视口转换窗口是将2D世界坐标对象转换为设备坐标的过程。世界或剪贴窗口中的对象被映射到视口，该视口是屏幕上要显示世界坐标的区域。
一般条款：
- 世界坐标–我们定义图表的是笛卡尔坐标wrt，例如X wmin ，X wmax ，Y wmin ，Y wmax
- 设备坐标–这是要显示对象的屏幕坐标，例如X vmin ，X vmax ，Y vmin ，Y vmax
- 窗口–这是世界坐标上选择显示的区域。
- ViewPort –这是设备坐标上要显示图形的区域。
视口窗口的数学计算：
视口的大小可能会小于或大于窗口。在这些情况下，我们必须根据视口增加或减小Window的大小，为此，我们需要一些数学计算。
(xw, yw): A point on Window
(xv, yv): Corresponding point on Viewport- 我们必须计算点(x v ，y v )
- 现在，对象在“窗口”和“视口”中的相对位置相同。
For x coordinate,
For y coordinate,
- 因此，在计算了x和y坐标之后，我们得到
- 其中，s x是x坐标的比例因子，而y是y坐标的比例因子
例子：
假设
- 对于窗口， X wmin = 20，X wmax = 80，Y wmin = 40，Y wmax = 80 。
- 对于视口， X vmin = 30，X vmax = 60，Y vmin = 40，Y vmax = 60 。
- 现在，窗口上的点(X w ，Y w )是(30，80)。我们必须在视口上计算该点
即(X v ，Y v ) 。 - 首先，使用上述公式计算x坐标S x的比例因子和y坐标S y的比例因子。
Sx = ( 60 - 30 ) / ( 80 - 20 ) = 30 / 60 Sy = ( 60 - 40 ) / ( 80 - 40 ) = 20 / 40 - 因此，现在计算视口上的点(X v ，Y v )。
Xv = 30 + ( 30 - 20 ) * ( 30 / 60 ) = 35 Yv = 40 + ( 80 - 40 ) * ( 20 / 40 ) = 60 - 因此，窗口上的点(X w ，Y w )=(30，80)将是视口上的(X v ，Y v )=(35，60) 。
这是上述方法的实现：
执行：
C++
// C program to implement
// Window to ViewPort Transformation
#include
// Function for window to viewport transformation
void WindowtoViewport(int x_w, int y_w, int x_wmax,
int y_wmax, int x_wmin, int y_wmin,
int x_vmax, int y_vmax, int x_vmin,
int y_vmin)
{
// point on viewport
int x_v, y_v;
// scaling factors for x coordinate and y coordinate
float sx, sy;
// calculatng Sx and Sy
sx = (float)(x_vmax - x_vmin) / (x_wmax - x_wmin);
sy = (float)(y_vmax - y_vmin) / (y_wmax - y_wmin);
// calculating the point on viewport
x_v = x_vmin + (float)((x_w - x_wmin) * sx);
y_v = y_vmin + (float)((y_w - y_wmin) * sy);
printf("The point on viewport: (%d, %d )\n ", x_v, y_v);
}
// Driver Code
void main()
{
// boundary values for window
int x_wmax = 80, y_wmax = 80, x_wmin = 20, y_wmin = 40;
// boundary values for viewport
int x_vmax = 60, y_vmax = 60, x_vmin = 30, y_vmin = 40;
// point on window
int x_w = 30, y_w = 80;
WindowtoViewport(30, 80, 80, 80, 20, 40, 60, 60, 30, 40);
} Java
// Java program to implement
// Window to ViewPort Transformation
class GFG
{
// Function for window to viewport transformation
static void WindowtoViewport(int x_w, int y_w, int x_wmax,
int y_wmax, int x_wmin, int y_wmin,
int x_vmax, int y_vmax, int x_vmin,
int y_vmin)
{
// point on viewport
int x_v, y_v;
// scaling factors for x coordinate and y coordinate
float sx, sy;
// calculatng Sx and Sy
sx = (float)(x_vmax - x_vmin) / (x_wmax - x_wmin);
sy = (float)(y_vmax - y_vmin) / (y_wmax - y_wmin);
// calculating the point on viewport
x_v = (int) (x_vmin + (float)((x_w - x_wmin) * sx));
y_v = (int) (y_vmin + (float)((y_w - y_wmin) * sy));
System.out.printf("The point on viewport: (%d, %d )\n ", x_v, y_v);
}
// Driver Code
public static void main(String[] args)
{
// boundary values for window
int x_wmax = 80, y_wmax = 80, x_wmin = 20, y_wmin = 40;
// boundary values for viewport
int x_vmax = 60, y_vmax = 60, x_vmin = 30, y_vmin = 40;
// point on window
int x_w = 30, y_w = 80;
WindowtoViewport(30, 80, 80, 80, 20, 40, 60, 60, 30, 40);
}
}
// This code is contributed by Rajput-JiPython 3
# Python3 program to implement
# Window to ViewPort Transformation
# Function for window to viewport transformation
def WindowtoViewport(x_w, y_w, x_wmax, y_wmax,
x_wmin, y_wmin, x_vmax,
y_vmax, x_vmin, y_vmin):
# point on viewport
# calculatng Sx and Sy
sx = (x_vmax - x_vmin) / (x_wmax - x_wmin)
sy = (y_vmax - y_vmin) / (y_wmax - y_wmin)
# calculating the point on viewport
x_v = x_vmin + ((x_w - x_wmin) * sx)
y_v = y_vmin + ((y_w - y_wmin) * sy)
print("The point on viewport:(", int(x_v),
",", int(y_v), ")")
# Driver Code
if __name__ == '__main__':
# boundary values for window
x_wmax = 80
y_wmax = 80
x_wmin = 20
y_wmin = 40
# boundary values for viewport
x_vmax = 60
y_vmax = 60
x_vmin = 30
y_vmin = 40
# point on window
x_w = 30
y_w = 80
WindowtoViewport(30, 80, 80, 80, 20,
40, 60, 60, 30, 40)
# This code is contributed by Surendra_GangwarC#
// C# program to implement
// Window to ViewPort Transformation
using System;
class GFG
{
// Function for window to viewport transformation
static void WindowtoViewport(int x_w, int y_w,
int x_wmax, int y_wmax,
int x_wmin, int y_wmin,
int x_vmax, int y_vmax,
int x_vmin, int y_vmin)
{
// point on viewport
int x_v, y_v;
// scaling factors for x coordinate
// and y coordinate
float sx, sy;
// calculatng Sx and Sy
sx = (float)(x_vmax - x_vmin) /
(x_wmax - x_wmin);
sy = (float)(y_vmax - y_vmin) /
(y_wmax - y_wmin);
// calculating the point on viewport
x_v = (int) (x_vmin +
(float)((x_w - x_wmin) * sx));
y_v = (int) (y_vmin +
(float)((y_w - y_wmin) * sy));
Console.Write("The point on viewport: " +
"({0}, {1} )\n ", x_v, y_v);
}
// Driver Code
public static void Main(String[] args)
{
// boundary values for window
int x_wmax = 80, y_wmax = 80,
x_wmin = 20, y_wmin = 40;
// boundary values for viewport
int x_vmax = 60, y_vmax = 60,
x_vmin = 30, y_vmin = 40;
// point on window
int x_w = 30, y_w = 80;
WindowtoViewport(30, 80, 80, 80, 20,
40, 60, 60, 30, 40);
}
}
// This code is contributed by PrinciRaj1992输出：
The point on viewport: (35, 60 )