add vidmode support

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/src/blueshift_vidmode_c.c b/src/blueshift_vidmode_c.c
new file mode 100644
index 0000000..b160e7e
--- /dev/null
+++ b/src/blueshift_vidmode_c.c
@@ -0,0 +1,151 @@
+/**
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program 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 Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+
+#include <X11/Xlib.h>
+#include <X11/extensions/xf86vmode.h>
+
+
+
+/**
+ * The X server display
+ */
+static Display* display;
+
+/**
+ * The X screen
+ */
+static int screen;
+
+/**
+ * Size of colour curves on the X-axis
+ */
+static int curve_size;
+
+
+
+/**
+ * Start stage of colour curve control
+ * 
+ * @param   use_screen  The screen to use
+ * @return              Zero on success
+ */
+int blueshift_vidmode_open(int use_screen)
+{
+  int _major, _minor;
+  uint16_t* r_gamma;
+  uint16_t* g_gamma;
+  uint16_t* b_gamma;
+  
+  
+  /* Get X display */
+  
+  if ((display = XOpenDisplay(NULL)) == NULL)
+    {
+      fprintf(stderr, "Cannot open X display\n");
+      return 1;
+    }
+  
+  
+  /* Check for VidMode extension */
+  
+  if (XF86VidModeQueryVersion(display, &_major, &_minor) == 0)
+    {
+      fprintf(stderr, "VidMode version query failed\n");
+      XCloseDisplay(display);
+      return 1;
+    }
+  
+  
+  /* Get curve X-axis size */
+  
+  screen = use_screen;
+  if (XF86VidModeGetGammaRampSize(display, screen, &curve_size) == 0)
+    {
+      fprintf(stderr, "VidMode gamma size query failed\n");
+      XCloseDisplay(display);
+      return 1;
+    }
+  
+  if (curve_size < 1)
+    {
+      fprintf(stderr, "VidMode gamma size query failed\n");
+      XCloseDisplay(display);
+      return 1;
+    }
+  
+  
+  /* Acquire curve control */
+  
+  r_gamma = malloc(3 * curve_size * sizeof(uint16_t));
+  if (r_gamma == NULL)
+    {
+      fprintf(stderr, "Out of memory\n");
+      return 1;
+    }
+  g_gamma = r_gamma + curve_size;
+  b_gamma = g_gamma + curve_size;
+  if (XF86VidModeGetGammaRamp(display, screen, curve_size, r_gamma, g_gamma, b_gamma) == 0)
+    {
+      fprintf(stderr, "VidMode gamma query failed\n");
+      free(r_gamma);
+      XCloseDisplay(display);
+      return 1;
+    }
+  free(r_gamma);
+  
+  return 0;
+}
+
+
+/**
+ * Apply stage of colour curve control
+ * 
+ * @param   use_crtcs  Mask of CRTC:s to use
+ * @param   r_curve    The red colour curve
+ * @param   g_curve    The green colour curve
+ * @param   b_curve    The blue colour curve
+ * @return             Zero on success
+ */
+int blueshift_vidmode_apply(uint64_t use_crtcs, uint16_t* r_curve, uint16_t* g_curve, uint16_t* b_curve)
+{
+  (void) use_crtcs;
+  
+  /* Apply curves */
+  
+  if (XF86VidModeSetGammaRamp(display, screen, curve_size, r_curve, g_curve, b_curve) == 0)
+    {
+      fprintf(stderr, "VidMode gamma control failed\n");
+      return 1;
+    }
+  
+  return 0;
+}
+
+
+/**
+ * Resource freeing stage of colour curve control
+ */
+void blueshift_vidmode_close(void)
+{
+  /* Free remaining resources */
+  
+  XCloseDisplay(display);
+}
+