用opengl生成螺旋线算法

深碍√TFBOYSˉ_ 2022-09-18 14:55 93阅读 0赞

// test01.cpp : Defines the entry point for the console application.
    //
    
    
    #include "stdafx.h"
    #include <gl/glut.h>
    #include <math.h>
    #define GL_PI 3.1415f
    
    
    // Rotation amounts
    static GLfloat xRot = 0.0f;
    static GLfloat yRot = 0.0f;
    
    
    
    
    // Called to draw scene
    void RenderScene(void)
    {
    GLfloat x,y,z,angle; // Storeage for coordinates and angles
    
    // Clear the window with current clearing color
    glClear(GL_COLOR_BUFFER_BIT);
    
    // Save matrix state and do the rotation
    glPushMatrix();
    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
    
    // Call only once for all remaining points
    /*glBegin(GL_POINTS);*/
    glBegin(GL_LINE_STRIP);
    z = -50.0f;
    for(angle = 0.0f; angle <= (2.0f*GL_PI)*3.0f; angle += 0.1f)
    {
    x = 50.0f*sin(angle);
    y = 50.0f*cos(angle);
    
    // Specify the point and move the Z value up a little
    glVertex3f(x, y, z);
    z += 0.5f;
    }
    
    // Done drawing points
    glEnd();
    
    // Restore transformations
    glPopMatrix();
    
    // Flush drawing commands
    glutSwapBuffers();
    }
    
    
    // This function does any needed initialization on the rendering
    // context. 
    void SetupRC()
    {
    // Black background
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f );
    
    // Set drawing color to green
    glColor3f(0.0f, 1.0f, 0.0f);
    }
    
    
    void SpecialKeys(int key, int x, int y)
    {
    if(key == GLUT_KEY_UP)
    xRot-= 5.0f;
    
    if(key == GLUT_KEY_DOWN)
    xRot += 5.0f;
    
    if(key == GLUT_KEY_LEFT)
    yRot -= 5.0f;
    
    if(key == GLUT_KEY_RIGHT)
    yRot += 5.0f;
    
    if(key > 356.0f)
    xRot = 0.0f;
    
    if(key < -1.0f)
    xRot = 355.0f;
    
    if(key > 356.0f)
    yRot = 0.0f;
    
    if(key < -1.0f)
    yRot = 355.0f;
    
    // Refresh the Window
    glutPostRedisplay();
    }
    
    
    
    
    void ChangeSize(int w, int h)
    {
    GLfloat nRange = 100.0f;
    
    // Prevent a divide by zero
    if(h == 0)
    h = 1;
    
    // Set Viewport to window dimensions
        glViewport(0, 0, w, h);
    
    // Reset projection matrix stack
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    
    // Establish clipping volume (left, right, bottom, top, near, far)
        if (w <= h) 
    glOrtho (-nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange);
        else 
    glOrtho (-nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange);
    
    // Reset Model view matrix stack
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    }
    
    
    int main(int argc, char* argv[])
    {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutCreateWindow("Points Example");
    glutReshapeFunc(ChangeSize);
    glutSpecialFunc(SpecialKeys);
    glutDisplayFunc(RenderScene);
    SetupRC();
    glutMainLoop();
    
    return 0;
    }