通过保持不同屏幕分辨率的宽高比来计算图像大小

Question

我试图通过保持纵横比来调整图像大小.它应该足够大,可以填充屏幕,没有空白区域,如果需要,一些图像应该在屏幕外.

下图显示了如何根据黑屏尺寸调整黄色图像的大小.

这是我实际使用的代码,有没有更好的方法来做到这一点？

if(bwidth > bheight) {
    if(bwidth > swidth && bheight > sheight) {
        new_height = sheight;
        new_width = (int) ((double) (bwidth/100)*(sheight/((double) (bheight)/100)));

    } else if(bwidth > swidth && bheight < sheight) {
        new_height = sheight;
        new_width = (int) ((double) (bwidth/100)*(sheight/((double) (bheight)/100)));

    } else if(bwidth < swidth && bheight < sheight) {
        new_height = sheight;
        new_width = (int) ((double) (bwidth/100)*(sheight/((double) (bheight)/100)));

    } else if(bwidth < swidth && bheight > sheight) {
        new_height = sheight;
        new_width = (int) ((double) (bwidth/100)*(sheight/((double) (bheight)/100)));

    } else if(bwidth >= swidth && bheight >= sheight) {
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));
    }

} else if(bwidth < bheight) {
    if(bwidth > swidth && bheight > sheight) {
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));

    } else if(bwidth < swidth && bheight > sheight) {        
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));

    } else if(bwidth < swidth && bheight < sheight) {
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));

    } else if(bwidth < swidth && bheight < sheight) {
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));

    } else if(bwidth >= swidth && bheight >= sheight) {
        new_width = swidth;
        new_height = (int) ((double) (bheight/100)*(swidth/((double) (bwidth)/100)));

    }
}

• swidth =屏幕宽度
• 高度=屏幕高度
• bwidth =图像宽度
• bheight =图像高度

Answer 1

比较比率.

如果图像的宽高比大于屏幕的宽高比,那么您知道您将使用屏幕宽度并计算高度.否则,您将使用屏幕高度并计算宽度.只要确保没有任何高度为零!

请注意,此处的代码将调整图像大小,使其始终填满屏幕.这有效地消除了图像的任何其他部分.要在完全可见的同时使图像尽可能大,请在第一行中更改<为a >.

if (bwidth / bheight < swidth / sheight) {
    new_width = swidth;
    new_height = (int) Math.floor((double) bheight
                                  * (double) swidth / (double) bwidth);
} else {
    new_height = sheight;
    new_width = (int) Math.floor((double) bwidth
                                 * (double) sheight / (double) bheight);
}

我还做了一些改进:

• 简化了方程式.将分子和分母两者除以100都不起作用.
• 简化了类型转换.我不知道每个变量的类型,但它们都需要加倍.
• 使用Math.floor而不仅仅是一个类型转换来int确保它不会向上舍入.

Answer 2

好吧，谢谢@Erick Robertson 改变了一点，但现在可以了！

这是更改后的代码：

if (bwidth / swidth <  bheight / sheight) {
    new_width = swidth;
    new_height = (int) Math.floor((double) bheight 
                                  * (double) swidth / (double) bwidth);
} else {
    new_height = sheight;
    new_width = (int) Math.floor((double) bwidth 
                                 * (double) sheight / (double) bheight);
}