[PATCH v5 2/3] winex11.drv: Add EDID to the virtual desktop monitor device.

[Eduard Permyakov]

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 <epermyakov at codeweavers.com>
---
 dlls/winex11.drv/desktop.c | 75 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 2 deletions(-)

diff --git a/dlls/winex11.drv/desktop.c b/dlls/winex11.drv/desktop.c
index 71b3a0a5a27..37e5624967e 100644
--- a/dlls/winex11.drv/desktop.c
+++ b/dlls/winex11.drv/desktop.c
@@ -20,6 +20,7 @@
  */
 
 #include "config.h"
+#include <stdint.h>
 #include <X11/cursorfont.h>
 #include <X11/Xlib.h>
 
@@ -111,6 +112,74 @@ 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 )
+{
+    static const size_t desc_size = 128;
+    int i;
+    uint8_t accum = 0;
+    /*Sample EDID for an LCD Desktop IT Display, from VESA spec */
+    static const unsigned char default_edid[128] = {
+        /* Header */
+        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
+        /* Manufacturer's code name */
+        0x04, 0x43,
+        /* Product code */
+        0x06, 0xf2,
+        /* Serial Number */
+        0x01, 0x00, 0x00, 0x00,
+        /* Date of manufacture */
+        0x01, 0x11,
+        /* EDID version */
+        0x01, 0x04,
+        /* Standard characteristics */
+        0x0f, 0x2b, 0x20, 0x78, 0x2b, 0x9c, 0x68, 0xa0,
+        0x57, 0x4a, 0x9b, 0x26, 0x12, 0x48, 0x4c, 0xff,
+        0xff, 0x80, 0xa9, 0x59, 0xa9, 0x4f, 0xa9, 0x4a,
+        0xa9, 0x45, 0x81, 0x99, 0x81, 0x80, 0x61, 0x59,
+        0x45, 0x59,
+        /* First 18-byte data block (Preferred Timing Mode) */
+        0x48, 0x3f, 0x40, 0x30, 0x62, 0xb0, 0x32, 0x40,
+        0x40, 0xc0, 0x13, 0x00, 0xab, 0x40, 0x11, 0x00,
+        0x00, 0x1e,
+        /* Second 18-byte data block */
+        0x00, 0x00, 0x00, 0xfd, 0x00, 0x32, 0x5a, 0x1e,
+        0x6e, 0x17, 0x04, 0x11, 0x00, 0xc8, 0x90, 0x00,
+        0x50, 0x3c,
+        /* Third 18-byte data block */
+        0x00, 0x00, 0x00, 0xf7, 0x00, 0x0a, 0xf7, 0x0f,
+        0x03, 0x87, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00,
+        /* Fourth 18-byte data block */
+        0x00, 0x00, 0x00, 0xfc, 0x00, 0x41, 0x42, 0x43,
+        0x20, 0x4c, 0x43, 0x44, 0x32, 0x31, 0x0a, 0x20,
+        0x20, 0x20,
+        /* Extension flag */
+        0x00,
+    };
+
+    *edid = heap_calloc( desc_size, 1 );
+    if (!*edid)
+    {
+        *len = 0;
+        return;
+    }
+
+    memcpy( *edid, default_edid, sizeof(default_edid) );
+    *len = desc_size;
+
+    /* Set the native resolution in the Preferred Timing Mode descriptor */
+    (*edid)[0x38] = max_width & 0xff;
+    (*edid)[0x3a] = ((max_width >> 8) & 0xf) << 4;
+
+    (*edid)[0x3b] = max_height & 0xff;
+    (*edid)[0x3d] = ((max_height >> 8) & 0xf) << 4;
+
+    /* Set checksum */
+    for (i = 0; i < desc_size-1; i++)
+        accum += (*edid)[i];
+    (*edid)[desc_size - 1] = 256 - accum;
+}
+
 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 +334,7 @@ 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 +345,9 @@ 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++)
+        heap_free( monitors[i].edid );
     heap_free( monitors );
 }
 
-- 
2.25.1