最后一幕出现黑色背景

Question

我有一个问题，一旦热气球到达地面，就会出现黑色背景。

// a switch case based on state with appropriate calls
switch (state) {
// scene 1
case 1:     
    drawBackground1(); // the first background to appear
    drawSlogan1(); // display the first slogan
    break;
// scene 2
case 2:     
    drawBackground2(); // the second background to appear
    drawSlogan2(); // display the second slogan
    break;
// scene 3
case 3:     
    drawBackground1(); // the third background to appear
    drawSlogan3(); // display the last slogan
    break;
}

我在这里显示这段代码是因为这是我更改的唯一代码，它使黑色背景出现。

Click here to see the full code

Answer 1

当气球到达最终位置时，state为0。如果state == 0，你也必须绘制背景：

switch (state) {
case 0: 
    drawBackground1(); // the third background to appear
    break;
case 1:     
    drawBackground1(); // the first background to appear
    drawSlogan1(); // display the first slogan
    break;
case 2:     
    drawBackground2(); // the second background to appear
    drawSlogan2(); // display the second slogan
    break;
case 3:     
    drawBackground1(); // the third background to appear
    drawSlogan3(); // display the last slogan
    break;
}

最后一幕出现黑色背景

Black background appears on the last scene

c++

opengl

glut