diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index 53b0e4c..51cf188 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -648,27 +648,89 @@
     return success;
 }
 
-status_t GLESRenderEngine::drawLayers(const DisplaySettings& /*settings*/,
-                                      const std::vector<LayerSettings>& /*layers*/,
-                                      ANativeWindowBuffer* const /*buffer*/,
-                                      base::unique_fd* /*displayFence*/) const {
+status_t GLESRenderEngine::drawLayers(const DisplaySettings& display,
+                                      const std::vector<LayerSettings>& layers,
+                                      ANativeWindowBuffer* const buffer,
+                                      base::unique_fd* drawFence) {
+    if (layers.empty()) {
+        ALOGV("Drawing empty layer stack");
+        return NO_ERROR;
+    }
+
+    BindNativeBufferAsFramebuffer fbo(*this, buffer);
+
+    if (fbo.getStatus() != NO_ERROR) {
+        ALOGE("Failed to bind framebuffer! Aborting GPU composition for buffer (%p).",
+              buffer->handle);
+        checkErrors();
+        return fbo.getStatus();
+    }
+
+    setViewportAndProjection(display.physicalDisplay, display.clip);
+
+    setOutputDataSpace(display.outputDataspace);
+    setDisplayMaxLuminance(display.maxLuminance);
+
+    mat4 projectionMatrix = mState.projectionMatrix * display.globalTransform;
+
+    Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2);
+    for (auto layer : layers) {
+        // for now, assume that all pixel sources are solid colors.
+        // TODO(alecmouri): support buffer sources
+        if (layer.source.buffer.buffer != nullptr) {
+            continue;
+        }
+
+        setColorTransform(display.colorTransform * layer.colorTransform);
+
+        mState.projectionMatrix = projectionMatrix * layer.geometry.positionTransform;
+
+        FloatRect bounds = layer.geometry.boundaries;
+        Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
+        position[0] = vec2(bounds.left, bounds.top);
+        position[1] = vec2(bounds.left, bounds.bottom);
+        position[2] = vec2(bounds.right, bounds.bottom);
+        position[3] = vec2(bounds.right, bounds.top);
+
+        half3 solidColor = layer.source.solidColor;
+        half4 color = half4(solidColor.r, solidColor.g, solidColor.b, layer.alpha);
+        setupLayerBlending(/*premultipliedAlpha=*/true, /*opaque=*/false, /*disableTexture=*/true,
+                           color, /*cornerRadius=*/0.0);
+        setSourceDataSpace(layer.sourceDataspace);
+
+        drawMesh(mesh);
+    }
+
+    *drawFence = flush();
+    // If flush failed or we don't support native fences, we need to force the
+    // gl command stream to be executed.
+    if (drawFence->get() < 0) {
+        bool success = finish();
+        if (!success) {
+            ALOGE("Failed to flush RenderEngine commands");
+            checkErrors();
+            // Chances are, something illegal happened (either the caller passed
+            // us bad parameters, or we messed up our shader generation).
+            return INVALID_OPERATION;
+        }
+    }
+
+    checkErrors();
     return NO_ERROR;
 }
 
 void GLESRenderEngine::setViewportAndProjection(size_t vpw, size_t vph, Rect sourceCrop,
                                                 ui::Transform::orientation_flags rotation) {
-    int32_t l = sourceCrop.left;
-    int32_t r = sourceCrop.right;
-    int32_t b = sourceCrop.bottom;
-    int32_t t = sourceCrop.top;
-    std::swap(t, b);
-    mat4 m = mat4::ortho(l, r, b, t, 0, 1);
+    setViewportAndProjection(Rect(vpw, vph), sourceCrop);
+
+    if (rotation == ui::Transform::ROT_0) {
+        return;
+    }
 
     // Apply custom rotation to the projection.
     float rot90InRadians = 2.0f * static_cast<float>(M_PI) / 4.0f;
+    mat4 m = mState.projectionMatrix;
     switch (rotation) {
-        case ui::Transform::ROT_0:
-            break;
         case ui::Transform::ROT_90:
             m = mat4::rotate(rot90InRadians, vec3(0, 0, 1)) * m;
             break;
@@ -681,11 +743,18 @@
         default:
             break;
     }
-
-    glViewport(0, 0, vpw, vph);
     mState.projectionMatrix = m;
-    mVpWidth = vpw;
-    mVpHeight = vph;
+}
+
+void GLESRenderEngine::setViewportAndProjection(Rect viewport, Rect clip) {
+    mVpWidth = viewport.getWidth();
+    mVpHeight = viewport.getHeight();
+
+    // We pass the the top left corner instead of the bottom left corner,
+    // because since we're rendering off-screen first.
+    glViewport(viewport.left, viewport.top, mVpWidth, mVpHeight);
+
+    mState.projectionMatrix = mat4::ortho(clip.left, clip.right, clip.top, clip.bottom, 0, 1);
 }
 
 void GLESRenderEngine::setupLayerBlending(bool premultipliedAlpha, bool opaque, bool disableTexture,
diff --git a/libs/renderengine/gl/GLESRenderEngine.h b/libs/renderengine/gl/GLESRenderEngine.h
index 07e5585..b6fff33 100644
--- a/libs/renderengine/gl/GLESRenderEngine.h
+++ b/libs/renderengine/gl/GLESRenderEngine.h
@@ -72,9 +72,8 @@
     bool isProtected() const override { return mInProtectedContext; }
     bool supportsProtectedContent() const override;
     bool useProtectedContext(bool useProtectedContext) override;
-    status_t drawLayers(const DisplaySettings& settings, const std::vector<LayerSettings>& layers,
-                        ANativeWindowBuffer* const buffer,
-                        base::unique_fd* displayFence) const override;
+    status_t drawLayers(const DisplaySettings& display, const std::vector<LayerSettings>& layers,
+                        ANativeWindowBuffer* buffer, base::unique_fd* drawFence) override;
 
     // internal to RenderEngine
     EGLDisplay getEGLDisplay() const { return mEGLDisplay; }
@@ -125,6 +124,9 @@
     // with PQ or HLG transfer function.
     bool isHdrDataSpace(const ui::Dataspace dataSpace) const;
     bool needsXYZTransformMatrix() const;
+    // Defines the viewport, and sets the projection matrix to the projection
+    // defined by the clip.
+    void setViewportAndProjection(Rect viewport, Rect clip);
 
     EGLDisplay mEGLDisplay;
     EGLConfig mEGLConfig;
diff --git a/libs/renderengine/include/renderengine/DisplaySettings.h b/libs/renderengine/include/renderengine/DisplaySettings.h
index aa4e319..0c92353 100644
--- a/libs/renderengine/include/renderengine/DisplaySettings.h
+++ b/libs/renderengine/include/renderengine/DisplaySettings.h
@@ -41,7 +41,7 @@
     mat4 globalTransform = mat4();
 
     // Maximum luminance pulled from the display's HDR capabilities.
-    float maxLuminence = 1.0f;
+    float maxLuminance = 1.0f;
 
     // Output dataspace that will be populated if wide color gamut is used, or
     // DataSpace::UNKNOWN otherwise.
diff --git a/libs/renderengine/include/renderengine/LayerSettings.h b/libs/renderengine/include/renderengine/LayerSettings.h
index 38dee40..93abf5c 100644
--- a/libs/renderengine/include/renderengine/LayerSettings.h
+++ b/libs/renderengine/include/renderengine/LayerSettings.h
@@ -85,7 +85,11 @@
     half alpha = half(0.0);
 
     // Color space describing how the source pixels should be interpreted.
-    ui::Dataspace sourceDataspace = ui::Dataspace::UNKNOWN;
+    ui::Dataspace sourceDataspace;
+
+    // Additional layer-specific color transform to be applied before the global
+    // transform.
+    mat4 colorTransform;
 };
 
 } // namespace renderengine
diff --git a/libs/renderengine/include/renderengine/RenderEngine.h b/libs/renderengine/include/renderengine/RenderEngine.h
index 5e88159..20dd996 100644
--- a/libs/renderengine/include/renderengine/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/RenderEngine.h
@@ -161,12 +161,12 @@
 
     // Renders layers for a particular display via GPU composition. This method
     // should be called for every display that needs to be rendered via the GPU.
-    // @param settings The display-wide settings that should be applied prior to
+    // @param display The display-wide settings that should be applied prior to
     // drawing any layers.
     // @param layers The layers to draw onto the display, in Z-order.
     // @param buffer The buffer which will be drawn to. This buffer will be
     // ready once displayFence fires.
-    // @param displayFence A pointer to a fence, which will fire when the buffer
+    // @param drawFence A pointer to a fence, which will fire when the buffer
     // has been drawn to and is ready to be examined. The fence will be
     // initialized by this method. The caller will be responsible for owning the
     // fence.
@@ -174,10 +174,9 @@
     // now, this always returns NO_ERROR.
     // TODO(alecmouri): Consider making this a multi-display API, so that the
     // caller deoes not need to handle multiple fences.
-    virtual status_t drawLayers(const DisplaySettings& settings,
+    virtual status_t drawLayers(const DisplaySettings& display,
                                 const std::vector<LayerSettings>& layers,
-                                ANativeWindowBuffer* const buffer,
-                                base::unique_fd* displayFence) const = 0;
+                                ANativeWindowBuffer* buffer, base::unique_fd* drawFence) = 0;
 
     // TODO(alecmouri): Expose something like bindTexImage() so that devices
     // that don't support native sync fences can get rid of code duplicated
diff --git a/libs/renderengine/tests/Android.bp b/libs/renderengine/tests/Android.bp
index 051b8b6..9b483ef 100644
--- a/libs/renderengine/tests/Android.bp
+++ b/libs/renderengine/tests/Android.bp
@@ -31,6 +31,7 @@
         "libgui",
         "liblog",
         "libnativewindow",
+        "libsync",
         "libui",
         "libutils",
     ],
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index 345c7ea..a0542dd 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -17,36 +17,430 @@
 #include <gtest/gtest.h>
 
 #include <renderengine/RenderEngine.h>
+#include <sync/sync.h>
 #include <ui/PixelFormat.h>
 
+constexpr int DEFAULT_DISPLAY_WIDTH = 128;
+constexpr int DEFAULT_DISPLAY_HEIGHT = 256;
+constexpr int DEFAULT_DISPLAY_OFFSET = 64;
+
 namespace android {
 
-class RenderEngineTest : public ::testing::Test {
-public:
-    RenderEngineTest() {
-        // Initialize with some sane defaults.
-        // TODO(alecmouri): This should probably be the same instance used by
-        // SurfaceFlinger eventually.
-        mRE = renderengine::RenderEngine::create(static_cast<int32_t>(ui::PixelFormat::RGBA_8888),
-                                                 0);
+struct RenderEngineTest : public ::testing::Test {
+    sp<GraphicBuffer> allocateDefaultBuffer() {
+        return new GraphicBuffer(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT,
+                                 HAL_PIXEL_FORMAT_RGBA_8888, 1,
+                                 GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
+                                 "output");
     }
 
-    status_t drawEmptyLayers() {
+    RenderEngineTest() { mBuffer = allocateDefaultBuffer(); }
+
+    void expectBufferColor(const Rect& region, uint8_t r, uint8_t g, uint8_t b, uint8_t a,
+                           uint8_t tolerance = 0) {
+        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;
+        };
+        int32_t maxFails = 10;
+        int32_t fails = 0;
+        for (int32_t j = 0; j < region.getHeight(); j++) {
+            const uint8_t* src =
+                    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);
+                EXPECT_TRUE(equal)
+                        << "pixel @ (" << region.left + i << ", " << region.top + j << "): "
+                        << "expected (" << static_cast<uint32_t>(r) << ", "
+                        << static_cast<uint32_t>(g) << ", " << static_cast<uint32_t>(b) << ", "
+                        << static_cast<uint32_t>(a) << "), "
+                        << "got (" << static_cast<uint32_t>(src[0]) << ", "
+                        << static_cast<uint32_t>(src[1]) << ", " << static_cast<uint32_t>(src[2])
+                        << ", " << static_cast<uint32_t>(src[3]) << ")";
+                src += 4;
+                if (!equal && ++fails >= maxFails) {
+                    break;
+                }
+            }
+            if (fails >= maxFails) {
+                break;
+            }
+        }
+        mBuffer->unlock();
+    }
+
+    static Rect fullscreenRect() { return Rect(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT); }
+
+    static Rect offsetRect() {
+        return Rect(DEFAULT_DISPLAY_OFFSET, DEFAULT_DISPLAY_OFFSET, DEFAULT_DISPLAY_WIDTH,
+                    DEFAULT_DISPLAY_HEIGHT);
+    }
+
+    static Rect offsetRectAtZero() {
+        return Rect(DEFAULT_DISPLAY_WIDTH - DEFAULT_DISPLAY_OFFSET,
+                    DEFAULT_DISPLAY_HEIGHT - DEFAULT_DISPLAY_OFFSET);
+    }
+
+    static void invokeDraw(renderengine::DisplaySettings settings,
+                           std::vector<renderengine::LayerSettings> layers,
+                           sp<GraphicBuffer> buffer) {
+        base::unique_fd fence;
+        status_t status = sRE->drawLayers(settings, layers, buffer->getNativeBuffer(), &fence);
+
+        int fd = fence.release();
+        if (fd >= 0) {
+            sync_wait(fd, -1);
+            close(fd);
+        }
+
+        ASSERT_EQ(NO_ERROR, status);
+    }
+
+    static void drawEmptyLayers() {
         renderengine::DisplaySettings settings;
         std::vector<renderengine::LayerSettings> layers;
         // Meaningless buffer since we don't do any drawing
         sp<GraphicBuffer> buffer = new GraphicBuffer();
-        base::unique_fd fence;
-        return mRE->drawLayers(settings, layers, buffer->getNativeBuffer(), &fence);
+        invokeDraw(settings, layers, buffer);
     }
 
-private:
-    std::unique_ptr<renderengine::RenderEngine> mRE;
+    template <typename SourceVariant>
+    void fillBuffer(half r, half g, half b, half a);
+
+    template <typename SourceVariant>
+    void fillRedBuffer();
+
+    template <typename SourceVariant>
+    void fillGreenBuffer();
+
+    template <typename SourceVariant>
+    void fillBlueBuffer();
+
+    template <typename SourceVariant>
+    void fillRedTransparentBuffer();
+
+    template <typename SourceVariant>
+    void fillRedOffsetBuffer();
+
+    template <typename SourceVariant>
+    void fillBufferPhysicalOffset();
+
+    template <typename SourceVariant>
+    void fillBufferCheckers(mat4 transform);
+
+    template <typename SourceVariant>
+    void fillBufferCheckersRotate0();
+
+    template <typename SourceVariant>
+    void fillBufferCheckersRotate90();
+
+    template <typename SourceVariant>
+    void fillBufferCheckersRotate180();
+
+    template <typename SourceVariant>
+    void fillBufferCheckersRotate270();
+
+    template <typename SourceVariant>
+    void fillBufferLayerTransform();
+
+    template <typename SourceVariant>
+    void fillBufferColorTransform();
+
+    // Dumb hack to get aroud the fact that tear-down for renderengine isn't
+    // well defined right now, so we can't create multiple instances
+    static std::unique_ptr<renderengine::RenderEngine> sRE;
+
+    sp<GraphicBuffer> mBuffer;
 };
 
-TEST_F(RenderEngineTest, drawLayers_noLayersToDraw_works) {
-    status_t result = drawEmptyLayers();
-    ASSERT_EQ(NO_ERROR, result);
+std::unique_ptr<renderengine::RenderEngine> RenderEngineTest::sRE =
+        renderengine::RenderEngine::create(static_cast<int32_t>(ui::PixelFormat::RGBA_8888), 0);
+
+struct ColorSourceVariant {
+    static void fillColor(renderengine::LayerSettings& layer, half r, half g, half b) {
+        layer.source.solidColor = half3(r, g, b);
+    }
+};
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBuffer(half r, half g, half b, half a) {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = fullscreenRect();
+    settings.clip = fullscreenRect();
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    renderengine::LayerSettings layer;
+    layer.geometry.boundaries = fullscreenRect().toFloatRect();
+    SourceVariant::fillColor(layer, r, g, b);
+    layer.alpha = a;
+
+    layers.push_back(layer);
+
+    invokeDraw(settings, layers, mBuffer);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillRedBuffer() {
+    fillBuffer<SourceVariant>(1.0f, 0.0f, 0.0f, 1.0f);
+    expectBufferColor(fullscreenRect(), 255, 0, 0, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillGreenBuffer() {
+    fillBuffer<SourceVariant>(0.0f, 1.0f, 0.0f, 1.0f);
+    expectBufferColor(fullscreenRect(), 0, 255, 0, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBlueBuffer() {
+    fillBuffer<SourceVariant>(0.0f, 0.0f, 1.0f, 1.0f);
+    expectBufferColor(fullscreenRect(), 0, 0, 255, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillRedTransparentBuffer() {
+    fillBuffer<SourceVariant>(1.0f, 0.0f, 0.0f, .2f);
+    expectBufferColor(fullscreenRect(), 51, 0, 0, 51);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillRedOffsetBuffer() {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = offsetRect();
+    settings.clip = offsetRectAtZero();
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    renderengine::LayerSettings layer;
+    layer.geometry.boundaries = offsetRectAtZero().toFloatRect();
+    SourceVariant::fillColor(layer, 1.0f, 0.0f, 0.0f);
+    layer.alpha = 1.0f;
+
+    layers.push_back(layer);
+    invokeDraw(settings, layers, mBuffer);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferPhysicalOffset() {
+    fillRedOffsetBuffer<SourceVariant>();
+
+    expectBufferColor(Rect(DEFAULT_DISPLAY_OFFSET, DEFAULT_DISPLAY_OFFSET, DEFAULT_DISPLAY_WIDTH,
+                           DEFAULT_DISPLAY_HEIGHT),
+                      255, 0, 0, 255);
+    Rect offsetRegionLeft(DEFAULT_DISPLAY_OFFSET, DEFAULT_DISPLAY_HEIGHT);
+    Rect offsetRegionTop(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_OFFSET);
+
+    expectBufferColor(offsetRegionLeft, 0, 0, 0, 0);
+    expectBufferColor(offsetRegionTop, 0, 0, 0, 0);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferCheckers(mat4 transform) {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = fullscreenRect();
+    // Here logical space is 2x2
+    settings.clip = Rect(2, 2);
+    settings.globalTransform = transform;
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    renderengine::LayerSettings layerOne;
+    Rect rectOne(0, 0, 1, 1);
+    layerOne.geometry.boundaries = rectOne.toFloatRect();
+    SourceVariant::fillColor(layerOne, 1.0f, 0.0f, 0.0f);
+    layerOne.alpha = 1.0f;
+
+    renderengine::LayerSettings layerTwo;
+    Rect rectTwo(0, 1, 1, 2);
+    layerTwo.geometry.boundaries = rectTwo.toFloatRect();
+    SourceVariant::fillColor(layerTwo, 0.0f, 1.0f, 0.0f);
+    layerTwo.alpha = 1.0f;
+
+    renderengine::LayerSettings layerThree;
+    Rect rectThree(1, 0, 2, 1);
+    layerThree.geometry.boundaries = rectThree.toFloatRect();
+    SourceVariant::fillColor(layerThree, 0.0f, 0.0f, 1.0f);
+    layerThree.alpha = 1.0f;
+
+    layers.push_back(layerOne);
+    layers.push_back(layerTwo);
+    layers.push_back(layerThree);
+
+    invokeDraw(settings, layers, mBuffer);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferCheckersRotate0() {
+    fillBufferCheckers<SourceVariant>(mat4());
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2), 255, 0, 0,
+                      255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, 0, DEFAULT_DISPLAY_WIDTH,
+                           DEFAULT_DISPLAY_HEIGHT / 2),
+                      0, 0, 255, 255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2,
+                           DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
+                      0, 0, 0, 0);
+    expectBufferColor(Rect(0, DEFAULT_DISPLAY_HEIGHT / 2, DEFAULT_DISPLAY_WIDTH / 2,
+                           DEFAULT_DISPLAY_HEIGHT),
+                      0, 255, 0, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferCheckersRotate90() {
+    mat4 matrix = mat4(0, 1, 0, 0, -1, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 1);
+    fillBufferCheckers<SourceVariant>(matrix);
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2), 0, 255, 0,
+                      255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, 0, DEFAULT_DISPLAY_WIDTH,
+                           DEFAULT_DISPLAY_HEIGHT / 2),
+                      255, 0, 0, 255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2,
+                           DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
+                      0, 0, 255, 255);
+    expectBufferColor(Rect(0, DEFAULT_DISPLAY_HEIGHT / 2, DEFAULT_DISPLAY_WIDTH / 2,
+                           DEFAULT_DISPLAY_HEIGHT),
+                      0, 0, 0, 0);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferCheckersRotate180() {
+    mat4 matrix = mat4(-1, 0, 0, 0, 0, -1, 0, 0, 0, 0, 1, 0, 2, 2, 0, 1);
+    fillBufferCheckers<SourceVariant>(matrix);
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2), 0, 0, 0,
+                      0);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, 0, DEFAULT_DISPLAY_WIDTH,
+                           DEFAULT_DISPLAY_HEIGHT / 2),
+                      0, 255, 0, 255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2,
+                           DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
+                      255, 0, 0, 255);
+    expectBufferColor(Rect(0, DEFAULT_DISPLAY_HEIGHT / 2, DEFAULT_DISPLAY_WIDTH / 2,
+                           DEFAULT_DISPLAY_HEIGHT),
+                      0, 0, 255, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferCheckersRotate270() {
+    mat4 matrix = mat4(0, -1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 1);
+    fillBufferCheckers<SourceVariant>(matrix);
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2), 0, 0, 255,
+                      255);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, 0, DEFAULT_DISPLAY_WIDTH,
+                           DEFAULT_DISPLAY_HEIGHT / 2),
+                      0, 0, 0, 0);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2,
+                           DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
+                      0, 255, 0, 255);
+    expectBufferColor(Rect(0, DEFAULT_DISPLAY_HEIGHT / 2, DEFAULT_DISPLAY_WIDTH / 2,
+                           DEFAULT_DISPLAY_HEIGHT),
+                      255, 0, 0, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferLayerTransform() {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = fullscreenRect();
+    // Here logical space is 2x2
+    settings.clip = Rect(2, 2);
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    renderengine::LayerSettings layer;
+    layer.geometry.boundaries = Rect(1, 1).toFloatRect();
+    // Translate one pixel diagonally
+    layer.geometry.positionTransform = mat4(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1);
+    layer.source.solidColor = half3(1.0f, 0.0f, 0.0f);
+    layer.alpha = 1.0f;
+
+    layers.push_back(layer);
+
+    invokeDraw(settings, layers, mBuffer);
+
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT / 2), 0, 0, 0, 0);
+    expectBufferColor(Rect(0, 0, DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT), 0, 0, 0, 0);
+    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT / 2,
+                           DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
+                      255, 0, 0, 255);
+}
+
+template <typename SourceVariant>
+void RenderEngineTest::fillBufferColorTransform() {
+    renderengine::DisplaySettings settings;
+    settings.physicalDisplay = fullscreenRect();
+    settings.clip = Rect(1, 1);
+
+    std::vector<renderengine::LayerSettings> layers;
+
+    renderengine::LayerSettings layer;
+    layer.geometry.boundaries = Rect(1, 1).toFloatRect();
+    layer.source.solidColor = half3(0.5f, 0.25f, 0.125f);
+    layer.alpha = 1.0f;
+
+    // construct a fake color matrix
+    // annihilate green and blue channels
+    settings.colorTransform = mat4::scale(vec4(1, 0, 0, 1));
+    // set red channel to red + green
+    layer.colorTransform = mat4(1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
+
+    layers.push_back(layer);
+
+    invokeDraw(settings, layers, mBuffer);
+
+    expectBufferColor(fullscreenRect(), 191, 0, 0, 255);
+}
+
+TEST_F(RenderEngineTest, drawLayers_noLayersToDraw) {
+    drawEmptyLayers();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillRedBuffer_colorSource) {
+    fillRedBuffer<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillGreenBuffer_colorSource) {
+    fillGreenBuffer<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBlueBuffer_colorSource) {
+    fillBlueBuffer<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillRedTransparentBuffer_colorSource) {
+    fillRedTransparentBuffer<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferPhysicalOffset_colorSource) {
+    fillBufferPhysicalOffset<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferCheckersRotate0_colorSource) {
+    fillBufferCheckersRotate0<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferCheckersRotate90_colorSource) {
+    fillBufferCheckersRotate90<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferCheckersRotate180_colorSource) {
+    fillBufferCheckersRotate180<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferCheckersRotate270_colorSource) {
+    fillBufferCheckersRotate270<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferLayerTransform_colorSource) {
+    fillBufferLayerTransform<ColorSourceVariant>();
+}
+
+TEST_F(RenderEngineTest, drawLayers_fillBufferColorTransform_colorSource) {
+    fillBufferLayerTransform<ColorSourceVariant>();
 }
 
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h b/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
index 1bee271..81a7768 100644
--- a/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
+++ b/services/surfaceflinger/tests/unittests/mock/RenderEngine/MockRenderEngine.h
@@ -77,9 +77,9 @@
     MOCK_CONST_METHOD0(isProtected, bool());
     MOCK_CONST_METHOD0(supportsProtectedContent, bool());
     MOCK_METHOD1(useProtectedContext, bool(bool));
-    MOCK_CONST_METHOD4(drawLayers,
-                       status_t(const DisplaySettings&, const std::vector<LayerSettings>&,
-                                ANativeWindowBuffer* const, base::unique_fd*));
+    MOCK_METHOD4(drawLayers,
+                 status_t(const DisplaySettings&, const std::vector<LayerSettings>&,
+                          ANativeWindowBuffer*, base::unique_fd*));
 };
 
 class Image : public renderengine::Image {