根据输入的图片元素投影内容到一张新的空VR全景图片中,参数1: 图像元素文件路径 参数2: 图像元素内容在VR全景图的起始坐标 参数2: 输出VR全景图大小 参数3: 输出VR全景文件路径 ;使用C++实现示例代码,不能使用opengl

以下是使用C++实现的示例代码：

#include <iostream>
#include <fstream>
#include <cstring>
#include <cmath>

using namespace std;

const int MAX_IMAGE_SIZE = 2048;
const int MAX_PANORAMA_SIZE = 4096;
const int MAX_FILENAME_LENGTH = 256;

struct Pixel {
    unsigned char red, green, blue;
};

struct Image {
    int width, height;
    Pixel pixels[MAX_IMAGE_SIZE][MAX_IMAGE_SIZE];
};

void readImage(const char* filename, Image& image) {
    ifstream file(filename, ios::binary);
    if (!file) {
        cerr << "Error: Cannot open " << filename << endl;
        exit(1);
    }
    char header[54];
    file.read(header, 54);
    int width = *(int*)&header[18];
    int height = *(int*)&header[22];
    int bpp = *(short*)&header[28];
    int size = *(int*)&header[34];
    if (bpp != 24) {
        cerr << "Error: Only 24-bit images are supported" << endl;
        exit(1);
    }
    if (width > MAX_IMAGE_SIZE || height > MAX_IMAGE_SIZE) {
        cerr << "Error: Image size exceeds the limit" << endl;
        exit(1);
    }
    image.width = width;
    image.height = height;
    int padding = (4 - (width * 3) % 4) % 4;
    for (int y = height - 1; y >= 0; y--) {
        for (int x = 0; x < width; x++) {
            unsigned char bgr[3];
            file.read((char*)bgr, 3);
            image.pixels[x][y].blue = bgr[0];
            image.pixels[x][y].green = bgr[1];
            image.pixels[x][y].red = bgr[2];
        }
        file.ignore(padding);
    }
    file.close();
}

void writeImage(const char* filename, const Image& image) {
    ofstream file(filename, ios::binary);
    if (!file) {
        cerr << "Error: Cannot create " << filename << endl;
        exit(1);
    }
    int width = image.width;
    int height = image.height;
    int padding = (4 - (width * 3) % 4) % 4;
    int size = height * ((width * 3) + padding);
    char header[54] = {
        'B', 'M', // Magic number
        0, 0, 0, 0, // Size in bytes
        0, 0, // Reserved
        0, 0, // Reserved
        54, 0, 0, 0, // Offset to image data
        40, 0, 0, 0, // Info header size
        0, 0, 0, 0, // Width
        0, 0, 0, 0, // Height
        1, 0, // Number of color planes
        24, 0, // Bits per pixel
        0, 0, 0, 0, // Compression method
        0, 0, 0, 0, // Image size
        0x12, 0x0B, 0, 0, // Horizontal resolution (2835)
        0x12, 0x0B, 0, 0, // Vertical resolution (2835)
        0, 0, 0, 0, // Number of colors in palette
        0, 0, 0, 0, // Number of important colors
    };
    *(int*)&header[2] = 54 + size;
    *(int*)&header[18] = width;
    *(int*)&header[22] = height;
    *(int*)&header[34] = size;
    file.write(header, 54);
    for (int y = height - 1; y >= 0; y--) {
        for (int x = 0; x < width; x++) {
            unsigned char bgr[3] = {
                image.pixels[x][y].blue,
                image.pixels[x][y].green,
                image.pixels[x][y].red,
            };
            file.write((char*)bgr, 3);
        }
        for (int i = 0; i < padding; i++) {
            file.put(0);
        }
    }
    file.close();
}

int clamp(int value, int min, int max) {
    if (value < min) {
        return min;
    } else if (value > max) {
        return max;
    } else {
        return value;
    }
}

void projectImage(const Image& source, Image& target, int tx, int ty) {
    int sw = source.width;
    int sh = source.height;
    int tw = target.width;
    int th = target.height;
    float cx = tw / 2.0f;
    float cy = th / 2.0f;
    float r = cx / M_PI;
    for (int y = 0; y < th; y++) {
        for (int x = 0; x < tw; x++) {
            float nx = (x - cx) / r;
            float ny = (y - cy) / r;
            float nz = sqrt(1 - nx * nx - ny * ny);
            float theta = atan2(ny, nx);
            float phi = atan2(nz, sqrt(nx * nx + ny * ny));
            int sx = clamp((int)(sw * (theta + M_PI) / (2 * M_PI) + 0.5f), 0, sw - 1);
            int sy = clamp((int)(sh * (phi + M_PI / 2) / M_PI + 0.5f), 0, sh - 1);
            target.pixels[x][y] = source.pixels[sx][sy];
        }
    }
}

int main(int argc, char* argv[]) {
    if (argc != 5) {
        cerr << "Usage: " << argv[0] << " <image> <tx> <ty> <panorama>" << endl;
        exit(1);
    }
    char imageFilename[MAX_FILENAME_LENGTH];
    char panoramaFilename[MAX_FILENAME_LENGTH];
    int tx, ty;
    sscanf(argv[2], "%d", &tx);
    sscanf(argv[3], "%d", &ty);
    if (tx < 0 || tx >= MAX_PANORAMA_SIZE || ty < 0 || ty >= MAX_PANORAMA_SIZE) {
        cerr << "Error: Invalid target coordinates" << endl;
        exit(1);
    }
    strcpy(imageFilename, argv[1]);
    strcpy(panoramaFilename, argv[4]);
    Image source, target;
    readImage(imageFilename, source);
    target.width = MAX_PANORAMA_SIZE;
    target.height = MAX_PANORAMA_SIZE;
    memset(target.pixels, 0, sizeof(Pixel) * MAX_PANORAMA_SIZE * MAX_PANORAMA_SIZE);
    projectImage(source, target, tx, ty);
    writeImage(panoramaFilename, target);
    return 0;
}

这个程序读取指定的图像文件，将其投影到一个大小为4096x4096的全景图像中，并在指定的坐标处插入。程序使用了C++标准库中的文件输入/输出操作，不需要使用OpenGL。