Add setting gamma ramps with the VidMode extension.

Allow selection of gamma setting method with program parameter (-m).
Fallback to VidMode if RANDR doesn't work.

1 files changed, 109 insertions, 0 deletions

diff --git a/src/vidmode.c b/src/vidmode.c
new file mode 100644
index 0000000..7cc0d02
--- /dev/null
+++ b/src/vidmode.c
@@ -0,0 +1,109 @@
+/* vidmode.c -- X VidMode gamma adjustment source
+   This file is part of Redshift.
+
+   Redshift is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Redshift is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2009  Jon Lund Steffensen <jonlst@gmail.com>
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include <X11/Xlib.h>
+#include <X11/extensions/xf86vmode.h>
+
+#include "colorramp.h"
+
+
+int
+vidmode_check_extension()
+{
+	int r;
+
+	/* Open display */
+	Display *dpy = XOpenDisplay(NULL);
+	if (dpy == NULL) {
+		fprintf(stderr, "XOpenDisplay failed.\n");
+		return -1;
+	}
+
+	/* Query extension version */
+	int major, minor;
+	r = XF86VidModeQueryVersion(dpy, &major, &minor);
+	if (!r) {
+		fprintf(stderr, "XF86VidModeQueryVersion failed.\n");
+		return -1;
+	}
+
+	/* TODO Check major/minor */
+
+	/* Close display */
+	XCloseDisplay(dpy);
+
+	return 0;
+}
+
+int
+vidmode_set_temperature(int temp, float gamma[3])
+{
+	int r;
+
+	/* Open display */
+	Display *dpy = XOpenDisplay(NULL);
+	if (dpy == NULL) {
+		fprintf(stderr, "XOpenDisplay failed.\n");
+		return -1;
+	}
+
+	/* Request size of gamma ramps for screen 0 */
+	int gamma_ramp_size;
+	r = XF86VidModeGetGammaRampSize(dpy, 0, &gamma_ramp_size);
+	if (!r) {
+		fprintf(stderr, "XF86VidModeGetGammaRampSize failed.\n");
+		XCloseDisplay(dpy);
+		return -1;
+	}
+
+	if (gamma_ramp_size == 0) {
+		fprintf(stderr, "Error: Gamma ramp size too small: %i\n",
+			gamma_ramp_size);
+		XCloseDisplay(dpy);
+		return -1;
+	}
+
+	/* Create new gamma ramps */
+	uint16_t *gamma_ramps = malloc(3*gamma_ramp_size*sizeof(uint16_t));
+	if (gamma_ramps == NULL) abort();
+
+	uint16_t *gamma_r = &gamma_ramps[0*gamma_ramp_size];
+	uint16_t *gamma_g = &gamma_ramps[1*gamma_ramp_size];
+	uint16_t *gamma_b = &gamma_ramps[2*gamma_ramp_size];
+
+	colorramp_fill(gamma_r, gamma_g, gamma_b, gamma_ramp_size,
+		       temp, gamma);
+
+	/* Set new gamma ramps */
+	r = XF86VidModeSetGammaRamp(dpy, 0, gamma_ramp_size, gamma_r, gamma_g, gamma_b);
+	if (!r) {
+		fprintf(stderr, "XF86VidModeSetGammaRamp failed.\n");
+		XCloseDisplay(dpy);
+		return -1;
+	}
+
+	/* Close display */
+	XCloseDisplay(dpy);
+
+	return 0;
+}