diff --git a/libs/renderengine/Android.bp b/libs/renderengine/Android.bp
index 136ad0d..348377e 100644
--- a/libs/renderengine/Android.bp
+++ b/libs/renderengine/Android.bp
@@ -52,6 +52,8 @@
         "gl/GLExtensions.cpp",
         "gl/GLFramebuffer.cpp",
         "gl/GLImage.cpp",
+        "gl/GLShadowVertexGenerator.cpp",
+        "gl/GLSkiaShadowPort.cpp",
         "gl/ImageManager.cpp",
         "gl/Program.cpp",
         "gl/ProgramCache.cpp",
diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index d1378d5..0748dfb 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -46,6 +46,7 @@
 #include "GLExtensions.h"
 #include "GLFramebuffer.h"
 #include "GLImage.h"
+#include "GLShadowVertexGenerator.h"
 #include "Program.h"
 #include "ProgramCache.h"
 
@@ -1046,7 +1047,8 @@
         setSourceDataSpace(layer.sourceDataspace);
 
         if (layer.shadow.length > 0.0f) {
-            // handle shadows
+            handleShadow(layer.geometry.boundaries, layer.geometry.roundedCornersRadius,
+                         layer.shadow);
         }
         // We only want to do a special handling for rounded corners when having rounded corners
         // is the only reason it needs to turn on blending, otherwise, we handle it like the
@@ -1561,6 +1563,35 @@
     }
 }
 
+void GLESRenderEngine::handleShadow(const FloatRect& casterRect, float casterCornerRadius,
+                                    const ShadowSettings& settings) {
+    ATRACE_CALL();
+    const float casterZ = settings.length / 2.0f;
+    const GLShadowVertexGenerator shadows(casterRect, casterCornerRadius, casterZ,
+                                          settings.casterIsTranslucent, settings.ambientColor,
+                                          settings.spotColor, settings.lightPos,
+                                          settings.lightRadius);
+
+    // setup mesh for both shadows
+    Mesh mesh = Mesh::Builder()
+                        .setPrimitive(Mesh::TRIANGLES)
+                        .setVertices(shadows.getVertexCount(), 2 /* size */)
+                        .setShadowAttrs()
+                        .setIndices(shadows.getIndexCount())
+                        .build();
+
+    Mesh::VertexArray<vec2> position = mesh.getPositionArray<vec2>();
+    Mesh::VertexArray<vec4> shadowColor = mesh.getShadowColorArray<vec4>();
+    Mesh::VertexArray<vec3> shadowParams = mesh.getShadowParamsArray<vec3>();
+    shadows.fillVertices(position, shadowColor, shadowParams);
+    shadows.fillIndices(mesh.getIndicesArray());
+
+    mState.cornerRadius = 0.0f;
+    mState.drawShadows = true;
+    drawMesh(mesh);
+    mState.drawShadows = false;
+}
+
 } // namespace gl
 } // namespace renderengine
 } // namespace android
diff --git a/libs/renderengine/gl/GLESRenderEngine.h b/libs/renderengine/gl/GLESRenderEngine.h
index 397bc16..f41eda2 100644
--- a/libs/renderengine/gl/GLESRenderEngine.h
+++ b/libs/renderengine/gl/GLESRenderEngine.h
@@ -148,6 +148,8 @@
     bool waitFence(base::unique_fd fenceFd);
     void clearWithColor(float red, float green, float blue, float alpha);
     void fillRegionWithColor(const Region& region, float red, float green, float blue, float alpha);
+    void handleShadow(const FloatRect& casterRect, float casterCornerRadius,
+                      const ShadowSettings& shadowSettings);
     void setupLayerBlending(bool premultipliedAlpha, bool opaque, bool disableTexture,
                             const half4& color, float cornerRadius);
     void setupLayerTexturing(const Texture& texture);
diff --git a/libs/renderengine/gl/GLShadowVertexGenerator.cpp b/libs/renderengine/gl/GLShadowVertexGenerator.cpp
new file mode 100644
index 0000000..3181f9b
--- /dev/null
+++ b/libs/renderengine/gl/GLShadowVertexGenerator.cpp
@@ -0,0 +1,98 @@
+/*
+ * 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 <renderengine/Mesh.h>
+
+#include <math/vec4.h>
+
+#include <ui/Rect.h>
+#include <ui/Transform.h>
+
+#include "GLShadowVertexGenerator.h"
+
+namespace android {
+namespace renderengine {
+namespace gl {
+
+GLShadowVertexGenerator::GLShadowVertexGenerator(const FloatRect& casterRect,
+                                                 float casterCornerRadius, float casterZ,
+                                                 bool casterIsTranslucent, const vec4& ambientColor,
+                                                 const vec4& spotColor, const vec3& lightPosition,
+                                                 float lightRadius) {
+    mDrawAmbientShadow = ambientColor.a > 0.f;
+    mDrawSpotShadow = spotColor.a > 0.f;
+
+    // Generate geometries and find number of vertices to generate
+    if (mDrawAmbientShadow) {
+        mAmbientShadowGeometry = getAmbientShadowGeometry(casterRect, casterCornerRadius, casterZ,
+                                                          casterIsTranslucent, ambientColor);
+        mAmbientShadowVertexCount = getVertexCountForGeometry(*mAmbientShadowGeometry.get());
+        mAmbientShadowIndexCount = getIndexCountForGeometry(*mAmbientShadowGeometry.get());
+    } else {
+        mAmbientShadowVertexCount = 0;
+        mAmbientShadowIndexCount = 0;
+    }
+
+    if (mDrawSpotShadow) {
+        mSpotShadowGeometry =
+                getSpotShadowGeometry(casterRect, casterCornerRadius, casterZ, casterIsTranslucent,
+                                      spotColor, lightPosition, lightRadius);
+        mSpotShadowVertexCount = getVertexCountForGeometry(*mSpotShadowGeometry.get());
+        mSpotShadowIndexCount = getIndexCountForGeometry(*mSpotShadowGeometry.get());
+    } else {
+        mSpotShadowVertexCount = 0;
+        mSpotShadowIndexCount = 0;
+    }
+}
+
+size_t GLShadowVertexGenerator::getVertexCount() const {
+    return mAmbientShadowVertexCount + mSpotShadowVertexCount;
+}
+
+size_t GLShadowVertexGenerator::getIndexCount() const {
+    return mAmbientShadowIndexCount + mSpotShadowIndexCount;
+}
+
+void GLShadowVertexGenerator::fillVertices(Mesh::VertexArray<vec2>& position,
+                                           Mesh::VertexArray<vec4>& color,
+                                           Mesh::VertexArray<vec3>& params) const {
+    if (mDrawAmbientShadow) {
+        fillVerticesForGeometry(*mAmbientShadowGeometry.get(), mAmbientShadowVertexCount, position,
+                                color, params);
+    }
+    if (mDrawSpotShadow) {
+        fillVerticesForGeometry(*mSpotShadowGeometry.get(), mSpotShadowVertexCount,
+                                Mesh::VertexArray<vec2>(position, mAmbientShadowVertexCount),
+                                Mesh::VertexArray<vec4>(color, mAmbientShadowVertexCount),
+                                Mesh::VertexArray<vec3>(params, mAmbientShadowVertexCount));
+    }
+}
+
+void GLShadowVertexGenerator::fillIndices(uint16_t* indices) const {
+    if (mDrawAmbientShadow) {
+        fillIndicesForGeometry(*mAmbientShadowGeometry.get(), mAmbientShadowIndexCount,
+                               0 /* starting vertex offset */, indices);
+    }
+    if (mDrawSpotShadow) {
+        fillIndicesForGeometry(*mSpotShadowGeometry.get(), mSpotShadowIndexCount,
+                               mAmbientShadowVertexCount /* starting vertex offset */,
+                               &(indices[mAmbientShadowIndexCount]));
+    }
+}
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/gl/GLShadowVertexGenerator.h b/libs/renderengine/gl/GLShadowVertexGenerator.h
new file mode 100644
index 0000000..112f976
--- /dev/null
+++ b/libs/renderengine/gl/GLShadowVertexGenerator.h
@@ -0,0 +1,65 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <math/vec4.h>
+#include <ui/Rect.h>
+
+#include "GLSkiaShadowPort.h"
+
+namespace android {
+namespace renderengine {
+
+class Mesh;
+
+namespace gl {
+
+/**
+ * Generates gl attributes required to draw shadow spot and/or ambient shadows.
+ *
+ * Each shadow can support different colors. This class generates three vertex attributes for
+ * each shadow, its position, color and shadow params(offset and distance). These can be sent
+ * using a single glDrawElements call.
+ */
+class GLShadowVertexGenerator {
+public:
+    GLShadowVertexGenerator(const FloatRect& casterRect, float casterCornerRadius, float casterZ,
+                            bool casterIsTranslucent, const vec4& ambientColor,
+                            const vec4& spotColor, const vec3& lightPosition, float lightRadius);
+    ~GLShadowVertexGenerator() = default;
+
+    size_t getVertexCount() const;
+    size_t getIndexCount() const;
+    void fillVertices(Mesh::VertexArray<vec2>& position, Mesh::VertexArray<vec4>& color,
+                      Mesh::VertexArray<vec3>& params) const;
+    void fillIndices(uint16_t* indices) const;
+
+private:
+    bool mDrawAmbientShadow;
+    std::unique_ptr<Geometry> mAmbientShadowGeometry;
+    int mAmbientShadowVertexCount = 0;
+    int mAmbientShadowIndexCount = 0;
+
+    bool mDrawSpotShadow;
+    std::unique_ptr<Geometry> mSpotShadowGeometry;
+    int mSpotShadowVertexCount = 0;
+    int mSpotShadowIndexCount = 0;
+};
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/gl/GLSkiaShadowPort.cpp b/libs/renderengine/gl/GLSkiaShadowPort.cpp
new file mode 100644
index 0000000..224ce6c
--- /dev/null
+++ b/libs/renderengine/gl/GLSkiaShadowPort.cpp
@@ -0,0 +1,649 @@
+/*
+ * 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));
+}
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/gl/GLSkiaShadowPort.h b/libs/renderengine/gl/GLSkiaShadowPort.h
new file mode 100644
index 0000000..e7d1861
--- /dev/null
+++ b/libs/renderengine/gl/GLSkiaShadowPort.h
@@ -0,0 +1,84 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <math/vec4.h>
+#include <ui/Rect.h>
+
+namespace android {
+namespace renderengine {
+
+class Mesh;
+
+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.
+ */
+
+enum RRectType {
+    kFill_RRectType,
+    kStroke_RRectType,
+    kOverstroke_RRectType,
+};
+
+struct Geometry {
+    vec4 fColor;
+    float fOuterRadius;
+    float fUmbraInset;
+    float fInnerRadius;
+    float fBlurRadius;
+    FloatRect fDevBounds;
+    RRectType fType;
+    bool fIsCircle;
+    bool fIsStroked;
+};
+
+std::unique_ptr<Geometry> getSpotShadowGeometry(const FloatRect& casterRect,
+                                                float casterCornerRadius, float casterZ,
+                                                bool casterIsTranslucent, const vec4& spotColor,
+                                                const vec3& lightPosition, float lightRadius);
+
+std::unique_ptr<Geometry> getAmbientShadowGeometry(const FloatRect& casterRect,
+                                                   float casterCornerRadius, float casterZ,
+                                                   bool casterIsTranslucent,
+                                                   const vec4& ambientColor);
+
+int getVertexCountForGeometry(const Geometry& shadowGeometry);
+
+int getIndexCountForGeometry(const Geometry& shadowGeometry);
+
+void fillVerticesForGeometry(const Geometry& shadowGeometry, int vertexCount,
+                             Mesh::VertexArray<vec2> position, Mesh::VertexArray<vec4> shadowColor,
+                             Mesh::VertexArray<vec3> shadowParams);
+
+void fillIndicesForGeometry(const Geometry& shadowGeometry, int indexCount,
+                            int startingVertexOffset, uint16_t* indices);
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/gl/ProgramCache.cpp b/libs/renderengine/gl/ProgramCache.cpp
index e2757e1..ba0e4ad 100644
--- a/libs/renderengine/gl/ProgramCache.cpp
+++ b/libs/renderengine/gl/ProgramCache.cpp
@@ -174,16 +174,15 @@
             .set(Key::OPACITY_MASK,
                  description.isOpaque ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT)
             .set(Key::Key::INPUT_TRANSFORM_MATRIX_MASK,
-                 description.hasInputTransformMatrix()
-                         ? Key::INPUT_TRANSFORM_MATRIX_ON : Key::INPUT_TRANSFORM_MATRIX_OFF)
+                 description.hasInputTransformMatrix() ? Key::INPUT_TRANSFORM_MATRIX_ON
+                                                       : Key::INPUT_TRANSFORM_MATRIX_OFF)
             .set(Key::Key::OUTPUT_TRANSFORM_MATRIX_MASK,
                  description.hasOutputTransformMatrix() || description.hasColorMatrix()
                          ? Key::OUTPUT_TRANSFORM_MATRIX_ON
                          : Key::OUTPUT_TRANSFORM_MATRIX_OFF)
             .set(Key::ROUNDED_CORNERS_MASK,
-                 description.cornerRadius > 0
-                         ? Key::ROUNDED_CORNERS_ON : Key::ROUNDED_CORNERS_OFF);
-
+                 description.cornerRadius > 0 ? Key::ROUNDED_CORNERS_ON : Key::ROUNDED_CORNERS_OFF)
+            .set(Key::SHADOW_MASK, description.drawShadows ? Key::SHADOW_ON : Key::SHADOW_OFF);
     needs.set(Key::Y410_BT2020_MASK,
               description.isY410BT2020 ? Key::Y410_BT2020_ON : Key::Y410_BT2020_OFF);
 
@@ -559,6 +558,12 @@
         vs << "attribute lowp vec4 cropCoords;";
         vs << "varying lowp vec2 outCropCoords;";
     }
+    if (needs.drawShadows()) {
+        vs << "attribute vec4 shadowColor;";
+        vs << "varying vec4 outShadowColor;";
+        vs << "attribute vec4 shadowParams;";
+        vs << "varying vec3 outShadowParams;";
+    }
     vs << "attribute vec4 position;"
        << "uniform mat4 projection;"
        << "uniform mat4 texture;"
@@ -569,6 +574,10 @@
     if (needs.hasRoundedCorners()) {
         vs << "outCropCoords = cropCoords.st;";
     }
+    if (needs.drawShadows()) {
+        vs << "outShadowColor = shadowColor;";
+        vs << "outShadowParams = shadowParams.xyz;";
+    }
     vs << dedent << "}";
     return vs.getString();
 }
@@ -614,6 +623,26 @@
             )__SHADER__";
     }
 
+    if (needs.drawShadows()) {
+        fs << R"__SHADER__(
+            varying vec4 outShadowColor;
+            varying vec3 outShadowParams;
+
+            /**
+             * Returns the shadow color.
+             */
+            vec4 getShadowColor()
+            {
+                // exponential falloff function provided by UX
+                float d = length(outShadowParams.xy);
+                float distance = outShadowParams.z * (1.0 - d);
+                float factor = 1.0 - clamp(distance, 0.0, 1.0);
+                factor = exp(-factor * factor * 4.0) - 0.018;
+                return outShadowColor * factor;
+            }
+            )__SHADER__";
+    }
+
     if (needs.getTextureTarget() == Key::TEXTURE_OFF || needs.hasAlpha()) {
         fs << "uniform vec4 color;";
     }
@@ -677,25 +706,29 @@
     }
 
     fs << "void main(void) {" << indent;
-    if (needs.isTexturing()) {
-        fs << "gl_FragColor = texture2D(sampler, outTexCoords);";
-        if (needs.isY410BT2020()) {
-            fs << "gl_FragColor.rgb = convertY410BT2020(gl_FragColor.rgb);";
-        }
+    if (needs.drawShadows()) {
+        fs << "gl_FragColor = getShadowColor();";
     } else {
-        fs << "gl_FragColor.rgb = color.rgb;";
-        fs << "gl_FragColor.a = 1.0;";
-    }
-    if (needs.isOpaque()) {
-        fs << "gl_FragColor.a = 1.0;";
-    }
-    if (needs.hasAlpha()) {
-        // modulate the current alpha value with alpha set
-        if (needs.isPremultiplied()) {
-            // ... and the color too if we're premultiplied
-            fs << "gl_FragColor *= color.a;";
+        if (needs.isTexturing()) {
+            fs << "gl_FragColor = texture2D(sampler, outTexCoords);";
+            if (needs.isY410BT2020()) {
+                fs << "gl_FragColor.rgb = convertY410BT2020(gl_FragColor.rgb);";
+            }
         } else {
-            fs << "gl_FragColor.a *= color.a;";
+            fs << "gl_FragColor.rgb = color.rgb;";
+            fs << "gl_FragColor.a = 1.0;";
+        }
+        if (needs.isOpaque()) {
+            fs << "gl_FragColor.a = 1.0;";
+        }
+        if (needs.hasAlpha()) {
+            // modulate the current alpha value with alpha set
+            if (needs.isPremultiplied()) {
+                // ... and the color too if we're premultiplied
+                fs << "gl_FragColor *= color.a;";
+            } else {
+                fs << "gl_FragColor.a *= color.a;";
+            }
         }
     }
 
diff --git a/libs/renderengine/gl/ProgramCache.h b/libs/renderengine/gl/ProgramCache.h
index 175c6e8..c8b6da7 100644
--- a/libs/renderengine/gl/ProgramCache.h
+++ b/libs/renderengine/gl/ProgramCache.h
@@ -112,6 +112,11 @@
             Y410_BT2020_MASK = 1 << Y410_BT2020_SHIFT,
             Y410_BT2020_OFF = 0 << Y410_BT2020_SHIFT,
             Y410_BT2020_ON = 1 << Y410_BT2020_SHIFT,
+
+            SHADOW_SHIFT = 13,
+            SHADOW_MASK = 1 << SHADOW_SHIFT,
+            SHADOW_OFF = 0 << SHADOW_SHIFT,
+            SHADOW_ON = 1 << SHADOW_SHIFT,
         };
 
         inline Key() : mKey(0) {}
@@ -130,6 +135,7 @@
         inline bool hasRoundedCorners() const {
             return (mKey & ROUNDED_CORNERS_MASK) == ROUNDED_CORNERS_ON;
         }
+        inline bool drawShadows() const { return (mKey & SHADOW_MASK) == SHADOW_ON; }
         inline bool hasInputTransformMatrix() const {
             return (mKey & INPUT_TRANSFORM_MATRIX_MASK) == INPUT_TRANSFORM_MATRIX_ON;
         }
diff --git a/libs/renderengine/include/renderengine/Mesh.h b/libs/renderengine/include/renderengine/Mesh.h
index 59db87a..167f13f 100644
--- a/libs/renderengine/include/renderengine/Mesh.h
+++ b/libs/renderengine/include/renderengine/Mesh.h
@@ -47,12 +47,12 @@
         size_t mOffset = 0;
         VertexArray(float* data, size_t stride) : mData(data), mStride(stride) {}
 
+    public:
         // Returns a vertex array at an offset so its easier to append attributes from
         // multiple sources.
         VertexArray(VertexArray<TYPE>& other, size_t offset)
               : mData(other.mData), mStride(other.mStride), mOffset(offset) {}
 
-    public:
         TYPE& operator[](size_t index) {
             return *reinterpret_cast<TYPE*>(&mData[(index + mOffset) * mStride]);
         }
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index d01c740..ba5a3f5 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -16,6 +16,7 @@
 
 #include <chrono>
 #include <condition_variable>
+#include <fstream>
 
 #include <gtest/gtest.h>
 #include <renderengine/RenderEngine.h>
@@ -26,6 +27,7 @@
 constexpr int DEFAULT_DISPLAY_WIDTH = 128;
 constexpr int DEFAULT_DISPLAY_HEIGHT = 256;
 constexpr int DEFAULT_DISPLAY_OFFSET = 64;
+constexpr bool WRITE_BUFFER_TO_FILE_ON_FAILURE = false;
 
 namespace android {
 
@@ -68,21 +70,80 @@
     RenderEngineTest() { mBuffer = allocateDefaultBuffer(); }
 
     ~RenderEngineTest() {
+        if (WRITE_BUFFER_TO_FILE_ON_FAILURE && ::testing::Test::HasFailure()) {
+            writeBufferToFile("/data/texture_out_");
+        }
         for (uint32_t texName : mTexNames) {
             sRE->deleteTextures(1, &texName);
         }
     }
 
-    void expectBufferColor(const Rect& region, uint8_t r, uint8_t g, uint8_t b, uint8_t a,
-                           uint8_t tolerance = 0) {
+    void writeBufferToFile(const char* basename) {
+        std::string filename(basename);
+        filename.append(::testing::UnitTest::GetInstance()->current_test_info()->name());
+        filename.append(".ppm");
+        std::ofstream file(filename.c_str(), std::ios::binary);
+        if (!file.is_open()) {
+            ALOGE("Unable to open file: %s", filename.c_str());
+            ALOGE("You may need to do: \"adb shell setenforce 0\" to enable "
+                  "surfaceflinger to write debug images");
+            return;
+        }
+
         uint8_t* pixels;
         mBuffer->lock(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
                       reinterpret_cast<void**>(&pixels));
 
-        auto colorCompare = [tolerance](uint8_t a, uint8_t b) {
-            uint8_t tmp = a >= b ? a - b : b - a;
-            return tmp <= tolerance;
+        file << "P6\n";
+        file << mBuffer->getWidth() << "\n";
+        file << mBuffer->getHeight() << "\n";
+        file << 255 << "\n";
+
+        std::vector<uint8_t> outBuffer(mBuffer->getWidth() * mBuffer->getHeight() * 3);
+        auto outPtr = reinterpret_cast<uint8_t*>(outBuffer.data());
+
+        for (int32_t j = 0; j < mBuffer->getHeight(); j++) {
+            const uint8_t* src = pixels + (mBuffer->getStride() * j) * 4;
+            for (int32_t i = 0; i < mBuffer->getWidth(); i++) {
+                // Only copy R, G and B components
+                outPtr[0] = src[0];
+                outPtr[1] = src[1];
+                outPtr[2] = src[2];
+                outPtr += 3;
+
+                src += 4;
+            }
+        }
+        file.write(reinterpret_cast<char*>(outBuffer.data()), outBuffer.size());
+        mBuffer->unlock();
+    }
+
+    void expectBufferColor(const Region& region, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
+        size_t c;
+        Rect const* rect = region.getArray(&c);
+        for (size_t i = 0; i < c; i++, rect++) {
+            expectBufferColor(*rect, r, g, b, a);
+        }
+    }
+
+    void expectBufferColor(const Rect& rect, uint8_t r, uint8_t g, uint8_t b, uint8_t a,
+                           uint8_t tolerance = 0) {
+        auto colorCompare = [tolerance](const uint8_t* colorA, const uint8_t* colorB) {
+            auto colorBitCompare = [tolerance](uint8_t a, uint8_t b) {
+                uint8_t tmp = a >= b ? a - b : b - a;
+                return tmp <= tolerance;
+            };
+            return std::equal(colorA, colorA + 4, colorB, colorBitCompare);
         };
+
+        expectBufferColor(rect, r, g, b, a, colorCompare);
+    }
+
+    void expectBufferColor(const Rect& region, uint8_t r, uint8_t g, uint8_t b, uint8_t a,
+                           std::function<bool(const uint8_t* a, const uint8_t* b)> colorCompare) {
+        uint8_t* pixels;
+        mBuffer->lock(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
+                      reinterpret_cast<void**>(&pixels));
         int32_t maxFails = 10;
         int32_t fails = 0;
         for (int32_t j = 0; j < region.getHeight(); j++) {
@@ -90,7 +151,7 @@
                     pixels + (mBuffer->getStride() * (region.top + j) + region.left) * 4;
             for (int32_t i = 0; i < region.getWidth(); i++) {
                 const uint8_t expected[4] = {r, g, b, a};
-                bool equal = std::equal(src, src + 4, expected, colorCompare);
+                bool equal = colorCompare(src, expected);
                 EXPECT_TRUE(equal)
                         << "pixel @ (" << region.left + i << ", " << region.top + j << "): "
                         << "expected (" << static_cast<uint32_t>(r) << ", "
@@ -111,6 +172,64 @@
         mBuffer->unlock();
     }
 
+    void expectAlpha(const Rect& rect, uint8_t a) {
+        auto colorCompare = [](const uint8_t* colorA, const uint8_t* colorB) {
+            return colorA[3] == colorB[3];
+        };
+        expectBufferColor(rect, 0.0f /* r */, 0.0f /*g */, 0.0f /* b */, a, colorCompare);
+    }
+
+    void expectShadowColor(const renderengine::LayerSettings& castingLayer,
+                           const renderengine::ShadowSettings& shadow, const ubyte4& casterColor,
+                           const ubyte4& backgroundColor) {
+        const Rect casterRect(castingLayer.geometry.boundaries);
+        Region casterRegion = Region(casterRect);
+        const float casterCornerRadius = castingLayer.geometry.roundedCornersRadius;
+        if (casterCornerRadius > 0.0f) {
+            // ignore the corners if a corner radius is set
+            Rect cornerRect(casterCornerRadius, casterCornerRadius);
+            casterRegion.subtractSelf(cornerRect.offsetTo(casterRect.left, casterRect.top));
+            casterRegion.subtractSelf(
+                    cornerRect.offsetTo(casterRect.right - casterCornerRadius, casterRect.top));
+            casterRegion.subtractSelf(
+                    cornerRect.offsetTo(casterRect.left, casterRect.bottom - casterCornerRadius));
+            casterRegion.subtractSelf(cornerRect.offsetTo(casterRect.right - casterCornerRadius,
+                                                          casterRect.bottom - casterCornerRadius));
+        }
+
+        const float shadowInset = shadow.length * -1.0f;
+        const Rect casterWithShadow =
+                Rect(casterRect).inset(shadowInset, shadowInset, shadowInset, shadowInset);
+        const Region shadowRegion = Region(casterWithShadow).subtractSelf(casterRect);
+        const Region backgroundRegion = Region(fullscreenRect()).subtractSelf(casterWithShadow);
+
+        // verify casting layer
+        expectBufferColor(casterRegion, casterColor.r, casterColor.g, casterColor.b, casterColor.a);
+
+        // verify shadows by testing just the alpha since its difficult to validate the shadow color
+        size_t c;
+        Rect const* r = shadowRegion.getArray(&c);
+        for (size_t i = 0; i < c; i++, r++) {
+            expectAlpha(*r, 255);
+        }
+
+        // verify background
+        expectBufferColor(backgroundRegion, backgroundColor.r, backgroundColor.g, backgroundColor.b,
+                          backgroundColor.a);
+    }
+
+    static renderengine::ShadowSettings getShadowSettings(const vec2& casterPos, float shadowLength,
+                                                          bool casterIsTranslucent) {
+        renderengine::ShadowSettings shadow;
+        shadow.ambientColor = {0.0f, 0.0f, 0.0f, 0.039f};
+        shadow.spotColor = {0.0f, 0.0f, 0.0f, 0.19f};
+        shadow.lightPos = vec3(casterPos.x, casterPos.y, 0);
+        shadow.lightRadius = 0.0f;
+        shadow.length = shadowLength;
+        shadow.casterIsTranslucent = casterIsTranslucent;
+        return shadow;
+    }
+
     static Rect fullscreenRect() { return Rect(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT); }
 
     static Rect offsetRect() {
@@ -225,6 +344,11 @@
 
     void clearRegion();
 
+    template <typename SourceVariant>
+    void drawShadow(const renderengine::LayerSettings& castingLayer,
+                    const renderengine::ShadowSettings& shadow, const ubyte4& casterColor,
+                    const ubyte4& backgroundColor);
+
     // Keep around the same renderengine object to save on initialization time.
     // For now, exercise the GL backend directly so that some caching specifics
     // can be tested without changing the interface.
@@ -766,6 +890,40 @@
                       0, 0, 0, 0);
 }
 
+template <typename SourceVariant>
+void RenderEngineTest::drawShadow(const renderengine::LayerSettings& castingLayer,
+                                  const renderengine::ShadowSettings& shadow,
+                                  const ubyte4& casterColor, const ubyte4& backgroundColor) {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = fullscreenRect();
+    settings.clip = fullscreenRect();
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    // add background layer
+    renderengine::LayerSettings bgLayer;
+    bgLayer.geometry.boundaries = fullscreenRect().toFloatRect();
+    ColorSourceVariant::fillColor(bgLayer, backgroundColor.r / 255.0f, backgroundColor.g / 255.0f,
+                                  backgroundColor.b / 255.0f, this);
+    bgLayer.alpha = backgroundColor.a / 255.0f;
+    layers.push_back(bgLayer);
+
+    // add shadow layer
+    renderengine::LayerSettings shadowLayer;
+    shadowLayer.geometry.boundaries = castingLayer.geometry.boundaries;
+    shadowLayer.alpha = castingLayer.alpha;
+    shadowLayer.shadow = shadow;
+    layers.push_back(shadowLayer);
+
+    // add layer casting the shadow
+    renderengine::LayerSettings layer = castingLayer;
+    SourceVariant::fillColor(layer, casterColor.r / 255.0f, casterColor.g / 255.0f,
+                             casterColor.b / 255.0f, this);
+    layers.push_back(layer);
+
+    invokeDraw(settings, layers, mBuffer);
+}
+
 TEST_F(RenderEngineTest, drawLayers_noLayersToDraw) {
     drawEmptyLayers();
 }
@@ -1083,4 +1241,101 @@
     EXPECT_FALSE(sRE->isImageCachedForTesting(bufferId));
 }
 
+TEST_F(RenderEngineTest, drawLayers_fillShadow_casterLayerMinSize) {
+    const ubyte4 casterColor(255, 0, 0, 255);
+    const ubyte4 backgroundColor(255, 255, 255, 255);
+    const float shadowLength = 5.0f;
+    Rect casterBounds(1, 1);
+    casterBounds.offsetBy(shadowLength + 1, shadowLength + 1);
+    renderengine::LayerSettings castingLayer;
+    castingLayer.geometry.boundaries = casterBounds.toFloatRect();
+    castingLayer.alpha = 1.0f;
+    renderengine::ShadowSettings settings =
+            getShadowSettings(vec2(casterBounds.left, casterBounds.top), shadowLength,
+                              false /* casterIsTranslucent */);
+
+    drawShadow<ColorSourceVariant>(castingLayer, settings, casterColor, backgroundColor);
+    expectShadowColor(castingLayer, settings, casterColor, backgroundColor);
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillShadow_casterColorLayer) {
+    const ubyte4 casterColor(255, 0, 0, 255);
+    const ubyte4 backgroundColor(255, 255, 255, 255);
+    const float shadowLength = 5.0f;
+    Rect casterBounds(DEFAULT_DISPLAY_WIDTH / 3.0f, DEFAULT_DISPLAY_HEIGHT / 3.0f);
+    casterBounds.offsetBy(shadowLength + 1, shadowLength + 1);
+    renderengine::LayerSettings castingLayer;
+    castingLayer.geometry.boundaries = casterBounds.toFloatRect();
+    castingLayer.alpha = 1.0f;
+    renderengine::ShadowSettings settings =
+            getShadowSettings(vec2(casterBounds.left, casterBounds.top), shadowLength,
+                              false /* casterIsTranslucent */);
+
+    drawShadow<ColorSourceVariant>(castingLayer, settings, casterColor, backgroundColor);
+    expectShadowColor(castingLayer, settings, casterColor, backgroundColor);
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillShadow_casterOpaqueBufferLayer) {
+    const ubyte4 casterColor(255, 0, 0, 255);
+    const ubyte4 backgroundColor(255, 255, 255, 255);
+    const float shadowLength = 5.0f;
+    Rect casterBounds(DEFAULT_DISPLAY_WIDTH / 3.0f, DEFAULT_DISPLAY_HEIGHT / 3.0f);
+    casterBounds.offsetBy(shadowLength + 1, shadowLength + 1);
+    renderengine::LayerSettings castingLayer;
+    castingLayer.geometry.boundaries = casterBounds.toFloatRect();
+    castingLayer.alpha = 1.0f;
+    renderengine::ShadowSettings settings =
+            getShadowSettings(vec2(casterBounds.left, casterBounds.top), shadowLength,
+                              false /* casterIsTranslucent */);
+
+    drawShadow<BufferSourceVariant<ForceOpaqueBufferVariant>>(castingLayer, settings, casterColor,
+                                                              backgroundColor);
+    expectShadowColor(castingLayer, settings, casterColor, backgroundColor);
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillShadow_casterWithRoundedCorner) {
+    const ubyte4 casterColor(255, 0, 0, 255);
+    const ubyte4 backgroundColor(255, 255, 255, 255);
+    const float shadowLength = 5.0f;
+    Rect casterBounds(DEFAULT_DISPLAY_WIDTH / 3.0f, DEFAULT_DISPLAY_HEIGHT / 3.0f);
+    casterBounds.offsetBy(shadowLength + 1, shadowLength + 1);
+    renderengine::LayerSettings castingLayer;
+    castingLayer.geometry.boundaries = casterBounds.toFloatRect();
+    castingLayer.geometry.roundedCornersRadius = 3.0f;
+    castingLayer.geometry.roundedCornersCrop = casterBounds.toFloatRect();
+    castingLayer.alpha = 1.0f;
+    renderengine::ShadowSettings settings =
+            getShadowSettings(vec2(casterBounds.left, casterBounds.top), shadowLength,
+                              false /* casterIsTranslucent */);
+
+    drawShadow<BufferSourceVariant<ForceOpaqueBufferVariant>>(castingLayer, settings, casterColor,
+                                                              backgroundColor);
+    expectShadowColor(castingLayer, settings, casterColor, backgroundColor);
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillShadow_translucentCasterWithAlpha) {
+    const ubyte4 casterColor(255, 0, 0, 255);
+    const ubyte4 backgroundColor(255, 255, 255, 255);
+    const float shadowLength = 5.0f;
+    Rect casterBounds(DEFAULT_DISPLAY_WIDTH / 3.0f, DEFAULT_DISPLAY_HEIGHT / 3.0f);
+    casterBounds.offsetBy(shadowLength + 1, shadowLength + 1);
+    renderengine::LayerSettings castingLayer;
+    castingLayer.geometry.boundaries = casterBounds.toFloatRect();
+    castingLayer.alpha = 0.5f;
+    renderengine::ShadowSettings settings =
+            getShadowSettings(vec2(casterBounds.left, casterBounds.top), shadowLength,
+                              true /* casterIsTranslucent */);
+
+    drawShadow<BufferSourceVariant<RelaxOpaqueBufferVariant>>(castingLayer, settings, casterColor,
+                                                              backgroundColor);
+
+    // verify only the background since the shadow will draw behind the caster
+    const float shadowInset = settings.length * -1.0f;
+    const Rect casterWithShadow =
+            Rect(casterBounds).inset(shadowInset, shadowInset, shadowInset, shadowInset);
+    const Region backgroundRegion = Region(fullscreenRect()).subtractSelf(casterWithShadow);
+    expectBufferColor(backgroundRegion, backgroundColor.r, backgroundColor.g, backgroundColor.b,
+                      backgroundColor.a);
+}
+
 } // namespace android