text: /*
   * 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) 2020 by Blender Foundation.
   */
  #include "testing/testing.h"
  
  #include "MEM_guardedalloc.h"
  
  extern "C" {
  #include "BKE_fcurve.h"
  
  #include "ED_keyframing.h"
  
  #include "DNA_anim_types.h"
  }
  
  // Epsilon for floating point comparisons.
  static const float EPSILON = 1e-7f;
  
  TEST(evaluate_fcurve, EmptyFCurve)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
    EXPECT_EQ(evaluate_fcurve(fcu, 47.0f), 0.0f);
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, OnKeys)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF);
    insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF);
    insert_vert_fcurve(fcu, 3.0f, 19.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF);
  
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.0f), 7.0f, EPSILON);   // hits 'on or before first' function
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.0f), 13.0f, EPSILON);  // hits 'between' function
    EXPECT_NEAR(evaluate_fcurve(fcu, 3.0f), 19.0f, EPSILON);  // hits 'on or after last' function
  
    /* Also test within a specific time epsilon of the keys, as this was an issue in T39207.
     * This epsilon is just slightly smaller than the epsilon given to binarysearch_bezt_index_ex()
     * in fcurve_eval_between_keyframes(), so it should hit the "exact" code path. */
    float time_epsilon = 0.00008f;
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.0f - time_epsilon), 13.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.0f + time_epsilon), 13.0f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, InterpolationConstant)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
  
    fcu->bezt[0].ipo = BEZT_IPO_CONST;
    fcu->bezt[1].ipo = BEZT_IPO_CONST;
  
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.25f), 7.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.50f), 7.0f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, InterpolationLinear)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
  
    fcu->bezt[0].ipo = BEZT_IPO_LIN;
    fcu->bezt[1].ipo = BEZT_IPO_LIN;
  
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.25f), 8.5f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.50f), 10.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.75f), 11.5f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, InterpolationBezier)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
  
    EXPECT_EQ(fcu->bezt[0].ipo, BEZT_IPO_BEZ);
    EXPECT_EQ(fcu->bezt[1].ipo, BEZT_IPO_BEZ);
  
    // Test with default handles.
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.25f), 7.8297067f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.50f), 10.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.75f), 12.170294f, EPSILON);
  
    // Test with modified handles.
    fcu->bezt[0].vec[0][0] = 0.71855f;  // left handle X
    fcu->bezt[0].vec[0][1] = 6.22482f;  // left handle Y
    fcu->bezt[0].vec[2][0] = 1.35148f;  // right handle X
    fcu->bezt[0].vec[2][1] = 7.96806f;  // right handle Y
  
    fcu->bezt[1].vec[0][0] = 1.66667f;  // left handle X
    fcu->bezt[1].vec[0][1] = 10.4136f;  // left handle Y
    fcu->bezt[1].vec[2][0] = 2.33333f;  // right handle X
    fcu->bezt[1].vec[2][1] = 15.5864f;  // right handle Y
  
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.25f), 7.945497f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.50f), 9.3495407f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.75f), 11.088551f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, InterpolationBounce)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
  
    fcu->bezt[0].ipo = BEZT_IPO_BOUNCE;
    fcu->bezt[1].ipo = BEZT_IPO_BOUNCE;
  
    fcu->bezt[0].easing = BEZT_IPO_EASE_IN;
    fcu->bezt[1].easing = BEZT_IPO_EASE_AUTO;
  
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.4f), 8.3649998f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.5f), 8.4062500f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 1.8f), 11.184999f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, ExtrapolationLinearKeys)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
    fcu->bezt[0].ipo = BEZT_IPO_LIN;
    fcu->bezt[1].ipo = BEZT_IPO_LIN;
  
    fcu->extend = FCURVE_EXTRAPOLATE_LINEAR;
    // Before first keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 0.75f), 5.5f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 0.50f), 4.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, -1.50f), -8.0f, EPSILON);
    // After last keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.75f), 17.5f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 3.50f), 22.0f, EPSILON);
  
    fcu->extend = FCURVE_EXTRAPOLATE_CONSTANT;
    // Before first keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 0.75f), 7.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, -1.50f), 7.0f, EPSILON);
    // After last keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.75f), 13.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 3.50f), 13.0f, EPSILON);
  
    free_fcurve(fcu);
  }
  
  TEST(evaluate_fcurve, ExtrapolationBezierKeys)
  {
    FCurve *fcu = static_cast<FCurve *>(MEM_callocN(sizeof(FCurve), "FCurve"));
  
    EXPECT_EQ(insert_vert_fcurve(fcu, 1.0f, 7.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 0);
    EXPECT_EQ(insert_vert_fcurve(fcu, 2.0f, 13.0f, BEZT_KEYTYPE_KEYFRAME, INSERTKEY_NO_USERPREF), 1);
  
    fcu->bezt[0].vec[0][0] = 0.71855f;  // left handle X
    fcu->bezt[0].vec[0][1] = 6.22482f;  // left handle Y
    fcu->bezt[0].vec[2][0] = 1.35148f;  // right handle X
    fcu->bezt[0].vec[2][1] = 7.96806f;  // right handle Y
  
    fcu->bezt[1].vec[0][0] = 1.66667f;  // left handle X
    fcu->bezt[1].vec[0][1] = 10.4136f;  // left handle Y
    fcu->bezt[1].vec[2][0] = 2.33333f;  // right handle X
    fcu->bezt[1].vec[2][1] = 15.5864f;  // right handle Y
  
    fcu->extend = FCURVE_EXTRAPOLATE_LINEAR;
    // Before first keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 0.75f), 6.3114409f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, -0.50f), 2.8686447f, EPSILON);
    // After last keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.75f), 18.81946f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 3.50f), 24.63892f, EPSILON);
  
    fcu->extend = FCURVE_EXTRAPOLATE_CONSTANT;
    // Before first keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 0.75f), 7.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, -1.50f), 7.0f, EPSILON);
    // After last keyframe.
    EXPECT_NEAR(evaluate_fcurve(fcu, 2.75f), 13.0f, EPSILON);
    EXPECT_NEAR(evaluate_fcurve(fcu, 3.50f), 13.0f, EPSILON);
  
    free_fcurve(fcu);
  }
  