xrandr: fix maximum gamma set

Gamma is an array of 3 16-bit values. Currently, the maximum value assigned is
255*256, which is only 65280. Make sure that when we set the gamma, the maximum
value is 65535. It's slightly brighter but also helps to avoid kludges to
detect clamped values when reading back the gamma.

Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net>
Reviewed-by: Matthias Hopf <mhopf@suse.de>

1 files changed, 9 insertions, 9 deletions

diff --git a/xrandr.c b/xrandr.c
index 65e0623..76c1342 100644
--- a/xrandr.c
+++ b/xrandr.c
@@ -1225,25 +1225,25 @@ set_gamma(void)
 
 	for (i = 0; i < size; i++) {
 	    if (output->gamma.red == 1.0 && output->brightness == 1.0)
-		gamma->red[i] = i << 8;
+		gamma->red[i] = (i << 8) + i;
 	    else
 		gamma->red[i] = dmin(pow((double)i/(double)(size - 1),
-			    (double)output->gamma.red) * (double)(size - 1)
-			    * (double)output->brightness * 256, 65535.0);
+					 output->gamma.red) * output->brightness,
+				     1.0) * 65535.0;
 
 	    if (output->gamma.green == 1.0 && output->brightness == 1.0)
-		gamma->green[i] = i << 8;
+		gamma->green[i] = (i << 8) + i;
 	    else
 		gamma->green[i] = dmin(pow((double)i/(double)(size - 1),
-			    (double)output->gamma.green) * (double)(size - 1)
-			    * (double)output->brightness * 256, 65535);
+					   output->gamma.green) * output->brightness,
+				       1.0) * 65535.0;
 
 	    if (output->gamma.blue == 1.0 && output->brightness == 1.0)
-		gamma->blue[i] = i << 8;
+		gamma->blue[i] = (i << 8) + i;
 	    else
 		gamma->blue[i] = dmin(pow((double)i/(double)(size - 1),
-			    (double)output->gamma.blue) * (double)(size - 1)
-			    * (double)output->brightness * 256, 65535);
+					  output->gamma.blue) * output->brightness,
+				      1.0) * 65535.0;
 	}
 
 	XRRSetCrtcGamma(dpy, crtc->crtc.xid, gamma);