Ios 创建ColorCube CIFilter

我想为我的应用程序创建ColorCube CIFilter，我在苹果网站上找到了相关文档

我还在这里贴代码

**//Allocate memory **
**const unsigned int size = 64;**
**float *cubeData = (float *)malloc (size * size * size * sizeof (float) * 4);**
float rgb[3], hsv[3], *c = cubeData;

 // Populate cube with a simple gradient going from 0 to 1
for (int z = 0; z < size; z++){
    rgb[2] = ((double)z)/(size-1); // Blue value
    for (int y = 0; y < size; y++){
        rgb[1] = ((double)y)/(size-1); // Green value
        for (int x = 0; x < size; x ++){
            rgb[0] = ((double)x)/(size-1); // Red value
            // Convert RGB to HSV
            // You can find publicly available rgbToHSV functions on the Internet
            rgbToHSV(rgb, hsv);
            // Use the hue value to determine which to make transparent
            // The minimum and maximum hue angle depends on
            // the color you want to remove
            float alpha = (hsv[0] > minHueAngle && hsv[0] < maxHueAngle) ? 0.0f: 1.0f;
            // Calculate premultiplied alpha values for the cube
            c[0] = rgb[0] * alpha;
            c[1] = rgb[1] * alpha;
            c[2] = rgb[2] * alpha;
            c[3] = alpha;
            c += 4; // advance our pointer into memory for the next color value
        }
    }
}

我想知道他们取的是什么尺寸=64，代码中那条粗体的线是什么意思

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感谢您的帮助……

很简单，立方体是由正方形的立方体组成的，正方形有4条边，所以4的立方体是64。好的，明白了，但是所有立方体数据是什么样的？