vnc: add alpha cursor support

There is a new vnc extension for cursors with an alpha channel.  Use
it if supported by the vnc client, prefer it over the "rich cursor"
extension which supports only a bitmask for transparency.

This is a visible improvement especially on modern desktops which
actually use the alpha channel when defining cursors.

https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#cursor-with-alpha-pseudo-encoding

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20201208115737.18581-7-kraxel@redhat.com
This commit is contained in:
Gerd Hoffmann 2020-12-08 12:57:34 +01:00
parent a7d83e4359
commit 074a86d0b3
2 changed files with 20 additions and 3 deletions

View file

@ -937,6 +937,18 @@ static int vnc_cursor_define(VncState *vs)
QEMUCursor *c = vs->vd->cursor;
int isize;
if (vnc_has_feature(vs, VNC_FEATURE_ALPHA_CURSOR)) {
vnc_lock_output(vs);
vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
vnc_write_u8(vs, 0); /* padding */
vnc_write_u16(vs, 1); /* # of rects */
vnc_framebuffer_update(vs, c->hot_x, c->hot_y, c->width, c->height,
VNC_ENCODING_ALPHA_CURSOR);
vnc_write_s32(vs, VNC_ENCODING_RAW);
vnc_write(vs, c->data, c->width * c->height * 4);
vnc_unlock_output(vs);
return 0;
}
if (vnc_has_feature(vs, VNC_FEATURE_RICH_CURSOR)) {
vnc_lock_output(vs);
vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
@ -2102,9 +2114,9 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
break;
case VNC_ENCODING_RICH_CURSOR:
vs->features |= VNC_FEATURE_RICH_CURSOR_MASK;
if (vs->vd->cursor) {
vnc_cursor_define(vs);
}
break;
case VNC_ENCODING_ALPHA_CURSOR:
vs->features |= VNC_FEATURE_ALPHA_CURSOR_MASK;
break;
case VNC_ENCODING_EXT_KEY_EVENT:
send_ext_key_event_ack(vs);
@ -2134,6 +2146,9 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
vnc_desktop_resize(vs);
check_pointer_type_change(&vs->mouse_mode_notifier, NULL);
vnc_led_state_change(vs);
if (vs->vd->cursor) {
vnc_cursor_define(vs);
}
}
static void set_pixel_conversion(VncState *vs)

View file

@ -448,6 +448,7 @@ enum VncFeatures {
VNC_FEATURE_TIGHT,
VNC_FEATURE_ZLIB,
VNC_FEATURE_RICH_CURSOR,
VNC_FEATURE_ALPHA_CURSOR,
VNC_FEATURE_TIGHT_PNG,
VNC_FEATURE_ZRLE,
VNC_FEATURE_ZYWRLE,
@ -461,6 +462,7 @@ enum VncFeatures {
#define VNC_FEATURE_TIGHT_MASK (1 << VNC_FEATURE_TIGHT)
#define VNC_FEATURE_ZLIB_MASK (1 << VNC_FEATURE_ZLIB)
#define VNC_FEATURE_RICH_CURSOR_MASK (1 << VNC_FEATURE_RICH_CURSOR)
#define VNC_FEATURE_ALPHA_CURSOR_MASK (1 << VNC_FEATURE_ALPHA_CURSOR)
#define VNC_FEATURE_TIGHT_PNG_MASK (1 << VNC_FEATURE_TIGHT_PNG)
#define VNC_FEATURE_ZRLE_MASK (1 << VNC_FEATURE_ZRLE)
#define VNC_FEATURE_ZYWRLE_MASK (1 << VNC_FEATURE_ZYWRLE)