[PATCH elographics] Configurable mirroring of X,Y input coordinates.

[Antti Peltonen]

Some hardware out there appears to report Y coordinates in reverse. I fixed this by adding an configurable parameter to drivers config in xorg.conf and while I was at it I also added the same functionality for X axis as well in case there are similarly "broken" implmentations in use.

Signed-off-by: Antti Peltonen <antti.peltonen at iki.fi>
---
 man/elographics.man |  6 ++++++
 src/xf86Elo.c       | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/man/elographics.man b/man/elographics.man
index 32efda4..e260644 100644
--- a/man/elographics.man
+++ b/man/elographics.man
@@ -71,6 +71,12 @@ Delay between report packets. Default: 1 (10ms).
 .TP
 .BI "Option \*qModel\*q \*q" string \*q
 The touchscreen model. Default: unset. Supported models: "Sunit dSeries".
+.TP
+.BI "Option \*qMirrorX\*q \*q" boolean \*q
+Mirror coordinates read from device on X axis. eg. Down becomes up
+.TP
+.BI "Option \*qMirrorY\*q \*q" boolean \*q
+Mirror coordinates read from device on Y axis. eg. Left becomes right
 .SH "SEE ALSO"
 __xservername__(__appmansuffix__), __xconfigfile__(__filemansuffix__), Xserver(__appmansuffix__), X(__miscmansuffix__).
 .SH AUTHORS
diff --git a/src/xf86Elo.c b/src/xf86Elo.c
index c37cf9a..dea4f48 100644
--- a/src/xf86Elo.c
+++ b/src/xf86Elo.c
@@ -194,6 +194,8 @@ typedef struct _EloPrivateRec {
   int		checksum;		/* Current checksum of data in assembly buffer	*/
   int		packet_buf_p;		/* Assembly buffer pointer			*/
   int		swap_axes;		/* Swap X an Y axes if != 0 */
+  int       mirror_x;       /* Mirror X axis input if != 0 */
+  int       mirror_y;       /* Mirror Y axis input if != 0 */
   unsigned char	packet_buf[ELO_PACKET_SIZE]; /* Assembly buffer				*/
   int		model;			/* one of MODEL_...				*/
 } EloPrivateRec, *EloPrivatePtr;
@@ -336,6 +338,9 @@ xf86EloReadInput(InputInfoPtr	pInfo)
   int				cur_x, cur_y;
   int				state;
 
+  int               eff_max_x, eff_max_y;
+  int               eff_min_x, eff_min_y;
+
   DBG(4, ErrorF("Entering ReadInput\n"));
 
   /*
@@ -365,16 +370,35 @@ xf86EloReadInput(InputInfoPtr	pInfo)
                       (state == ELO_PRESS) ? "Press" :
 			((state == ELO_RELEASE) ? "Release" : "Stream")));
 
+          eff_max_y = priv->max_y;
+          eff_min_y = priv->min_y;
           if (priv->min_y > priv->max_y) {
             /* inverted y axis */
             cur_y = priv->max_y - cur_y + priv->min_y;
+            /* change effective values */
+            eff_max_y = priv->min_y;
+            eff_min_y = priv->max_y;
           }
 
           if (priv->min_x > priv->max_x) {
             /* inverted x axis */
             cur_x = priv->max_x - cur_x + priv->min_x;
+            /* change effective values */
+            eff_max_x = priv->min_x;
+            eff_min_x = priv->max_x;
           }
 
+          /*
+           * Mirror axis coordinates if so configured
+           */
+          if (priv->mirror_x)
+          {
+            cur_x = abs(cur_x - eff_max_x) + eff_min_x;
+          }
+          if (priv->mirror_y)
+          {
+            cur_y = abs(cur_y - eff_max_y) + eff_min_y;
+          }
 
           /*
            * Send events.
@@ -912,6 +936,8 @@ xf86EloAllocate(InputDriverPtr drv, InputInfoPtr pInfo)
   priv->checksum = ELO_INIT_CHECKSUM;
   priv->packet_buf_p = 0;
   priv->swap_axes = 0;
+  priv->mirror_x = 0;
+  priv->mirror_y = 0;
 
   pInfo->device_control = xf86EloControl;
   pInfo->read_input   = xf86EloReadInput;
@@ -1018,6 +1044,14 @@ xf86EloInit(InputDriverPtr	drv,
   if (priv->swap_axes) {
     xf86Msg(X_CONFIG, "Elographics device will work with X and Y axes swapped\n");
   }
+  priv->mirror_x = xf86SetBoolOption(pInfo->options, "MirrorX", 0);
+  if (priv->mirror_x) {
+    xf86Msg(X_CONFIG, "Elographics device will work with X axis coordinates mirrored\n");
+  }
+  priv->mirror_y = xf86SetBoolOption(pInfo->options, "MirrorY", 0);
+  if (priv->mirror_y) {
+    xf86Msg(X_CONFIG, "Elographics device will work with Y axis coordinates mirrored\n");
+  }
   debug_level = xf86SetIntOption(pInfo->options, "DebugLevel", 0);
   if (debug_level) {
 #if DEBUG
-- 
1.8.1.4