Re: [PATCH 2/2] winex11.drv: Add EDID to the virtual desktop monitor device.

[Zhiyi Zhang]

On 9/3/21 4:34 PM, Eduard Permyakov wrote:
> Some applications use the EDID property of the monitor device
> to detect supported resolutions, and set the viewport size. Add
> a computed EDID to the virtual desktop monitor device to allow
> the virtual desktop driver to be better compatible with such
> applications.
>
> Most fields of the EDID contain details that are of no relevance
> to applications, so populate only the native resolution and physical
> monitor dimensions. This should cover the vast majority of use
> cases.
> Signed-off-by: Eduard Permyakov
>
> dlls/winex11.drv/desktop.c | 41 ++++++++++++++++++++++++++++++++++++--
>  1 file changed, 39 insertions(+), 2 deletions(-)
>
> diff --git a/dlls/winex11.drv/desktop.c b/dlls/winex11.drv/desktop.c
> index 71b3a0a5a27..3c39035b4db 100644
> --- a/dlls/winex11.drv/desktop.c
> +++ b/dlls/winex11.drv/desktop.c
> @@ -20,6 +20,8 @@
>   */
>
> #include "config.h"
> +#include <stdlib.h>
> +#include <stdint.h>
>  #include <X11/cursorfont.h>
>  #include <X11/Xlib.h>
>
> @@ -111,6 +113,38 @@ static void add_desktop_mode( DEVMODEW *mode, DWORD depth, DWORD width, DWORD he
>      mode->dmDisplayFrequency = 60;
>  }
>
> +static void get_virtual_edid(unsigned char **edid, unsigned long *len)
> +{
> - const size_t desc_size = 128;

static const
> - unsigned width_mm, height_mm;

unsigned int
> - unsigned char *ret;
> -
> - *edid = NULL;
> - *len = 0;
> -
> - ret = calloc(desc_size, 1);
> - if(!ret)
> -
>    return;
> -
> - /* Set the native resolution in the Preferred Timing Mode descriptor */
> - ret[0x38] = desktop_width & 0xff;
> - ret[0x3A] = ((desktop_width >> 8) & 0xf) << 4;

desktop_width and desktop_height could change. I assume you want max_width and max_height.
> -
> - ret[0x3B] = desktop_height & 0xff;
> - ret[0x3D] = ((desktop_height >> 8) & 0xf) << 4;
> -
> - /* Set the monitor size (mm) in the Preferred Timing Mode descriptor */
> - height_mm = 2000;

2000mm doesn't seem to be a common monitor height.
> - width_mm = height_mm / ((float)desktop_height) * desktop_width;
> -
> - ret[0x42] = width_mm & 0xff;
> - ret[0x43] = height_mm & 0xff;
> - ret[0x44] = (((width_mm >> 8) & 0xf) << 4) | ((height_mm >> 8) & 0xf);
> -
> - *edid = ret;
> - *len = desc_size;
>
> +}
> -
>
> static BOOL X11DRV_desktop_get_modes( ULONG_PTR id, DWORD flags, DEVMODEW **new_modes, UINT *mode_count )
>  {
>      UINT depth_idx, size_idx, mode_idx = 0;
> @@ -265,8 +299,7 @@ static BOOL X11DRV_desktop_get_monitors( ULONG_PTR adapter_id, struct x11drv_mon
>      SetRect( &monitor->rc_work, 0, 0, desktop_width, desktop_height );
>      query_desktop_work_area( &monitor->rc_work );
>      monitor->state_flags = DISPLAY_DEVICE_ATTACHED;
> - monitor->edid_len = 0;
> - monitor->edid = NULL;
> - get_virtual_edid(&monitor->edid, &monitor->edid_len);
> if (desktop_width && desktop_height)
>     monitor->state_flags |= DISPLAY_DEVICE_ACTIVE;
>
> @@ -277,6 +310,10 @@ static BOOL X11DRV_desktop_get_monitors( ULONG_PTR adapter_id, struct x11drv_mon
>
> static void X11DRV_desktop_free_monitors( struct x11drv_monitor *monitors, int count )
>  {
> - int i;
> - for(i = 0; i < count; i++) {
> -
>    free(monitors[i].edid);
> - }
> heap_free( monitors );
>
> }