1/*
2 * Copyright 2011 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
9#include "src/gpu/GrStencilSettings.h"
10
11#include "src/gpu/GrProcessor.h"
12
13constexpr const GrUserStencilSettings gUnused(
14 GrUserStencilSettings::StaticInit<
15 0x0000,
16 GrUserStencilTest::kAlwaysIfInClip,
17 0xffff,
18 GrUserStencilOp::kKeep,
19 GrUserStencilOp::kKeep,
20 0x0000>()
21);
22
23static_assert(kAll_StencilFlags == (gUnused.fCWFlags[0] & gUnused.fCCWFlags[0]));
24
25const GrUserStencilSettings& GrUserStencilSettings::kUnused = gUnused;
26
27void GrStencilSettings::reset(const GrUserStencilSettings& user, bool hasStencilClip,
28 int numStencilBits) {
29 uint16_t cwFlags = user.fCWFlags[hasStencilClip];
30 if (cwFlags & kSingleSided_StencilFlag) {
31 SkASSERT(cwFlags == user.fCCWFlags[hasStencilClip]);
32 fFlags = cwFlags;
33 if (!this->isDisabled()) {
34 fCWFace.reset(user.fCWFace, hasStencilClip, numStencilBits);
35 }
36 return;
37 }
38
39 uint16_t ccwFlags = user.fCCWFlags[hasStencilClip];
40 fFlags = cwFlags & ccwFlags;
41 if (this->isDisabled()) {
42 return;
43 }
44 if (!(cwFlags & kDisabled_StencilFlag)) {
45 fCWFace.reset(user.fCWFace, hasStencilClip, numStencilBits);
46 } else {
47 fCWFace.setDisabled();
48 }
49 if (!(ccwFlags & kDisabled_StencilFlag)) {
50 fCCWFace.reset(user.fCCWFace, hasStencilClip, numStencilBits);
51 } else {
52 fCCWFace.setDisabled();
53 }
54}
55
56void GrStencilSettings::reset(const GrStencilSettings& that) {
57 fFlags = that.fFlags;
58 if ((kInvalid_PrivateFlag | kDisabled_StencilFlag) & fFlags) {
59 return;
60 }
61 if (!this->isTwoSided()) {
62 memcpy(&fCWFace, &that.fCWFace, sizeof(Face));
63 } else {
64 memcpy(&fCWFace, &that.fCWFace, 2 * sizeof(Face));
65 static_assert(sizeof(Face) ==
66 offsetof(GrStencilSettings, fCCWFace) - offsetof(GrStencilSettings, fCWFace));
67 }
68}
69
70bool GrStencilSettings::operator==(const GrStencilSettings& that) const {
71 if ((kInvalid_PrivateFlag | kDisabled_StencilFlag) & (fFlags | that.fFlags)) {
72 // At least one is invalid and/or disabled.
73 if (kInvalid_PrivateFlag & (fFlags | that.fFlags)) {
74 return false; // We never allow invalid stencils to be equal.
75 }
76 // They're only equal if both are disabled.
77 return kDisabled_StencilFlag & (fFlags & that.fFlags);
78 }
79 if (kSingleSided_StencilFlag & (fFlags & that.fFlags)) {
80 return 0 == memcmp(&fCWFace, &that.fCWFace, sizeof(Face)); // Both are single sided.
81 } else if (kSingleSided_StencilFlag & (fFlags | that.fFlags)) {
82 return false;
83 } else {
84 return 0 == memcmp(&fCWFace, &that.fCWFace, 2 * sizeof(Face));
85 static_assert(sizeof(Face) ==
86 offsetof(GrStencilSettings, fCCWFace) - offsetof(GrStencilSettings, fCWFace));
87 }
88 // memcmp relies on GrStencilSettings::Face being tightly packed.
89 static_assert(0 == offsetof(Face, fRef));
90 static_assert(2 == sizeof(Face::fRef));
91 static_assert(2 == offsetof(Face, fTest));
92 static_assert(2 == sizeof(Face::fTest));
93 static_assert(4 == offsetof(Face, fTestMask));
94 static_assert(2 == sizeof(Face::fTestMask));
95 static_assert(6 == offsetof(Face, fPassOp));
96 static_assert(1 == sizeof(Face::fPassOp));
97 static_assert(7 == offsetof(Face, fFailOp));
98 static_assert(1 == sizeof(Face::fFailOp));
99 static_assert(8 == offsetof(Face, fWriteMask));
100 static_assert(2 == sizeof(Face::fWriteMask));
101 static_assert(10 == sizeof(Face));
102}
103
104static constexpr GrStencilTest gUserStencilTestToRaw[kGrUserStencilTestCount] = {
105 // Tests that respect the clip.
106 GrStencilTest::kAlways, // kAlwaysIfInClip (This is only for when there is not a stencil clip).
107 GrStencilTest::kEqual, // kEqualIfInClip.
108 GrStencilTest::kLess, // kLessIfInClip.
109 GrStencilTest::kLEqual, // kLEqualIfInClip.
110
111 // Tests that ignore the clip.
112 GrStencilTest::kAlways,
113 GrStencilTest::kNever,
114 GrStencilTest::kGreater,
115 GrStencilTest::kGEqual,
116 GrStencilTest::kLess,
117 GrStencilTest::kLEqual,
118 GrStencilTest::kEqual,
119 GrStencilTest::kNotEqual
120};
121
122static_assert(0 == (int)GrUserStencilTest::kAlwaysIfInClip);
123static_assert(1 == (int)GrUserStencilTest::kEqualIfInClip);
124static_assert(2 == (int)GrUserStencilTest::kLessIfInClip);
125static_assert(3 == (int)GrUserStencilTest::kLEqualIfInClip);
126static_assert(4 == (int)GrUserStencilTest::kAlways);
127static_assert(5 == (int)GrUserStencilTest::kNever);
128static_assert(6 == (int)GrUserStencilTest::kGreater);
129static_assert(7 == (int)GrUserStencilTest::kGEqual);
130static_assert(8 == (int)GrUserStencilTest::kLess);
131static_assert(9 == (int)GrUserStencilTest::kLEqual);
132static_assert(10 == (int)GrUserStencilTest::kEqual);
133static_assert(11 == (int)GrUserStencilTest::kNotEqual);
134
135static constexpr GrStencilOp gUserStencilOpToRaw[kGrUserStencilOpCount] = {
136 GrStencilOp::kKeep,
137
138 // Ops that only modify user bits.
139 GrStencilOp::kZero,
140 GrStencilOp::kReplace,
141 GrStencilOp::kInvert,
142 GrStencilOp::kIncWrap,
143 GrStencilOp::kDecWrap,
144 GrStencilOp::kIncClamp, // kIncMaybeClamp.
145 GrStencilOp::kDecClamp, // kDecMaybeClamp.
146
147 // Ops that only modify the clip bit.
148 GrStencilOp::kZero, // kZeroClipBit.
149 GrStencilOp::kReplace, // kSetClipBit.
150 GrStencilOp::kInvert, // kInvertClipBit.
151
152 // Ops that modify clip and user bits.
153 GrStencilOp::kReplace, // kSetClipAndReplaceUserBits.
154 GrStencilOp::kZero // kZeroClipAndUserBits.
155};
156
157static_assert(0 == (int)GrUserStencilOp::kKeep);
158static_assert(1 == (int)GrUserStencilOp::kZero);
159static_assert(2 == (int)GrUserStencilOp::kReplace);
160static_assert(3 == (int)GrUserStencilOp::kInvert);
161static_assert(4 == (int)GrUserStencilOp::kIncWrap);
162static_assert(5 == (int)GrUserStencilOp::kDecWrap);
163static_assert(6 == (int)GrUserStencilOp::kIncMaybeClamp);
164static_assert(7 == (int)GrUserStencilOp::kDecMaybeClamp);
165static_assert(8 == (int)GrUserStencilOp::kZeroClipBit);
166static_assert(9 == (int)GrUserStencilOp::kSetClipBit);
167static_assert(10 == (int)GrUserStencilOp::kInvertClipBit);
168static_assert(11 == (int)GrUserStencilOp::kSetClipAndReplaceUserBits);
169static_assert(12 == (int)GrUserStencilOp::kZeroClipAndUserBits);
170
171void GrStencilSettings::Face::reset(const GrUserStencilSettings::Face& user, bool hasStencilClip,
172 int numStencilBits) {
173 SkASSERT(user.fTest < (GrUserStencilTest)kGrUserStencilTestCount);
174 SkASSERT(user.fPassOp < (GrUserStencilOp)kGrUserStencilOpCount);
175 SkASSERT(user.fFailOp < (GrUserStencilOp)kGrUserStencilOpCount);
176 SkASSERT(numStencilBits > 0 && numStencilBits <= 16);
177 int clipBit = 1 << (numStencilBits - 1);
178 int userMask = clipBit - 1;
179
180 GrUserStencilOp maxOp = std::max(user.fPassOp, user.fFailOp);
181 SkDEBUGCODE(GrUserStencilOp otherOp = std::min(user.fPassOp, user.fFailOp);)
182 if (maxOp <= kLastUserOnlyStencilOp) {
183 // Ops that only modify user bits.
184 fWriteMask = user.fWriteMask & userMask;
185 SkASSERT(otherOp <= kLastUserOnlyStencilOp);
186 } else if (maxOp <= kLastClipOnlyStencilOp) {
187 // Ops that only modify the clip bit.
188 fWriteMask = clipBit;
189 SkASSERT(GrUserStencilOp::kKeep == otherOp ||
190 (otherOp > kLastUserOnlyStencilOp && otherOp <= kLastClipOnlyStencilOp));
191 } else {
192 // Ops that modify both clip and user bits.
193 fWriteMask = clipBit | (user.fWriteMask & userMask);
194 SkASSERT(GrUserStencilOp::kKeep == otherOp || otherOp > kLastClipOnlyStencilOp);
195 }
196
197 fFailOp = gUserStencilOpToRaw[(int)user.fFailOp];
198 fPassOp = gUserStencilOpToRaw[(int)user.fPassOp];
199
200 if (!hasStencilClip || user.fTest > kLastClippedStencilTest) {
201 // Ignore the clip.
202 fTestMask = user.fTestMask & userMask;
203 fTest = gUserStencilTestToRaw[(int)user.fTest];
204 } else if (GrUserStencilTest::kAlwaysIfInClip != user.fTest) {
205 // Respect the clip.
206 fTestMask = clipBit | (user.fTestMask & userMask);
207 fTest = gUserStencilTestToRaw[(int)user.fTest];
208 } else {
209 // Test only for clip.
210 fTestMask = clipBit;
211 fTest = GrStencilTest::kEqual;
212 }
213
214 fRef = (clipBit | user.fRef) & (fTestMask | fWriteMask);
215}
216
217void GrStencilSettings::Face::setDisabled() {
218 memset(this, 0, sizeof(*this));
219 static_assert(0 == (int)GrStencilTest::kAlways);
220 static_assert(0 == (int)GrStencilOp::kKeep);
221}
222
223static constexpr GrUserStencilSettings gZeroStencilClipBit(
224 GrUserStencilSettings::StaticInit<
225 0x0000,
226 GrUserStencilTest::kAlways,
227 0xffff,
228 GrUserStencilOp::kZeroClipBit,
229 GrUserStencilOp::kZeroClipBit,
230 0x0000>()
231);
232static constexpr GrUserStencilSettings gSetStencilClipBit(
233 GrUserStencilSettings::StaticInit<
234 0x0000,
235 GrUserStencilTest::kAlways,
236 0xffff,
237 GrUserStencilOp::kSetClipBit,
238 GrUserStencilOp::kSetClipBit,
239 0x0000>()
240);
241
242const GrUserStencilSettings* GrStencilSettings::SetClipBitSettings(bool setToInside) {
243 return setToInside ? &gSetStencilClipBit : &gZeroStencilClipBit;
244}
245
246void GrStencilSettings::genKey(GrProcessorKeyBuilder* b, bool includeRefs) const {
247 b->add32(fFlags);
248 if (this->isDisabled()) {
249 return;
250 }
251 if (!this->isTwoSided()) {
252 constexpr int kCount16 = sizeof(Face) / sizeof(uint16_t);
253 static_assert(0 == sizeof(Face) % sizeof(uint16_t));
254 uint16_t* key = reinterpret_cast<uint16_t*>(b->add32n((kCount16 + 1) / 2));
255 if (includeRefs) {
256 memcpy(key, &fCWFace, sizeof(Face));
257 } else {
258 Face tempFace = fCWFace;
259 tempFace.fRef = 0;
260 memcpy(key, &tempFace, sizeof(Face));
261 }
262 key[kCount16] = 0;
263 static_assert(1 == kCount16 % 2);
264 } else {
265 constexpr int kCount32 = (2 * sizeof(Face)) / sizeof(uint32_t);
266 static_assert(0 == (2 * sizeof(Face)) % sizeof(uint32_t));
267 uint32_t* key = b->add32n(kCount32);
268 if (includeRefs) {
269 memcpy(key, &fCWFace, 2 * sizeof(Face));
270 static_assert(
271 sizeof(Face) ==
272 offsetof(GrStencilSettings, fCCWFace) - offsetof(GrStencilSettings, fCWFace));
273 } else {
274 Face tempFaces[2];
275 tempFaces[0] = fCWFace;
276 tempFaces[0].fRef = 0;
277 tempFaces[1] = fCCWFace;
278 tempFaces[1].fRef = 0;
279 memcpy(key, &tempFaces, 2 * sizeof(Face));
280 }
281 }
282 // We rely on GrStencilSettings::Face being tightly packed for the key to be reliable.
283 static_assert(0 == offsetof(Face, fRef));
284 static_assert(2 == sizeof(Face::fRef));
285 static_assert(2 == offsetof(Face, fTest));
286 static_assert(2 == sizeof(Face::fTest));
287 static_assert(4 == offsetof(Face, fTestMask));
288 static_assert(2 == sizeof(Face::fTestMask));
289 static_assert(6 == offsetof(Face, fPassOp));
290 static_assert(1 == sizeof(Face::fPassOp));
291 static_assert(7 == offsetof(Face, fFailOp));
292 static_assert(1 == sizeof(Face::fFailOp));
293 static_assert(8 == offsetof(Face, fWriteMask));
294 static_assert(2 == sizeof(Face::fWriteMask));
295 static_assert(10 == sizeof(Face));
296}
297