GAMSE101-作业1

OpenCV的配置

 配置教程
 运行程序如果出现缺少.dll，就把对应的文件放到你VS STDIO的运行目录下(别放错了，不知道放哪就在每个Debug放一个)。

作业

 把作业里的.cpp文件都添加到你VS STDIO项目的源代码中，把.hpp文件都添加到头文件中。

 主程序源代码：

#include "Triangle.hpp"
#include "rasterizer.hpp"
#include <Eigen/Dense>
#include <Eigen/Core>
#include <iostream>
#include <opencv2/opencv.hpp>

constexpr double MY_PI = 3.1415926;

Eigen::Matrix4f get_view_matrix(Eigen::Vector3f eye_pos)
{
    Eigen::Matrix4f view = Eigen::Matrix4f::Identity();

    Eigen::Matrix4f translate;
    translate << 1, 0, 0, -eye_pos[0], 0, 1, 0, -eye_pos[1], 0, 0, 1,
        -eye_pos[2], 0, 0, 0, 1;

    view = translate * view;

    return view;
}


Eigen::Matrix4f get_model_matrix(float rotation_angle)
{
    Eigen::Matrix4f rotateModel = Eigen::Matrix4f::Identity();
    rotation_angle /= 180 * MY_PI;
    rotateModel(0, 0) = cos(rotation_angle);
    rotateModel(0, 1) = -sin(rotation_angle);
    rotateModel(1, 0) = -rotateModel(0, 1);
    rotateModel(1, 1) = rotateModel(0, 0);
    rotateModel(3, 3) = 1;
    return rotateModel;
}
Eigen::Matrix4f get_rotation(Vector3f axis, float angle)
{
    //会用到罗德里格旋转公式 Rodrigues' rotation formula
    Eigen::Matrix3f I = Eigen::Matrix3f::Identity();
    double a = angle / 180 * MY_PI;
    Eigen::Matrix3f N, R;
    N <<
        0, -axis[2], axis[1],
        axis[2], 0, -axis[0],
        -axis[1], axis[0], 0;
    R = cos(a) * I + (1 - cos(a)) * axis * axis.transpose() + sin(a) * N;
    Eigen::Matrix4f rotation;
    rotation <<
        R(0, 0), R(0, 1), R(0, 2), 0,
        R(1, 0), R(1, 1), R(1, 2), 0,
        R(2, 0), R(2, 1), R(2, 2), 0,
        0, 0, 0, 1;
    return rotation;

}

Eigen::Matrix4f get_projection_matrix(float eye_fov, float aspect_ratio,
    float zNear, float zFar)
{
    Eigen::Matrix4f projection = Eigen::Matrix4f::Identity();
    //完全按照课程里的参数取值，这道题的相机就在(0,0,0)，因此远近平面都是在z的负半轴，所以n和f的值应该为负
    float f, n, l, r, b, t, fov;
    fov = eye_fov / 180 * MY_PI;
    n = -zNear; //znear是正值
    f = zFar;
    t = tan(fov / 2) * zNear;
    b = -t;
    r = t * aspect_ratio;
    l = -r;
    //透视->正交 perspective->orthographic
    Eigen::Matrix4f pertoorth;
    pertoorth << n, 0, 0, 0,
        0, n, 0, 0,
        0, 0, n + f, -n * f,
        0, 0, 1, 0;
    //正交——移动
    Eigen::Matrix4f orth1;
    orth1 <<
        1, 0, 0, -(r + l) / 2,
        0, 1, 0, -(t + b) / 2,
        0, 0, 1, -(n + f) / 2,
        0, 0, 0, 1;
    //正交——缩放
    Eigen::Matrix4f orth2;
    orth2 <<
        2 / (r - l), 0, 0, 0,
        0, 2 / (t - b), 0, 0,
        0, 0, 2 / (n - f), 0,
        0, 0, 0, 1;
    projection = orth2 * orth1 * pertoorth;//注意矩阵顺序，变换从右往左依次进行
    return projection;
}


int main(int argc, const char** argv)
{
    float angle = 0;
    bool command_line = false;
    std::string filename = "output.png";

    if (argc >= 3) {
        command_line = true;
        angle = std::stof(argv[2]); // -r by default
        if (argc == 4) {
            filename = std::string(argv[3]);
        }
    }

    rst::rasterizer r(700, 700);

    Eigen::Vector3f eye_pos = { 0, 0, 5 };

    std::vector<Eigen::Vector3f> pos{ {2, 0, -2}, {0, 2, -2}, {-2, 0, -2} };

    std::vector<Eigen::Vector3i> ind{ {0, 1, 2} };

    auto pos_id = r.load_positions(pos);
    auto ind_id = r.load_indices(ind);

    int key = 0;
    int frame_count = 0;

    if (command_line) {
        r.clear(rst::Buffers::Color | rst::Buffers::Depth);

        r.set_model(get_model_matrix(angle));
        r.set_view(get_view_matrix(eye_pos));
        r.set_projection(get_projection_matrix(45, 1, 0.1, 50));

        r.draw(pos_id, ind_id, rst::Primitive::Triangle);
        cv::Mat image(700, 700, CV_32FC3, r.frame_buffer().data());
        image.convertTo(image, CV_8UC3, 1.0f);

        cv::imwrite(filename, image);

        return 0;
    }

    while (key != 27) {
        r.clear(rst::Buffers::Color | rst::Buffers::Depth);

        r.set_model(get_model_matrix(angle));
        r.set_view(get_view_matrix(eye_pos));
        r.set_projection(get_projection_matrix(45, 1, 0.1, 50));

        r.draw(pos_id, ind_id, rst::Primitive::Triangle);

        cv::Mat image(700, 700, CV_32FC3, r.frame_buffer().data());
        image.convertTo(image, CV_8UC3, 1.0f);
        cv::imshow("image", image);
        key = cv::waitKey(10);

        std::cout << "frame count: " << frame_count++ << '\n';

        if (key == 'a') {
            angle += 10;
        }
        else if (key == 'd') {
            angle -= 10;
        }
    }

    return 0;
}