draw_utils.hpp

/*
 * eos - A 3D Morphable Model fitting library written in modern C++11/14.
 *
 * File: include/eos/render/opencv/draw_utils.hpp
 *
 * Copyright 2017-2019, 2023 Patrik Huber
 *
 * 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.
 */
#pragma once
 
#ifndef EOS_RENDER_OPENCV_DRAW_UTILS_HPP
#define EOS_RENDER_OPENCV_DRAW_UTILS_HPP
 
#include "eos/core/Mesh.hpp"
#include "eos/render/matrix_projection.hpp"
#include "eos/render/detail/utils.hpp"
 
#include "Eigen/Core"
 
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
 
namespace eos {
namespace render {
 
inline void draw_wireframe(cv::Mat image, const core::Mesh& mesh, Eigen::Matrix4f modelview,
                           Eigen::Matrix4f projection, Eigen::Vector4f viewport,
                           cv::Scalar color = cv::Scalar(0, 255, 0, 255))
{
    for (const auto& triangle : mesh.tvi)
    {
        const auto p1 = project(mesh.vertices[triangle[0]], modelview, projection, viewport);
        const auto p2 = project(mesh.vertices[triangle[1]], modelview, projection, viewport);
        const auto p3 = project(mesh.vertices[triangle[2]], modelview, projection, viewport);
        if (render::detail::are_vertices_ccw_in_screen_space<float>(p1.head<2>(), p2.head<2>(), p3.head<2>()))
        {
            cv::line(image, cv::Point(p1.x(), p1.y()), cv::Point(p2.x(), p2.y()), color);
            cv::line(image, cv::Point(p2.x(), p2.y()), cv::Point(p3.x(), p3.y()), color);
            cv::line(image, cv::Point(p3.x(), p3.y()), cv::Point(p1.x(), p1.y()), color);
        }
    }
};
 
inline cv::Mat draw_texcoords(core::Mesh mesh, cv::Mat image = cv::Mat())
{
    using cv::Point2f;
    using cv::Scalar;
    if (image.empty())
    {
        image = cv::Mat(512, 512, CV_8UC4, Scalar(0.0f, 0.0f, 0.0f, 255.0f));
    }
 
    for (const auto& triIdx : mesh.tvi)
    {
        cv::line(
            image,
            Point2f(mesh.texcoords[triIdx[0]][0] * image.cols, mesh.texcoords[triIdx[0]][1] * image.rows),
            Point2f(mesh.texcoords[triIdx[1]][0] * image.cols, mesh.texcoords[triIdx[1]][1] * image.rows),
            Scalar(255.0f, 0.0f, 0.0f));
        cv::line(
            image,
            Point2f(mesh.texcoords[triIdx[1]][0] * image.cols, mesh.texcoords[triIdx[1]][1] * image.rows),
            Point2f(mesh.texcoords[triIdx[2]][0] * image.cols, mesh.texcoords[triIdx[2]][1] * image.rows),
            Scalar(255.0f, 0.0f, 0.0f));
        cv::line(
            image,
            Point2f(mesh.texcoords[triIdx[2]][0] * image.cols, mesh.texcoords[triIdx[2]][1] * image.rows),
            Point2f(mesh.texcoords[triIdx[0]][0] * image.cols, mesh.texcoords[triIdx[0]][1] * image.rows),
            Scalar(255.0f, 0.0f, 0.0f));
    }
    return image;
};
 
} /* namespace render */
} /* namespace eos */
 
#endif /* EOS_RENDER_OPENCV_DRAW_UTILS_HPP */