1 files changed, 173 insertions, 0 deletions
diff --git a/gfx/layers/mlgpu/MaskOperation.cpp b/gfx/layers/mlgpu/MaskOperation.cpp
new file mode 100644
index 0000000000..9976ec4f62
--- /dev/null
+++ b/gfx/layers/mlgpu/MaskOperation.cpp
@@ -0,0 +1,173 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MaskOperation.h"
+#include "FrameBuilder.h"
+#include "LayerMLGPU.h"
+#include "mozilla/layers/LayersHelpers.h"
+#include "MLGDevice.h"
+#include "TexturedLayerMLGPU.h"
+
+namespace mozilla {
+namespace layers {
+
+using namespace gfx;
+
+MaskOperation::MaskOperation(FrameBuilder* aBuilder) {}
+
+MaskOperation::MaskOperation(FrameBuilder* aBuilder, MLGTexture* aSource)
+    : mTexture(aSource) {}
+
+MaskOperation::~MaskOperation() = default;
+
+static gfx::Rect ComputeQuadForMaskLayer(Layer* aLayer, const IntSize& aSize) {
+  const Matrix4x4& transform = aLayer->GetEffectiveTransform();
+  MOZ_ASSERT(transform.Is2D(), "Mask layers should not have 3d transforms");
+
+  Rect bounds(Point(0, 0), Size(aSize));
+  return transform.As2D().TransformBounds(bounds);
+}
+
+Rect MaskOperation::ComputeMaskRect(Layer* aLayer) const {
+  Layer* maskLayer = aLayer->GetMaskLayer() ? aLayer->GetMaskLayer()
+                                            : aLayer->GetAncestorMaskLayerAt(0);
+  MOZ_ASSERT(
+      (aLayer->GetAncestorMaskLayerCount() == 0 && aLayer->GetMaskLayer()) ||
+      (aLayer->GetAncestorMaskLayerCount() == 1 && !aLayer->GetMaskLayer()));
+
+  return ComputeQuadForMaskLayer(maskLayer, mTexture->GetSize());
+}
+
+// This is only needed for std::map.
+bool MaskTexture::operator<(const MaskTexture& aOther) const {
+  if (mRect.X() != aOther.mRect.X()) {
+    return mRect.X() < aOther.mRect.X();
+  }
+  if (mRect.Y() != aOther.mRect.Y()) {
+    return mRect.Y() < aOther.mRect.Y();
+  }
+  if (mRect.Width() != aOther.mRect.Width()) {
+    return mRect.Width() < aOther.mRect.Width();
+  }
+  if (mRect.Height() != aOther.mRect.Height()) {
+    return mRect.Height() < aOther.mRect.Height();
+  }
+  return mSource < aOther.mSource;
+}
+
+RefPtr<TextureSource> GetMaskLayerTexture(Layer* aLayer) {
+  LayerMLGPU* layer = aLayer->AsHostLayer()->AsLayerMLGPU();
+  TexturedLayerMLGPU* texLayer = layer->AsTexturedLayerMLGPU();
+  if (!texLayer) {
+    MOZ_ASSERT_UNREACHABLE("Mask layers should be texture layers");
+    return nullptr;
+  }
+
+  RefPtr<TextureSource> source = texLayer->BindAndGetTexture();
+  if (!source) {
+    gfxWarning() << "Mask layer does not have a TextureSource";
+    return nullptr;
+  }
+  return source;
+}
+
+MaskCombineOperation::MaskCombineOperation(FrameBuilder* aBuilder)
+    : MaskOperation(aBuilder), mBuilder(aBuilder) {}
+
+MaskCombineOperation::~MaskCombineOperation() = default;
+
+void MaskCombineOperation::Init(const MaskTextureList& aTextures) {
+  // All masks for a single layer exist in the same coordinate space. Find the
+  // area that covers all rects.
+  Rect area = aTextures[0].mRect;
+  for (size_t i = 1; i < aTextures.size(); i++) {
+    area = area.Intersect(aTextures[i].mRect);
+  }
+
+  // Go through and decide which areas of the textures are relevant.
+  for (size_t i = 0; i < aTextures.size(); i++) {
+    Rect rect = aTextures[i].mRect.Intersect(area);
+    if (rect.IsEmpty()) {
+      continue;
+    }
+
+    rect -= aTextures[i].mRect.TopLeft();
+    mTextures.push_back(MaskTexture(rect, aTextures[i].mSource));
+  }
+
+  IntRect size;
+  Rect bounds = area;
+  bounds.RoundOut();
+  bounds.ToIntRect(&size);
+
+  if (size.IsEmpty()) {
+    return;
+  }
+
+  mTarget = mBuilder->GetDevice()->CreateRenderTarget(size.Size());
+  if (mTarget) {
+    mTexture = mTarget->GetTexture();
+  }
+  mArea = area;
+}
+
+void MaskCombineOperation::PrepareForRendering() {
+  for (const auto& entry : mTextures) {
+    Rect texCoords = TextureRectToCoords(entry.mRect, entry.mSource->GetSize());
+
+    SharedVertexBuffer* shared = mBuilder->GetDevice()->GetSharedVertexBuffer();
+
+    VertexBufferSection section;
+    if (!shared->Allocate(&section, 1, sizeof(texCoords), &texCoords)) {
+      continue;
+    }
+    mInputBuffers.push_back(section);
+  }
+}
+
+void MaskCombineOperation::Render() {
+  if (!mTarget) {
+    return;
+  }
+
+  RefPtr<MLGDevice> device = mBuilder->GetDevice();
+
+  device->SetTopology(MLGPrimitiveTopology::UnitQuad);
+  device->SetVertexShader(VertexShaderID::MaskCombiner);
+
+  device->SetPixelShader(PixelShaderID::MaskCombiner);
+  device->SetSamplerMode(0, SamplerMode::LinearClamp);
+  device->SetBlendState(MLGBlendState::Min);
+
+  // Since the mask operation is effectively an AND operation, we initialize
+  // the entire r-channel to 1.
+  device->Clear(mTarget, DeviceColor(1, 0, 0, 1));
+  device->SetScissorRect(Nothing());
+  device->SetRenderTarget(mTarget);
+  device->SetViewport(IntRect(IntPoint(0, 0), mTarget->GetSize()));
+
+  for (size_t i = 0; i < mInputBuffers.size(); i++) {
+    if (!mInputBuffers[i].IsValid()) {
+      continue;
+    }
+    device->SetVertexBuffer(1, &mInputBuffers[i]);
+    device->SetPSTexture(0, mTextures[i].mSource);
+    device->DrawInstanced(4, mInputBuffers[i].NumVertices(), 0, 0);
+  }
+}
+
+void AppendToMaskTextureList(MaskTextureList& aList, Layer* aLayer) {
+  RefPtr<TextureSource> source = GetMaskLayerTexture(aLayer);
+  if (!source) {
+    return;
+  }
+
+  gfx::Rect rect = ComputeQuadForMaskLayer(aLayer, source->GetSize());
+  aList.push_back(MaskTexture(rect, source));
+}
+
+}  // namespace layers
+}  // namespace mozilla