1 files changed, 58 insertions, 0 deletions
diff --git a/plug-ins/file-dds/color.c b/plug-ins/file-dds/color.c
new file mode 100644
index 0000000..0c1be40
--- /dev/null
+++ b/plug-ins/file-dds/color.c
@@ -0,0 +1,58 @@
+/*
+ * DDS GIMP plugin
+ *
+ * Copyright (C) 2004-2012 Shawn Kirst <skirst@gmail.com>,
+ * with parts (C) 2003 Arne Reuter <homepage@arnereuter.de> where specified.
+ *
+ * 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 2 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <math.h>
+#include "color.h"
+
+int
+linear_to_sRGB(int c)
+{
+  float v = (float)c / 255.0f;
+
+  if(v < 0)
+    v = 0;
+  else if(v > 1)
+    v = 1;
+  else if(v <= 0.0031308f)
+    v = 12.92f * v;
+  else
+    v = 1.055f * powf(v, 0.41666f) - 0.055f;
+
+  return (int)floorf(255.0f * v + 0.5f);
+}
+
+int
+sRGB_to_linear(int c)
+{
+  float v = (float)c / 255.0f;
+
+  if(v < 0)
+    v = 0;
+  else if(v > 1)
+    v = 1;
+  else if(v <= 0.04045f)
+    v /= 12.92f;
+  else
+    v = powf((v + 0.055f) / 1.055f, 2.4f);
+
+  return (int)floorf(255.0f * v + 0.5f);
+}