/**
* 合并颜色，支持argb8888
* @param fg 前景色
* @param bg 背景色
*/
public static int blendColor(int fg, int bg) {
int scr = Color.red(fg);
int scg = Color.green(fg);
int scb = Color.blue(fg);
int sa = fg >>> 24;
int dcr = Color.red(bg);
int dcg = Color.green(bg);
int dcb = Color.blue(bg);
int color_r = dcr * (0xff - sa) / 0xff + scr * sa / 0xff;
int color_g = dcg * (0xff - sa) / 0xff + scg * sa / 0xff;
int color_b = dcb * (0xff - sa) / 0xff + scb * sa / 0xff;
return ((color_r << 16) + (color_g << 8) + color_b) | (0xff000000);
}
/** Calculates the constrast between two colors, using the algorithm provided by the WCAG v2. */
public static float computeContrastBetweenColors(int bg, int fg) {
float bgR = Color.red(bg) / 255f;
float bgG = Color.green(bg) / 255f;
float bgB = Color.blue(bg) / 255f;
bgR = (bgR < 0.03928f) ? bgR / 12.92f : (float) Math.pow((bgR + 0.055f) / 1.055f, 2.4f);
bgG = (bgG < 0.03928f) ? bgG / 12.92f : (float) Math.pow((bgG + 0.055f) / 1.055f, 2.4f);
bgB = (bgB < 0.03928f) ? bgB / 12.92f : (float) Math.pow((bgB + 0.055f) / 1.055f, 2.4f);
float bgL = 0.2126f * bgR + 0.7152f * bgG + 0.0722f * bgB;
float fgR = Color.red(fg) / 255f;
float fgG = Color.green(fg) / 255f;
float fgB = Color.blue(fg) / 255f;
fgR = (fgR < 0.03928f) ? fgR / 12.92f : (float) Math.pow((fgR + 0.055f) / 1.055f, 2.4f);
fgG = (fgG < 0.03928f) ? fgG / 12.92f : (float) Math.pow((fgG + 0.055f) / 1.055f, 2.4f);
fgB = (fgB < 0.03928f) ? fgB / 12.92f : (float) Math.pow((fgB + 0.055f) / 1.055f, 2.4f);
float fgL = 0.2126f * fgR + 0.7152f * fgG + 0.0722f * fgB;
return Math.abs((fgL + 0.05f) / (bgL + 0.05f));
}
//判断是否是深色
isDark = computeContrastBetweenColors(color,Color.WHITE) > 3f;