compositor: use smoother range for backlight control
now it goes from 0 to 255.
Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>
diff --git a/src/compositor-drm.c b/src/compositor-drm.c
index ba7e642..fe8ef49 100644
--- a/src/compositor-drm.c
+++ b/src/compositor-drm.c
@@ -927,7 +927,7 @@
sprite->pending_surface = NULL;
}
-/* returns a value between 1-10 range, where higher is brighter */
+/* returns a value between 0-255 range, where higher is brighter */
static uint32_t
drm_get_backlight(struct drm_output *output)
{
@@ -936,13 +936,13 @@
brightness = backlight_get_brightness(output->backlight);
max_brightness = backlight_get_max_brightness(output->backlight);
- /* convert it on a scale of 1 to 10 */
- norm = 1 + ((brightness) * 9)/(max_brightness);
+ /* convert it on a scale of 0 to 255 */
+ norm = (brightness * 255)/(max_brightness);
return (uint32_t) norm;
}
-/* values accepted are between 1-10 range */
+/* values accepted are between 0-255 range */
static void
drm_set_backlight(struct weston_output *output_base, uint32_t value)
{
@@ -952,13 +952,13 @@
if (!output->backlight)
return;
- if (value < 1 || value > 10)
+ if (value < 0 || value > 255)
return;
max_brightness = backlight_get_max_brightness(output->backlight);
/* get denormalized value */
- new_brightness = ((value - 1) * (max_brightness)) / 9;
+ new_brightness = (value * max_brightness) / 255;
backlight_set_brightness(output->backlight, new_brightness);
}