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>
---
ui/vnc.h | 2 ++
ui/vnc.c | 21 ++++++++++++++++++---
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/ui/vnc.h b/ui/vnc.h
index 6f5006da3593..c8d3ad9ec496 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -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)
diff --git a/ui/vnc.c b/ui/vnc.c
index 8c2771c1ce3b..247e80d8f5c8 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -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)
--
2.27.0
Hi
On Thu, Dec 3, 2020 at 3:11 PM Gerd Hoffmann <kraxel@redhat.com> wrote:
> 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>
> ---
> ui/vnc.h | 2 ++
> ui/vnc.c | 21 ++++++++++++++++++---
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/ui/vnc.h b/ui/vnc.h
> index 6f5006da3593..c8d3ad9ec496 100644
> --- a/ui/vnc.h
> +++ b/ui/vnc.h
> @@ -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)
> diff --git a/ui/vnc.c b/ui/vnc.c
> index 8c2771c1ce3b..247e80d8f5c8 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -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);
> + }
>
Looks good. Minor nit, I would suggest to do the "if (!vs->vd->cursor)
return" in vnc_cursor_define().
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
}
>
> static void set_pixel_conversion(VncState *vs)
> --
> 2.27.0
>
>
>
--
Marc-André Lureau
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