diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index e392bc5..e033f93 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -109,7 +109,7 @@
             return err;
         }
     }
-
+    output.writeFloat(shadowRadius);
     return NO_ERROR;
 }
 
@@ -187,6 +187,7 @@
         input.readInt64Vector(&callbackIds);
         listeners.emplace_back(listener, callbackIds);
     }
+    shadowRadius = input.readFloat();
     return NO_ERROR;
 }
 
diff --git a/libs/renderengine/Mesh.cpp b/libs/renderengine/Mesh.cpp
index f5387f2..ed2f45f 100644
--- a/libs/renderengine/Mesh.cpp
+++ b/libs/renderengine/Mesh.cpp
@@ -21,38 +21,46 @@
 namespace android {
 namespace renderengine {
 
-Mesh::Mesh(Primitive primitive, size_t vertexCount, size_t vertexSize, size_t texCoordSize)
+Mesh::Mesh(Primitive primitive, size_t vertexCount, size_t vertexSize, size_t texCoordSize,
+           size_t cropCoordsSize, size_t shadowColorSize, size_t shadowParamsSize,
+           size_t indexCount)
       : mVertexCount(vertexCount),
         mVertexSize(vertexSize),
         mTexCoordsSize(texCoordSize),
-        mPrimitive(primitive) {
+        mCropCoordsSize(cropCoordsSize),
+        mShadowColorSize(shadowColorSize),
+        mShadowParamsSize(shadowParamsSize),
+        mPrimitive(primitive),
+        mIndexCount(indexCount) {
     if (vertexCount == 0) {
         mVertices.resize(1);
         mVertices[0] = 0.0f;
         mStride = 0;
         return;
     }
-
-    const size_t CROP_COORD_SIZE = 2;
-    size_t stride = vertexSize + texCoordSize + CROP_COORD_SIZE;
+    size_t stride = vertexSize + texCoordSize + cropCoordsSize + shadowColorSize + shadowParamsSize;
     size_t remainder = (stride * vertexCount) / vertexCount;
     // Since all of the input parameters are unsigned, if stride is less than
     // either vertexSize or texCoordSize, it must have overflowed. remainder
     // will be equal to stride as long as stride * vertexCount doesn't overflow.
     if ((stride < vertexSize) || (remainder != stride)) {
-        ALOGE("Overflow in Mesh(..., %zu, %zu, %zu, %zu)", vertexCount, vertexSize, texCoordSize,
-              CROP_COORD_SIZE);
+        ALOGE("Overflow in Mesh(..., %zu, %zu, %zu, %zu, %zu, %zu)", vertexCount, vertexSize,
+              texCoordSize, cropCoordsSize, shadowColorSize, shadowParamsSize);
         mVertices.resize(1);
         mVertices[0] = 0.0f;
         mVertexCount = 0;
         mVertexSize = 0;
         mTexCoordsSize = 0;
+        mCropCoordsSize = 0;
+        mShadowColorSize = 0;
+        mShadowParamsSize = 0;
         mStride = 0;
         return;
     }
 
     mVertices.resize(stride * vertexCount);
     mStride = stride;
+    mIndices.resize(indexCount);
 }
 
 Mesh::Primitive Mesh::getPrimitive() const {
@@ -80,6 +88,28 @@
     return mVertices.data() + mVertexSize + mTexCoordsSize;
 }
 
+float const* Mesh::getShadowColor() const {
+    return mVertices.data() + mVertexSize + mTexCoordsSize + mCropCoordsSize;
+}
+float* Mesh::getShadowColor() {
+    return mVertices.data() + mVertexSize + mTexCoordsSize + mCropCoordsSize;
+}
+
+float const* Mesh::getShadowParams() const {
+    return mVertices.data() + mVertexSize + mTexCoordsSize + mCropCoordsSize + mShadowColorSize;
+}
+float* Mesh::getShadowParams() {
+    return mVertices.data() + mVertexSize + mTexCoordsSize + mCropCoordsSize + mShadowColorSize;
+}
+
+uint16_t const* Mesh::getIndices() const {
+    return mIndices.data();
+}
+
+uint16_t* Mesh::getIndices() {
+    return mIndices.data();
+}
+
 size_t Mesh::getVertexCount() const {
     return mVertexCount;
 }
@@ -92,6 +122,14 @@
     return mTexCoordsSize;
 }
 
+size_t Mesh::getShadowColorSize() const {
+    return mShadowColorSize;
+}
+
+size_t Mesh::getShadowParamsSize() const {
+    return mShadowParamsSize;
+}
+
 size_t Mesh::getByteStride() const {
     return mStride * sizeof(float);
 }
@@ -100,5 +138,9 @@
     return mStride;
 }
 
+size_t Mesh::getIndexCount() const {
+    return mIndexCount;
+}
+
 } // namespace renderengine
 } // namespace android
diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index 394d05a..d1378d5 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -566,7 +566,10 @@
                                            float alpha) {
     size_t c;
     Rect const* r = region.getArray(&c);
-    Mesh mesh(Mesh::TRIANGLES, c * 6, 2);
+    Mesh mesh = Mesh::Builder()
+                        .setPrimitive(Mesh::TRIANGLES)
+                        .setVertices(c * 6 /* count */, 2 /* size */)
+                        .build();
     Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
     for (size_t i = 0; i < c; i++, r++) {
         position[i * 6 + 0].x = r->left;
@@ -981,7 +984,12 @@
         fillRegionWithColor(display.clearRegion, 0.0, 0.0, 0.0, 1.0);
     }
 
-    Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2, 2);
+    Mesh mesh = Mesh::Builder()
+                        .setPrimitive(Mesh::TRIANGLE_FAN)
+                        .setVertices(4 /* count */, 2 /* size */)
+                        .setTexCoords(2 /* size */)
+                        .setCropCoords(2 /* size */)
+                        .build();
     for (auto layer : layers) {
         mState.maxMasteringLuminance = layer.source.buffer.maxMasteringLuminance;
         mState.maxContentLuminance = layer.source.buffer.maxContentLuminance;
@@ -1037,10 +1045,13 @@
         }
         setSourceDataSpace(layer.sourceDataspace);
 
+        if (layer.shadow.length > 0.0f) {
+            // handle shadows
+        }
         // 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
         // usual way since it needs to turn on blending anyway.
-        if (layer.geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
+        else if (layer.geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
             handleRoundedCorners(display, layer, mesh);
         } else {
             drawMesh(mesh);
@@ -1178,13 +1189,23 @@
                               mesh.getByteStride(), mesh.getCropCoords());
     }
 
+    if (mState.drawShadows) {
+        glEnableVertexAttribArray(Program::shadowColor);
+        glVertexAttribPointer(Program::shadowColor, mesh.getShadowColorSize(), GL_FLOAT, GL_FALSE,
+                              mesh.getByteStride(), mesh.getShadowColor());
+
+        glEnableVertexAttribArray(Program::shadowParams);
+        glVertexAttribPointer(Program::shadowParams, mesh.getShadowParamsSize(), GL_FLOAT, GL_FALSE,
+                              mesh.getByteStride(), mesh.getShadowParams());
+    }
+
+    Description managedState = mState;
     // By default, DISPLAY_P3 is the only supported wide color output. However,
     // when HDR content is present, hardware composer may be able to handle
     // BT2020 data space, in that case, the output data space is set to be
     // BT2020_HLG or BT2020_PQ respectively. In GPU fall back we need
     // to respect this and convert non-HDR content to HDR format.
     if (mUseColorManagement) {
-        Description managedState = mState;
         Dataspace inputStandard = static_cast<Dataspace>(mDataSpace & Dataspace::STANDARD_MASK);
         Dataspace inputTransfer = static_cast<Dataspace>(mDataSpace & Dataspace::TRANSFER_MASK);
         Dataspace outputStandard =
@@ -1275,27 +1296,25 @@
             managedState.outputTransferFunction =
                     Description::dataSpaceToTransferFunction(outputTransfer);
         }
+    }
 
-        ProgramCache::getInstance().useProgram(mInProtectedContext ? mProtectedEGLContext
-                                                                   : mEGLContext,
-                                               managedState);
+    ProgramCache::getInstance().useProgram(mInProtectedContext ? mProtectedEGLContext : mEGLContext,
+                                           managedState);
 
-        glDrawArrays(mesh.getPrimitive(), 0, mesh.getVertexCount());
-
-        if (outputDebugPPMs) {
-            static uint64_t managedColorFrameCount = 0;
-            std::ostringstream out;
-            out << "/data/texture_out" << managedColorFrameCount++;
-            writePPM(out.str().c_str(), mVpWidth, mVpHeight);
-        }
+    if (mState.drawShadows) {
+        glDrawElements(mesh.getPrimitive(), mesh.getIndexCount(), GL_UNSIGNED_SHORT,
+                       mesh.getIndices());
     } else {
-        ProgramCache::getInstance().useProgram(mInProtectedContext ? mProtectedEGLContext
-                                                                   : mEGLContext,
-                                               mState);
-
         glDrawArrays(mesh.getPrimitive(), 0, mesh.getVertexCount());
     }
 
+    if (mUseColorManagement && outputDebugPPMs) {
+        static uint64_t managedColorFrameCount = 0;
+        std::ostringstream out;
+        out << "/data/texture_out" << managedColorFrameCount++;
+        writePPM(out.str().c_str(), mVpWidth, mVpHeight);
+    }
+
     if (mesh.getTexCoordsSize()) {
         glDisableVertexAttribArray(Program::texCoords);
     }
@@ -1303,6 +1322,11 @@
     if (mState.cornerRadius > 0.0f) {
         glDisableVertexAttribArray(Program::cropCoords);
     }
+
+    if (mState.drawShadows) {
+        glDisableVertexAttribArray(Program::shadowColor);
+        glDisableVertexAttribArray(Program::shadowParams);
+    }
 }
 
 size_t GLESRenderEngine::getMaxTextureSize() const {
diff --git a/libs/renderengine/gl/Program.cpp b/libs/renderengine/gl/Program.cpp
index 4eb5eb6..f4fbf35 100644
--- a/libs/renderengine/gl/Program.cpp
+++ b/libs/renderengine/gl/Program.cpp
@@ -37,6 +37,8 @@
     glBindAttribLocation(programId, position, "position");
     glBindAttribLocation(programId, texCoords, "texCoords");
     glBindAttribLocation(programId, cropCoords, "cropCoords");
+    glBindAttribLocation(programId, shadowColor, "shadowColor");
+    glBindAttribLocation(programId, shadowParams, "shadowParams");
     glLinkProgram(programId);
 
     GLint status;
diff --git a/libs/renderengine/gl/Program.h b/libs/renderengine/gl/Program.h
index c9beb68..fc3755e 100644
--- a/libs/renderengine/gl/Program.h
+++ b/libs/renderengine/gl/Program.h
@@ -44,7 +44,13 @@
         texCoords = 1,
 
         /* Crop coordinates, in pixels */
-        cropCoords = 2
+        cropCoords = 2,
+
+        /* Shadow color */
+        shadowColor = 3,
+
+        /* Shadow params */
+        shadowParams = 4,
     };
 
     Program(const ProgramCache::Key& needs, const char* vertex, const char* fragment);
diff --git a/libs/renderengine/include/renderengine/Mesh.h b/libs/renderengine/include/renderengine/Mesh.h
index 7618424..59db87a 100644
--- a/libs/renderengine/include/renderengine/Mesh.h
+++ b/libs/renderengine/include/renderengine/Mesh.h
@@ -26,13 +26,14 @@
 
 class Mesh {
 public:
+    class Builder;
+
     enum Primitive {
         TRIANGLES = 0x0004,      // GL_TRIANGLES
         TRIANGLE_STRIP = 0x0005, // GL_TRIANGLE_STRIP
         TRIANGLE_FAN = 0x0006    // GL_TRIANGLE_FAN
     };
 
-    Mesh(Primitive primitive, size_t vertexCount, size_t vertexSize, size_t texCoordsSize = 0);
     ~Mesh() = default;
 
     /*
@@ -43,12 +44,20 @@
         friend class Mesh;
         float* mData;
         size_t mStride;
+        size_t mOffset = 0;
         VertexArray(float* data, size_t stride) : mData(data), mStride(stride) {}
 
+        // 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 * mStride]); }
+        TYPE& operator[](size_t index) {
+            return *reinterpret_cast<TYPE*>(&mData[(index + mOffset) * mStride]);
+        }
         TYPE const& operator[](size_t index) const {
-            return *reinterpret_cast<TYPE const*>(&mData[index * mStride]);
+            return *reinterpret_cast<TYPE const*>(&mData[(index + mOffset) * mStride]);
         }
     };
 
@@ -67,6 +76,18 @@
         return VertexArray<TYPE>(getCropCoords(), mStride);
     }
 
+    template <typename TYPE>
+    VertexArray<TYPE> getShadowColorArray() {
+        return VertexArray<TYPE>(getShadowColor(), mStride);
+    }
+
+    template <typename TYPE>
+    VertexArray<TYPE> getShadowParamsArray() {
+        return VertexArray<TYPE>(getShadowParams(), mStride);
+    }
+
+    uint16_t* getIndicesArray() { return getIndices(); }
+
     Primitive getPrimitive() const;
 
     // returns a pointer to the vertices positions
@@ -78,6 +99,15 @@
     // returns a pointer to the vertices crop coordinates
     float const* getCropCoords() const;
 
+    // returns a pointer to colors
+    float const* getShadowColor() const;
+
+    // returns a pointer to the shadow params
+    float const* getShadowParams() const;
+
+    // returns a pointer to indices
+    uint16_t const* getIndices() const;
+
     // number of vertices in this mesh
     size_t getVertexCount() const;
 
@@ -87,6 +117,12 @@
     // dimension of texture coordinates
     size_t getTexCoordsSize() const;
 
+    size_t getShadowParamsSize() const;
+
+    size_t getShadowColorSize() const;
+
+    size_t getIndexCount() const;
+
     // return stride in bytes
     size_t getByteStride() const;
 
@@ -94,6 +130,8 @@
     size_t getStride() const;
 
 private:
+    Mesh(Primitive primitive, size_t vertexCount, size_t vertexSize, size_t texCoordSize,
+         size_t cropCoordsSize, size_t shadowColorSize, size_t shadowParamsSize, size_t indexCount);
     Mesh(const Mesh&);
     Mesh& operator=(const Mesh&);
     Mesh const& operator=(const Mesh&) const;
@@ -101,13 +139,65 @@
     float* getPositions();
     float* getTexCoords();
     float* getCropCoords();
+    float* getShadowColor();
+    float* getShadowParams();
+    uint16_t* getIndices();
 
     std::vector<float> mVertices;
     size_t mVertexCount;
     size_t mVertexSize;
     size_t mTexCoordsSize;
+    size_t mCropCoordsSize;
+    size_t mShadowColorSize;
+    size_t mShadowParamsSize;
     size_t mStride;
     Primitive mPrimitive;
+    std::vector<uint16_t> mIndices;
+    size_t mIndexCount;
+};
+
+class Mesh::Builder {
+public:
+    Builder& setPrimitive(Primitive primitive) {
+        mPrimitive = primitive;
+        return *this;
+    };
+    Builder& setVertices(size_t vertexCount, size_t vertexSize) {
+        mVertexCount = vertexCount;
+        mVertexSize = vertexSize;
+        return *this;
+    };
+    Builder& setTexCoords(size_t texCoordsSize) {
+        mTexCoordsSize = texCoordsSize;
+        return *this;
+    };
+    Builder& setCropCoords(size_t cropCoordsSize) {
+        mCropCoordsSize = cropCoordsSize;
+        return *this;
+    };
+    Builder& setShadowAttrs() {
+        mShadowParamsSize = 3;
+        mShadowColorSize = 4;
+        return *this;
+    };
+    Builder& setIndices(size_t indexCount) {
+        mIndexCount = indexCount;
+        return *this;
+    };
+    Mesh build() const {
+        return Mesh{mPrimitive,      mVertexCount,     mVertexSize,       mTexCoordsSize,
+                    mCropCoordsSize, mShadowColorSize, mShadowParamsSize, mIndexCount};
+    }
+
+private:
+    size_t mVertexCount = 0;
+    size_t mVertexSize = 0;
+    size_t mTexCoordsSize = 0;
+    size_t mCropCoordsSize = 0;
+    size_t mShadowColorSize = 0;
+    size_t mShadowParamsSize = 0;
+    size_t mIndexCount = 0;
+    Primitive mPrimitive;
 };
 
 } // namespace renderengine
diff --git a/libs/renderengine/include/renderengine/private/Description.h b/libs/renderengine/include/renderengine/private/Description.h
index bad64c2..a62161a 100644
--- a/libs/renderengine/include/renderengine/private/Description.h
+++ b/libs/renderengine/include/renderengine/private/Description.h
@@ -81,6 +81,9 @@
     mat4 colorMatrix;
     mat4 inputTransformMatrix;
     mat4 outputTransformMatrix;
+
+    // True if this layer will draw a shadow.
+    bool drawShadows = false;
 };
 
 } // namespace renderengine