[qcms] Provide an API to compute xyY gamut area relative to NTSC 1953

third_party/qcms/src/qcms_util.c

Index: third_party/qcms/src/qcms_util.c
diff --git a/third_party/qcms/src/qcms_util.c b/third_party/qcms/src/qcms_util.c
new file mode 100644
index 0000000000000000000000000000000000000000..a9b2fc53e093cb3e2d60631bfff34eb00189fd7f
--- /dev/null
+++ b/third_party/qcms/src/qcms_util.c
@@ -0,0 +1,70 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.

[Noel Gordon, 2016/02/17 10:42:24]

Nit: 2015 -> 2016.

[radu.velea, 2016/02/17 11:31:00]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the Chromium LICENSE file.
+
+#include "qcmsint.h"
+
+#include <math.h>
+
+typedef struct _qcms_coords {
+    float x;
+    float y;
+} qcms_coords;
+
+typedef struct _qcms_triangle {
+    qcms_coords verticies[3];
+} qcms_triangle;
+
+#define NTSC_1953_GAMUT_SIZE	0.1582
+
+static qcms_triangle get_profile_triangle(qcms_profile *profile)
+{
+    float sumRed = s15Fixed16Number_to_float(profile->redColorant.X) +
+            s15Fixed16Number_to_float(profile->redColorant.Y) +

[Noel Gordon, 2016/02/17 10:42:24]

Make the s15Fixed16Number_to_float line-up.

 float sumRed = s15Fixed16Number_to_float(profile->redColorant.X) + 
                s15Fixed16Number_to_float(profile->redColorant.Y) +
                s15Fixed16Number_to_float(...

Same for the sumBlue & sumGreen expressions.

[radu.velea, 2016/02/17 11:31:00]

Done.

+            s15Fixed16Number_to_float(profile->redColorant.Z);
+    float xRed = s15Fixed16Number_to_float(profile->redColorant.X) / sumRed;
+    float yRed = s15Fixed16Number_to_float(profile->redColorant.Y) / sumRed;
+
+    float sumGreen = s15Fixed16Number_to_float(profile->greenColorant.X) +
+            s15Fixed16Number_to_float(profile->greenColorant.Y) +
+            s15Fixed16Number_to_float(profile->greenColorant.Z);
+    float xGreen = s15Fixed16Number_to_float(profile->greenColorant.X) / sumGreen;
+    float yGreen = s15Fixed16Number_to_float(profile->greenColorant.Y) / sumGreen;
+
+    float sumBlue = s15Fixed16Number_to_float(profile->blueColorant.X) +
+            s15Fixed16Number_to_float(profile->blueColorant.Y) +
+            s15Fixed16Number_to_float(profile->blueColorant.Z);
+    float xBlue = s15Fixed16Number_to_float(profile->blueColorant.X) / sumBlue;
+    float yBlue = s15Fixed16Number_to_float(profile->blueColorant.Y) / sumBlue;
+
+    qcms_triangle triangle = {{{xRed, yRed}, {xGreen, yGreen}, {xBlue, yBlue}}};
+

[Noel Gordon, 2016/02/17 10:42:24]

Remove this blank line.

[radu.velea, 2016/02/17 11:31:00]

Done.

+    return triangle;
+}
+
+static float get_triangle_area(const qcms_triangle candidate)
+{
+    float xRed = candidate.verticies[0].x;
+    float yRed = candidate.verticies[0].y;
+    float xGreen = candidate.verticies[1].x;
+    float yGreen = candidate.verticies[1].y;
+    float xBlue = candidate.verticies[2].x;
+    float yBlue = candidate.verticies[2].y;
+    float A = fabs((xRed - xBlue) * (yGreen - yBlue) - (xGreen - xBlue) * (yRed - yBlue)) / 2;

[Noel Gordon, 2016/02/17 10:42:24]

nit: Space before this line.

Also, A -> area.

float area = fabs((xRed - xBlue) * (yGreen ...
return area;

[radu.velea, 2016/02/17 11:31:00]

Done.

+
+    return A;
+}
+
+static float get_ntsc_gamut_metric_area(const qcms_triangle candidate)
+{
+    float A = get_triangle_area(candidate);

[Noel Gordon, 2016/02/17 10:42:24]

nit: A -> area.

[radu.velea, 2016/02/17 11:31:00]

Done.

+    return A * 100 / NTSC_1953_GAMUT_SIZE;
+}
+
+float qcms_profile_ntsc_relative_gamut_size(qcms_profile *profile)
+{
+	qcms_triangle triangle = get_profile_triangle(profile);

[Noel Gordon, 2016/02/17 10:42:24]

nit: alignment / spacing.

Compare with this alignment of the get_ntsc_gamut_metric_area(), for example.  

Simple fix: make the alignment in this function consistent with the other
changes in this file.

[radu.velea, 2016/02/17 11:31:00]

Done.

+	return get_ntsc_gamut_metric_area(triangle);
+}
+
+