ImBuf: Make luminance calculation inlined

Title actually tells it all, it is rather simple function which totally makes
sense to be inlined.

This gives up to 5% of speedup when updating scopes for a large image.

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D1310

1 files changed, 65 insertions, 0 deletions

diff --git a/source/blender/imbuf/intern/colormanagement_inline.c b/source/blender/imbuf/intern/colormanagement_inline.c
new file mode 100644
index 00000000000..8382e2a9bfa
--- /dev/null
+++ b/source/blender/imbuf/intern/colormanagement_inline.c
@@ -0,0 +1,65 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2015 by Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Sergey Sharybin
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ *
+ */
+
+/** \file blender/imbuf/intern/colormanagement_inline.c
+ *  \ingroup imbuf
+ */
+
+#ifndef __IMB_COLORMANAGEMENT_INLINE_C__
+#define __IMB_COLORMANAGEMENT_INLINE_C__
+
+#include "IMB_colormanagement_intern.h"
+#include "BLI_math_vector.h"
+
+/* Convert a float RGB triplet to the correct luminance weighted average.
+ *
+ * Grayscale, or Luma is a distillation of RGB data values down to a weighted average
+ * based on the luminance positions of the red, green, and blue primaries.
+ * Given that the internal reference space may be arbitrarily set, any
+ * effort to glean the luminance coefficients must be aware of the reference
+ * space primaries.
+ *
+ * See http://wiki.blender.org/index.php/User:Nazg-gul/ColorManagement#Luminance
+ */
+
+float IMB_colormanagement_get_luminance(const float rgb[3])
+{
+	return dot_v3v3(imbuf_luma_coefficients, rgb);
+}
+
+/* Byte equivalent of IMB_colormanagement_get_luminance(). */
+unsigned char IMB_colormanagement_get_luminance_byte(const unsigned char rgb[3])
+{
+	float rgbf[3];
+	float val;
+
+	rgb_uchar_to_float(rgbf, rgb);
+	val = dot_v3v3(imbuf_luma_coefficients, rgbf);
+
+	return FTOCHAR(val);
+}
+
+#endif  /* __IMB_COLORMANAGEMENT_INLINE_H__ */