1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/*
* Copyright 2013 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkBitmap.h"
#include "SkColorPriv.h"
#include "SkBlurImage_opts.h"
#include "SkRect.h"
#include <arm_neon.h>
namespace {
enum BlurDirection {
kX, kY
};
/**
* Helper function to spread the components of a 32-bit integer into the
* lower 8 bits of each 16-bit element of a NEON register.
*/
static inline uint16x4_t expand(uint32_t a) {
// ( ARGB ) -> ( ARGB ARGB ) -> ( A R G B A R G B )
uint8x8_t v8 = vreinterpret_u8_u32(vdup_n_u32(a));
// ( A R G B A R G B ) -> ( 0A 0R 0G 0B 0A 0R 0G 0B ) -> ( 0A 0R 0G 0B )
return vget_low_u16(vmovl_u8(v8));
}
template<BlurDirection srcDirection, BlurDirection dstDirection>
void SkBoxBlur_NEON(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
int leftOffset, int rightOffset, int width, int height)
{
const int rightBorder = SkMin32(rightOffset + 1, width);
const int srcStrideX = srcDirection == kX ? 1 : srcStride;
const int dstStrideX = dstDirection == kX ? 1 : height;
const int srcStrideY = srcDirection == kX ? srcStride : 1;
const int dstStrideY = dstDirection == kX ? width : 1;
const uint32x4_t scale = vdupq_n_u32((1 << 24) / kernelSize);
const uint32x4_t half = vdupq_n_u32(1 << 23);
for (int y = 0; y < height; ++y) {
uint32x4_t sum = vdupq_n_u32(0);
const SkPMColor* p = src;
for (int i = 0; i < rightBorder; ++i) {
sum = vaddw_u16(sum, expand(*p));
p += srcStrideX;
}
const SkPMColor* sptr = src;
SkPMColor* dptr = dst;
for (int x = 0; x < width; ++x) {
// ( half+sumA*scale half+sumR*scale half+sumG*scale half+sumB*scale )
uint32x4_t result = vmlaq_u32(half, sum, scale);
// Saturated conversion to 16-bit.
// ( AAAA RRRR GGGG BBBB ) -> ( 0A 0R 0G 0B )
uint16x4_t result16 = vqshrn_n_u32(result, 16);
// Saturated conversion to 8-bit.
// ( 0A 0R 0G 0B ) -> ( 0A 0R 0G 0B 0A 0R 0G 0B ) -> ( A R G B A R G B )
uint8x8_t result8 = vqshrn_n_u16(vcombine_u16(result16, result16), 8);
// ( A R G B A R G B ) -> ( ARGB ARGB ) -> ( ARGB )
// Store low 32 bits to destination.
vst1_lane_u32(dptr, vreinterpret_u32_u8(result8), 0);
if (x >= leftOffset) {
const SkPMColor* l = sptr - leftOffset * srcStrideX;
sum = vsubw_u16(sum, expand(*l));
}
if (x + rightOffset + 1 < width) {
const SkPMColor* r = sptr + (rightOffset + 1) * srcStrideX;
sum = vaddw_u16(sum, expand(*r));
}
sptr += srcStrideX;
if (srcDirection == kY) {
SK_PREFETCH(sptr + (rightOffset + 1) * srcStrideX);
}
dptr += dstStrideX;
}
src += srcStrideY;
dst += dstStrideY;
}
}
} // namespace
bool SkBoxBlurGetPlatformProcs_NEON(SkBoxBlurProc* boxBlurX,
SkBoxBlurProc* boxBlurY,
SkBoxBlurProc* boxBlurXY,
SkBoxBlurProc* boxBlurYX) {
*boxBlurX = SkBoxBlur_NEON<kX, kX>;
*boxBlurY = SkBoxBlur_NEON<kY, kY>;
*boxBlurXY = SkBoxBlur_NEON<kX, kY>;
*boxBlurYX = SkBoxBlur_NEON<kY, kX>;
return true;
}
|
