Vishnu Nair | 16efdbf | 2019-12-10 11:55:42 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2019 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include <math/vec4.h> |
| 18 | |
| 19 | #include <renderengine/Mesh.h> |
| 20 | |
| 21 | #include <ui/Rect.h> |
| 22 | #include <ui/Transform.h> |
| 23 | |
| 24 | #include <utils/Log.h> |
| 25 | |
| 26 | #include "GLSkiaShadowPort.h" |
| 27 | |
| 28 | namespace android { |
| 29 | namespace renderengine { |
| 30 | namespace gl { |
| 31 | |
| 32 | /** |
| 33 | * The shadow geometry logic and vertex generation code has been ported from skia shadow |
| 34 | * fast path OpenGL implementation to draw shadows around rects and rounded rects including |
| 35 | * circles. |
| 36 | * |
| 37 | * path: skia/src/gpu/GrRenderTargetContext.cpp GrRenderTargetContext::drawFastShadow |
| 38 | * |
| 39 | * Modifications made: |
| 40 | * - Switched to using std lib math functions |
| 41 | * - Fall off function is implemented in vertex shader rather than a shadow texture |
| 42 | * - Removed transformations applied on the caster rect since the caster will be in local |
| 43 | * coordinate space and will be transformed by the vertex shader. |
| 44 | */ |
| 45 | |
| 46 | static inline float divide_and_pin(float numer, float denom, float min, float max) { |
| 47 | if (denom == 0.0f) return min; |
| 48 | return std::clamp(numer / denom, min, max); |
| 49 | } |
| 50 | |
| 51 | static constexpr auto SK_ScalarSqrt2 = 1.41421356f; |
| 52 | static constexpr auto kAmbientHeightFactor = 1.0f / 128.0f; |
| 53 | static constexpr auto kAmbientGeomFactor = 64.0f; |
| 54 | // Assuming that we have a light height of 600 for the spot shadow, |
| 55 | // the spot values will reach their maximum at a height of approximately 292.3077. |
| 56 | // We'll round up to 300 to keep it simple. |
| 57 | static constexpr auto kMaxAmbientRadius = 300 * kAmbientHeightFactor * kAmbientGeomFactor; |
| 58 | |
| 59 | inline float AmbientBlurRadius(float height) { |
| 60 | return std::min(height * kAmbientHeightFactor * kAmbientGeomFactor, kMaxAmbientRadius); |
| 61 | } |
| 62 | inline float AmbientRecipAlpha(float height) { |
| 63 | return 1.0f + std::max(height * kAmbientHeightFactor, 0.0f); |
| 64 | } |
| 65 | |
| 66 | ////////////////////////////////////////////////////////////////////////////// |
| 67 | // Circle Data |
| 68 | // |
| 69 | // We have two possible cases for geometry for a circle: |
| 70 | |
| 71 | // In the case of a normal fill, we draw geometry for the circle as an octagon. |
| 72 | static const uint16_t gFillCircleIndices[] = { |
| 73 | // enter the octagon |
| 74 | // clang-format off |
| 75 | 0, 1, 8, 1, 2, 8, |
| 76 | 2, 3, 8, 3, 4, 8, |
| 77 | 4, 5, 8, 5, 6, 8, |
| 78 | 6, 7, 8, 7, 0, 8, |
| 79 | // clang-format on |
| 80 | }; |
| 81 | |
| 82 | // For stroked circles, we use two nested octagons. |
| 83 | static const uint16_t gStrokeCircleIndices[] = { |
| 84 | // enter the octagon |
| 85 | // clang-format off |
| 86 | 0, 1, 9, 0, 9, 8, |
| 87 | 1, 2, 10, 1, 10, 9, |
| 88 | 2, 3, 11, 2, 11, 10, |
| 89 | 3, 4, 12, 3, 12, 11, |
| 90 | 4, 5, 13, 4, 13, 12, |
| 91 | 5, 6, 14, 5, 14, 13, |
| 92 | 6, 7, 15, 6, 15, 14, |
| 93 | 7, 0, 8, 7, 8, 15, |
| 94 | // clang-format on |
| 95 | }; |
| 96 | |
| 97 | #define SK_ARRAY_COUNT(a) (sizeof(a) / sizeof((a)[0])) |
| 98 | static const int kIndicesPerFillCircle = SK_ARRAY_COUNT(gFillCircleIndices); |
| 99 | static const int kIndicesPerStrokeCircle = SK_ARRAY_COUNT(gStrokeCircleIndices); |
| 100 | static const int kVertsPerStrokeCircle = 16; |
| 101 | static const int kVertsPerFillCircle = 9; |
| 102 | |
| 103 | static int circle_type_to_vert_count(bool stroked) { |
| 104 | return stroked ? kVertsPerStrokeCircle : kVertsPerFillCircle; |
| 105 | } |
| 106 | |
| 107 | static int circle_type_to_index_count(bool stroked) { |
| 108 | return stroked ? kIndicesPerStrokeCircle : kIndicesPerFillCircle; |
| 109 | } |
| 110 | |
| 111 | static const uint16_t* circle_type_to_indices(bool stroked) { |
| 112 | return stroked ? gStrokeCircleIndices : gFillCircleIndices; |
| 113 | } |
| 114 | |
| 115 | /////////////////////////////////////////////////////////////////////////////// |
| 116 | // RoundRect Data |
| 117 | // |
| 118 | // The geometry for a shadow roundrect is similar to a 9-patch: |
| 119 | // ____________ |
| 120 | // |_|________|_| |
| 121 | // | | | | |
| 122 | // | | | | |
| 123 | // | | | | |
| 124 | // |_|________|_| |
| 125 | // |_|________|_| |
| 126 | // |
| 127 | // However, each corner is rendered as a fan rather than a simple quad, as below. (The diagram |
| 128 | // shows the upper part of the upper left corner. The bottom triangle would similarly be split |
| 129 | // into two triangles.) |
| 130 | // ________ |
| 131 | // |\ \ | |
| 132 | // | \ \ | |
| 133 | // | \\ | |
| 134 | // | \| |
| 135 | // -------- |
| 136 | // |
| 137 | // The center of the fan handles the curve of the corner. For roundrects where the stroke width |
| 138 | // is greater than the corner radius, the outer triangles blend from the curve to the straight |
| 139 | // sides. Otherwise these triangles will be degenerate. |
| 140 | // |
| 141 | // In the case where the stroke width is greater than the corner radius and the |
| 142 | // blur radius (overstroke), we add additional geometry to mark out the rectangle in the center. |
| 143 | // This rectangle extends the coverage values of the center edges of the 9-patch. |
| 144 | // ____________ |
| 145 | // |_|________|_| |
| 146 | // | |\ ____ /| | |
| 147 | // | | | | | | |
| 148 | // | | |____| | | |
| 149 | // |_|/______\|_| |
| 150 | // |_|________|_| |
| 151 | // |
| 152 | // For filled rrects we reuse the stroke geometry but add an additional quad to the center. |
| 153 | |
| 154 | static const uint16_t gRRectIndices[] = { |
| 155 | // clang-format off |
| 156 | // overstroke quads |
| 157 | // we place this at the beginning so that we can skip these indices when rendering as filled |
| 158 | 0, 6, 25, 0, 25, 24, |
| 159 | 6, 18, 27, 6, 27, 25, |
| 160 | 18, 12, 26, 18, 26, 27, |
| 161 | 12, 0, 24, 12, 24, 26, |
| 162 | |
| 163 | // corners |
| 164 | 0, 1, 2, 0, 2, 3, 0, 3, 4, 0, 4, 5, |
| 165 | 6, 11, 10, 6, 10, 9, 6, 9, 8, 6, 8, 7, |
| 166 | 12, 17, 16, 12, 16, 15, 12, 15, 14, 12, 14, 13, |
| 167 | 18, 19, 20, 18, 20, 21, 18, 21, 22, 18, 22, 23, |
| 168 | |
| 169 | // edges |
| 170 | 0, 5, 11, 0, 11, 6, |
| 171 | 6, 7, 19, 6, 19, 18, |
| 172 | 18, 23, 17, 18, 17, 12, |
| 173 | 12, 13, 1, 12, 1, 0, |
| 174 | |
| 175 | // fill quad |
| 176 | // we place this at the end so that we can skip these indices when rendering as stroked |
| 177 | 0, 6, 18, 0, 18, 12, |
| 178 | // clang-format on |
| 179 | }; |
| 180 | |
| 181 | // overstroke count |
| 182 | static const int kIndicesPerOverstrokeRRect = SK_ARRAY_COUNT(gRRectIndices) - 6; |
| 183 | // simple stroke count skips overstroke indices |
| 184 | static const int kIndicesPerStrokeRRect = kIndicesPerOverstrokeRRect - 6 * 4; |
| 185 | // fill count adds final quad to stroke count |
| 186 | static const int kIndicesPerFillRRect = kIndicesPerStrokeRRect + 6; |
| 187 | static const int kVertsPerStrokeRRect = 24; |
| 188 | static const int kVertsPerOverstrokeRRect = 28; |
| 189 | static const int kVertsPerFillRRect = 24; |
| 190 | |
| 191 | static int rrect_type_to_vert_count(RRectType type) { |
| 192 | switch (type) { |
| 193 | case kFill_RRectType: |
| 194 | return kVertsPerFillRRect; |
| 195 | case kStroke_RRectType: |
| 196 | return kVertsPerStrokeRRect; |
| 197 | case kOverstroke_RRectType: |
| 198 | return kVertsPerOverstrokeRRect; |
| 199 | } |
| 200 | ALOGE("Invalid rect type: %d", type); |
| 201 | return -1; |
| 202 | } |
| 203 | |
| 204 | static int rrect_type_to_index_count(RRectType type) { |
| 205 | switch (type) { |
| 206 | case kFill_RRectType: |
| 207 | return kIndicesPerFillRRect; |
| 208 | case kStroke_RRectType: |
| 209 | return kIndicesPerStrokeRRect; |
| 210 | case kOverstroke_RRectType: |
| 211 | return kIndicesPerOverstrokeRRect; |
| 212 | } |
| 213 | ALOGE("Invalid rect type: %d", type); |
| 214 | return -1; |
| 215 | } |
| 216 | |
| 217 | static const uint16_t* rrect_type_to_indices(RRectType type) { |
| 218 | switch (type) { |
| 219 | case kFill_RRectType: |
| 220 | case kStroke_RRectType: |
| 221 | return gRRectIndices + 6 * 4; |
| 222 | case kOverstroke_RRectType: |
| 223 | return gRRectIndices; |
| 224 | } |
| 225 | ALOGE("Invalid rect type: %d", type); |
| 226 | return nullptr; |
| 227 | } |
| 228 | |
| 229 | static void fillInCircleVerts(const Geometry& args, bool isStroked, |
| 230 | Mesh::VertexArray<vec2>& position, |
| 231 | Mesh::VertexArray<vec4>& shadowColor, |
| 232 | Mesh::VertexArray<vec3>& shadowParams) { |
| 233 | vec4 color = args.fColor; |
| 234 | float outerRadius = args.fOuterRadius; |
| 235 | float innerRadius = args.fInnerRadius; |
| 236 | float blurRadius = args.fBlurRadius; |
| 237 | float distanceCorrection = outerRadius / blurRadius; |
| 238 | |
| 239 | const FloatRect& bounds = args.fDevBounds; |
| 240 | |
| 241 | // The inner radius in the vertex data must be specified in normalized space. |
| 242 | innerRadius = innerRadius / outerRadius; |
| 243 | |
| 244 | vec2 center = vec2(bounds.getWidth() / 2.0f, bounds.getHeight() / 2.0f); |
| 245 | float halfWidth = 0.5f * bounds.getWidth(); |
| 246 | float octOffset = 0.41421356237f; // sqrt(2) - 1 |
| 247 | int vertexCount = 0; |
| 248 | |
| 249 | position[vertexCount] = center + vec2(-octOffset * halfWidth, -halfWidth); |
| 250 | shadowColor[vertexCount] = color; |
| 251 | shadowParams[vertexCount] = vec3(-octOffset, -1, distanceCorrection); |
| 252 | vertexCount++; |
| 253 | |
| 254 | position[vertexCount] = center + vec2(octOffset * halfWidth, -halfWidth); |
| 255 | shadowColor[vertexCount] = color; |
| 256 | shadowParams[vertexCount] = vec3(octOffset, -1, distanceCorrection); |
| 257 | vertexCount++; |
| 258 | |
| 259 | position[vertexCount] = center + vec2(halfWidth, -octOffset * halfWidth); |
| 260 | shadowColor[vertexCount] = color; |
| 261 | shadowParams[vertexCount] = vec3(1, -octOffset, distanceCorrection); |
| 262 | vertexCount++; |
| 263 | |
| 264 | position[vertexCount] = center + vec2(halfWidth, octOffset * halfWidth); |
| 265 | shadowColor[vertexCount] = color; |
| 266 | shadowParams[vertexCount] = vec3(1, octOffset, distanceCorrection); |
| 267 | vertexCount++; |
| 268 | |
| 269 | position[vertexCount] = center + vec2(octOffset * halfWidth, halfWidth); |
| 270 | shadowColor[vertexCount] = color; |
| 271 | shadowParams[vertexCount] = vec3(octOffset, 1, distanceCorrection); |
| 272 | vertexCount++; |
| 273 | |
| 274 | position[vertexCount] = center + vec2(-octOffset * halfWidth, halfWidth); |
| 275 | shadowColor[vertexCount] = color; |
| 276 | shadowParams[vertexCount] = vec3(-octOffset, 1, distanceCorrection); |
| 277 | vertexCount++; |
| 278 | |
| 279 | position[vertexCount] = center + vec2(-halfWidth, octOffset * halfWidth); |
| 280 | shadowColor[vertexCount] = color; |
| 281 | shadowParams[vertexCount] = vec3(-1, octOffset, distanceCorrection); |
| 282 | vertexCount++; |
| 283 | |
| 284 | position[vertexCount] = center + vec2(-halfWidth, -octOffset * halfWidth); |
| 285 | shadowColor[vertexCount] = color; |
| 286 | shadowParams[vertexCount] = vec3(-1, -octOffset, distanceCorrection); |
| 287 | vertexCount++; |
| 288 | |
| 289 | if (isStroked) { |
| 290 | // compute the inner ring |
| 291 | |
| 292 | // cosine and sine of pi/8 |
| 293 | float c = 0.923579533f; |
| 294 | float s = 0.382683432f; |
| 295 | float r = args.fInnerRadius; |
| 296 | |
| 297 | position[vertexCount] = center + vec2(-s * r, -c * r); |
| 298 | shadowColor[vertexCount] = color; |
| 299 | shadowParams[vertexCount] = vec3(-s * innerRadius, -c * innerRadius, distanceCorrection); |
| 300 | vertexCount++; |
| 301 | |
| 302 | position[vertexCount] = center + vec2(s * r, -c * r); |
| 303 | shadowColor[vertexCount] = color; |
| 304 | shadowParams[vertexCount] = vec3(s * innerRadius, -c * innerRadius, distanceCorrection); |
| 305 | vertexCount++; |
| 306 | |
| 307 | position[vertexCount] = center + vec2(c * r, -s * r); |
| 308 | shadowColor[vertexCount] = color; |
| 309 | shadowParams[vertexCount] = vec3(c * innerRadius, -s * innerRadius, distanceCorrection); |
| 310 | vertexCount++; |
| 311 | |
| 312 | position[vertexCount] = center + vec2(c * r, s * r); |
| 313 | shadowColor[vertexCount] = color; |
| 314 | shadowParams[vertexCount] = vec3(c * innerRadius, s * innerRadius, distanceCorrection); |
| 315 | vertexCount++; |
| 316 | |
| 317 | position[vertexCount] = center + vec2(s * r, c * r); |
| 318 | shadowColor[vertexCount] = color; |
| 319 | shadowParams[vertexCount] = vec3(s * innerRadius, c * innerRadius, distanceCorrection); |
| 320 | vertexCount++; |
| 321 | |
| 322 | position[vertexCount] = center + vec2(-s * r, c * r); |
| 323 | shadowColor[vertexCount] = color; |
| 324 | shadowParams[vertexCount] = vec3(-s * innerRadius, c * innerRadius, distanceCorrection); |
| 325 | vertexCount++; |
| 326 | |
| 327 | position[vertexCount] = center + vec2(-c * r, s * r); |
| 328 | shadowColor[vertexCount] = color; |
| 329 | shadowParams[vertexCount] = vec3(-c * innerRadius, s * innerRadius, distanceCorrection); |
| 330 | vertexCount++; |
| 331 | |
| 332 | position[vertexCount] = center + vec2(-c * r, -s * r); |
| 333 | shadowColor[vertexCount] = color; |
| 334 | shadowParams[vertexCount] = vec3(-c * innerRadius, -s * innerRadius, distanceCorrection); |
| 335 | vertexCount++; |
| 336 | } else { |
| 337 | // filled |
| 338 | position[vertexCount] = center; |
| 339 | shadowColor[vertexCount] = color; |
| 340 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 341 | vertexCount++; |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | static void fillInRRectVerts(const Geometry& args, Mesh::VertexArray<vec2>& position, |
| 346 | Mesh::VertexArray<vec4>& shadowColor, |
| 347 | Mesh::VertexArray<vec3>& shadowParams) { |
| 348 | vec4 color = args.fColor; |
| 349 | float outerRadius = args.fOuterRadius; |
| 350 | |
| 351 | const FloatRect& bounds = args.fDevBounds; |
| 352 | |
| 353 | float umbraInset = args.fUmbraInset; |
| 354 | float minDim = 0.5f * std::min(bounds.getWidth(), bounds.getHeight()); |
| 355 | if (umbraInset > minDim) { |
| 356 | umbraInset = minDim; |
| 357 | } |
| 358 | |
| 359 | float xInner[4] = {bounds.left + umbraInset, bounds.right - umbraInset, |
| 360 | bounds.left + umbraInset, bounds.right - umbraInset}; |
| 361 | float xMid[4] = {bounds.left + outerRadius, bounds.right - outerRadius, |
| 362 | bounds.left + outerRadius, bounds.right - outerRadius}; |
| 363 | float xOuter[4] = {bounds.left, bounds.right, bounds.left, bounds.right}; |
| 364 | float yInner[4] = {bounds.top + umbraInset, bounds.top + umbraInset, bounds.bottom - umbraInset, |
| 365 | bounds.bottom - umbraInset}; |
| 366 | float yMid[4] = {bounds.top + outerRadius, bounds.top + outerRadius, |
| 367 | bounds.bottom - outerRadius, bounds.bottom - outerRadius}; |
| 368 | float yOuter[4] = {bounds.top, bounds.top, bounds.bottom, bounds.bottom}; |
| 369 | |
| 370 | float blurRadius = args.fBlurRadius; |
| 371 | |
| 372 | // In the case where we have to inset more for the umbra, our two triangles in the |
| 373 | // corner get skewed to a diamond rather than a square. To correct for that, |
| 374 | // we also skew the vectors we send to the shader that help define the circle. |
| 375 | // By doing so, we end up with a quarter circle in the corner rather than the |
| 376 | // elliptical curve. |
| 377 | |
| 378 | // This is a bit magical, but it gives us the correct results at extrema: |
| 379 | // a) umbraInset == outerRadius produces an orthogonal vector |
| 380 | // b) outerRadius == 0 produces a diagonal vector |
| 381 | // And visually the corner looks correct. |
| 382 | vec2 outerVec = vec2(outerRadius - umbraInset, -outerRadius - umbraInset); |
| 383 | outerVec = normalize(outerVec); |
| 384 | // We want the circle edge to fall fractionally along the diagonal at |
| 385 | // (sqrt(2)*(umbraInset - outerRadius) + outerRadius)/sqrt(2)*umbraInset |
| 386 | // |
| 387 | // Setting the components of the diagonal offset to the following value will give us that. |
| 388 | float diagVal = umbraInset / (SK_ScalarSqrt2 * (outerRadius - umbraInset) - outerRadius); |
| 389 | vec2 diagVec = vec2(diagVal, diagVal); |
| 390 | float distanceCorrection = umbraInset / blurRadius; |
| 391 | |
| 392 | int vertexCount = 0; |
| 393 | // build corner by corner |
| 394 | for (int i = 0; i < 4; ++i) { |
| 395 | // inner point |
| 396 | position[vertexCount] = vec2(xInner[i], yInner[i]); |
| 397 | shadowColor[vertexCount] = color; |
| 398 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 399 | vertexCount++; |
| 400 | |
| 401 | // outer points |
| 402 | position[vertexCount] = vec2(xOuter[i], yInner[i]); |
| 403 | shadowColor[vertexCount] = color; |
| 404 | shadowParams[vertexCount] = vec3(0, -1, distanceCorrection); |
| 405 | vertexCount++; |
| 406 | |
| 407 | position[vertexCount] = vec2(xOuter[i], yMid[i]); |
| 408 | shadowColor[vertexCount] = color; |
| 409 | shadowParams[vertexCount] = vec3(outerVec.x, outerVec.y, distanceCorrection); |
| 410 | vertexCount++; |
| 411 | |
| 412 | position[vertexCount] = vec2(xOuter[i], yOuter[i]); |
| 413 | shadowColor[vertexCount] = color; |
| 414 | shadowParams[vertexCount] = vec3(diagVec.x, diagVec.y, distanceCorrection); |
| 415 | vertexCount++; |
| 416 | |
| 417 | position[vertexCount] = vec2(xMid[i], yOuter[i]); |
| 418 | shadowColor[vertexCount] = color; |
| 419 | shadowParams[vertexCount] = vec3(outerVec.x, outerVec.y, distanceCorrection); |
| 420 | vertexCount++; |
| 421 | |
| 422 | position[vertexCount] = vec2(xInner[i], yOuter[i]); |
| 423 | shadowColor[vertexCount] = color; |
| 424 | shadowParams[vertexCount] = vec3(0, -1, distanceCorrection); |
| 425 | vertexCount++; |
| 426 | } |
| 427 | |
| 428 | // Add the additional vertices for overstroked rrects. |
| 429 | // Effectively this is an additional stroked rrect, with its |
| 430 | // parameters equal to those in the center of the 9-patch. This will |
| 431 | // give constant values across this inner ring. |
| 432 | if (kOverstroke_RRectType == args.fType) { |
| 433 | float inset = umbraInset + args.fInnerRadius; |
| 434 | |
| 435 | // TL |
| 436 | position[vertexCount] = vec2(bounds.left + inset, bounds.top + inset); |
| 437 | shadowColor[vertexCount] = color; |
| 438 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 439 | vertexCount++; |
| 440 | |
| 441 | // TR |
| 442 | position[vertexCount] = vec2(bounds.right - inset, bounds.top + inset); |
| 443 | shadowColor[vertexCount] = color; |
| 444 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 445 | vertexCount++; |
| 446 | |
| 447 | // BL |
| 448 | position[vertexCount] = vec2(bounds.left + inset, bounds.bottom - inset); |
| 449 | shadowColor[vertexCount] = color; |
| 450 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 451 | vertexCount++; |
| 452 | |
| 453 | // BR |
| 454 | position[vertexCount] = vec2(bounds.right - inset, bounds.bottom - inset); |
| 455 | shadowColor[vertexCount] = color; |
| 456 | shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| 457 | vertexCount++; |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | int getVertexCountForGeometry(const Geometry& shadowGeometry) { |
| 462 | if (shadowGeometry.fIsCircle) { |
| 463 | return circle_type_to_vert_count(shadowGeometry.fType); |
| 464 | } |
| 465 | |
| 466 | return rrect_type_to_vert_count(shadowGeometry.fType); |
| 467 | } |
| 468 | |
| 469 | int getIndexCountForGeometry(const Geometry& shadowGeometry) { |
| 470 | if (shadowGeometry.fIsCircle) { |
| 471 | return circle_type_to_index_count(kStroke_RRectType == shadowGeometry.fType); |
| 472 | } |
| 473 | |
| 474 | return rrect_type_to_index_count(shadowGeometry.fType); |
| 475 | } |
| 476 | |
| 477 | void fillVerticesForGeometry(const Geometry& shadowGeometry, int /* vertexCount */, |
| 478 | Mesh::VertexArray<vec2> position, Mesh::VertexArray<vec4> shadowColor, |
| 479 | Mesh::VertexArray<vec3> shadowParams) { |
| 480 | if (shadowGeometry.fIsCircle) { |
| 481 | fillInCircleVerts(shadowGeometry, shadowGeometry.fIsStroked, position, shadowColor, |
| 482 | shadowParams); |
| 483 | } else { |
| 484 | fillInRRectVerts(shadowGeometry, position, shadowColor, shadowParams); |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | void fillIndicesForGeometry(const Geometry& shadowGeometry, int indexCount, |
| 489 | int startingVertexOffset, uint16_t* indices) { |
| 490 | if (shadowGeometry.fIsCircle) { |
| 491 | const uint16_t* primIndices = circle_type_to_indices(shadowGeometry.fIsStroked); |
| 492 | for (int i = 0; i < indexCount; ++i) { |
| 493 | indices[i] = primIndices[i] + startingVertexOffset; |
| 494 | } |
| 495 | } else { |
| 496 | const uint16_t* primIndices = rrect_type_to_indices(shadowGeometry.fType); |
| 497 | for (int i = 0; i < indexCount; ++i) { |
| 498 | indices[i] = primIndices[i] + startingVertexOffset; |
| 499 | } |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | inline void GetSpotParams(float occluderZ, float lightX, float lightY, float lightZ, |
| 504 | float lightRadius, float& blurRadius, float& scale, vec2& translate) { |
| 505 | float zRatio = divide_and_pin(occluderZ, lightZ - occluderZ, 0.0f, 0.95f); |
| 506 | blurRadius = lightRadius * zRatio; |
| 507 | scale = divide_and_pin(lightZ, lightZ - occluderZ, 1.0f, 1.95f); |
| 508 | translate.x = -zRatio * lightX; |
| 509 | translate.y = -zRatio * lightY; |
| 510 | } |
| 511 | |
| 512 | static std::unique_ptr<Geometry> getShadowGeometry(const vec4& color, const FloatRect& devRect, |
| 513 | float devRadius, float blurRadius, |
| 514 | float insetWidth) { |
| 515 | // An insetWidth > 1/2 rect width or height indicates a simple fill. |
| 516 | const bool isCircle = ((devRadius >= devRect.getWidth()) && (devRadius >= devRect.getHeight())); |
| 517 | |
| 518 | FloatRect bounds = devRect; |
| 519 | float innerRadius = 0.0f; |
| 520 | float outerRadius = devRadius; |
| 521 | float umbraInset; |
| 522 | |
| 523 | RRectType type = kFill_RRectType; |
| 524 | if (isCircle) { |
| 525 | umbraInset = 0; |
| 526 | } else { |
| 527 | umbraInset = std::max(outerRadius, blurRadius); |
| 528 | } |
| 529 | |
| 530 | // If stroke is greater than width or height, this is still a fill, |
| 531 | // otherwise we compute stroke params. |
| 532 | if (isCircle) { |
| 533 | innerRadius = devRadius - insetWidth; |
| 534 | type = innerRadius > 0 ? kStroke_RRectType : kFill_RRectType; |
| 535 | } else { |
| 536 | if (insetWidth <= 0.5f * std::min(devRect.getWidth(), devRect.getHeight())) { |
| 537 | // We don't worry about a real inner radius, we just need to know if we |
| 538 | // need to create overstroke vertices. |
| 539 | innerRadius = std::max(insetWidth - umbraInset, 0.0f); |
| 540 | type = innerRadius > 0 ? kOverstroke_RRectType : kStroke_RRectType; |
| 541 | } |
| 542 | } |
| 543 | const bool isStroked = (kStroke_RRectType == type); |
| 544 | return std::make_unique<Geometry>(Geometry{color, outerRadius, umbraInset, innerRadius, |
| 545 | blurRadius, bounds, type, isCircle, isStroked}); |
| 546 | } |
| 547 | |
| 548 | std::unique_ptr<Geometry> getAmbientShadowGeometry(const FloatRect& casterRect, |
| 549 | float casterCornerRadius, float casterZ, |
| 550 | bool casterIsTranslucent, |
| 551 | const vec4& ambientColor) { |
| 552 | float devSpaceInsetWidth = AmbientBlurRadius(casterZ); |
| 553 | const float umbraRecipAlpha = AmbientRecipAlpha(casterZ); |
| 554 | const float devSpaceAmbientBlur = devSpaceInsetWidth * umbraRecipAlpha; |
| 555 | |
| 556 | // Outset the shadow rrect to the border of the penumbra |
| 557 | float ambientPathOutset = devSpaceInsetWidth; |
| 558 | FloatRect outsetRect(casterRect); |
| 559 | outsetRect.left -= ambientPathOutset; |
| 560 | outsetRect.top -= ambientPathOutset; |
| 561 | outsetRect.right += ambientPathOutset; |
| 562 | outsetRect.bottom += ambientPathOutset; |
| 563 | |
| 564 | float outsetRad = casterCornerRadius + ambientPathOutset; |
| 565 | if (casterIsTranslucent) { |
| 566 | // set a large inset to force a fill |
| 567 | devSpaceInsetWidth = outsetRect.getWidth(); |
| 568 | } |
| 569 | |
| 570 | return getShadowGeometry(ambientColor, outsetRect, std::abs(outsetRad), devSpaceAmbientBlur, |
| 571 | std::abs(devSpaceInsetWidth)); |
| 572 | } |
| 573 | |
| 574 | std::unique_ptr<Geometry> getSpotShadowGeometry(const FloatRect& casterRect, |
| 575 | float casterCornerRadius, float casterZ, |
| 576 | bool casterIsTranslucent, const vec4& spotColor, |
| 577 | const vec3& lightPosition, float lightRadius) { |
| 578 | float devSpaceSpotBlur; |
| 579 | float spotScale; |
| 580 | vec2 spotOffset; |
| 581 | GetSpotParams(casterZ, lightPosition.x, lightPosition.y, lightPosition.z, lightRadius, |
| 582 | devSpaceSpotBlur, spotScale, spotOffset); |
| 583 | // handle scale of radius due to CTM |
| 584 | const float srcSpaceSpotBlur = devSpaceSpotBlur; |
| 585 | |
| 586 | // Adjust translate for the effect of the scale. |
| 587 | spotOffset.x += spotScale; |
| 588 | spotOffset.y += spotScale; |
| 589 | |
| 590 | // Compute the transformed shadow rect |
| 591 | ui::Transform shadowTransform; |
| 592 | shadowTransform.set(spotOffset.x, spotOffset.y); |
| 593 | shadowTransform.set(spotScale, 0, 0, spotScale); |
| 594 | FloatRect spotShadowRect = shadowTransform.transform(casterRect); |
| 595 | float spotShadowRadius = casterCornerRadius * spotScale; |
| 596 | |
| 597 | // Compute the insetWidth |
| 598 | float blurOutset = srcSpaceSpotBlur; |
| 599 | float insetWidth = blurOutset; |
| 600 | if (casterIsTranslucent) { |
| 601 | // If transparent, just do a fill |
| 602 | insetWidth += spotShadowRect.getWidth(); |
| 603 | } else { |
| 604 | // For shadows, instead of using a stroke we specify an inset from the penumbra |
| 605 | // border. We want to extend this inset area so that it meets up with the caster |
| 606 | // geometry. The inset geometry will by default already be inset by the blur width. |
| 607 | // |
| 608 | // We compare the min and max corners inset by the radius between the original |
| 609 | // rrect and the shadow rrect. The distance between the two plus the difference |
| 610 | // between the scaled radius and the original radius gives the distance from the |
| 611 | // transformed shadow shape to the original shape in that corner. The max |
| 612 | // of these gives the maximum distance we need to cover. |
| 613 | // |
| 614 | // Since we are outsetting by 1/2 the blur distance, we just add the maxOffset to |
| 615 | // that to get the full insetWidth. |
| 616 | float maxOffset; |
| 617 | if (casterCornerRadius <= 0.f) { |
| 618 | // Manhattan distance works better for rects |
| 619 | maxOffset = std::max(std::max(std::abs(spotShadowRect.left - casterRect.left), |
| 620 | std::abs(spotShadowRect.top - casterRect.top)), |
| 621 | std::max(std::abs(spotShadowRect.right - casterRect.right), |
| 622 | std::abs(spotShadowRect.bottom - casterRect.bottom))); |
| 623 | } else { |
| 624 | float dr = spotShadowRadius - casterCornerRadius; |
| 625 | vec2 upperLeftOffset = vec2(spotShadowRect.left - casterRect.left + dr, |
| 626 | spotShadowRect.top - casterRect.top + dr); |
| 627 | vec2 lowerRightOffset = vec2(spotShadowRect.right - casterRect.right - dr, |
| 628 | spotShadowRect.bottom - casterRect.bottom - dr); |
| 629 | maxOffset = sqrt(std::max(dot(upperLeftOffset, lowerRightOffset), |
| 630 | dot(lowerRightOffset, lowerRightOffset))) + |
| 631 | dr; |
| 632 | } |
| 633 | insetWidth += std::max(blurOutset, maxOffset); |
| 634 | } |
| 635 | |
| 636 | // Outset the shadow rrect to the border of the penumbra |
| 637 | spotShadowRadius += blurOutset; |
| 638 | spotShadowRect.left -= blurOutset; |
| 639 | spotShadowRect.top -= blurOutset; |
| 640 | spotShadowRect.right += blurOutset; |
| 641 | spotShadowRect.bottom += blurOutset; |
| 642 | |
| 643 | return getShadowGeometry(spotColor, spotShadowRect, std::abs(spotShadowRadius), |
| 644 | 2.0f * devSpaceSpotBlur, std::abs(insetWidth)); |
| 645 | } |
| 646 | |
| 647 | } // namespace gl |
| 648 | } // namespace renderengine |
| 649 | } // namespace android |