1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/gpu/GrStencil.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,395 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2011 Google Inc.
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#include "GrStencil.h"
1.14 +
1.15 +////////////////////////////////////////////////////////////////////////////////
1.16 +// Stencil Rules for Merging user stencil space into clip
1.17 +
1.18 +// We can't include the clip bit in the ref or mask values because the division
1.19 +// between user and clip bits in the stencil depends on the number of stencil
1.20 +// bits in the runtime. Comments below indicate what the code should do to
1.21 +// incorporate the clip bit into these settings.
1.22 +
1.23 +///////
1.24 +// Replace
1.25 +
1.26 +// set the ref to be the clip bit, but mask it out for the test
1.27 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipReplace,
1.28 + kReplace_StencilOp,
1.29 + kZero_StencilOp,
1.30 + kLess_StencilFunc,
1.31 + 0xffff, // unset clip bit
1.32 + 0x0000, // set clip bit
1.33 + 0xffff);
1.34 +
1.35 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipReplace,
1.36 + kReplace_StencilOp,
1.37 + kZero_StencilOp,
1.38 + kEqual_StencilFunc,
1.39 + 0xffff, // unset clip bit
1.40 + 0x0000, // set clip bit
1.41 + 0xffff);
1.42 +
1.43 +///////
1.44 +// Intersect
1.45 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipIsect,
1.46 + kReplace_StencilOp,
1.47 + kZero_StencilOp,
1.48 + kLess_StencilFunc,
1.49 + 0xffff,
1.50 + 0x0000, // set clip bit
1.51 + 0xffff);
1.52 +
1.53 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipIsect,
1.54 + kReplace_StencilOp,
1.55 + kZero_StencilOp,
1.56 + kEqual_StencilFunc,
1.57 + 0xffff,
1.58 + 0x0000, // set clip bit
1.59 + 0xffff);
1.60 +
1.61 +///////
1.62 +// Difference
1.63 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipDiff,
1.64 + kReplace_StencilOp,
1.65 + kZero_StencilOp,
1.66 + kEqual_StencilFunc,
1.67 + 0xffff,
1.68 + 0x0000, // set clip bit
1.69 + 0xffff);
1.70 +
1.71 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipDiff,
1.72 + kReplace_StencilOp,
1.73 + kZero_StencilOp,
1.74 + kLess_StencilFunc,
1.75 + 0xffff,
1.76 + 0x0000, // set clip bit
1.77 + 0xffff);
1.78 +
1.79 +///////
1.80 +// Union
1.81 +
1.82 +// first pass makes all the passing cases >= just clip bit set.
1.83 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipUnionPass0,
1.84 + kReplace_StencilOp,
1.85 + kKeep_StencilOp,
1.86 + kLEqual_StencilFunc,
1.87 + 0xffff,
1.88 + 0x0001, // set clip bit
1.89 + 0xffff);
1.90 +
1.91 +// second pass allows anything greater than just clip bit set to pass
1.92 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipUnionPass1,
1.93 + kReplace_StencilOp,
1.94 + kZero_StencilOp,
1.95 + kLEqual_StencilFunc,
1.96 + 0xffff,
1.97 + 0x0000, // set clip bit
1.98 + 0xffff);
1.99 +
1.100 +// first pass finds zeros in the user bits and if found sets
1.101 +// the clip bit to 1
1.102 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipUnionPass0,
1.103 + kReplace_StencilOp,
1.104 + kKeep_StencilOp,
1.105 + kEqual_StencilFunc,
1.106 + 0xffff,
1.107 + 0x0000, // set clip bit
1.108 + 0x0000 // set clip bit
1.109 +);
1.110 +
1.111 +// second pass zeros the user bits
1.112 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipUnionPass1,
1.113 + kZero_StencilOp,
1.114 + kZero_StencilOp,
1.115 + kLess_StencilFunc,
1.116 + 0xffff,
1.117 + 0x0000,
1.118 + 0xffff // unset clip bit
1.119 +);
1.120 +
1.121 +///////
1.122 +// Xor
1.123 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipXorPass0,
1.124 + kInvert_StencilOp,
1.125 + kKeep_StencilOp,
1.126 + kEqual_StencilFunc,
1.127 + 0xffff, // unset clip bit
1.128 + 0x0000,
1.129 + 0xffff);
1.130 +
1.131 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipXorPass1,
1.132 + kReplace_StencilOp,
1.133 + kZero_StencilOp,
1.134 + kGreater_StencilFunc,
1.135 + 0xffff,
1.136 + 0x0000, // set clip bit
1.137 + 0xffff);
1.138 +
1.139 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipXorPass0,
1.140 + kInvert_StencilOp,
1.141 + kKeep_StencilOp,
1.142 + kEqual_StencilFunc,
1.143 + 0xffff, // unset clip bit
1.144 + 0x0000,
1.145 + 0xffff);
1.146 +
1.147 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipXorPass1,
1.148 + kReplace_StencilOp,
1.149 + kZero_StencilOp,
1.150 + kLess_StencilFunc,
1.151 + 0xffff,
1.152 + 0x0000, // set clip bit
1.153 + 0xffff);
1.154 +
1.155 +///////
1.156 +// Reverse Diff
1.157 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipRDiffPass0,
1.158 + kInvert_StencilOp,
1.159 + kZero_StencilOp,
1.160 + kLess_StencilFunc,
1.161 + 0xffff, // unset clip bit
1.162 + 0x0000, // set clip bit
1.163 + 0xffff);
1.164 +
1.165 +GR_STATIC_CONST_SAME_STENCIL(gUserToClipRDiffPass1,
1.166 + kReplace_StencilOp,
1.167 + kZero_StencilOp,
1.168 + kEqual_StencilFunc,
1.169 + 0x0000, // set clip bit
1.170 + 0x0000, // set clip bit
1.171 + 0xffff);
1.172 +
1.173 +// We are looking for stencil values that are all zero. The first pass sets the
1.174 +// clip bit if the stencil is all zeros. The second pass clears the user bits.
1.175 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipRDiffPass0,
1.176 + kInvert_StencilOp,
1.177 + kZero_StencilOp,
1.178 + kEqual_StencilFunc,
1.179 + 0xffff,
1.180 + 0x0000,
1.181 + 0x0000 // set clip bit
1.182 +);
1.183 +
1.184 +GR_STATIC_CONST_SAME_STENCIL(gInvUserToClipRDiffPass1,
1.185 + kZero_StencilOp,
1.186 + kZero_StencilOp,
1.187 + kAlways_StencilFunc,
1.188 + 0xffff,
1.189 + 0x0000,
1.190 + 0xffff // unset clip bit
1.191 +);
1.192 +
1.193 +///////
1.194 +// Direct to Stencil
1.195 +
1.196 +// We can render a clip element directly without first writing to the client
1.197 +// portion of the clip when the fill is not inverse and the set operation will
1.198 +// only modify the in/out status of samples covered by the clip element.
1.199 +
1.200 +// this one only works if used right after stencil clip was cleared.
1.201 +// Our clip mask creation code doesn't allow midstream replace ops.
1.202 +GR_STATIC_CONST_SAME_STENCIL(gReplaceClip,
1.203 + kReplace_StencilOp,
1.204 + kReplace_StencilOp,
1.205 + kAlways_StencilFunc,
1.206 + 0xffff,
1.207 + 0x0000, // set clip bit
1.208 + 0x0000 // set clipBit
1.209 +);
1.210 +
1.211 +GR_STATIC_CONST_SAME_STENCIL(gUnionClip,
1.212 + kReplace_StencilOp,
1.213 + kReplace_StencilOp,
1.214 + kAlways_StencilFunc,
1.215 + 0xffff,
1.216 + 0x0000, // set clip bit
1.217 + 0x0000 // set clip bit
1.218 +);
1.219 +
1.220 +GR_STATIC_CONST_SAME_STENCIL(gXorClip,
1.221 + kInvert_StencilOp,
1.222 + kInvert_StencilOp,
1.223 + kAlways_StencilFunc,
1.224 + 0xffff,
1.225 + 0x0000,
1.226 + 0x0000 // set clip bit
1.227 +);
1.228 +
1.229 +GR_STATIC_CONST_SAME_STENCIL(gDiffClip,
1.230 + kZero_StencilOp,
1.231 + kZero_StencilOp,
1.232 + kAlways_StencilFunc,
1.233 + 0xffff,
1.234 + 0x0000,
1.235 + 0x0000 // set clip bit
1.236 +);
1.237 +
1.238 +bool GrStencilSettings::GetClipPasses(
1.239 + SkRegion::Op op,
1.240 + bool canBeDirect,
1.241 + unsigned int stencilClipMask,
1.242 + bool invertedFill,
1.243 + int* numPasses,
1.244 + GrStencilSettings settings[kMaxStencilClipPasses]) {
1.245 + if (canBeDirect && !invertedFill) {
1.246 + *numPasses = 0;
1.247 + switch (op) {
1.248 + case SkRegion::kReplace_Op:
1.249 + *numPasses = 1;
1.250 + settings[0] = gReplaceClip;
1.251 + break;
1.252 + case SkRegion::kUnion_Op:
1.253 + *numPasses = 1;
1.254 + settings[0] = gUnionClip;
1.255 + break;
1.256 + case SkRegion::kXOR_Op:
1.257 + *numPasses = 1;
1.258 + settings[0] = gXorClip;
1.259 + break;
1.260 + case SkRegion::kDifference_Op:
1.261 + *numPasses = 1;
1.262 + settings[0] = gDiffClip;
1.263 + break;
1.264 + default: // suppress warning
1.265 + break;
1.266 + }
1.267 + if (1 == *numPasses) {
1.268 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.269 + settings[0].fWriteMasks[kFront_Face] |= stencilClipMask;
1.270 + settings[0].fFuncRefs[kBack_Face] =
1.271 + settings[0].fFuncRefs[kFront_Face];
1.272 + settings[0].fWriteMasks[kBack_Face] =
1.273 + settings[0].fWriteMasks[kFront_Face];
1.274 + return true;
1.275 + }
1.276 + }
1.277 + switch (op) {
1.278 + // if we make the path renderer go to stencil we always give it a
1.279 + // non-inverted fill and we use the stencil rules on the client->clipbit
1.280 + // pass to select either the zeros or nonzeros.
1.281 + case SkRegion::kReplace_Op:
1.282 + *numPasses= 1;
1.283 + settings[0] = invertedFill ? gInvUserToClipReplace :
1.284 + gUserToClipReplace;
1.285 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.286 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.287 + settings[0].fFuncMasks[kBack_Face] =
1.288 + settings[0].fFuncMasks[kFront_Face];
1.289 + settings[0].fFuncRefs[kBack_Face] =
1.290 + settings[0].fFuncRefs[kFront_Face];
1.291 + break;
1.292 + case SkRegion::kIntersect_Op:
1.293 + *numPasses = 1;
1.294 + settings[0] = invertedFill ? gInvUserToClipIsect : gUserToClipIsect;
1.295 + settings[0].fFuncRefs[kFront_Face] = stencilClipMask;
1.296 + settings[0].fFuncRefs[kBack_Face] =
1.297 + settings[0].fFuncRefs[kFront_Face];
1.298 + break;
1.299 + case SkRegion::kUnion_Op:
1.300 + *numPasses = 2;
1.301 + if (invertedFill) {
1.302 + settings[0] = gInvUserToClipUnionPass0;
1.303 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.304 + settings[0].fFuncMasks[kBack_Face] =
1.305 + settings[0].fFuncMasks[kFront_Face];
1.306 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.307 + settings[0].fFuncRefs[kBack_Face] =
1.308 + settings[0].fFuncRefs[kFront_Face];
1.309 + settings[0].fWriteMasks[kFront_Face] |= stencilClipMask;
1.310 + settings[0].fWriteMasks[kBack_Face] =
1.311 + settings[0].fWriteMasks[kFront_Face];
1.312 +
1.313 + settings[1] = gInvUserToClipUnionPass1;
1.314 + settings[1].fWriteMasks[kFront_Face] &= ~stencilClipMask;
1.315 + settings[1].fWriteMasks[kBack_Face] &=
1.316 + settings[1].fWriteMasks[kFront_Face];
1.317 +
1.318 + } else {
1.319 + settings[0] = gUserToClipUnionPass0;
1.320 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.321 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.322 + settings[0].fFuncMasks[kBack_Face] =
1.323 + settings[0].fFuncMasks[kFront_Face];
1.324 + settings[0].fFuncRefs[kBack_Face] =
1.325 + settings[0].fFuncRefs[kFront_Face];
1.326 +
1.327 + settings[1] = gUserToClipUnionPass1;
1.328 + settings[1].fFuncRefs[kFront_Face] |= stencilClipMask;
1.329 + settings[1].fFuncRefs[kBack_Face] =
1.330 + settings[1].fFuncRefs[kFront_Face];
1.331 + }
1.332 + break;
1.333 + case SkRegion::kXOR_Op:
1.334 + *numPasses = 2;
1.335 + if (invertedFill) {
1.336 + settings[0] = gInvUserToClipXorPass0;
1.337 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.338 + settings[0].fFuncMasks[kBack_Face] =
1.339 + settings[0].fFuncMasks[kFront_Face];
1.340 +
1.341 + settings[1] = gInvUserToClipXorPass1;
1.342 + settings[1].fFuncRefs[kFront_Face] |= stencilClipMask;
1.343 + settings[1].fFuncRefs[kBack_Face] =
1.344 + settings[1].fFuncRefs[kFront_Face];
1.345 + } else {
1.346 + settings[0] = gUserToClipXorPass0;
1.347 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.348 + settings[0].fFuncMasks[kBack_Face] =
1.349 + settings[0].fFuncMasks[kFront_Face];
1.350 +
1.351 + settings[1] = gUserToClipXorPass1;
1.352 + settings[1].fFuncRefs[kFront_Face] |= stencilClipMask;
1.353 + settings[1].fFuncRefs[kBack_Face] =
1.354 + settings[1].fFuncRefs[kFront_Face];
1.355 + }
1.356 + break;
1.357 + case SkRegion::kDifference_Op:
1.358 + *numPasses = 1;
1.359 + settings[0] = invertedFill ? gInvUserToClipDiff : gUserToClipDiff;
1.360 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.361 + settings[0].fFuncRefs[kBack_Face] =
1.362 + settings[0].fFuncRefs[kFront_Face];
1.363 + break;
1.364 + case SkRegion::kReverseDifference_Op:
1.365 + if (invertedFill) {
1.366 + *numPasses = 2;
1.367 + settings[0] = gInvUserToClipRDiffPass0;
1.368 + settings[0].fWriteMasks[kFront_Face] |= stencilClipMask;
1.369 + settings[0].fWriteMasks[kBack_Face] =
1.370 + settings[0].fWriteMasks[kFront_Face];
1.371 + settings[1] = gInvUserToClipRDiffPass1;
1.372 + settings[1].fWriteMasks[kFront_Face] &= ~stencilClipMask;
1.373 + settings[1].fWriteMasks[kBack_Face] =
1.374 + settings[1].fWriteMasks[kFront_Face];
1.375 + } else {
1.376 + *numPasses = 2;
1.377 + settings[0] = gUserToClipRDiffPass0;
1.378 + settings[0].fFuncMasks[kFront_Face] &= ~stencilClipMask;
1.379 + settings[0].fFuncMasks[kBack_Face] =
1.380 + settings[0].fFuncMasks[kFront_Face];
1.381 + settings[0].fFuncRefs[kFront_Face] |= stencilClipMask;
1.382 + settings[0].fFuncRefs[kBack_Face] =
1.383 + settings[0].fFuncRefs[kFront_Face];
1.384 +
1.385 + settings[1] = gUserToClipRDiffPass1;
1.386 + settings[1].fFuncMasks[kFront_Face] |= stencilClipMask;
1.387 + settings[1].fFuncRefs[kFront_Face] |= stencilClipMask;
1.388 + settings[1].fFuncMasks[kBack_Face] =
1.389 + settings[1].fFuncMasks[kFront_Face];
1.390 + settings[1].fFuncRefs[kBack_Face] =
1.391 + settings[1].fFuncRefs[kFront_Face];
1.392 + }
1.393 + break;
1.394 + default:
1.395 + GrCrash("Unknown set op");
1.396 + }
1.397 + return false;
1.398 +}
