1 /*
2  * Copyright 2015 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkBlitMask_opts_DEFINED
9 #define SkBlitMask_opts_DEFINED
10 
11 #include "Sk4px.h"
12 
13 namespace SK_OPTS_NS {
14 
15 #if defined(SK_ARM_HAS_NEON)
16     // The Sk4px versions below will work fine with NEON, but we have had many indications
17     // that it doesn't perform as well as this NEON-specific code.  TODO(mtklein): why?
18     #include "SkColor_opts_neon.h"
19 
20     template <bool isColor>
D32_A8_Opaque_Color_neon(void * SK_RESTRICT dst,size_t dstRB,const void * SK_RESTRICT maskPtr,size_t maskRB,SkColor color,int width,int height)21     static void D32_A8_Opaque_Color_neon(void* SK_RESTRICT dst, size_t dstRB,
22                                          const void* SK_RESTRICT maskPtr, size_t maskRB,
23                                          SkColor color, int width, int height) {
24         SkPMColor pmc = SkPreMultiplyColor(color);
25         SkPMColor* SK_RESTRICT device = (SkPMColor*)dst;
26         const uint8_t* SK_RESTRICT mask = (const uint8_t*)maskPtr;
27         uint8x8x4_t vpmc;
28 
29         maskRB -= width;
30         dstRB -= (width << 2);
31 
32         if (width >= 8) {
33             vpmc.val[NEON_A] = vdup_n_u8(SkGetPackedA32(pmc));
34             vpmc.val[NEON_R] = vdup_n_u8(SkGetPackedR32(pmc));
35             vpmc.val[NEON_G] = vdup_n_u8(SkGetPackedG32(pmc));
36             vpmc.val[NEON_B] = vdup_n_u8(SkGetPackedB32(pmc));
37         }
38         do {
39             int w = width;
40             while (w >= 8) {
41                 uint8x8_t vmask = vld1_u8(mask);
42                 uint16x8_t vscale, vmask256 = SkAlpha255To256_neon8(vmask);
43                 if (isColor) {
44                     vscale = vsubw_u8(vdupq_n_u16(256),
45                             SkAlphaMul_neon8(vpmc.val[NEON_A], vmask256));
46                 } else {
47                     vscale = vsubw_u8(vdupq_n_u16(256), vmask);
48                 }
49                 uint8x8x4_t vdev = vld4_u8((uint8_t*)device);
50 
51                 vdev.val[NEON_A] =   SkAlphaMul_neon8(vpmc.val[NEON_A], vmask256)
52                     + SkAlphaMul_neon8(vdev.val[NEON_A], vscale);
53                 vdev.val[NEON_R] =   SkAlphaMul_neon8(vpmc.val[NEON_R], vmask256)
54                     + SkAlphaMul_neon8(vdev.val[NEON_R], vscale);
55                 vdev.val[NEON_G] =   SkAlphaMul_neon8(vpmc.val[NEON_G], vmask256)
56                     + SkAlphaMul_neon8(vdev.val[NEON_G], vscale);
57                 vdev.val[NEON_B] =   SkAlphaMul_neon8(vpmc.val[NEON_B], vmask256)
58                     + SkAlphaMul_neon8(vdev.val[NEON_B], vscale);
59 
60                 vst4_u8((uint8_t*)device, vdev);
61 
62                 mask += 8;
63                 device += 8;
64                 w -= 8;
65             }
66 
67             while (w--) {
68                 unsigned aa = *mask++;
69                 if (isColor) {
70                     *device = SkBlendARGB32(pmc, *device, aa);
71                 } else {
72                     *device = SkAlphaMulQ(pmc, SkAlpha255To256(aa))
73                         + SkAlphaMulQ(*device, SkAlpha255To256(255 - aa));
74                 }
75                 device += 1;
76             };
77 
78             device = (uint32_t*)((char*)device + dstRB);
79             mask += maskRB;
80 
81         } while (--height != 0);
82     }
83 
blit_mask_d32_a8_general(SkPMColor * dst,size_t dstRB,const SkAlpha * mask,size_t maskRB,SkColor color,int w,int h)84     static void blit_mask_d32_a8_general(SkPMColor* dst, size_t dstRB,
85                                          const SkAlpha* mask, size_t maskRB,
86                                          SkColor color, int w, int h) {
87         D32_A8_Opaque_Color_neon<true>(dst, dstRB, mask, maskRB, color, w, h);
88     }
89 
90     // As above, but made slightly simpler by requiring that color is opaque.
blit_mask_d32_a8_opaque(SkPMColor * dst,size_t dstRB,const SkAlpha * mask,size_t maskRB,SkColor color,int w,int h)91     static void blit_mask_d32_a8_opaque(SkPMColor* dst, size_t dstRB,
92                                         const SkAlpha* mask, size_t maskRB,
93                                         SkColor color, int w, int h) {
94         D32_A8_Opaque_Color_neon<false>(dst, dstRB, mask, maskRB, color, w, h);
95     }
96 
97     // Same as _opaque, but assumes color == SK_ColorBLACK, a very common and even simpler case.
blit_mask_d32_a8_black(SkPMColor * dst,size_t dstRB,const SkAlpha * maskPtr,size_t maskRB,int width,int height)98     static void blit_mask_d32_a8_black(SkPMColor* dst, size_t dstRB,
99                                        const SkAlpha* maskPtr, size_t maskRB,
100                                        int width, int height) {
101         SkPMColor* SK_RESTRICT device = (SkPMColor*)dst;
102         const uint8_t* SK_RESTRICT mask = (const uint8_t*)maskPtr;
103 
104         maskRB -= width;
105         dstRB -= (width << 2);
106         do {
107             int w = width;
108             while (w >= 8) {
109                 uint8x8_t vmask = vld1_u8(mask);
110                 uint16x8_t vscale = vsubw_u8(vdupq_n_u16(256), vmask);
111                 uint8x8x4_t vdevice = vld4_u8((uint8_t*)device);
112 
113                 vdevice = SkAlphaMulQ_neon8(vdevice, vscale);
114                 vdevice.val[NEON_A] += vmask;
115 
116                 vst4_u8((uint8_t*)device, vdevice);
117 
118                 mask += 8;
119                 device += 8;
120                 w -= 8;
121             }
122             while (w-- > 0) {
123                 unsigned aa = *mask++;
124                 *device = (aa << SK_A32_SHIFT)
125                             + SkAlphaMulQ(*device, SkAlpha255To256(255 - aa));
126                 device += 1;
127             };
128             device = (uint32_t*)((char*)device + dstRB);
129             mask += maskRB;
130         } while (--height != 0);
131     }
132 
133 #else
134     static void blit_mask_d32_a8_general(SkPMColor* dst, size_t dstRB,
135                                          const SkAlpha* mask, size_t maskRB,
136                                          SkColor color, int w, int h) {
137         auto s = Sk4px::DupPMColor(SkPreMultiplyColor(color));
138         auto fn = [&](const Sk4px& d, const Sk4px& aa) {
139             //  = (s + d(1-sa))aa + d(1-aa)
140             //  = s*aa + d(1-sa*aa)
141             auto left  = s.approxMulDiv255(aa),
142                  right = d.approxMulDiv255(left.alphas().inv());
143             return left + right;  // This does not overflow (exhaustively checked).
144         };
145         while (h --> 0) {
146             Sk4px::MapDstAlpha(w, dst, mask, fn);
147             dst  +=  dstRB / sizeof(*dst);
148             mask += maskRB / sizeof(*mask);
149         }
150     }
151 
152     // As above, but made slightly simpler by requiring that color is opaque.
153     static void blit_mask_d32_a8_opaque(SkPMColor* dst, size_t dstRB,
154                                         const SkAlpha* mask, size_t maskRB,
155                                         SkColor color, int w, int h) {
156         SkASSERT(SkColorGetA(color) == 0xFF);
157         auto s = Sk4px::DupPMColor(SkPreMultiplyColor(color));
158         auto fn = [&](const Sk4px& d, const Sk4px& aa) {
159             //  = (s + d(1-sa))aa + d(1-aa)
160             //  = s*aa + d(1-sa*aa)
161             //   ~~~>
162             //  = s*aa + d(1-aa)
163             return s.approxMulDiv255(aa) + d.approxMulDiv255(aa.inv());
164         };
165         while (h --> 0) {
166             Sk4px::MapDstAlpha(w, dst, mask, fn);
167             dst  +=  dstRB / sizeof(*dst);
168             mask += maskRB / sizeof(*mask);
169         }
170     }
171 
172     // Same as _opaque, but assumes color == SK_ColorBLACK, a very common and even simpler case.
173     static void blit_mask_d32_a8_black(SkPMColor* dst, size_t dstRB,
174                                        const SkAlpha* mask, size_t maskRB,
175                                        int w, int h) {
176         auto fn = [](const Sk4px& d, const Sk4px& aa) {
177             //   = (s + d(1-sa))aa + d(1-aa)
178             //   = s*aa + d(1-sa*aa)
179             //   ~~~>
180             // a = 1*aa + d(1-1*aa) = aa + d(1-aa)
181             // c = 0*aa + d(1-1*aa) =      d(1-aa)
182             return aa.zeroColors() + d.approxMulDiv255(aa.inv());
183         };
184         while (h --> 0) {
185             Sk4px::MapDstAlpha(w, dst, mask, fn);
186             dst  +=  dstRB / sizeof(*dst);
187             mask += maskRB / sizeof(*mask);
188         }
189     }
190 #endif
191 
blit_mask_d32_a8(SkPMColor * dst,size_t dstRB,const SkAlpha * mask,size_t maskRB,SkColor color,int w,int h)192 /*not static*/ inline void blit_mask_d32_a8(SkPMColor* dst, size_t dstRB,
193                                             const SkAlpha* mask, size_t maskRB,
194                                             SkColor color, int w, int h) {
195     if (color == SK_ColorBLACK) {
196         blit_mask_d32_a8_black(dst, dstRB, mask, maskRB, w, h);
197     } else if (SkColorGetA(color) == 0xFF) {
198         blit_mask_d32_a8_opaque(dst, dstRB, mask, maskRB, color, w, h);
199     } else {
200         blit_mask_d32_a8_general(dst, dstRB, mask, maskRB, color, w, h);
201     }
202 }
203 
204 }  // SK_OPTS_NS
205 
206 #endif//SkBlitMask_opts_DEFINED
207