高程等高线opengl

// 假设heightMap是一个二维数组，表示高程数据
float heightMap[WIDTH][HEIGHT];

// 设置顶点数据和索引数据
std::vector<GLfloat> vertices;
std::vector<GLuint> indices;

// 根据heightMap和等高线间隔生成顶点和索引数据
for (int y = 0; y < HEIGHT - 1; ++y) {
    for (int x = 0; x < WIDTH - 1; ++x) {
        // 计算四个角的坐标
        GLfloat x1 = x, y1 = heightMap[x][y], z1 = 0;
        GLfloat x2 = x + 1, y2 = heightMap[x + 1][y], z2 = 0;
        GLfloat x3 = x, y3 = heightMap[x][y + 1], z3 = 0;
        GLfloat x4 = x + 1, y4 = heightMap[x + 1][y + 1], z4 = 0;

        // 根据高度差判断是否需要绘制等高线
        if (abs(y2 - y1) >= contourInterval || abs(y4 - y3) >= contourInterval) {
            vertices.push_back(x1); vertices.push_back(y1); vertices.push_back(z1);
            vertices.push_back(x2); vertices.push_back(y2); vertices.push_back(z2);
        }
        if (abs(y3 - y2) >= contourInterval || abs(y1 - y4) >= contourInterval) {
            vertices.push_back(x2); vertices.push_back(y2); vertices.push_back(z2);
            vertices.push_back(x3); vertices.push_back(y3); vertices.push_back(z3);
        }
    }
}

// 生成索引数据
for (size_t i = 0; i < vertices.size() / 3 - 1; i += 2) {
    indices.push_back(i);
    indices.push_back(i + 1);
}

// 设置OpenGL状态
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, &vertices[0]);

// 绘制等高线
glDrawElements(GL_LINES, indices.size(), GL_UNSIGNED_INT, &indices[0]);

// 清理
glDisableClientState(GL_VERTEX_ARRAY);