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#include <private/qdrawhelper_p.h>

#ifdef QT_HAVE_NEON

#include <private/qdrawhelper_neon_p.h>

#include <arm_neon.h>

QT_BEGIN_NAMESPACE

static inline uint16x8_t qvdiv_255_u16(uint16x8_t x, uint16x8_t half)

{

    // result = (x + (x >> 8) + 0x80) >> 8

    const uint16x8_t temp = vshrq_n_u16(x, 8); // x >> 8

    const uint16x8_t sum_part = vaddq_u16(x, half); // x + 0x80

    const uint16x8_t sum = vaddq_u16(temp, sum_part);

    return vshrq_n_u16(sum, 8);

}

static inline uint16x8_t qvbyte_mul_u16(uint16x8_t x, uint16x8_t alpha, uint16x8_t half)

{

    // t = qRound(x * alpha / 255.0)

    const uint16x8_t t = vmulq_u16(x, alpha); // t

    return qvdiv_255_u16(t, half);

}

static inline uint16x8_t qvinterpolate_pixel_255(uint16x8_t x, uint16x8_t a, uint16x8_t y, uint16x8_t b, uint16x8_t half)

{

    // t = x * a + y * b

    const uint16x8_t ta = vmulq_u16(x, a);

    const uint16x8_t tb = vmulq_u16(y, b);

    return qvdiv_255_u16(vaddq_u16(ta, tb), half);

}

static inline uint16x8_t qvsource_over_u16(uint16x8_t src16, uint16x8_t dst16, uint16x8_t half, uint16x8_t full)

{

    const uint16x4_t alpha16_high = vdup_lane_u16(vget_high_u16(src16), 3);

    const uint16x4_t alpha16_low = vdup_lane_u16(vget_low_u16(src16), 3);

    const uint16x8_t alpha16 = vsubq_u16(full, vcombine_u16(alpha16_low, alpha16_high));

    return vaddq_u16(src16, qvbyte_mul_u16(dst16, alpha16, half));

}

void qt_blend_argb32_on_argb32_neon(uchar *destPixels, int dbpl,

                                    const uchar *srcPixels, int sbpl,

                                    int w, int h,

                                    int const_alpha)

{

    const uint *src = (const uint *) srcPixels;

    uint *dst = (uint *) destPixels;

    uint16x8_t half = vdupq_n_u16(0x80);

    uint16x8_t full = vdupq_n_u16(0xff);

    if (const_alpha == 256) {

        for (int y = 0; y < h; ++y) {

            int x = 0;

            for (; x < w-3; x += 4) {

                uint32x4_t src32 = vld1q_u32((uint32_t *)&src[x]);

                if ((src[x] & src[x+1] & src[x+2] & src[x+3]) >= 0xff000000) {

                    // all opaque

                    vst1q_u32((uint32_t *)&dst[x], src32);

                } else if (src[x] | src[x+1] | src[x+2] | src[x+3]) {

                    uint32x4_t dst32 = vld1q_u32((uint32_t *)&dst[x]);

                    const uint8x16_t src8 = vreinterpretq_u8_u32(src32);

                    const uint8x16_t dst8 = vreinterpretq_u8_u32(dst32);

                    const uint8x8_t src8_low = vget_low_u8(src8);

                    const uint8x8_t dst8_low = vget_low_u8(dst8);

                    const uint8x8_t src8_high = vget_high_u8(src8);

                    const uint8x8_t dst8_high = vget_high_u8(dst8);

                    const uint16x8_t src16_low = vmovl_u8(src8_low);

                    const uint16x8_t dst16_low = vmovl_u8(dst8_low);

                    const uint16x8_t src16_high = vmovl_u8(src8_high);

                    const uint16x8_t dst16_high = vmovl_u8(dst8_high);

                    const uint16x8_t result16_low = qvsource_over_u16(src16_low, dst16_low, half, full);

                    const uint16x8_t result16_high = qvsource_over_u16(src16_high, dst16_high, half, full);

                    const uint32x2_t result32_low = vreinterpret_u32_u8(vmovn_u16(result16_low));

                    const uint32x2_t result32_high = vreinterpret_u32_u8(vmovn_u16(result16_high));

                    vst1q_u32((uint32_t *)&dst[x], vcombine_u32(result32_low, result32_high));

                }

            }

            for (; x<w; ++x) {

                uint s = src[x];

                if (s >= 0xff000000)

                    dst[x] = s;

                else if (s != 0)

                    dst[x] = s + BYTE_MUL(dst[x], qAlpha(~s));

            }

            dst = (quint32 *)(((uchar *) dst) + dbpl);

            src = (const quint32 *)(((const uchar *) src) + sbpl);

        }

    } else if (const_alpha != 0) {

        const_alpha = (const_alpha * 255) >> 8;

        uint16x8_t const_alpha16 = vdupq_n_u16(const_alpha);

        for (int y = 0; y < h; ++y) {

            int x = 0;

            for (; x < w-3; x += 4) {

                if (src[x] | src[x+1] | src[x+2] | src[x+3]) {

                    uint32x4_t src32 = vld1q_u32((uint32_t *)&src[x]);

                    uint32x4_t dst32 = vld1q_u32((uint32_t *)&dst[x]);

                    const uint8x16_t src8 = vreinterpretq_u8_u32(src32);

                    const uint8x16_t dst8 = vreinterpretq_u8_u32(dst32);

                    const uint8x8_t src8_low = vget_low_u8(src8);

                    const uint8x8_t dst8_low = vget_low_u8(dst8);

                    const uint8x8_t src8_high = vget_high_u8(src8);

                    const uint8x8_t dst8_high = vget_high_u8(dst8);

                    const uint16x8_t src16_low = vmovl_u8(src8_low);

                    const uint16x8_t dst16_low = vmovl_u8(dst8_low);

                    const uint16x8_t src16_high = vmovl_u8(src8_high);

                    const uint16x8_t dst16_high = vmovl_u8(dst8_high);

                    const uint16x8_t srcalpha16_low = qvbyte_mul_u16(src16_low, const_alpha16, half);

                    const uint16x8_t srcalpha16_high = qvbyte_mul_u16(src16_high, const_alpha16, half);

                    const uint16x8_t result16_low = qvsource_over_u16(srcalpha16_low, dst16_low, half, full);

                    const uint16x8_t result16_high = qvsource_over_u16(srcalpha16_high, dst16_high, half, full);

                    const uint32x2_t result32_low = vreinterpret_u32_u8(vmovn_u16(result16_low));

                    const uint32x2_t result32_high = vreinterpret_u32_u8(vmovn_u16(result16_high));

                    vst1q_u32((uint32_t *)&dst[x], vcombine_u32(result32_low, result32_high));

                }

            }

            for (; x<w; ++x) {

                uint s = src[x];

                if (s != 0) {

                    s = BYTE_MUL(s, const_alpha);

                    dst[x] = s + BYTE_MUL(dst[x], qAlpha(~s));

                }

            }

            dst = (quint32 *)(((uchar *) dst) + dbpl);

            src = (const quint32 *)(((const uchar *) src) + sbpl);

        }

    }

}

// qblendfunctions.cpp

void qt_blend_rgb32_on_rgb32(uchar *destPixels, int dbpl,

                             const uchar *srcPixels, int sbpl,

                             int w, int h,

                             int const_alpha);

void qt_blend_rgb32_on_rgb32_neon(uchar *destPixels, int dbpl,

                                  const uchar *srcPixels, int sbpl,

                                  int w, int h,

                                  int const_alpha)

{

    if (const_alpha != 256) {

        if (const_alpha != 0) {

            const uint *src = (const uint *) srcPixels;

            uint *dst = (uint *) destPixels;

            uint16x8_t half = vdupq_n_u16(0x80);

            const_alpha = (const_alpha * 255) >> 8;

            int one_minus_const_alpha = 255 - const_alpha;

            uint16x8_t const_alpha16 = vdupq_n_u16(const_alpha);

            uint16x8_t one_minus_const_alpha16 = vdupq_n_u16(255 - const_alpha);

            for (int y = 0; y < h; ++y) {

                int x = 0;

                for (; x < w-3; x += 4) {

                    uint32x4_t src32 = vld1q_u32((uint32_t *)&src[x]);

                    uint32x4_t dst32 = vld1q_u32((uint32_t *)&dst[x]);

                    const uint8x16_t src8 = vreinterpretq_u8_u32(src32);

                    const uint8x16_t dst8 = vreinterpretq_u8_u32(dst32);

                    const uint8x8_t src8_low = vget_low_u8(src8);

                    const uint8x8_t dst8_low = vget_low_u8(dst8);

                    const uint8x8_t src8_high = vget_high_u8(src8);

                    const uint8x8_t dst8_high = vget_high_u8(dst8);

                    const uint16x8_t src16_low = vmovl_u8(src8_low);

                    const uint16x8_t dst16_low = vmovl_u8(dst8_low);

                    const uint16x8_t src16_high = vmovl_u8(src8_high);

                    const uint16x8_t dst16_high = vmovl_u8(dst8_high);

                    const uint16x8_t result16_low = qvinterpolate_pixel_255(src16_low, const_alpha16, dst16_low, one_minus_const_alpha16, half);

                    const uint16x8_t result16_high = qvinterpolate_pixel_255(src16_high, const_alpha16, dst16_high, one_minus_const_alpha16, half);

                    const uint32x2_t result32_low = vreinterpret_u32_u8(vmovn_u16(result16_low));

                    const uint32x2_t result32_high = vreinterpret_u32_u8(vmovn_u16(result16_high));

                    vst1q_u32((uint32_t *)&dst[x], vcombine_u32(result32_low, result32_high));

                }

                for (; x<w; ++x) {

                    uint s = src[x];

                    s = BYTE_MUL(s, const_alpha);

                    dst[x] = INTERPOLATE_PIXEL_255(src[x], const_alpha, dst[x], one_minus_const_alpha);

                }

                dst = (quint32 *)(((uchar *) dst) + dbpl);

                src = (const quint32 *)(((const uchar *) src) + sbpl);

            }

        }

    } else {

        qt_blend_rgb32_on_rgb32(destPixels, dbpl, srcPixels, sbpl, w, h, const_alpha);

    }

}

QT_END_NAMESPACE

#endif // QT_HAVE_NEON