[qcms] Use a static table in build_output_lut to invert para curves

third_party/qcms/src/tests/qcms_test_output_trc.c

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the Chromium LICENSE file.
 
 #include "qcms.h"
 #include "qcms_test_util.h"
 
 #include <assert.h>
 #include <math.h>
 #include <stdio.h>
@@ skipping 81 matching lines @@
         int iterations,
         const char *in_path,
         const char *out_path,
         const int force_software)
 {
     qcms_profile *profile;
     uint16_t *gamma_table_out;
     size_t output_size;
     size_t i;
 
-    printf("Test qcms output gamma curve table integrity.\n");
-
     if (!in_path) {
         fprintf(stderr, "%s: please provide valid ICC profiles via -i option\n", __FUNCTION__);
         return EXIT_FAILURE;
     }
 
+    printf("Test qcms output gamma curve table integrity.\n");
+
     // Create profiles and transforms, get table and then free resources to make sure none
     // of the internal tables are initialized by previous calls.
     gamma_table_out = NULL;
     output_size = 0;
     if (get_output_gamma_table(in_path, &gamma_table_out, &output_size) != 0) {
         fprintf(stderr, "Unable to extract output gamma table\n");
         return EXIT_FAILURE;
     }
 
-    printf("Output gamma LUT size = %zu\n", output_size);
+    printf("Output gamma table size = %zu\n", output_size);
 
     profile = qcms_profile_from_path(in_path);
     if (!profile) {
         fprintf(stderr, "Invalid input profile\n");
         free(gamma_table_out);
         return EXIT_FAILURE;
     }
 
     // Check only for red curve for now.
     if (profile->redTRC->type == PARAMETRIC_CURVE_TYPE) {
@@ skipping 26 matching lines @@
 
         get_input_gamma_table(in_path, &gamma_table_in, &input_size);
         if (!gamma_table_in) {
             fprintf(stderr, "Unable to compute input trc. Aborting\n");
             fclose(output_file);
             qcms_profile_release(profile);
             free(gamma_table_out);
             return EXIT_FAILURE;
         }
 
+        fprintf(output_file, "\nInput curve size: %zu", input_size);
+        fprintf(output_file, "\nOutput curve size: %zu", output_size);
+
         scale_factor = (float)(output_size - 1) / (input_size - 1);
 
-        fprintf(output_file, "\nInput curve size: %zu\nOutput curve size: %zu\n", input_size, output_size);
         fprintf(output_file, "\n\nInput gamma, Output gamma, LCMS Output gamma, Output gamma error\n");
 
         for (i = 0; i < input_size; ++i) {
             float input = gamma_table_in[i * 4] * inverse65535;
             size_t out_index = (size_t)floor(i * scale_factor + 0.5);
             float p = out_index / (float)(output_size - 1);
             float reference = clamp_float(evaluate_parametric_curve(type, profile->redTRC->parameter, p));
             float actual = gamma_table_out[out_index * 4] * inverse65535;
             float difference = fabs(actual - reference);
 
             fprintf(output_file, "%.6f, %.6f, %6f, %6f\n", input, actual, reference, difference);
         }
 
-        fprintf(output_file, "\nNote: the output curves we down sampled by a factor of %zu / %zu\n",
+        fprintf(output_file, "\nNote: the output gamma curves are down-sampled by a factor of %zu / %zu\n",
                 output_size, input_size);
 
         fclose(output_file);
         free(gamma_table_in);
     }
 
     qcms_profile_release(profile);
     free(gamma_table_out);
 
     return 0;
 }
 
 struct qcms_test_case qcms_test_output_trc_info = {
         "qcms_test_output_trc",
         qcms_test_output_trc,
         QCMS_TEST_DISABLED
 };