Re: [Qemu-devel] [PATCH] vnc fixes and improvements

[Anthony Liguori <aliguori@us.ibm.com>]

Stefano Stabellini wrote:
> Hi all,
> this patch fixes a bug and improves the generic pixel conversion
> function in vnc.c.
> The bug is that when a new vnc client connects we need to reset the flag
> has_WMVi but currently we don't.
> The generic pixel conversion function is vnc_convert_pixel and currently
> is not very efficient since uses the division and multiplication
> operators.
> To make it more efficient I changed to use bit shift operators instead.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>   

Applied.  Thanks.

Regards,

Anthony Liguori

> diff --git a/console.c b/console.c
> index 4bcdac1..68ac970 100644
> --- a/console.c
> +++ b/console.c
> @@ -1470,6 +1470,9 @@ PixelFormat qemu_different_endianness_pixelformat(int bpp)
>              pf.rshift = 0;
>              pf.gshift = 8;
>              pf.bshift = 16;
> +            pf.rbits = 8;
> +            pf.gbits = 8;
> +            pf.bbits = 8;
>              break;
>          case 32:
>              pf.rmask = 0x0000FF00;
> @@ -1484,6 +1487,10 @@ PixelFormat qemu_different_endianness_pixelformat(int bpp)
>              pf.rshift = 8;
>              pf.gshift = 16;
>              pf.bshift = 24;
> +            pf.rbits = 8;
> +            pf.gbits = 8;
> +            pf.bbits = 8;
> +            pf.abits = 8;
>              break;
>          default:
>              break;
> @@ -1512,6 +1519,9 @@ PixelFormat qemu_default_pixelformat(int bpp)
>              pf.rshift = 11;
>              pf.gshift = 5;
>              pf.bshift = 0;
> +            pf.rbits = 5;
> +            pf.gbits = 6;
> +            pf.bbits = 5;
>              break;
>          case 24:
>              pf.rmask = 0x00FF0000;
> @@ -1523,6 +1533,9 @@ PixelFormat qemu_default_pixelformat(int bpp)
>              pf.rshift = 16;
>              pf.gshift = 8;
>              pf.bshift = 0;
> +            pf.rbits = 8;
> +            pf.gbits = 8;
> +            pf.bbits = 8;
>          case 32:
>              pf.rmask = 0x00FF0000;
>              pf.gmask = 0x0000FF00;
> @@ -1535,6 +1548,10 @@ PixelFormat qemu_default_pixelformat(int bpp)
>              pf.rshift = 16;
>              pf.gshift = 8;
>              pf.bshift = 0;
> +            pf.rbits = 8;
> +            pf.gbits = 8;
> +            pf.bbits = 8;
> +            pf.abits = 8;
>              break;
>          default:
>              break;
> diff --git a/console.h b/console.h
> index 6e764b3..4a2f06f 100644
> --- a/console.h
> +++ b/console.h
> @@ -83,6 +83,7 @@ struct PixelFormat {
>      uint32_t rmask, gmask, bmask, amask;
>      uint8_t rshift, gshift, bshift, ashift;
>      uint8_t rmax, gmax, bmax, amax;
> +    uint8_t rbits, gbits, bbits, abits;
>  };
>  
>  struct DisplaySurface {
> diff --git a/vnc.c b/vnc.c
> index 17ea9a2..2b3a6eb 100644
> --- a/vnc.c
> +++ b/vnc.c
> @@ -56,6 +56,12 @@ static void vnc_debug_gnutls_log(int level, const char* str) {
>  #define VNC_DEBUG(fmt, ...) do { } while (0)
>  #endif
>  
> +#define count_bits(c, v) { \
> +    for (c = 0; v; v >>= 1) \
> +    { \
> +        c += v & 1; \
> +    } \
> +}
>  
>  typedef struct Buffer
>  {
> @@ -329,12 +335,12 @@ static void vnc_convert_pixel(VncState *vs, uint8_t *buf, uint32_t v)
>  {
>      uint8_t r, g, b;
>  
> -    r = ((v >> vs->serverds.pf.rshift) & vs->serverds.pf.rmax) * (vs->clientds.pf.rmax + 1) /
> -        (vs->serverds.pf.rmax + 1);
> -    g = ((v >> vs->serverds.pf.gshift) & vs->serverds.pf.gmax) * (vs->clientds.pf.gmax + 1) /
> -        (vs->serverds.pf.gmax + 1);
> -    b = ((v >> vs->serverds.pf.bshift) & vs->serverds.pf.bmax) * (vs->clientds.pf.bmax + 1) /
> -        (vs->serverds.pf.bmax + 1);
> +    r = ((((v & vs->serverds.pf.rmask) >> vs->serverds.pf.rshift) << vs->clientds.pf.rbits) >>
> +        vs->serverds.pf.rbits);
> +    g = ((((v & vs->serverds.pf.gmask) >> vs->serverds.pf.gshift) << vs->clientds.pf.gbits) >>
> +        vs->serverds.pf.gbits);
> +    b = ((((v & vs->serverds.pf.bmask) >> vs->serverds.pf.bshift) << vs->clientds.pf.bbits) >>
> +        vs->serverds.pf.bbits);
>      v = (r << vs->clientds.pf.rshift) |
>          (g << vs->clientds.pf.gshift) |
>          (b << vs->clientds.pf.bshift);
> @@ -1272,12 +1278,15 @@ static void set_pixel_format(VncState *vs,
>  
>      vs->clientds = vs->serverds;
>      vs->clientds.pf.rmax = red_max;
> +    count_bits(vs->clientds.pf.rbits, red_max);
>      vs->clientds.pf.rshift = red_shift;
>      vs->clientds.pf.rmask = red_max << red_shift;
>      vs->clientds.pf.gmax = green_max;
> +    count_bits(vs->clientds.pf.gbits, green_max);
>      vs->clientds.pf.gshift = green_shift;
>      vs->clientds.pf.gmask = green_max << green_shift;
>      vs->clientds.pf.bmax = blue_max;
> +    count_bits(vs->clientds.pf.bbits, blue_max);
>      vs->clientds.pf.bshift = blue_shift;
>      vs->clientds.pf.bmask = blue_max << blue_shift;
>      vs->clientds.pf.bits_per_pixel = bits_per_pixel;
> @@ -2106,6 +2115,7 @@ static void vnc_connect(VncState *vs)
>      memset(vs->dirty_row, 0xFF, sizeof(vs->dirty_row));
>      vs->has_resize = 0;
>      vs->has_hextile = 0;
> +    vs->has_WMVi = 0;
>      dcl->dpy_copy = NULL;
>      vnc_update_client(vs);
>      reset_keys(vs);
>
>
>
>