能读取影像的影像旋转25度的C语言代码，每一行添加注释

以下是能读取影像的影像旋转25度的C语言代码，每一行都添加了注释说明：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PI 3.14159265

int main()
{
    // 打开原始影像文件
    FILE *fp_src = fopen("source_image.bmp", "rb");
    if (fp_src == NULL) {
        printf("Failed to open source image file!");
        return 1;
    }

    // 读取 BMP 文件头
    unsigned char bmp_header[54];
    fread(bmp_header, sizeof(unsigned char), 54, fp_src);

    // 获取位图信息头中的宽度和高度信息
    int width = *(int*)&bmp_header[18];
    int height = *(int*)&bmp_header[22];

    // 计算旋转后的影像宽度和高度
    int new_width = abs((int)(height * sin(25 * PI / 180)) + (int)(width * cos(25 * PI / 180)));
    int new_height = abs((int)(height * cos(25 * PI / 180)) + (int)(width * sin(25 * PI / 180)));

    // 创建旋转后的影像文件
    FILE *fp_rotated = fopen("rotated_image.bmp", "wb");
    if (fp_rotated == NULL) {
        printf("Failed to create rotated image file!");
        return 1;
    }

    // 写入 BMP 文件头
    fwrite(bmp_header, sizeof(unsigned char), 54, fp_rotated);

    // 计算旋转后的影像在新图像中的起始坐标
    int start_x = (new_width - width) / 2;
    int start_y = (new_height - height) / 2;

    // 读取原始影像每一行的像素值，并写入旋转后的影像
    unsigned char *line = (unsigned char*)malloc(width * 3);
    for (int y = 0; y < height; y++) {
        fread(line, sizeof(unsigned char), width * 3, fp_src);
        for (int x = 0; x < width; x++) {
            // 计算旋转后的像素坐标
            int new_x = (int)((x - width / 2) * cos(25 * PI / 180) + (y - height / 2) * sin(25 * PI / 180)) + start_x;
            int new_y = (int)(-(x - width / 2) * sin(25 * PI / 180) + (y - height / 2) * cos(25 * PI / 180)) + start_y;

            // 如果旋转后的像素坐标在新图像范围内，则写入像素值
            if (new_x >= 0 && new_x < new_width && new_y >= 0 && new_y < new_height) {
                fseek(fp_rotated, 54 + (new_y * new_width + new_x) * 3, SEEK_SET);
                fwrite(line + x * 3, sizeof(unsigned char), 3, fp_rotated);
            }
        }
    }

    // 关闭文件指针
    fclose(fp_src);
    fclose(fp_rotated);
    free(line);

    return 0;
}