text: // Copyright 2019 The MediaPipe Authors.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #include "mediapipe/util/annotation_renderer.h"
  
  #include <math.h>
  
  #include <algorithm>
  #include <cmath>
  
  #include "mediapipe/framework/port/logging.h"
  #include "mediapipe/framework/port/vector.h"
  #include "mediapipe/util/color.pb.h"
  
  namespace mediapipe {
  namespace {
  
  using Arrow = RenderAnnotation::Arrow;
  using FilledOval = RenderAnnotation::FilledOval;
  using FilledRectangle = RenderAnnotation::FilledRectangle;
  using FilledRoundedRectangle = RenderAnnotation::FilledRoundedRectangle;
  using Point = RenderAnnotation::Point;
  using Line = RenderAnnotation::Line;
  using GradientLine = RenderAnnotation::GradientLine;
  using Oval = RenderAnnotation::Oval;
  using Rectangle = RenderAnnotation::Rectangle;
  using RoundedRectangle = RenderAnnotation::RoundedRectangle;
  using Text = RenderAnnotation::Text;
  
  int ClampThickness(int thickness) {
    constexpr int kMaxThickness = 32767;  // OpenCV MAX_THICKNESS
    return std::clamp(thickness, 1, kMaxThickness);
  }
  
  bool NormalizedtoPixelCoordinates(double normalized_x, double normalized_y,
                                    int image_width, int image_height, int* x_px,
                                    int* y_px) {
    CHECK(x_px != nullptr);
    CHECK(y_px != nullptr);
    CHECK_GT(image_width, 0);
    CHECK_GT(image_height, 0);
  
    if (normalized_x < 0 || normalized_x > 1.0 || normalized_y < 0 ||
        normalized_y > 1.0) {
      VLOG(1) << "Normalized coordinates must be between 0.0 and 1.0";
    }
  
    *x_px = static_cast<int32>(round(normalized_x * image_width));
    *y_px = static_cast<int32>(round(normalized_y * image_height));
  
    return true;
  }
  
  cv::Scalar MediapipeColorToOpenCVColor(const Color& color) {
    return cv::Scalar(color.r(), color.g(), color.b());
  }
  
  cv::RotatedRect RectangleToOpenCVRotatedRect(int left, int top, int right,
                                               int bottom, double rotation) {
    return cv::RotatedRect(
        cv::Point2f((left + right) / 2.f, (top + bottom) / 2.f),
        cv::Size2f(right - left, bottom - top), rotation / M_PI * 180.f);
  }
  
  void cv_line2(cv::Mat& img, const cv::Point& start, const cv::Point& end,
                const cv::Scalar& color1, const cv::Scalar& color2,
                int thickness) {
    cv::LineIterator iter(img, start, end, /*cv::LINE_4=*/4);
    for (int i = 0; i < iter.count; i++, iter++) {
      const double alpha = static_cast<double>(i) / iter.count;
      const cv::Scalar new_color(color1 * (1.0 - alpha) + color2 * alpha);
      const cv::Rect rect(iter.pos(), cv::Size(thickness, thickness));
      cv::rectangle(img, rect, new_color, /*cv::FILLED=*/-1, /*cv::LINE_4=*/4);
    }
  }
  
  }  // namespace
  
  void AnnotationRenderer::RenderDataOnImage(const RenderData& render_data) {
    for (const auto& annotation : render_data.render_annotations()) {
      if (annotation.data_case() == RenderAnnotation::kRectangle) {
        DrawRectangle(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kRoundedRectangle) {
        DrawRoundedRectangle(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kFilledRectangle) {
        DrawFilledRectangle(annotation);
      } else if (annotation.data_case() ==
                 RenderAnnotation::kFilledRoundedRectangle) {
        DrawFilledRoundedRectangle(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kOval) {
        DrawOval(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kFilledOval) {
        DrawFilledOval(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kText) {
        DrawText(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kPoint) {
        DrawPoint(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kLine) {
        DrawLine(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kGradientLine) {
        DrawGradientLine(annotation);
      } else if (annotation.data_case() == RenderAnnotation::kArrow) {
        DrawArrow(annotation);
      } else {
        LOG(FATAL) << "Unknown annotation type: " << annotation.data_case();
      }
    }
  }
  
  void AnnotationRenderer::AdoptImage(cv::Mat* input_image) {
    image_width_ = input_image->cols;
    image_height_ = input_image->rows;
  
    // No pixel data copy here, only headers are copied.
    mat_image_ = *input_image;
  }
  
  int AnnotationRenderer::GetImageWidth() const { return mat_image_.cols; }
  int AnnotationRenderer::GetImageHeight() const { return mat_image_.rows; }
  
  void AnnotationRenderer::SetFlipTextVertically(bool flip) {
    flip_text_vertically_ = flip;
  }
  
  void AnnotationRenderer::SetScaleFactor(float scale_factor) {
    if (scale_factor > 0.0f) scale_factor_ = std::min(scale_factor, 1.0f);
  }
  
  void AnnotationRenderer::DrawRectangle(const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& rectangle = annotation.rectangle();
    if (rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(rectangle.left(), rectangle.top(),
                                         image_width_, image_height_, &left,
                                         &top));
      CHECK(NormalizedtoPixelCoordinates(rectangle.right(), rectangle.bottom(),
                                         image_width_, image_height_, &right,
                                         &bottom));
    } else {
      left = static_cast<int>(rectangle.left() * scale_factor_);
      top = static_cast<int>(rectangle.top() * scale_factor_);
      right = static_cast<int>(rectangle.right() * scale_factor_);
      bottom = static_cast<int>(rectangle.bottom() * scale_factor_);
    }
  
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    if (rectangle.rotation() != 0.0) {
      const auto& rect = RectangleToOpenCVRotatedRect(left, top, right, bottom,
                                                      rectangle.rotation());
      const int kNumVertices = 4;
      cv::Point2f vertices[kNumVertices];
      rect.points(vertices);
      for (int i = 0; i < kNumVertices; i++) {
        cv::line(mat_image_, vertices[i], vertices[(i + 1) % kNumVertices], color,
                 thickness);
      }
    } else {
      cv::Rect rect(left, top, right - left, bottom - top);
      cv::rectangle(mat_image_, rect, color, thickness);
    }
  }
  
  void AnnotationRenderer::DrawFilledRectangle(
      const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& rectangle = annotation.filled_rectangle().rectangle();
    if (rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(rectangle.left(), rectangle.top(),
                                         image_width_, image_height_, &left,
                                         &top));
      CHECK(NormalizedtoPixelCoordinates(rectangle.right(), rectangle.bottom(),
                                         image_width_, image_height_, &right,
                                         &bottom));
    } else {
      left = static_cast<int>(rectangle.left() * scale_factor_);
      top = static_cast<int>(rectangle.top() * scale_factor_);
      right = static_cast<int>(rectangle.right() * scale_factor_);
      bottom = static_cast<int>(rectangle.bottom() * scale_factor_);
    }
  
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    if (rectangle.rotation() != 0.0) {
      const auto& rect = RectangleToOpenCVRotatedRect(left, top, right, bottom,
                                                      rectangle.rotation());
      const int kNumVertices = 4;
      cv::Point2f vertices2f[kNumVertices];
      rect.points(vertices2f);
      // Convert cv::Point2f[] to cv::Point[].
      cv::Point vertices[kNumVertices];
      for (int i = 0; i < kNumVertices; ++i) {
        vertices[i] = vertices2f[i];
      }
      cv::fillConvexPoly(mat_image_, vertices, kNumVertices, color);
    } else {
      cv::Rect rect(left, top, right - left, bottom - top);
      cv::rectangle(mat_image_, rect, color, -1);
    }
  }
  
  void AnnotationRenderer::DrawRoundedRectangle(
      const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& rectangle = annotation.rounded_rectangle().rectangle();
    if (rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(rectangle.left(), rectangle.top(),
                                         image_width_, image_height_, &left,
                                         &top));
      CHECK(NormalizedtoPixelCoordinates(rectangle.right(), rectangle.bottom(),
                                         image_width_, image_height_, &right,
                                         &bottom));
    } else {
      left = static_cast<int>(rectangle.left() * scale_factor_);
      top = static_cast<int>(rectangle.top() * scale_factor_);
      right = static_cast<int>(rectangle.right() * scale_factor_);
      bottom = static_cast<int>(rectangle.bottom() * scale_factor_);
    }
  
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    const int corner_radius =
        round(annotation.rounded_rectangle().corner_radius() * scale_factor_);
    const int line_type = annotation.rounded_rectangle().line_type();
    DrawRoundedRectangle(mat_image_, cv::Point(left, top),
                         cv::Point(right, bottom), color, thickness, line_type,
                         corner_radius);
  }
  
  void AnnotationRenderer::DrawFilledRoundedRectangle(
      const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& rectangle =
        annotation.filled_rounded_rectangle().rounded_rectangle().rectangle();
    if (rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(rectangle.left(), rectangle.top(),
                                         image_width_, image_height_, &left,
                                         &top));
      CHECK(NormalizedtoPixelCoordinates(rectangle.right(), rectangle.bottom(),
                                         image_width_, image_height_, &right,
                                         &bottom));
    } else {
      left = static_cast<int>(rectangle.left() * scale_factor_);
      top = static_cast<int>(rectangle.top() * scale_factor_);
      right = static_cast<int>(rectangle.right() * scale_factor_);
      bottom = static_cast<int>(rectangle.bottom() * scale_factor_);
    }
  
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int corner_radius =
        annotation.rounded_rectangle().corner_radius() * scale_factor_;
    const int line_type = annotation.rounded_rectangle().line_type();
    DrawRoundedRectangle(mat_image_, cv::Point(left, top),
                         cv::Point(right, bottom), color, -1, line_type,
                         corner_radius);
  }
  
  void AnnotationRenderer::DrawRoundedRectangle(cv::Mat src, cv::Point top_left,
                                                cv::Point bottom_right,
                                                const cv::Scalar& line_color,
                                                int thickness, int line_type,
                                                int corner_radius) {
    // Corners:
    // p1 - p2
    // |     |
    // p4 - p3
    cv::Point p1 = top_left;
    cv::Point p2 = cv::Point(bottom_right.x, top_left.y);
    cv::Point p3 = bottom_right;
    cv::Point p4 = cv::Point(top_left.x, bottom_right.y);
  
    // Draw edges of the rectangle
    cv::line(src, cv::Point(p1.x + corner_radius, p1.y),
             cv::Point(p2.x - corner_radius, p2.y), line_color, thickness,
             line_type);
    cv::line(src, cv::Point(p2.x, p2.y + corner_radius),
             cv::Point(p3.x, p3.y - corner_radius), line_color, thickness,
             line_type);
    cv::line(src, cv::Point(p4.x + corner_radius, p4.y),
             cv::Point(p3.x - corner_radius, p3.y), line_color, thickness,
             line_type);
    cv::line(src, cv::Point(p1.x, p1.y + corner_radius),
             cv::Point(p4.x, p4.y - corner_radius), line_color, thickness,
             line_type);
  
    // Draw arcs at corners.
    cv::ellipse(src, p1 + cv::Point(corner_radius, corner_radius),
                cv::Size(corner_radius, corner_radius), 180.0, 0, 90, line_color,
                thickness, line_type);
    cv::ellipse(src, p2 + cv::Point(-corner_radius, corner_radius),
                cv::Size(corner_radius, corner_radius), 270.0, 0, 90, line_color,
                thickness, line_type);
    cv::ellipse(src, p3 + cv::Point(-corner_radius, -corner_radius),
                cv::Size(corner_radius, corner_radius), 0.0, 0, 90, line_color,
                thickness, line_type);
    cv::ellipse(src, p4 + cv::Point(corner_radius, -corner_radius),
                cv::Size(corner_radius, corner_radius), 90.0, 0, 90, line_color,
                thickness, line_type);
  }
  
  void AnnotationRenderer::DrawOval(const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& enclosing_rectangle = annotation.oval().rectangle();
    if (enclosing_rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(enclosing_rectangle.left(),
                                         enclosing_rectangle.top(), image_width_,
                                         image_height_, &left, &top));
      CHECK(NormalizedtoPixelCoordinates(
          enclosing_rectangle.right(), enclosing_rectangle.bottom(), image_width_,
          image_height_, &right, &bottom));
    } else {
      left = static_cast<int>(enclosing_rectangle.left() * scale_factor_);
      top = static_cast<int>(enclosing_rectangle.top() * scale_factor_);
      right = static_cast<int>(enclosing_rectangle.right() * scale_factor_);
      bottom = static_cast<int>(enclosing_rectangle.bottom() * scale_factor_);
    }
  
    cv::Point center((left + right) / 2, (top + bottom) / 2);
    cv::Size size((right - left) / 2, (bottom - top) / 2);
    const double rotation = enclosing_rectangle.rotation() / M_PI * 180.f;
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    cv::ellipse(mat_image_, center, size, rotation, 0, 360, color, thickness);
  }
  
  void AnnotationRenderer::DrawFilledOval(const RenderAnnotation& annotation) {
    int left = -1;
    int top = -1;
    int right = -1;
    int bottom = -1;
    const auto& enclosing_rectangle = annotation.filled_oval().oval().rectangle();
    if (enclosing_rectangle.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(enclosing_rectangle.left(),
                                         enclosing_rectangle.top(), image_width_,
                                         image_height_, &left, &top));
      CHECK(NormalizedtoPixelCoordinates(
          enclosing_rectangle.right(), enclosing_rectangle.bottom(), image_width_,
          image_height_, &right, &bottom));
    } else {
      left = static_cast<int>(enclosing_rectangle.left() * scale_factor_);
      top = static_cast<int>(enclosing_rectangle.top() * scale_factor_);
      right = static_cast<int>(enclosing_rectangle.right() * scale_factor_);
      bottom = static_cast<int>(enclosing_rectangle.bottom() * scale_factor_);
    }
  
    cv::Point center((left + right) / 2, (top + bottom) / 2);
    cv::Size size(std::max(0, (right - left) / 2),
                  std::max(0, (bottom - top) / 2));
    const double rotation = enclosing_rectangle.rotation() / M_PI * 180.f;
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    cv::ellipse(mat_image_, center, size, rotation, 0, 360, color, -1);
  }
  
  void AnnotationRenderer::DrawArrow(const RenderAnnotation& annotation) {
    int x_start = -1;
    int y_start = -1;
    int x_end = -1;
    int y_end = -1;
  
    const auto& arrow = annotation.arrow();
    if (arrow.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(arrow.x_start(), arrow.y_start(),
                                         image_width_, image_height_, &x_start,
                                         &y_start));
      CHECK(NormalizedtoPixelCoordinates(arrow.x_end(), arrow.y_end(),
                                         image_width_, image_height_, &x_end,
                                         &y_end));
    } else {
      x_start = static_cast<int>(arrow.x_start() * scale_factor_);
      y_start = static_cast<int>(arrow.y_start() * scale_factor_);
      x_end = static_cast<int>(arrow.x_end() * scale_factor_);
      y_end = static_cast<int>(arrow.y_end() * scale_factor_);
    }
  
    cv::Point arrow_start(x_start, y_start);
    cv::Point arrow_end(x_end, y_end);
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
  
    // Draw the main arrow line.
    cv::line(mat_image_, arrow_start, arrow_end, color, thickness);
  
    // Compute the arrowtip left and right vectors.
    Vector2_d L_start(static_cast<double>(x_start), static_cast<double>(y_start));
    Vector2_d L_end(static_cast<double>(x_end), static_cast<double>(y_end));
    Vector2_d U = (L_end - L_start).Normalize();
    Vector2_d V = U.Ortho();
    double line_length = (L_end - L_start).Norm();
    constexpr double kArrowTipLengthProportion = 0.2;
    double arrowtip_length = kArrowTipLengthProportion * line_length;
    Vector2_d arrowtip_left = L_end - arrowtip_length * U + arrowtip_length * V;
    Vector2_d arrowtip_right = L_end - arrowtip_length * U - arrowtip_length * V;
  
    // Draw the arrowtip left and right lines.
    cv::Point arrowtip_left_start(static_cast<int>(round(arrowtip_left[0])),
                                  static_cast<int>(round(arrowtip_left[1])));
    cv::Point arrowtip_right_start(static_cast<int>(round(arrowtip_right[0])),
                                   static_cast<int>(round(arrowtip_right[1])));
    cv::line(mat_image_, arrowtip_left_start, arrow_end, color, thickness);
    cv::line(mat_image_, arrowtip_right_start, arrow_end, color, thickness);
  }
  
  void AnnotationRenderer::DrawPoint(const RenderAnnotation& annotation) {
    const auto& point = annotation.point();
    int x = -1;
    int y = -1;
    if (point.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(point.x(), point.y(), image_width_,
                                         image_height_, &x, &y));
    } else {
      x = static_cast<int>(point.x() * scale_factor_);
      y = static_cast<int>(point.y() * scale_factor_);
    }
  
    cv::Point point_to_draw(x, y);
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    cv::circle(mat_image_, point_to_draw, thickness, color, -1);
  }
  
  void AnnotationRenderer::DrawLine(const RenderAnnotation& annotation) {
    int x_start = -1;
    int y_start = -1;
    int x_end = -1;
    int y_end = -1;
  
    const auto& line = annotation.line();
    if (line.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(line.x_start(), line.y_start(),
                                         image_width_, image_height_, &x_start,
                                         &y_start));
      CHECK(NormalizedtoPixelCoordinates(line.x_end(), line.y_end(), image_width_,
                                         image_height_, &x_end, &y_end));
    } else {
      x_start = static_cast<int>(line.x_start() * scale_factor_);
      y_start = static_cast<int>(line.y_start() * scale_factor_);
      x_end = static_cast<int>(line.x_end() * scale_factor_);
      y_end = static_cast<int>(line.y_end() * scale_factor_);
    }
  
    cv::Point start(x_start, y_start);
    cv::Point end(x_end, y_end);
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    cv::line(mat_image_, start, end, color, thickness);
  }
  
  void AnnotationRenderer::DrawGradientLine(const RenderAnnotation& annotation) {
    int x_start = -1;
    int y_start = -1;
    int x_end = -1;
    int y_end = -1;
  
    const auto& line = annotation.gradient_line();
    if (line.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(line.x_start(), line.y_start(),
                                         image_width_, image_height_, &x_start,
                                         &y_start));
      CHECK(NormalizedtoPixelCoordinates(line.x_end(), line.y_end(), image_width_,
                                         image_height_, &x_end, &y_end));
    } else {
      x_start = static_cast<int>(line.x_start() * scale_factor_);
      y_start = static_cast<int>(line.y_start() * scale_factor_);
      x_end = static_cast<int>(line.x_end() * scale_factor_);
      y_end = static_cast<int>(line.y_end() * scale_factor_);
    }
  
    const cv::Point start(x_start, y_start);
    const cv::Point end(x_end, y_end);
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    const cv::Scalar color1 = MediapipeColorToOpenCVColor(line.color1());
    const cv::Scalar color2 = MediapipeColorToOpenCVColor(line.color2());
    cv_line2(mat_image_, start, end, color1, color2, thickness);
  }
  
  void AnnotationRenderer::DrawText(const RenderAnnotation& annotation) {
    int left = -1;
    int baseline = -1;
    int font_size = -1;
  
    const auto& text = annotation.text();
    if (text.normalized()) {
      CHECK(NormalizedtoPixelCoordinates(text.left(), text.baseline(),
                                         image_width_, image_height_, &left,
                                         &baseline));
      font_size = static_cast<int>(round(text.font_height() * image_height_));
    } else {
      left = static_cast<int>(text.left() * scale_factor_);
      baseline = static_cast<int>(text.baseline() * scale_factor_);
      font_size = static_cast<int>(text.font_height() * scale_factor_);
    }
  
    cv::Point origin(left, baseline);
    const cv::Scalar color = MediapipeColorToOpenCVColor(annotation.color());
    const int thickness =
        ClampThickness(round(annotation.thickness() * scale_factor_));
    const int font_face = text.font_face();
  
    const double font_scale = ComputeFontScale(font_face, font_size, thickness);
    int text_baseline = 0;
    cv::Size text_size = cv::getTextSize(text.display_text(), font_face,
                                         font_scale, thickness, &text_baseline);
  
    if (text.center_horizontally()) {
      origin.x -= text_size.width / 2;
    }
    if (text.center_vertically()) {
      origin.y += text_size.height / 2;
    }
  
    cv::putText(mat_image_, text.display_text(), origin, font_face, font_scale,
                color, thickness, /*lineType=*/8,
                /*bottomLeftOrigin=*/flip_text_vertically_);
  }
  
  double AnnotationRenderer::ComputeFontScale(int font_face, int font_size,
                                              int thickness) {
    double base_line;
    double cap_line;
  
    // The details below of how to compute the font scale from font face,
    // thickness, and size were inferred from the OpenCV implementation.
    switch (font_face) {
      case cv::FONT_HERSHEY_SIMPLEX:
      case cv::FONT_HERSHEY_DUPLEX:
      case cv::FONT_HERSHEY_COMPLEX:
      case cv::FONT_HERSHEY_TRIPLEX:
      case cv::FONT_HERSHEY_SCRIPT_SIMPLEX:
      case cv::FONT_HERSHEY_SCRIPT_COMPLEX:
        base_line = 9;
        cap_line = 12;
        break;
      case cv::FONT_HERSHEY_PLAIN:
        base_line = 5;
        cap_line = 4;
        break;
      case cv::FONT_HERSHEY_COMPLEX_SMALL:
        base_line = 6;
        cap_line = 7;
        break;
      default:
        return -1;
    }
  
    const double thick = static_cast<double>(thickness + 1);
    return (static_cast<double>(font_size) - (thick / 2.0F)) /
           (cap_line + base_line);
  }
  
  }  // namespace mediapipe
  