remove U16 support, just support F16

src/core/SkXfermodeU64.cpp

-/*
- * 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 "SkHalf.h"
-#include "SkPM4fPriv.h"
-#include "SkUtils.h"
-#include "SkXfermode.h"
-
-enum DstType {
-    kU16_Dst,
-    kF16_Dst,
-};
-
-static Sk4f lerp_by_coverage(const Sk4f& src, const Sk4f& dst, uint8_t srcCoverage) {
-    return dst + (src - dst) * Sk4f(srcCoverage * (1/255.0f));
-}
-
-template <DstType D> Sk4f unit_to_bias(const Sk4f& x4) {
-    return (D == kU16_Dst) ? x4 * Sk4f(65535) : x4;
-}
-
-template <DstType D> Sk4f bias_to_unit(const Sk4f& x4) {
-    return (D == kU16_Dst) ? x4 * Sk4f(1.0f/65535) : x4;
-}
-
-// returns value already biased by 65535
-static Sk4f load_from_u16(uint64_t value) {
-    return SkNx_cast<float>(Sk4h::Load(&value));
-}
-
-// takes floats already biased by 65535
-static uint64_t store_to_u16(const Sk4f& x4) {
-    uint64_t value;
-    SkNx_cast<uint16_t>(x4 + Sk4f(0.5f)).store(&value);
-    return value;
-}
-
-// Returns dst in its "natural" bias (either unit-float or 16bit int)
-//
-template <DstType D> Sk4f load_from_dst(uint64_t dst) {
-    return (D == kU16_Dst) ? load_from_u16(dst) : SkHalfToFloat_01(dst);
-}
-
-// Assumes x4 is already in the "natural" bias (either unit-float or 16bit int)
-template <DstType D> uint64_t store_to_dst(const Sk4f& x4) {
-    return (D == kU16_Dst) ? store_to_u16(x4) : SkFloatToHalf_01(x4);
-}
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-template <DstType D> void xfer_u64_1(const SkXfermode* xfer, uint64_t dst[],
-                                     const SkPM4f* src, int count, const SkAlpha aa[]) {
-    SkXfermodeProc4f proc = xfer->getProc4f();
-    SkPM4f d;
-    if (aa) {
-        for (int i = 0; i < count; ++i) {
-            Sk4f d4 = bias_to_unit<D>(load_from_dst<D>(dst[i]));
-            d4.store(d.fVec);
-            Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(*src, d).fVec));
-            dst[i] = store_to_dst<D>(lerp_by_coverage(r4, d4, aa[i]));
-        }
-    } else {
-        for (int i = 0; i < count; ++i) {
-            bias_to_unit<D>(load_from_dst<D>(dst[i])).store(d.fVec);
-            Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(*src, d).fVec));
-            dst[i] = store_to_dst<D>(r4);
-        }
-    }
-}
-
-template <DstType D> void xfer_u64_n(const SkXfermode* xfer, uint64_t dst[],
-                                     const SkPM4f src[], int count, const SkAlpha aa[]) {
-    SkXfermodeProc4f proc = xfer->getProc4f();
-    SkPM4f d;
-    if (aa) {
-        for (int i = 0; i < count; ++i) {
-            Sk4f d4 = bias_to_unit<D>(load_from_dst<D>(dst[i]));
-            d4.store(d.fVec);
-            Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(src[i], d).fVec));
-            dst[i] = store_to_dst<D>(lerp_by_coverage(r4, d4, aa[i]));
-        }
-    } else {
-        for (int i = 0; i < count; ++i) {
-            bias_to_unit<D>(load_from_dst<D>(dst[i])).store(d.fVec);
-            Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(src[i], d).fVec));
-            dst[i] = store_to_dst<D>(r4);
-        }
-    }
-}
-
-const SkXfermode::D64Proc gProcs_General[] = {
-    xfer_u64_n<kU16_Dst>,   xfer_u64_n<kU16_Dst>,
-    xfer_u64_1<kU16_Dst>,   xfer_u64_1<kU16_Dst>,
-    xfer_u64_n<kF16_Dst>,   xfer_u64_n<kF16_Dst>,
-    xfer_u64_1<kF16_Dst>,   xfer_u64_1<kF16_Dst>,
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-template <DstType D> void clear(const SkXfermode*, uint64_t dst[],
-                                const SkPM4f*, int count, const SkAlpha aa[]) {
-    if (aa) {
-        for (int i = 0; i < count; ++i) {
-            if (aa[i]) {
-                const Sk4f d4 = load_from_dst<D>(dst[i]);
-                dst[i] = store_to_dst<D>(d4 * Sk4f((255 - aa[i]) * 1.0f/255));
-            }
-        }
-    } else {
-        sk_memset64(dst, 0, count);
-    }
-}
-
-const SkXfermode::D64Proc gProcs_Clear[] = {
-    clear<kU16_Dst>,    clear<kU16_Dst>,
-    clear<kU16_Dst>,    clear<kU16_Dst>,
-    clear<kF16_Dst>,    clear<kF16_Dst>,
-    clear<kF16_Dst>,    clear<kF16_Dst>,
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-template <DstType D> void src_1(const SkXfermode*, uint64_t dst[],
-                                const SkPM4f* src, int count, const SkAlpha aa[]) {
-    const Sk4f s4 = unit_to_bias<D>(Sk4f::Load(src->fVec));
-    if (aa) {
-        for (int i = 0; i < count; ++i) {
-            const Sk4f d4 = load_from_dst<D>(dst[i]);
-            dst[i] = store_to_dst<D>(lerp_by_coverage(s4, d4, aa[i]));
-        }
-    } else {
-        sk_memset64(dst, store_to_dst<D>(s4), count);
-    }
-}
-
-template <DstType D> void src_n(const SkXfermode*, uint64_t dst[],
-                                const SkPM4f src[], int count, const SkAlpha aa[]) {
-    if (aa) {
-        for (int i = 0; i < count; ++i) {
-            const Sk4f s4 = unit_to_bias<D>(Sk4f::Load(src[i].fVec));
-            const Sk4f d4 = load_from_dst<D>(dst[i]);
-            dst[i] = store_to_dst<D>(lerp_by_coverage(s4, d4, aa[i]));
-        }
-    } else {
-        for (int i = 0; i < count; ++i) {
-            const Sk4f s4 = unit_to_bias<D>(Sk4f::Load(src[i].fVec));
-            dst[i] = store_to_dst<D>(s4);
-        }
-    }
-}
-
-const SkXfermode::D64Proc gProcs_Src[] = {
-    src_n<kU16_Dst>,    src_n<kU16_Dst>,
-    src_1<kU16_Dst>,    src_1<kU16_Dst>,
-    src_n<kF16_Dst>,    src_n<kF16_Dst>,
-    src_1<kF16_Dst>,    src_1<kF16_Dst>,
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-static void dst(const SkXfermode*, uint64_t*, const SkPM4f*, int count, const SkAlpha[]) {}
-
-const SkXfermode::D64Proc gProcs_Dst[] = {
-    dst, dst, dst, dst, dst, dst, dst, dst,
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-template <DstType D> void srcover_1(const SkXfermode*, uint64_t dst[],
-                                    const SkPM4f* src, int count, const SkAlpha aa[]) {
-    const Sk4f s4 = Sk4f::Load(src->fVec);
-    const Sk4f dst_scale = Sk4f(1 - get_alpha(s4));
-    const Sk4f s4bias = unit_to_bias<D>(s4);
-    for (int i = 0; i < count; ++i) {
-        const Sk4f d4bias = load_from_dst<D>(dst[i]);
-        const Sk4f r4bias = s4bias + d4bias * dst_scale;
-        if (aa) {
-            dst[i] = store_to_dst<D>(lerp_by_coverage(r4bias, d4bias, aa[i]));
-        } else {
-            dst[i] = store_to_dst<D>(r4bias);
-        }
-    }
-}
-
-template <DstType D> void srcover_n(const SkXfermode*, uint64_t dst[],
-                                    const SkPM4f src[], int count, const SkAlpha aa[]) {
-    for (int i = 0; i < count; ++i) {
-        const Sk4f s4 = Sk4f::Load(src[i].fVec);
-        const Sk4f dst_scale = Sk4f(1 - get_alpha(s4));
-        const Sk4f s4bias = unit_to_bias<D>(s4);
-        const Sk4f d4bias = load_from_dst<D>(dst[i]);
-        const Sk4f r4bias = s4bias + d4bias * dst_scale;
-        if (aa) {
-            dst[i] = store_to_dst<D>(lerp_by_coverage(r4bias, d4bias, aa[i]));
-        } else {
-            dst[i] = store_to_dst<D>(r4bias);
-        }
-    }
-}
-
-const SkXfermode::D64Proc gProcs_SrcOver[] = {
-    srcover_n<kU16_Dst>,    src_n<kU16_Dst>,
-    srcover_1<kU16_Dst>,    src_1<kU16_Dst>,
-    srcover_n<kF16_Dst>,    src_n<kF16_Dst>,
-    srcover_1<kF16_Dst>,    src_1<kF16_Dst>,
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-static SkXfermode::D64Proc find_proc(SkXfermode::Mode mode, uint32_t flags) {
-    SkASSERT(0 == (flags & ~7));
-    flags &= 7;
-
-    switch (mode) {
-        case SkXfermode::kClear_Mode:   return gProcs_Clear[flags];
-        case SkXfermode::kSrc_Mode:     return gProcs_Src[flags];
-        case SkXfermode::kDst_Mode:     return gProcs_Dst[flags];
-        case SkXfermode::kSrcOver_Mode: return gProcs_SrcOver[flags];
-        default:
-            break;
-    }
-    return gProcs_General[flags];
-}
-
-SkXfermode::D64Proc SkXfermode::onGetD64Proc(uint32_t flags) const {
-    SkASSERT(0 == (flags & ~7));
-    flags &= 7;
-
-    Mode mode;
-    return this->asMode(&mode) ? find_proc(mode, flags) : gProcs_General[flags];
-}
-
-SkXfermode::D64Proc SkXfermode::GetD64Proc(SkXfermode* xfer, uint32_t flags) {
-    return xfer ? xfer->onGetD64Proc(flags) : find_proc(SkXfermode::kSrcOver_Mode, flags);
-}