在同一 window 中绘制 3d 和 2d 无法正常工作 openGl

Question

我正在尝试在同一 window 中绘制一些 3d（太阳）和 2d（地面、云...）形状，它确实有效！但问题是当我运行程序时，它不显示流畅的屏幕，它显示一个形状然后另一个（第一个消失），然后是下一个形状等等...... 这是代码，比你。

#include<windows.h>
#include<stdio.h>
#include<GL/glut.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#define CIRCLE_RADIUS  0.15f
# define PI 3.14159265358979323846
int eggs_caught = 0, missed_eggs = 0, level_count = 1, points = 0;


int egg_xc, egg_yc;
// for coordinates of egg
int basket_x, basket_y;
// for coordinates of basket
int a = 600, b = 650; // for default size of the screen
int s = 0;
// for menu option
int dropped_eggs = 0;
int speed_1 = 1, speed_2 = 1.5, speed_3 = 2, speed_4 = 2.5;
int w = 48, h = 48, t = 10, e = 9, g = 12;
void myinit();
void start_screen(int, int);
void cloud1();
void egg();
void basket(int, int);
void duck(int, int);
void print_score();
void egg_start();
void color();
void score();
void display(void);
void basket_set(int, int);
void myReshape(int, int);
void keys(unsigned char, int, int);
void menu(int);
void myinit()
{

}


void sun()
{
    GLfloat black[] = { 0.0, 0.0, 0.0, 1.0 };
    GLfloat yellow[] = { 1.0, 1.0, 0.0, 1.0 };
    GLfloat direction[] = { 1.0, 1.0, 1.0, 0.0 };

    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, yellow);
    glMaterialfv(GL_FRONT, GL_SPECULAR, yellow);
    glMaterialf(GL_FRONT, GL_SHININESS, 30);

    glLightfv(GL_LIGHT0, GL_AMBIENT, black);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, yellow);
    glLightfv(GL_LIGHT0, GL_SPECULAR, yellow);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);

    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();

    glPushMatrix();
    glTranslatef(0, 0.0, 0);
    glutSolidSphere(0.5, 30, 30);
    glPopMatrix();

    glPopMatrix();
    glFlush();

    glDisable(GL_LIGHTING);
    glDisable(GL_LIGHT0);
    glDisable(GL_DEPTH_TEST);

}
void cloud1()
{

    float theta;
    GLfloat angle;
    glLineWidth(1.5);
    glColor3f(1, 1, 1);
    glBegin(GL_POLYGON);
    for (int i = 0; i < 360; i++)
    {
        theta = i * PI * i / 180;
        glVertex2f(100 + 50 * cos(theta) / 2, 590 + 50 * sin(theta) / 2);
    }

    glEnd();
    glLineWidth(1.5);
    glColor3f(1, 1, 1);
    glBegin(GL_POLYGON);
    for (int i = 0; i < 360; i++)
    {
        theta = i * PI * i / 180;
        glVertex2f(130 + 50 * cos(theta) / 2, 580 + 50 * sin(theta) / 2);
    }
    glEnd();

    glLineWidth(1.5);
    glColor3f(1, 1, 1);
    glBegin(GL_POLYGON);
    for (int i = 0; i < 360; i++)
    {
        theta = i * PI * i / 180;
        glVertex2f(140 + 50 * cos(theta) / 2, 600 + 50 * sin(theta) / 2);
    }
    glEnd();

    glLineWidth(1.5);
    glColor3f(1, 1, 1);
    glBegin(GL_POLYGON);
    for (int i = 0; i < 360; i++)
    {
        theta = i * PI * i / 180;
        glVertex2f(170 + 50 * cos(theta) / 2, 590 + 50 * sin(theta) / 2);
    }

    glEnd();
    glFlush();
}

void backk(int i, int j)
{


    glColor3f(0, .5, 1);
    glBegin(GL_QUADS);
    glVertex2f(0.0 + i, 0.0 + j);
    glVertex2f(600.0 + i, 0.0 + j);
    glVertex2f(600.0 + i, -500 + j);
    glVertex2f(0.0 + i, -500 + j);
    glEnd();
    glFlush();


}
void ground(int i, int j)
{

    glBegin(GL_QUADS);
    glColor3f(0, 1.0, 0);
    glVertex2f(0.0 + i, 0.0 + j);
    glVertex2f(600.0 + i, 0.0 + j);
    glVertex2f(600.0 + i, -j);
    glVertex2f(0.0 + i, -j);
    glEnd();
}


void duck(int i, int j)
{
    int h;
    glColor3f(1.0, 1.0, 0.0);
    glBegin(GL_POLYGON);
    glVertex2f(45 + i, 45 + j);
    glVertex2f(70 + i, 20 + j);
    glVertex2f(95 + i, 20 + j);
    glVertex2f(120 + i, 45 + j);
    glVertex2f(95 + i, 70 + j);
    glVertex2f(70 + i, 70 + j);
    glVertex2f(95 + i, 95 + j);
    glVertex2f(82.5 + i, 107.5 + j);
    glVertex2f(32.5 + i, 57.5 + j);
    glEnd();
    glFlush();
    for (h = 0; h < 13; h += 4)
    {
        glBegin(GL_LINES);
        glColor3f(0.7, 0.4, 0);
        glVertex2f(57.5 + h + i, 52.5 + h + j);
        glVertex2f(100 + h + i, 30 + h + j);
        glEnd();
        glFlush();
    }
    glColor3f(0.0, 1.0, 0.0);
    glBegin(GL_POLYGON);
    glVertex2f(82.5 + i, 107.5 + j);
    glVertex2f(65 + i, 107.5 + j);
    glVertex2f(50 + i, 95 + j);
    glVertex2f(70 + i, 95 + j);
    glEnd();
    glFlush();
    glColor3f(0.0, 0.0, 0.0);
    glPointSize(5);
    glBegin(GL_POINTS);
    glVertex2f(76 + i, 101 + j);
    glEnd();
    glColor3f(0.0, 1.0, 0.0);
    glBegin(GL_LINE_LOOP);
    glVertex2f(72.5 + i, 107.5 + j);
    glVertex2f(67.5 + i, 112.5 + j);
    glVertex2f(72.5 + i, 110 + j);
    glVertex2f(77.5 + i, 112.5 + j);
    glEnd();
    glFlush();
}


void display(void)
{
    GLfloat aspect = GLfloat(a) / GLfloat(b);
    glOrtho(-2.5 * aspect, 2.5 * aspect, -2.5, 2.5, -10.0, 10.0);
    glClear(GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-2.5 * aspect, 2.5 * aspect, -2.5, 2.5, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    sun();

    glClear(GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, (GLdouble)a, 0.0, (GLdouble)b, 0, 1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    cloud1();
    ground(0, 650);
    backk(0, 650);
    duck(40, 375);
    duck(180, 375);
    duck(320, 375);
}

void myReshape(int w, int h)
{
}
void keys(unsigned char key, int x, int y)
{
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);

    glutInitWindowSize(a, b);
    glutCreateWindow("EGG GAME");
    myinit();
    glutInitWindowPosition(100, 100);
    glutAttachMenu(GLUT_RIGHT_BUTTON);
    glutDisplayFunc(display);
    glutKeyboardFunc(keys);
    glutIdleFunc(display);
    glutReshapeFunc(myReshape);
    glutMainLoop();
}

Answer 1

没有使用 GLUT，但这是我第一眼看到的。

glClear(GL_DEPTH_BUFFER_BIT);

为什么颜色也不清晰？尝试 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
没有glutSwapBuffers();

如果在显示函数末尾没有调用，您的渲染将不会在需要时更新。
没有glFlush/glFinish交换缓冲区

将它们放在最后是安全的。我看到你在一些渲染调用中得到了它们，但不是全部。
对 glVertex2f
使用 int 个操作数
既然你所有的坐标都是整数，为什么不使用 glVertex2i 呢？ int to float 转换速度变慢了...

看看我刚刚找到的一些简单的 GLUT 示例：

cube.c

在那里显示是这样的：

void display(void)
  {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  drawBox(); // here yoru rendering stuff instead
  glFlush(); // I usually add this before swapping buffers
  glutSwapBuffers();
  }

因此请相应地更改您的代码...

除此之外，我可能会尝试对云使用混合 ...

在同一 window 中绘制 3d 和 2d 无法正常工作 openGl

Drawing 3d and 2d in the same window not working correctly openGl

c++

opengl

glut

opengl-compat