blue()

本参考资料用于Processing 3.0+。 如果你使用的是前一版本,请在使用软件帮助菜单内的参考资料。. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Core Javadoc and Libraries Javadoc.

名称

blue()

示例
 color c = color(175, 100, 220);

// Define color 'c' fill(c);

// Use color variable 'c' as fill color rect(15, 20, 35, 60);

// Draw left rectangle float blueValue = blue(c);

// Get blue in 'c'
println(blueValue);

// Prints "220.0" fill(0, 0, blueValue);

// Use 'blueValue' in new fill rect(50, 20, 35, 60);

// Draw right rectangle 
描述 Extracts the blue value from a color, scaled to match current colorMode(). The value is always returned as afloat, so be careful not to assign it to an
int value.

The blue() function is easy to use and understand, but it is slower than a technique called bit masking. When working in colorMode(RGB, 255), you can acheive the same results as blue() but with greater speed by using a bit mask to remove the other color components. For example, the following two lines of code are equivalent means of getting the blue value of the color value c:

float b1 = blue(c);


// Simpler, but slower to calculatefloat b2 = c & 0xFF;

 // Very fast to calculate
语法
blue(rgb)
参数
rgb int: any value of the color datatype
返回值 float
相关 red()
green()
alpha()
hue()
saturation()
brightness()
>> (right shift)

Updated on October 2, 2018 05:02:10pm EDT

blue()