C side implemention of w32gdi support

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

1 files changed, 179 insertions, 0 deletions

diff --git a/src/blueshift_w32gdi_c.c b/src/blueshift_w32gdi_c.c
new file mode 100644
index 0000000..6b5a394
--- /dev/null
+++ b/src/blueshift_w32gdi_c.c
@@ -0,0 +1,179 @@
+/**
+ * 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 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "blueshift_w32gdi_c.h"
+
+
+
+/**
+ * The number of CRTC:s on the system
+ */
+static int crtc_count;
+
+/**
+ * The device contexts for each CRTC
+ */
+static HDC* crtcs;
+
+
+
+/**
+ * Start stage of colour curve control
+ * 
+ * @return  Zero on success
+ */
+int blueshift_w32gdi_open(void)
+{
+  int c;
+  DISPLAY_DEVICE display;
+  display.cb = sizeof(DISPLAY_DEVICE);
+  
+  crtc_count = 0;
+  while (EnumDisplayDevices(NULL, crtc_count, &display, 0))
+    crtc_count++;
+  
+  if (crtc_count == 0)
+    {
+      crtcs == NULL;
+      return 0;
+    }
+  
+  crtcs = malloc(crtc_count * sizeof(HDC));
+  if (crtcs == NULL)
+    {
+      fprintf(stderr, "Out of memory\n");
+      return 1;
+    }
+  
+  for (c = 0; c < crtc_count; c++)
+    {
+      /* Open device context */
+      if (EnumDisplayDevices(NULL, c, &display, 0) == FALSE)
+	{
+	  fprintf(stderr, "Cannot find display, are you unplugging stuff?\n");
+	  crtc_count = c;
+	  return 1;
+	}
+      if (!(display.StateFlags & DISPLAY_DEVICE_ACTIVE))
+	{
+	  fprintf(stderr, "Cannot to open device context, it is not active\n");
+	  crtc_count = c;
+	  return 1;
+	}
+      *(crtcs + c) = CreateDC(TEXT("DISPLAY"), display.DeviceName, NULL, NULL);
+      if (*(crtcs + c) == NULL)
+	{
+	  fprintf(stderr, "Unable to open device context\n");
+	  crtc_count = c;
+	  return 1;
+	}
+      
+      /* Check support for gamma ramps */
+      if (GetDeviceCaps(hDC, COLORMGMTCAPS) != CM_GAMMA_RAMP)
+	{
+	  fprintf(stderr, "CRTC %i does not support gamma ramps\n", c);
+	  ReleaseDC(NULL, *(crtcs + c));
+	  crtc_count = c;
+	  return 1;
+	}
+    }
+  
+  return 0;
+}
+
+
+/**
+ * Get the number of CRTC:s on the system
+ * 
+ * @return  The number of CRTC:s on the system
+ */
+int blueshift_w32gdi_crtc_count(void)
+{
+  return crtc_count;
+}
+
+
+/**
+ * Gets the current colour curves
+ * 
+ * @param   use_crtc  The CRTC to use
+ * @return            {the size of the each curve, *the red curve,
+ *                    *the green curve, *the blue curve},
+ *                    needs to be free:d. `NULL` on error.
+ */
+uint16_t* blueshift_w32gdi_read(int use_crtc)
+{
+  uint16_t* rc = NULL;
+  if ((use_crtc < 0) || (use_crtc >= crtc_count))
+    fprintf(stderr, "CRTC %i does not exist\n", use_crtc);
+  else
+    {
+      rc = malloc((1 + 3 * GAMMA_RAMP_SIZE) * sizeof(uint16_t));
+      if (rc == NULL)
+	fprintf(stderr, "Out of memory\n");
+      else
+	{
+	  *rc = GAMMA_RAMP_SIZE;
+	  if (GetDeviceGammaRamp(*(crtcs + use_crtc), rc + 1) == FALSE)
+	    {
+	      fprintf(stderr, "Unable to read current gamma ramps from CRTC %i\n", use_crtc);
+	      free(rc);
+	      rc = NULL;
+	    }
+	}
+    }
+  return rc;
+}
+
+
+/**
+ * Apply stage of colour curve control
+ * 
+ * @param   use_crtc   The CRTC to use, -1 if all
+ * @param   rgb_curve  The concatenation of the red, the green and the blue colour curves
+ * @return             Zero on success
+ */
+int blueshift_w32gdi_apply(int use_crtc, uint16_t* rgb_curves)
+{
+  int r = 1;
+  if (use_crtc < crtc_count)
+    {
+      int c = use_crtc < 0 ? 0 : use_crtc;
+      int n = use_crtc < 0 ? crtc_count : (use_crtc + 1);
+      for (; c < n; c++)
+	if (!(r = SetDeviceGammaRamp(*(crtcs + c), rgb_curves)))
+	  {
+	    fprintf(stderr, "Unable to set gamma ramps\n");
+	    break;
+	  }
+    }
+  else
+    fprintf(stderr, "CRTC %i does not exist\n", use_crtc);
+  return !r;
+}
+
+
+/**
+ * Resource freeing stage of colour curve control
+ */
+void blueshift_w32gdi_close(void)
+{
+  for (c = 0; c < crtc_count; c++)
+    ReleaseDC(NULL, *(crtcs + c));
+  if (crtcs != NULL)
+    free(crtcs);
+}
+