vc实现bezier曲面,要求用不同颜色显 示曲面和曲面的控制网格,并且可以取消曲面控制网格的显示,允 许交互式地改变控制网格的定点位置,以观看曲面形状的改变;能 够通过对话框、菜单等方式设置曲面的配置参数（书写代码）

以下是一个简单的实现Bezier曲面的代码，使用OpenGL来绘制曲面和控制网格，并且可以通过鼠标交互来改变控制点的位置。同时提供了一个对话框来设置曲面的配置参数。

#include <GL/glut.h>
#include <iostream>

// 控制网格的行数和列数，可根据需要修改
const int ROWS = 4;
const int COLS = 4;

// 控制点的坐标
GLfloat ctrlPoints[ROWS][COLS][3] = {
    {-1.5, -1.5, 4.0}, {-0.5, -1.5, 2.0}, {0.5, -1.5, -1.0}, {1.5, -1.5, 2.0},
    {-1.5, -0.5, 1.0}, {-0.5, -0.5, 3.0}, {0.5, -0.5, 0.0}, {1.5, -0.5, -1.0},
    {-1.5, 0.5, 4.0}, {-0.5, 0.5, 0.0}, {0.5, 0.5, 3.0}, {1.5, 0.5, 4.0},
    {-1.5, 1.5, -2.0}, {-0.5, 1.5, -2.0}, {0.5, 1.5, 0.0}, {1.5, 1.5, -1.0}
};

// 是否显示控制网格
bool showControlGrid = true;

// 曲面的配置参数
int tessellationLevel = 20; // 曲面细分级别
GLfloat lineWidth = 1.0; // 曲面线宽
GLfloat pointSize = 5.0; // 控制点大小
GLfloat colorSurface[3] = {1.0, 1.0, 0.0}; // 曲面颜色
GLfloat colorGrid[3] = {0.0, 1.0, 1.0}; // 网格颜色

// 交互式修改控制点的位置
int selectedRow = -1, selectedCol = -1;
GLfloat mouseX = 0, mouseY = 0;

// 绘制Bezier曲面
void drawBezierSurface()
{
    glMap2f(GL_MAP2_VERTEX_3, 0.0, 1.0, 3, COLS, 0.0, 1.0, ROWS * 3, COLS, &ctrlPoints[0][0][0]);
    glEnable(GL_MAP2_VERTEX_3);
    
    // 绘制曲面
    glColor3fv(colorSurface);
    glLineWidth(lineWidth);
    glPointSize(pointSize);
    glMapGrid2f(tessellationLevel, 0.0, 1.0, tessellationLevel, 0.0, 1.0);
    glEvalMesh2(GL_FILL, 0, tessellationLevel, 0, tessellationLevel);
    
    // 绘制控制网格
    if (showControlGrid) {
        glColor3fv(colorGrid);
        glLineWidth(1.0);
        for (int i = 0; i < ROWS; i++) {
            for (int j = 0; j < COLS; j++) {
                glBegin(GL_LINE_LOOP);
                for (int k = 0; k < 4; k++) {
                    glVertex3fv(ctrlPoints[i][j + k][0]);
                }
                glEnd();

                glBegin(GL_LINE_LOOP);
                for (int k = 0; k < 4; k++) {
                    glVertex3fv(ctrlPoints[i + k][j][0]);
                }
                glEnd();
            }
        }
    }
}

// 绘制回调函数
void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glPushMatrix();
    glTranslatef(-2.5, -2.5, -15.0);
    drawBezierSurface();
    glPopMatrix();
    glutSwapBuffers();
}

// 鼠标事件回调函数
void mouse(int button, int state, int x, int y)
{
    if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) {
        // 根据鼠标位置获取选中的控制点
        float winX = (float)x;
        float winY = (float)glutGet(GLUT_WINDOW_HEIGHT) - (float)y;
        GLfloat modelView[16], projection[16];
        GLint viewport[4];
        glGetIntegerv(GL_VIEWPORT, viewport);
        glGetDoublev(GL_MODELVIEW_MATRIX, modelView);
        glGetDoublev(GL_PROJECTION_MATRIX, projection);
        GLfloat objX, objY, objZ;
        gluUnProject(winX, winY, 0.0, modelView, projection, viewport, &objX, &objY, &objZ);
        for (int i = 0; i < ROWS; i++) {
            for (int j = 0; j < COLS; j++) {
                GLfloat dist = sqrt(pow(ctrlPoints[i][j][0] - objX, 2) + pow(ctrlPoints[i][j][1] - objY, 2) + pow(ctrlPoints[i][j][2] - objZ, 2));
                if (dist < pointSize / 2) {
                    selectedRow = i;
                    selectedCol = j;
                    mouseX = objX;
                    mouseY = objY;
                    break;
                }
            }
        }
    }
    else if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) {
        selectedRow = -1;
        selectedCol = -1;
    }
}

// 鼠标移动回调函数
void motion(int x, int y)
{
    if (selectedRow >= 0 && selectedCol >= 0) {
        // 根据鼠标移动的距离修改控制点的位置
        float winX = (float)x;
        float winY = (float)glutGet(GLUT_WINDOW_HEIGHT) - (float)y;
        GLfloat modelView[16], projection[16];
        GLint viewport[4];
        glGetIntegerv(GL_VIEWPORT, viewport);
        glGetDoublev(GL_MODELVIEW_MATRIX, modelView);
        glGetDoublev(GL_PROJECTION_MATRIX, projection);
        GLfloat objX, objY, objZ;
        gluUnProject(winX, winY, 0.0, modelView, projection, viewport, &objX, &objY, &objZ);
        GLfloat deltaX = objX - mouseX;
        GLfloat deltaY = objY - mouseY;
        ctrlPoints[selectedRow][selectedCol][0] += deltaX;
        ctrlPoints[selectedRow][selectedCol][1] += deltaY;
        mouseX = objX;
        mouseY = objY;
        glutPostRedisplay();
    }
}

// 菜单回调函数
void menu(int value)
{
    switch (value) {
    case 1:
        showControlGrid = !showControlGrid;
        glutPostRedisplay();
        break;
    case 2:
        std::cout << "Enter tessellation level: ";
        std::cin >> tessellationLevel;
        glutPostRedisplay();
        break;
    case 3:
        std::cout << "Enter line width: ";
        std::cin >> lineWidth;
        glutPostRedisplay();
        break;
    case 4:
        std::cout << "Enter point size: ";
        std::cin >> pointSize;
        glutPostRedisplay();
        break;
    case 5:
        std::cout << "Enter surface color (R G B): ";
        std::cin >> colorSurface[0] >> colorSurface[1] >> colorSurface[2];
        glutPostRedisplay();
        break;
    case 6:
        std::cout << "Enter grid color (R G B): ";
        std::cin >> colorGrid[0] >> colorGrid[1] >> colorGrid[2];
        glutPostRedisplay();
        break;
    case 7:
        exit(0);
        break;
    default:
        break;
    }
}

// 初始化OpenGL
void init()
{
    glEnable(GL_DEPTH_TEST);
    glMatrixMode(GL_PROJECTION);
    gluPerspective(45.0, 1.0, 1.0, 100.0);
    glMatrixMode(GL_MODELVIEW);
    gluLookAt(0.0, 0.0, 10.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}

int main(int argc, char* argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(800, 800);
    glutCreateWindow("Bezier Surface");
    init();
    glutDisplayFunc(display);
    glutMouseFunc(mouse);
    glutMotionFunc(motion);
    glutCreateMenu(menu);
    glutAddMenuEntry("Toggle Control Grid", 1);
    glutAddMenuEntry("Set Tessellation Level", 2);
    glutAddMenuEntry("Set Line Width", 3);
    glutAddMenuEntry("Set Point Size", 4);
    glutAddMenuEntry("Set Surface Color", 5);
    glutAddMenuEntry("Set Grid Color", 6);
    glutAddMenuEntry("Exit", 7);
    glutAttachMenu(GLUT_RIGHT_BUTTON);
    glutMainLoop();
    return 0;
}

运行程序后，可以通过右键菜单来设置曲面的配置参数。左键单击控制点并拖动鼠标来交互式地修改曲面形状。按下鼠标左键后，程序会根据鼠标位置自动选中最近的控制点，并在移动鼠标时修改其位置。松开鼠标左键后，控制点将不再选中。