| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <math/vec4.h> |
| |
| #include <renderengine/Mesh.h> |
| |
| #include <ui/Rect.h> |
| #include <ui/Transform.h> |
| |
| #include <utils/Log.h> |
| |
| #include "GLSkiaShadowPort.h" |
| |
| namespace android { |
| namespace renderengine { |
| namespace gl { |
| |
| /** |
| * The shadow geometry logic and vertex generation code has been ported from skia shadow |
| * fast path OpenGL implementation to draw shadows around rects and rounded rects including |
| * circles. |
| * |
| * path: skia/src/gpu/GrRenderTargetContext.cpp GrRenderTargetContext::drawFastShadow |
| * |
| * Modifications made: |
| * - Switched to using std lib math functions |
| * - Fall off function is implemented in vertex shader rather than a shadow texture |
| * - Removed transformations applied on the caster rect since the caster will be in local |
| * coordinate space and will be transformed by the vertex shader. |
| */ |
| |
| static inline float divide_and_pin(float numer, float denom, float min, float max) { |
| if (denom == 0.0f) return min; |
| return std::clamp(numer / denom, min, max); |
| } |
| |
| static constexpr auto SK_ScalarSqrt2 = 1.41421356f; |
| static constexpr auto kAmbientHeightFactor = 1.0f / 128.0f; |
| static constexpr auto kAmbientGeomFactor = 64.0f; |
| // Assuming that we have a light height of 600 for the spot shadow, |
| // the spot values will reach their maximum at a height of approximately 292.3077. |
| // We'll round up to 300 to keep it simple. |
| static constexpr auto kMaxAmbientRadius = 300 * kAmbientHeightFactor * kAmbientGeomFactor; |
| |
| inline float AmbientBlurRadius(float height) { |
| return std::min(height * kAmbientHeightFactor * kAmbientGeomFactor, kMaxAmbientRadius); |
| } |
| inline float AmbientRecipAlpha(float height) { |
| return 1.0f + std::max(height * kAmbientHeightFactor, 0.0f); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // Circle Data |
| // |
| // We have two possible cases for geometry for a circle: |
| |
| // In the case of a normal fill, we draw geometry for the circle as an octagon. |
| static const uint16_t gFillCircleIndices[] = { |
| // enter the octagon |
| // clang-format off |
| 0, 1, 8, 1, 2, 8, |
| 2, 3, 8, 3, 4, 8, |
| 4, 5, 8, 5, 6, 8, |
| 6, 7, 8, 7, 0, 8, |
| // clang-format on |
| }; |
| |
| // For stroked circles, we use two nested octagons. |
| static const uint16_t gStrokeCircleIndices[] = { |
| // enter the octagon |
| // clang-format off |
| 0, 1, 9, 0, 9, 8, |
| 1, 2, 10, 1, 10, 9, |
| 2, 3, 11, 2, 11, 10, |
| 3, 4, 12, 3, 12, 11, |
| 4, 5, 13, 4, 13, 12, |
| 5, 6, 14, 5, 14, 13, |
| 6, 7, 15, 6, 15, 14, |
| 7, 0, 8, 7, 8, 15, |
| // clang-format on |
| }; |
| |
| #define SK_ARRAY_COUNT(a) (sizeof(a) / sizeof((a)[0])) |
| static const int kIndicesPerFillCircle = SK_ARRAY_COUNT(gFillCircleIndices); |
| static const int kIndicesPerStrokeCircle = SK_ARRAY_COUNT(gStrokeCircleIndices); |
| static const int kVertsPerStrokeCircle = 16; |
| static const int kVertsPerFillCircle = 9; |
| |
| static int circle_type_to_vert_count(bool stroked) { |
| return stroked ? kVertsPerStrokeCircle : kVertsPerFillCircle; |
| } |
| |
| static int circle_type_to_index_count(bool stroked) { |
| return stroked ? kIndicesPerStrokeCircle : kIndicesPerFillCircle; |
| } |
| |
| static const uint16_t* circle_type_to_indices(bool stroked) { |
| return stroked ? gStrokeCircleIndices : gFillCircleIndices; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // RoundRect Data |
| // |
| // The geometry for a shadow roundrect is similar to a 9-patch: |
| // ____________ |
| // |_|________|_| |
| // | | | | |
| // | | | | |
| // | | | | |
| // |_|________|_| |
| // |_|________|_| |
| // |
| // However, each corner is rendered as a fan rather than a simple quad, as below. (The diagram |
| // shows the upper part of the upper left corner. The bottom triangle would similarly be split |
| // into two triangles.) |
| // ________ |
| // |\ \ | |
| // | \ \ | |
| // | \\ | |
| // | \| |
| // -------- |
| // |
| // The center of the fan handles the curve of the corner. For roundrects where the stroke width |
| // is greater than the corner radius, the outer triangles blend from the curve to the straight |
| // sides. Otherwise these triangles will be degenerate. |
| // |
| // In the case where the stroke width is greater than the corner radius and the |
| // blur radius (overstroke), we add additional geometry to mark out the rectangle in the center. |
| // This rectangle extends the coverage values of the center edges of the 9-patch. |
| // ____________ |
| // |_|________|_| |
| // | |\ ____ /| | |
| // | | | | | | |
| // | | |____| | | |
| // |_|/______\|_| |
| // |_|________|_| |
| // |
| // For filled rrects we reuse the stroke geometry but add an additional quad to the center. |
| |
| static const uint16_t gRRectIndices[] = { |
| // clang-format off |
| // overstroke quads |
| // we place this at the beginning so that we can skip these indices when rendering as filled |
| 0, 6, 25, 0, 25, 24, |
| 6, 18, 27, 6, 27, 25, |
| 18, 12, 26, 18, 26, 27, |
| 12, 0, 24, 12, 24, 26, |
| |
| // corners |
| 0, 1, 2, 0, 2, 3, 0, 3, 4, 0, 4, 5, |
| 6, 11, 10, 6, 10, 9, 6, 9, 8, 6, 8, 7, |
| 12, 17, 16, 12, 16, 15, 12, 15, 14, 12, 14, 13, |
| 18, 19, 20, 18, 20, 21, 18, 21, 22, 18, 22, 23, |
| |
| // edges |
| 0, 5, 11, 0, 11, 6, |
| 6, 7, 19, 6, 19, 18, |
| 18, 23, 17, 18, 17, 12, |
| 12, 13, 1, 12, 1, 0, |
| |
| // fill quad |
| // we place this at the end so that we can skip these indices when rendering as stroked |
| 0, 6, 18, 0, 18, 12, |
| // clang-format on |
| }; |
| |
| // overstroke count |
| static const int kIndicesPerOverstrokeRRect = SK_ARRAY_COUNT(gRRectIndices) - 6; |
| // simple stroke count skips overstroke indices |
| static const int kIndicesPerStrokeRRect = kIndicesPerOverstrokeRRect - 6 * 4; |
| // fill count adds final quad to stroke count |
| static const int kIndicesPerFillRRect = kIndicesPerStrokeRRect + 6; |
| static const int kVertsPerStrokeRRect = 24; |
| static const int kVertsPerOverstrokeRRect = 28; |
| static const int kVertsPerFillRRect = 24; |
| |
| static int rrect_type_to_vert_count(RRectType type) { |
| switch (type) { |
| case kFill_RRectType: |
| return kVertsPerFillRRect; |
| case kStroke_RRectType: |
| return kVertsPerStrokeRRect; |
| case kOverstroke_RRectType: |
| return kVertsPerOverstrokeRRect; |
| } |
| ALOGE("Invalid rect type: %d", type); |
| return -1; |
| } |
| |
| static int rrect_type_to_index_count(RRectType type) { |
| switch (type) { |
| case kFill_RRectType: |
| return kIndicesPerFillRRect; |
| case kStroke_RRectType: |
| return kIndicesPerStrokeRRect; |
| case kOverstroke_RRectType: |
| return kIndicesPerOverstrokeRRect; |
| } |
| ALOGE("Invalid rect type: %d", type); |
| return -1; |
| } |
| |
| static const uint16_t* rrect_type_to_indices(RRectType type) { |
| switch (type) { |
| case kFill_RRectType: |
| case kStroke_RRectType: |
| return gRRectIndices + 6 * 4; |
| case kOverstroke_RRectType: |
| return gRRectIndices; |
| } |
| ALOGE("Invalid rect type: %d", type); |
| return nullptr; |
| } |
| |
| static void fillInCircleVerts(const Geometry& args, bool isStroked, |
| Mesh::VertexArray<vec2>& position, |
| Mesh::VertexArray<vec4>& shadowColor, |
| Mesh::VertexArray<vec3>& shadowParams) { |
| vec4 color = args.fColor; |
| float outerRadius = args.fOuterRadius; |
| float innerRadius = args.fInnerRadius; |
| float blurRadius = args.fBlurRadius; |
| float distanceCorrection = outerRadius / blurRadius; |
| |
| const FloatRect& bounds = args.fDevBounds; |
| |
| // The inner radius in the vertex data must be specified in normalized space. |
| innerRadius = innerRadius / outerRadius; |
| |
| vec2 center = vec2(bounds.getWidth() / 2.0f, bounds.getHeight() / 2.0f); |
| float halfWidth = 0.5f * bounds.getWidth(); |
| float octOffset = 0.41421356237f; // sqrt(2) - 1 |
| int vertexCount = 0; |
| |
| position[vertexCount] = center + vec2(-octOffset * halfWidth, -halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-octOffset, -1, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(octOffset * halfWidth, -halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(octOffset, -1, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(halfWidth, -octOffset * halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(1, -octOffset, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(halfWidth, octOffset * halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(1, octOffset, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(octOffset * halfWidth, halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(octOffset, 1, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-octOffset * halfWidth, halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-octOffset, 1, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-halfWidth, octOffset * halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-1, octOffset, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-halfWidth, -octOffset * halfWidth); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-1, -octOffset, distanceCorrection); |
| vertexCount++; |
| |
| if (isStroked) { |
| // compute the inner ring |
| |
| // cosine and sine of pi/8 |
| float c = 0.923579533f; |
| float s = 0.382683432f; |
| float r = args.fInnerRadius; |
| |
| position[vertexCount] = center + vec2(-s * r, -c * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-s * innerRadius, -c * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(s * r, -c * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(s * innerRadius, -c * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(c * r, -s * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(c * innerRadius, -s * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(c * r, s * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(c * innerRadius, s * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(s * r, c * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(s * innerRadius, c * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-s * r, c * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-s * innerRadius, c * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-c * r, s * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-c * innerRadius, s * innerRadius, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = center + vec2(-c * r, -s * r); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(-c * innerRadius, -s * innerRadius, distanceCorrection); |
| vertexCount++; |
| } else { |
| // filled |
| position[vertexCount] = center; |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| } |
| } |
| |
| static void fillInRRectVerts(const Geometry& args, Mesh::VertexArray<vec2>& position, |
| Mesh::VertexArray<vec4>& shadowColor, |
| Mesh::VertexArray<vec3>& shadowParams) { |
| vec4 color = args.fColor; |
| float outerRadius = args.fOuterRadius; |
| |
| const FloatRect& bounds = args.fDevBounds; |
| |
| float umbraInset = args.fUmbraInset; |
| float minDim = 0.5f * std::min(bounds.getWidth(), bounds.getHeight()); |
| if (umbraInset > minDim) { |
| umbraInset = minDim; |
| } |
| |
| float xInner[4] = {bounds.left + umbraInset, bounds.right - umbraInset, |
| bounds.left + umbraInset, bounds.right - umbraInset}; |
| float xMid[4] = {bounds.left + outerRadius, bounds.right - outerRadius, |
| bounds.left + outerRadius, bounds.right - outerRadius}; |
| float xOuter[4] = {bounds.left, bounds.right, bounds.left, bounds.right}; |
| float yInner[4] = {bounds.top + umbraInset, bounds.top + umbraInset, bounds.bottom - umbraInset, |
| bounds.bottom - umbraInset}; |
| float yMid[4] = {bounds.top + outerRadius, bounds.top + outerRadius, |
| bounds.bottom - outerRadius, bounds.bottom - outerRadius}; |
| float yOuter[4] = {bounds.top, bounds.top, bounds.bottom, bounds.bottom}; |
| |
| float blurRadius = args.fBlurRadius; |
| |
| // In the case where we have to inset more for the umbra, our two triangles in the |
| // corner get skewed to a diamond rather than a square. To correct for that, |
| // we also skew the vectors we send to the shader that help define the circle. |
| // By doing so, we end up with a quarter circle in the corner rather than the |
| // elliptical curve. |
| |
| // This is a bit magical, but it gives us the correct results at extrema: |
| // a) umbraInset == outerRadius produces an orthogonal vector |
| // b) outerRadius == 0 produces a diagonal vector |
| // And visually the corner looks correct. |
| vec2 outerVec = vec2(outerRadius - umbraInset, -outerRadius - umbraInset); |
| outerVec = normalize(outerVec); |
| // We want the circle edge to fall fractionally along the diagonal at |
| // (sqrt(2)*(umbraInset - outerRadius) + outerRadius)/sqrt(2)*umbraInset |
| // |
| // Setting the components of the diagonal offset to the following value will give us that. |
| float diagVal = umbraInset / (SK_ScalarSqrt2 * (outerRadius - umbraInset) - outerRadius); |
| vec2 diagVec = vec2(diagVal, diagVal); |
| float distanceCorrection = umbraInset / blurRadius; |
| |
| int vertexCount = 0; |
| // build corner by corner |
| for (int i = 0; i < 4; ++i) { |
| // inner point |
| position[vertexCount] = vec2(xInner[i], yInner[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| |
| // outer points |
| position[vertexCount] = vec2(xOuter[i], yInner[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, -1, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = vec2(xOuter[i], yMid[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(outerVec.x, outerVec.y, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = vec2(xOuter[i], yOuter[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(diagVec.x, diagVec.y, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = vec2(xMid[i], yOuter[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(outerVec.x, outerVec.y, distanceCorrection); |
| vertexCount++; |
| |
| position[vertexCount] = vec2(xInner[i], yOuter[i]); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, -1, distanceCorrection); |
| vertexCount++; |
| } |
| |
| // Add the additional vertices for overstroked rrects. |
| // Effectively this is an additional stroked rrect, with its |
| // parameters equal to those in the center of the 9-patch. This will |
| // give constant values across this inner ring. |
| if (kOverstroke_RRectType == args.fType) { |
| float inset = umbraInset + args.fInnerRadius; |
| |
| // TL |
| position[vertexCount] = vec2(bounds.left + inset, bounds.top + inset); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| |
| // TR |
| position[vertexCount] = vec2(bounds.right - inset, bounds.top + inset); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| |
| // BL |
| position[vertexCount] = vec2(bounds.left + inset, bounds.bottom - inset); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| |
| // BR |
| position[vertexCount] = vec2(bounds.right - inset, bounds.bottom - inset); |
| shadowColor[vertexCount] = color; |
| shadowParams[vertexCount] = vec3(0, 0, distanceCorrection); |
| vertexCount++; |
| } |
| } |
| |
| int getVertexCountForGeometry(const Geometry& shadowGeometry) { |
| if (shadowGeometry.fIsCircle) { |
| return circle_type_to_vert_count(shadowGeometry.fType); |
| } |
| |
| return rrect_type_to_vert_count(shadowGeometry.fType); |
| } |
| |
| int getIndexCountForGeometry(const Geometry& shadowGeometry) { |
| if (shadowGeometry.fIsCircle) { |
| return circle_type_to_index_count(kStroke_RRectType == shadowGeometry.fType); |
| } |
| |
| return rrect_type_to_index_count(shadowGeometry.fType); |
| } |
| |
| void fillVerticesForGeometry(const Geometry& shadowGeometry, int /* vertexCount */, |
| Mesh::VertexArray<vec2> position, Mesh::VertexArray<vec4> shadowColor, |
| Mesh::VertexArray<vec3> shadowParams) { |
| if (shadowGeometry.fIsCircle) { |
| fillInCircleVerts(shadowGeometry, shadowGeometry.fIsStroked, position, shadowColor, |
| shadowParams); |
| } else { |
| fillInRRectVerts(shadowGeometry, position, shadowColor, shadowParams); |
| } |
| } |
| |
| void fillIndicesForGeometry(const Geometry& shadowGeometry, int indexCount, |
| int startingVertexOffset, uint16_t* indices) { |
| if (shadowGeometry.fIsCircle) { |
| const uint16_t* primIndices = circle_type_to_indices(shadowGeometry.fIsStroked); |
| for (int i = 0; i < indexCount; ++i) { |
| indices[i] = primIndices[i] + startingVertexOffset; |
| } |
| } else { |
| const uint16_t* primIndices = rrect_type_to_indices(shadowGeometry.fType); |
| for (int i = 0; i < indexCount; ++i) { |
| indices[i] = primIndices[i] + startingVertexOffset; |
| } |
| } |
| } |
| |
| inline void GetSpotParams(float occluderZ, float lightX, float lightY, float lightZ, |
| float lightRadius, float& blurRadius, float& scale, vec2& translate) { |
| float zRatio = divide_and_pin(occluderZ, lightZ - occluderZ, 0.0f, 0.95f); |
| blurRadius = lightRadius * zRatio; |
| scale = divide_and_pin(lightZ, lightZ - occluderZ, 1.0f, 1.95f); |
| translate.x = -zRatio * lightX; |
| translate.y = -zRatio * lightY; |
| } |
| |
| static std::unique_ptr<Geometry> getShadowGeometry(const vec4& color, const FloatRect& devRect, |
| float devRadius, float blurRadius, |
| float insetWidth) { |
| // An insetWidth > 1/2 rect width or height indicates a simple fill. |
| const bool isCircle = ((devRadius >= devRect.getWidth()) && (devRadius >= devRect.getHeight())); |
| |
| FloatRect bounds = devRect; |
| float innerRadius = 0.0f; |
| float outerRadius = devRadius; |
| float umbraInset; |
| |
| RRectType type = kFill_RRectType; |
| if (isCircle) { |
| umbraInset = 0; |
| } else { |
| umbraInset = std::max(outerRadius, blurRadius); |
| } |
| |
| // If stroke is greater than width or height, this is still a fill, |
| // otherwise we compute stroke params. |
| if (isCircle) { |
| innerRadius = devRadius - insetWidth; |
| type = innerRadius > 0 ? kStroke_RRectType : kFill_RRectType; |
| } else { |
| if (insetWidth <= 0.5f * std::min(devRect.getWidth(), devRect.getHeight())) { |
| // We don't worry about a real inner radius, we just need to know if we |
| // need to create overstroke vertices. |
| innerRadius = std::max(insetWidth - umbraInset, 0.0f); |
| type = innerRadius > 0 ? kOverstroke_RRectType : kStroke_RRectType; |
| } |
| } |
| const bool isStroked = (kStroke_RRectType == type); |
| return std::make_unique<Geometry>(Geometry{color, outerRadius, umbraInset, innerRadius, |
| blurRadius, bounds, type, isCircle, isStroked}); |
| } |
| |
| std::unique_ptr<Geometry> getAmbientShadowGeometry(const FloatRect& casterRect, |
| float casterCornerRadius, float casterZ, |
| bool casterIsTranslucent, |
| const vec4& ambientColor) { |
| float devSpaceInsetWidth = AmbientBlurRadius(casterZ); |
| const float umbraRecipAlpha = AmbientRecipAlpha(casterZ); |
| const float devSpaceAmbientBlur = devSpaceInsetWidth * umbraRecipAlpha; |
| |
| // Outset the shadow rrect to the border of the penumbra |
| float ambientPathOutset = devSpaceInsetWidth; |
| FloatRect outsetRect(casterRect); |
| outsetRect.left -= ambientPathOutset; |
| outsetRect.top -= ambientPathOutset; |
| outsetRect.right += ambientPathOutset; |
| outsetRect.bottom += ambientPathOutset; |
| |
| float outsetRad = casterCornerRadius + ambientPathOutset; |
| if (casterIsTranslucent) { |
| // set a large inset to force a fill |
| devSpaceInsetWidth = outsetRect.getWidth(); |
| } |
| |
| return getShadowGeometry(ambientColor, outsetRect, std::abs(outsetRad), devSpaceAmbientBlur, |
| std::abs(devSpaceInsetWidth)); |
| } |
| |
| std::unique_ptr<Geometry> getSpotShadowGeometry(const FloatRect& casterRect, |
| float casterCornerRadius, float casterZ, |
| bool casterIsTranslucent, const vec4& spotColor, |
| const vec3& lightPosition, float lightRadius) { |
| float devSpaceSpotBlur; |
| float spotScale; |
| vec2 spotOffset; |
| GetSpotParams(casterZ, lightPosition.x, lightPosition.y, lightPosition.z, lightRadius, |
| devSpaceSpotBlur, spotScale, spotOffset); |
| // handle scale of radius due to CTM |
| const float srcSpaceSpotBlur = devSpaceSpotBlur; |
| |
| // Adjust translate for the effect of the scale. |
| spotOffset.x += spotScale; |
| spotOffset.y += spotScale; |
| |
| // Compute the transformed shadow rect |
| ui::Transform shadowTransform; |
| shadowTransform.set(spotOffset.x, spotOffset.y); |
| shadowTransform.set(spotScale, 0, 0, spotScale); |
| FloatRect spotShadowRect = shadowTransform.transform(casterRect); |
| float spotShadowRadius = casterCornerRadius * spotScale; |
| |
| // Compute the insetWidth |
| float blurOutset = srcSpaceSpotBlur; |
| float insetWidth = blurOutset; |
| if (casterIsTranslucent) { |
| // If transparent, just do a fill |
| insetWidth += spotShadowRect.getWidth(); |
| } else { |
| // For shadows, instead of using a stroke we specify an inset from the penumbra |
| // border. We want to extend this inset area so that it meets up with the caster |
| // geometry. The inset geometry will by default already be inset by the blur width. |
| // |
| // We compare the min and max corners inset by the radius between the original |
| // rrect and the shadow rrect. The distance between the two plus the difference |
| // between the scaled radius and the original radius gives the distance from the |
| // transformed shadow shape to the original shape in that corner. The max |
| // of these gives the maximum distance we need to cover. |
| // |
| // Since we are outsetting by 1/2 the blur distance, we just add the maxOffset to |
| // that to get the full insetWidth. |
| float maxOffset; |
| if (casterCornerRadius <= 0.f) { |
| // Manhattan distance works better for rects |
| maxOffset = std::max(std::max(std::abs(spotShadowRect.left - casterRect.left), |
| std::abs(spotShadowRect.top - casterRect.top)), |
| std::max(std::abs(spotShadowRect.right - casterRect.right), |
| std::abs(spotShadowRect.bottom - casterRect.bottom))); |
| } else { |
| float dr = spotShadowRadius - casterCornerRadius; |
| vec2 upperLeftOffset = vec2(spotShadowRect.left - casterRect.left + dr, |
| spotShadowRect.top - casterRect.top + dr); |
| vec2 lowerRightOffset = vec2(spotShadowRect.right - casterRect.right - dr, |
| spotShadowRect.bottom - casterRect.bottom - dr); |
| maxOffset = sqrt(std::max(dot(upperLeftOffset, lowerRightOffset), |
| dot(lowerRightOffset, lowerRightOffset))) + |
| dr; |
| } |
| insetWidth += std::max(blurOutset, maxOffset); |
| } |
| |
| // Outset the shadow rrect to the border of the penumbra |
| spotShadowRadius += blurOutset; |
| spotShadowRect.left -= blurOutset; |
| spotShadowRect.top -= blurOutset; |
| spotShadowRect.right += blurOutset; |
| spotShadowRect.bottom += blurOutset; |
| |
| return getShadowGeometry(spotColor, spotShadowRect, std::abs(spotShadowRadius), |
| 2.0f * devSpaceSpotBlur, std::abs(insetWidth)); |
| } |
| |
| void fillShadowTextureData(uint8_t* data, size_t shadowTextureWidth) { |
| for (int i = 0; i < shadowTextureWidth; i++) { |
| const float d = 1 - i / ((shadowTextureWidth * 1.0f) - 1.0f); |
| data[i] = static_cast<uint8_t>((exp(-4.0f * d * d) - 0.018f) * 255); |
| } |
| } |
| |
| } // namespace gl |
| } // namespace renderengine |
| } // namespace android |
