用於C++的顏色地圖庫，可將給定值轉換爲紅色，綠色和藍色值

Question

我正在尋找將給定值轉換爲紅色，綠色和藍色值的顏色地圖庫。類似於matlab的色彩映射功能[1]。最好在C++中。

[1] http://www.mathworks.com/help/techdoc/ref/colormap.html

Answer 1

在想這個的方式，對於庫太簡單了個人而言，我已經實現了它我的自我他們在C的例子（你可以看一下維基百科的解釋數學）：

/** 
    * Computes the color gradiant 
    * color: the output vector 
    * x: the gradiant (beetween 0 and 360) 
    * min and max: variation of the RGB channels (Move3D 0 -> 1) 
    */ 
    void GroundColorMix(double* color, double x, double min, double max) 
{ 
    /* 
    * Red = 0 
    * Green = 1 
    * Blue = 2 
    */ 
    double posSlope = (max-min)/60; 
    double negSlope = (min-max)/60; 

    if(x < 60) 
    { 
     color[0] = max; 
     color[1] = posSlope*x+min; 
     color[2] = min; 
     return; 
    } 
    else if (x < 120) 
    { 
     color[0] = negSlope*x+2*max+min; 
     color[1] = max; 
     color[2] = min; 
     return; 
    } 
    else if (x < 180 ) 
    { 
     color[0] = min; 
     color[1] = max; 
     color[2] = posSlope*x-2*max+min; 
     return; 
    } 
    else if (x < 240 ) 
    { 
     color[0] = min; 
     color[1] = negSlope*x+4*max+min; 
     color[2] = max; 
     return; 
    } 
    else if (x < 300 ) 
    { 
     color[0] = posSlope*x-4*max+min; 
     color[1] = min; 
     color[2] = max; 
     return; 
    } 
    else 
    { 
     color[0] = max; 
     color[1] = min; 
     color[2] = negSlope*x+6*max; 
     return; 
    } 
}