor_cache;
} Wayland_CustomCursor;
typedef struct
@@ -70,13 +83,14 @@ struct SDL_CursorData
{
union
{
- struct Wayland_SHMBuffer custom;
+ Wayland_CustomCursor custom;
Wayland_SystemCursor system;
} cursor_data;
+
struct wl_surface *surface;
+ struct wp_viewport *viewport;
int hot_x, hot_y;
- int w, h;
SDL_bool is_system_cursor;
};
@@ -342,7 +356,7 @@ static SDL_bool wayland_get_system_cursor(SDL_VideoData *vdata, SDL_CursorData *
/* First, find the appropriate theme based on the current scale... */
focus = SDL_GetMouse()->focus;
if (focus) {
- /* Cursors use integer scaling. */
+ /* TODO: Use the fractional scale once GNOME supports viewports on cursor surfaces. */
*scale = SDL_ceilf(focus->internal->windowed_scale_factor);
} else {
*scale = 1.0f;
@@ -411,43 +425,92 @@ static SDL_bool wayland_get_system_cursor(SDL_VideoData *vdata, SDL_CursorData *
}
cdata->hot_x = cursor->images[0]->hotspot_x;
cdata->hot_y = cursor->images[0]->hotspot_y;
- cdata->w = cursor->images[0]->width;
- cdata->h = cursor->images[0]->height;
return SDL_TRUE;
}
+static Wayland_CachedCustomCursor *Wayland_GetCachedCustomCursor(SDL_Cursor *cursor)
+{
+ SDL_VideoDevice *vd = SDL_GetVideoDevice();
+ SDL_VideoData *wd = vd->internal;
+ SDL_CursorData *data = cursor->internal;
+ Wayland_CachedCustomCursor *cache;
+ SDL_Window *focus = SDL_GetMouseFocus();
+ float scale = 1.0f;
+
+ if (focus && SDL_SurfaceHasAlternateImages(data->cursor_data.custom.sdl_cursor_surface)) {
+ scale = focus->internal->windowed_scale_factor;
+ }
+
+ /* Only use fractional scale values if viewports are available. */
+ if (!wd->viewporter) {
+ scale = SDL_ceilf(scale);
+ }
+
+ /* Is this cursor already cached at the target scale? */
+ wl_list_for_each(cache, &data->cursor_data.custom.cursor_cache, node) {
+ if (cache->scale == scale) {
+ return cache;
+ }
+ }
+
+ cache = SDL_calloc(1, sizeof(Wayland_CachedCustomCursor));
+ if (!cache) {
+ return NULL;
+ }
+
+ SDL_Surface *surface = SDL_GetSurfaceImage(data->cursor_data.custom.sdl_cursor_surface, scale);
+ if (!surface) {
+ SDL_free(cache);
+ return NULL;
+ }
+
+ /* Allocate shared memory buffer for this cursor */
+ if (Wayland_AllocSHMBuffer(surface->w, surface->h, &cache->shmBuffer) != 0) {
+ SDL_free(cursor->internal);
+ SDL_free(cursor);
+ return NULL;
+ }
+
+ /* Wayland requires premultiplied alpha for its surfaces. */
+ SDL_PremultiplyAlpha(surface->w, surface->h,
+ surface->format, surface->pixels, surface->pitch,
+ SDL_PIXELFORMAT_ARGB8888, cache->shmBuffer.shm_data, surface->w * 4, SDL_TRUE);
+
+ cache->dst_width = data->cursor_data.custom.sdl_cursor_surface->w;
+ cache->dst_height = data->cursor_data.custom.sdl_cursor_surface->h;
+ cache->scale = scale;
+ WAYLAND_wl_list_insert(&data->cursor_data.custom.cursor_cache, &cache->node);
+ SDL_DestroySurface(surface);
+
+ return cache;
+}
+
static SDL_Cursor *Wayland_CreateCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
+ SDL_VideoDevice *vd = SDL_GetVideoDevice();
+ SDL_VideoData *wd = vd->internal;
+
SDL_Cursor *cursor = SDL_calloc(1, sizeof(*cursor));
if (cursor) {
- SDL_VideoDevice *vd = SDL_GetVideoDevice();
- SDL_VideoData *wd = vd->internal;
SDL_CursorData *data = SDL_calloc(1, sizeof(*data));
if (!data) {
SDL_free(cursor);
return NULL;
}
cursor->internal = data;
-
- /* Allocate shared memory buffer for this cursor */
- if (Wayland_AllocSHMBuffer(surface->w, surface->h, &data->cursor_data.custom) != 0) {
- SDL_free(cursor->internal);
- SDL_free(cursor);
- return NULL;
- }
-
- /* Wayland requires premultiplied alpha for its surfaces. */
- SDL_PremultiplyAlpha(surface->w, surface->h,
- surface->format, surface->pixels, surface->pitch,
- SDL_PIXELFORMAT_ARGB8888, data->cursor_data.custom.shm_data, surface->w * 4, SDL_TRUE);
-
+ WAYLAND_wl_list_init(&data->cursor_data.custom.cursor_cache);
+ data->hot_x = hot_x;
+ data->hot_y = hot_y;
data->surface = wl_compositor_create_surface(wd->compositor);
wl_surface_set_user_data(data->surface, NULL);
- data->hot_x = hot_x;
- data->hot_y = hot_y;
- data->w = surface->w;
- data->h = surface->h;
+ data->cursor_data.custom.sdl_cursor_surface = surface;
+ ++surface->refcount;
+
+ /* If the cursor has only one size, just prepare it now. */
+ if (!SDL_SurfaceHasAlternateImages(surface)) {
+ Wayland_GetCachedCustomCursor(cursor);
+ }
}
return cursor;
@@ -496,7 +559,18 @@ static void Wayland_FreeCursorData(SDL_CursorData *d)
}
SDL_free(d->cursor_data.system.frames);
} else {
- Wayland_ReleaseSHMBuffer(&d->cursor_data.custom);
+ Wayland_CachedCustomCursor *c, *temp;
+ wl_list_for_each_safe(c, temp, &d->cursor_data.custom.cursor_cache, node) {
+ Wayland_ReleaseSHMBuffer(&c->shmBuffer);
+ SDL_free(c);
+ }
+
+ SDL_DestroySurface(d->cursor_data.custom.sdl_cursor_surface);
+ }
+
+ if (d->viewport) {
+ wp_viewport_destroy(d->viewport);
+ d->viewport = NULL;
}
if (d->surface) {
@@ -602,6 +676,8 @@ static int Wayland_ShowCursor(SDL_Cursor *cursor)
struct SDL_WaylandInput *input = d->input;
struct wl_pointer *pointer = d->pointer;
float scale = 1.0f;
+ int dst_width = 0;
+ int dst_height = 0;
if (!pointer) {
return -1;
@@ -617,25 +693,19 @@ static int Wayland_ShowCursor(SDL_Cursor *cursor)
if (cursor) {
SDL_CursorData *data = cursor->internal;
- /* TODO: High-DPI custom cursors? -flibit */
if (data->is_system_cursor) {
if (input->cursor_shape) {
Wayland_SetSystemCursorShape(input, data->cursor_data.system.id);
-
input->current_cursor = data;
return 0;
- } else if (!wayland_get_system_cursor(d, data, &scale)) {
+ }
+
+ if (!wayland_get_system_cursor(d, data, &scale)) {
return -1;
}
}
- wl_surface_set_buffer_scale(data->surface, (int32_t)scale);
- wl_pointer_set_cursor(pointer,
- input->pointer_enter_serial,
- data->surface,
- (int32_t)(data->hot_x / scale),
- (int32_t)(data->hot_y / scale));
if (data->is_system_cursor) {
wl_surface_attach(data->surface, data->cursor_data.system.frames[0].wl_buffer, 0, 0);
@@ -647,8 +717,31 @@ static int Wayland_ShowCursor(SDL_Cursor *cursor)
wl_callback_add_listener(data->cursor_data.system.frame_callback, &cursor_frame_listener, data);
}
} else {
- wl_surface_attach(data->surface, data->cursor_data.custom.wl_buffer, 0, 0);
+ Wayland_CachedCustomCursor *cached = Wayland_GetCachedCustomCursor(cursor);
+ dst_width = cached->dst_width;
+ dst_height = cached->dst_height;
+ scale = cached->scale;
+ wl_surface_attach(data->surface, cached->shmBuffer.wl_buffer, 0, 0);
}
+
+ /* TODO: Make the viewport path the default in all cases once GNOME finally supports viewports on cursor surfaces. */
+ if (SDL_ceilf(scale) != scale && d->viewporter) {
+ if (!data->viewport) {
+ data->viewport = wp_viewporter_get_viewport(d->viewporter, data->surface);
+ }
+ wl_surface_set_buffer_scale(data->surface, 1);
+ wp_viewport_set_source(data->viewport, wl_fixed_from_int(-1), wl_fixed_from_int(-1), wl_fixed_from_int(-1), wl_fixed_from_int(-1));
+ wp_viewport_set_destination(data->viewport, dst_width, dst_height);
+ wl_pointer_set_cursor(pointer, input->pointer_enter_serial, data->surface, data->hot_x, data->hot_y);
+ } else {
+ if (data->viewport) {
+ wp_viewport_destroy(data->viewport);
+ data->viewport = NULL;
+ }
+ wl_surface_set_buffer_scale(data->surface, (int32_t)scale);
+ wl_pointer_set_cursor(pointer, input->pointer_enter_serial, data->surface, (int32_t)(data->hot_x / scale), (int32_t)(data->hot_y / scale));
+ }
+
if (wl_surface_get_version(data->surface) >= WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION) {
wl_surface_damage_buffer(data->surface, 0, 0, SDL_MAX_SINT32, SDL_MAX_SINT32);
} else {