[qcms] Add API to get parametric gamma curve data

third_party/qcms/src/transform_util.c

 //  qcms
 //  Copyright (C) 2009 Mozilla Foundation
 //
 // Permission is hereby granted, free of charge, to any person obtaining
 // a copy of this software and associated documentation files (the "Software"),
 // to deal in the Software without restriction, including without limitation
 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
 // and/or sell copies of the Software, and to permit persons to whom the Software
 // is furnished to do so, subject to the following conditions:
 //
@@ skipping 619 matching lines @@
                         //     measurement or data, however it is what lcms uses.
                         *output_gamma_lut_length = trc->count;
                         if (*output_gamma_lut_length < 256)
                                 *output_gamma_lut_length = 256;
 
                         *output_gamma_lut = invert_lut(trc->data, trc->count, *output_gamma_lut_length);
                 }
         }
 
 }
+
+size_t qcms_profile_get_parametric_curve(qcms_profile *profile, qcms_trc_channel channel, float data[7])
+{
+    static const uint32_t COUNT_TO_LENGTH[5] = {1, 3, 4, 5, 7};
+    struct curveType *curve = NULL;
+    size_t size;
+
+    if (profile->color_space != RGB_SIGNATURE)
+        return 0;
+
+    switch(channel) {
+    case QCMS_TRC_RED:
+        curve = profile->redTRC;
+        break;
+    case QCMS_TRC_GREEN:
+        curve = profile->greenTRC;
+        break;
+    case QCMS_TRC_BLUE:
+        curve = profile->blueTRC;
+        break;
+    default:
+        return 0;
+    }
+
+    if (!curve || curve->type != PARAMETRIC_CURVE_TYPE)
+        return 0;
+
+    size = COUNT_TO_LENGTH[curve->count];
+
+    if (data)
+        memcpy(data, curve->parameter, size * sizeof(float));
+
+    return size;
+}