[汎用関数]HSV2RGB 関数 - Qiita

// (float h, float s, float v) float r = v; float g = v; float b = v; if (s > 0.0f) { h *= 6.0f; final int i = (int) h; final float f = h - (float) i; switch (i) { default: case 0: g *= 1 - s * (1 - f); b *= 1 - s; break; case 1: r *= 1 - s * f; b *= 1 - s; break; case 2: r *= 1 - s; b *= 1 - s * (1 - f); break; case 3: r *= 1 - s; g *= 1 - s * f; break; case 4: r *= 1 - s * (1 - f); g *= 1 - s; b