/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkPM4f.h"
#include "SkColorPriv.h"
#include "SkNx.h"

static inline float get_alpha(const Sk4f& f4) {
    return f4[SkPM4f::A];
}

static inline Sk4f set_alpha(const Sk4f& f4, float alpha) {
    static_assert(3 == SkPM4f::A, "");
    return Sk4f(f4[0], f4[1], f4[2], alpha);
}

static inline uint32_t to_4b(const Sk4f& f4) {
    uint32_t b4;
    SkNx_cast<uint8_t>(f4).store((uint8_t*)&b4);
    return b4;
}

static inline Sk4f to_4f(uint32_t b4) {
    return SkNx_cast<float>(Sk4b::Load((const uint8_t*)&b4));
}

static inline Sk4f srgb_to_linear(const Sk4f& s4) {
    return set_alpha(s4 * s4, get_alpha(s4));
}

static inline Sk4f linear_to_srgb(const Sk4f& l4) {
    return set_alpha(l4.sqrt(), get_alpha(l4));
}

///////////////////////////////////////////////////////////////////////////////////////////////////

static inline Sk4f Sk4f_fromL32(uint32_t src) {
    return to_4f(src) * Sk4f(1.0f/255);
}

static inline Sk4f Sk4f_fromS32(uint32_t src) {
    return srgb_to_linear(to_4f(src) * Sk4f(1.0f/255));
}

static inline uint32_t Sk4f_toL32(const Sk4f& x4) {
    return to_4b(x4 * Sk4f(255) + Sk4f(0.5f));
}

static inline uint32_t Sk4f_toS32(const Sk4f& x4) {
    return to_4b(linear_to_srgb(x4) * Sk4f(255) + Sk4f(0.5f));
}