颜色渐变基本算法

                        // 3颜色等比线性变换
                        int startColor = COLORS[colorType][0];
                        int endColor = COLORS[colorType][1];
                        int delaR = [AColor getRed:endColor] - [AColor getRed:startColor];
                        int delaG = [AColor getGreen:endColor] - [AColor getGreen:startColor];
                        int delaB = [AColor getBlue:endColor] -  [AColor getBlue:startColor];
                        LONG delaTime = SYS_TIME - publicVoiceTimeCount;
                        float rate = delaTime * 1.0f / (PublicVoice_TIME); // 0 - 1
                        int curColor = [AColor getRGB:[AColor getRed:startColor] + delaR * rate 
                                                    g:[AColor getGreen:startColor] + delaG * rate  
                                                    b:[AColor getBlue:startColor] + delaB * rate];
                        

原来准备用这个做喇叭喊话的，但是由于渐变过度太平滑，效果不好，后来改成6颜色闪烁效果。

                        // 闪烁效果
                        int colors[6] = { 
                            COLORS[colorType][0], 
                            COLORS[colorType][1],
                            COLORS[colorType][2],
                            COLORS[colorType][3],
                            COLORS[colorType][2],
                            COLORS[colorType][1]};
                        int _colorCount = (SYS_TIME - publicVoiceTimeCount) / 100; // 1000/100s一变
                        if (_colorCount > colorCount) {
                            colorCount = _colorCount;
                            int index = _colorCount % 6;
                            int curColor = colors[index]; }