RESTRICT AUTOMERGE pixel-snap on HWUI side

Bug: 254771190
Test: android.uirendering.cts.testclasses.ExactCanvasTests#testDrawLine
Change-Id: Idfb5027fe3230f2c2b0cad224f2c7640e147ce4a

libs/hwui/RecordingCanvas.cpp

@@ -39,6 +39,9 @@
 #include "VectorDrawable.h"
 #include "pipeline/skia/AnimatedDrawables.h"
 #include "pipeline/skia/FunctorDrawable.h"
+#ifdef __ANDROID__
+#include "renderthread/CanvasContext.h"
+#endif
 
 namespace android {
 namespace uirenderer {
@@ -434,7 +437,19 @@ struct DrawPoints final : Op {
     size_t count;
     SkPaint paint;
     void draw(SkCanvas* c, const SkMatrix&) const {
-        c->drawPoints(mode, count, pod<SkPoint>(this), paint);
+        if (paint.isAntiAlias()) {
+            c->drawPoints(mode, count, pod<SkPoint>(this), paint);
+        } else {
+            c->save();
+#ifdef __ANDROID__
+            auto pixelSnap = renderthread::CanvasContext::getActiveContext()->getPixelSnapMatrix();
+            auto transform = c->getLocalToDevice();
+            transform.postConcat(pixelSnap);
+            c->setMatrix(transform);
+#endif
+            c->drawPoints(mode, count, pod<SkPoint>(this), paint);
+            c->restore();
+        }
     }
 };
 struct DrawVertices final : Op {

libs/hwui/pipeline/skia/SkiaOpenGLPipeline.h

@@ -53,6 +53,14 @@ public:
     bool isSurfaceReady() override;
     bool isContextReady() override;
 
+    const SkM44& getPixelSnapMatrix() const override {
+        // Small (~1/16th) nudge to ensure that pixel-aligned non-AA'd draws fill the
+        // desired fragment
+        static const SkScalar kOffset = 0.063f;
+        static const SkM44 sSnapMatrix = SkM44::Translate(kOffset, kOffset);
+        return sSnapMatrix;
+    }
+
     static void invokeFunctor(const renderthread::RenderThread& thread, Functor* functor);
 
 protected:

libs/hwui/pipeline/skia/SkiaVulkanPipeline.cpp

@@ -180,6 +180,10 @@ void SkiaVulkanPipeline::onContextDestroyed() {
     }
 }
 
+const SkM44& SkiaVulkanPipeline::getPixelSnapMatrix() const {
+    return mVkSurface->getPixelSnapMatrix();
+}
+
 } /* namespace skiapipeline */
 } /* namespace uirenderer */
 } /* namespace android */

libs/hwui/pipeline/skia/SkiaVulkanPipeline.h

@@ -49,6 +49,7 @@ public:
     void onStop() override;
     bool isSurfaceReady() override;
     bool isContextReady() override;
+    const SkM44& getPixelSnapMatrix() const override;
 
     static void invokeFunctor(const renderthread::RenderThread& thread, Functor* functor);
     static sk_sp<Bitmap> allocateHardwareBitmap(renderthread::RenderThread& thread,

libs/hwui/renderthread/CanvasContext.cpp

@@ -793,6 +793,10 @@ SkISize CanvasContext::getNextFrameSize() const {
     return size;
 }
 
+const SkM44& CanvasContext::getPixelSnapMatrix() const {
+    return mRenderPipeline->getPixelSnapMatrix();
+}
+
 void CanvasContext::prepareAndDraw(RenderNode* node) {
     ATRACE_CALL();
 

libs/hwui/renderthread/CanvasContext.h

@@ -195,6 +195,9 @@ public:
 
     SkISize getNextFrameSize() const;
 
+    // Returns the matrix to use to nudge non-AA'd points/lines towards the fragment center
+    const SkM44& getPixelSnapMatrix() const;
+
     // Called when SurfaceStats are available.
     static void onSurfaceStatsAvailable(void* context, int32_t surfaceControlId,
                                         ASurfaceControlStats* stats);

libs/hwui/renderthread/IRenderPipeline.h

@@ -88,6 +88,8 @@ public:
     virtual void setPictureCapturedCallback(
             const std::function<void(sk_sp<SkPicture>&&)>& callback) = 0;
 
+    virtual const SkM44& getPixelSnapMatrix() const = 0;
+
     virtual ~IRenderPipeline() {}
 };
 

libs/hwui/renderthread/VulkanSurface.cpp

@@ -63,6 +63,18 @@ static SkMatrix GetPreTransformMatrix(SkISize windowSize, int transform) {
     return SkMatrix::I();
 }
 
+static SkM44 GetPixelSnapMatrix(SkISize windowSize, int transform) {
+    // Small (~1/16th) nudge to ensure that pixel-aligned non-AA'd draws fill the
+    // desired fragment
+    static const SkScalar kOffset = 0.063f;
+    SkMatrix preRotation = GetPreTransformMatrix(windowSize, transform);
+    SkMatrix invert;
+    LOG_ALWAYS_FATAL_IF(!preRotation.invert(&invert));
+    return SkM44::Translate(kOffset, kOffset)
+            .postConcat(SkM44(preRotation))
+            .preConcat(SkM44(invert));
+}
+
 static bool ConnectAndSetWindowDefaults(ANativeWindow* window) {
     ATRACE_CALL();
 
@@ -178,6 +190,8 @@ bool VulkanSurface::InitializeWindowInfoStruct(ANativeWindow* window, ColorMode
 
     outWindowInfo->preTransform =
             GetPreTransformMatrix(outWindowInfo->size, outWindowInfo->transform);
+    outWindowInfo->pixelSnapMatrix =
+            GetPixelSnapMatrix(outWindowInfo->size, outWindowInfo->transform);
 
     err = window->query(window, NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, &query_value);
     if (err != 0 || query_value < 0) {
@@ -406,6 +420,7 @@ VulkanSurface::NativeBufferInfo* VulkanSurface::dequeueNativeBuffer() {
         }
 
         mWindowInfo.preTransform = GetPreTransformMatrix(mWindowInfo.size, mWindowInfo.transform);
+        mWindowInfo.pixelSnapMatrix = GetPixelSnapMatrix(mWindowInfo.size, mWindowInfo.transform);
     }
 
     uint32_t idx;

libs/hwui/renderthread/VulkanSurface.h

@@ -45,6 +45,8 @@ public:
     }
     const SkMatrix& getCurrentPreTransform() { return mWindowInfo.preTransform; }
 
+    const SkM44& getPixelSnapMatrix() const { return mWindowInfo.pixelSnapMatrix; }
+
 private:
     /*
      * All structs/methods in this private section are specifically for use by the VulkanManager
@@ -101,6 +103,7 @@ private:
         SkISize actualSize;
         // transform to be applied to the SkSurface to map the coordinates to the provided transform
         SkMatrix preTransform;
+        SkM44 pixelSnapMatrix;
     };
 
     VulkanSurface(ANativeWindow* window, const WindowInfo& windowInfo, GrDirectContext* grContext);