1 files changed, 254 insertions, 0 deletions
diff --git a/widget/gtk/WindowSurfaceX11Image.cpp b/widget/gtk/WindowSurfaceX11Image.cpp
new file mode 100644
index 0000000000..f83b64336c
--- /dev/null
+++ b/widget/gtk/WindowSurfaceX11Image.cpp
@@ -0,0 +1,254 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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 "WindowSurfaceX11Image.h"
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/Tools.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "gfxPlatform.h"
+#include "gfx2DGlue.h"
+
+#include <X11/extensions/shape.h>
+
+namespace mozilla {
+namespace widget {
+
+using namespace mozilla::gfx;
+
+// gfxImageSurface pixel format configuration.
+#define SHAPED_IMAGE_SURFACE_BPP 4
+#ifdef IS_BIG_ENDIAN
+#  define SHAPED_IMAGE_SURFACE_ALPHA_INDEX 0
+#else
+#  define SHAPED_IMAGE_SURFACE_ALPHA_INDEX 3
+#endif
+
+WindowSurfaceX11Image::WindowSurfaceX11Image(Display* aDisplay, Window aWindow,
+                                             Visual* aVisual,
+                                             unsigned int aDepth,
+                                             bool aIsShaped)
+    : WindowSurfaceX11(aDisplay, aWindow, aVisual, aDepth),
+      mTransparencyBitmap(nullptr),
+      mTransparencyBitmapWidth(0),
+      mTransparencyBitmapHeight(0),
+      mIsShaped(aIsShaped) {}
+
+WindowSurfaceX11Image::~WindowSurfaceX11Image() {
+  if (mTransparencyBitmap) {
+    delete[] mTransparencyBitmap;
+  }
+}
+
+already_AddRefed<gfx::DrawTarget> WindowSurfaceX11Image::Lock(
+    const LayoutDeviceIntRegion& aRegion) {
+  gfx::IntRect bounds = aRegion.GetBounds().ToUnknownRect();
+  gfx::IntSize size(bounds.XMost(), bounds.YMost());
+
+  if (!mWindowSurface || mWindowSurface->CairoStatus() ||
+      !(size <= mWindowSurface->GetSize())) {
+    mWindowSurface = new gfxXlibSurface(mDisplay, mWindow, mVisual, size);
+  }
+  if (mWindowSurface->CairoStatus()) {
+    return nullptr;
+  }
+
+  if (!mImageSurface || mImageSurface->CairoStatus() ||
+      !(size <= mImageSurface->GetSize())) {
+    gfxImageFormat format = SurfaceFormatToImageFormat(mFormat);
+    if (format == gfx::SurfaceFormat::UNKNOWN) {
+      format = mDepth == 32 ? gfx::SurfaceFormat::A8R8G8B8_UINT32
+                            : gfx::SurfaceFormat::X8R8G8B8_UINT32;
+    }
+
+    // Use alpha image format for shaped window as we derive
+    // the shape bitmap from alpha channel. Must match SHAPED_IMAGE_SURFACE_BPP
+    // and SHAPED_IMAGE_SURFACE_ALPHA_INDEX.
+    if (mIsShaped) {
+      format = gfx::SurfaceFormat::A8R8G8B8_UINT32;
+    }
+
+    mImageSurface = new gfxImageSurface(size, format);
+    if (mImageSurface->CairoStatus()) {
+      return nullptr;
+    }
+  }
+
+  gfxImageFormat format = mImageSurface->Format();
+  // Cairo prefers compositing to BGRX instead of BGRA where possible.
+  // Cairo/pixman lacks some fast paths for compositing BGRX onto BGRA, so
+  // just report it as BGRX directly in that case.
+  // Otherwise, for Skia, report it as BGRA to the compositor. The alpha
+  // channel will be discarded when we put the image.
+  if (format == gfx::SurfaceFormat::X8R8G8B8_UINT32) {
+    gfx::BackendType backend = gfxVars::ContentBackend();
+    if (!gfx::Factory::DoesBackendSupportDataDrawtarget(backend)) {
+      backend = gfx::BackendType::SKIA;
+    }
+    if (backend != gfx::BackendType::CAIRO) {
+      format = gfx::SurfaceFormat::A8R8G8B8_UINT32;
+    }
+  }
+
+  return gfxPlatform::CreateDrawTargetForData(
+      mImageSurface->Data(), mImageSurface->GetSize(), mImageSurface->Stride(),
+      ImageFormatToSurfaceFormat(format));
+}
+
+// The transparency bitmap routines are derived form the ones at nsWindow.cpp.
+// The difference here is that we compose to RGBA image and then create
+// the shape mask from final image alpha channel.
+static inline int32_t GetBitmapStride(int32_t width) { return (width + 7) / 8; }
+
+static bool ChangedMaskBits(gchar* aMaskBits, int32_t aMaskWidth,
+                            int32_t aMaskHeight, const nsIntRect& aRect,
+                            uint8_t* aImageData) {
+  int32_t stride = aMaskWidth * SHAPED_IMAGE_SURFACE_BPP;
+  int32_t x, y, xMax = aRect.XMost(), yMax = aRect.YMost();
+  int32_t maskBytesPerRow = GetBitmapStride(aMaskWidth);
+  for (y = aRect.y; y < yMax; y++) {
+    gchar* maskBytes = aMaskBits + y * maskBytesPerRow;
+    uint8_t* alphas = aImageData;
+    for (x = aRect.x; x < xMax; x++) {
+      bool newBit = *(alphas + SHAPED_IMAGE_SURFACE_ALPHA_INDEX) > 0x7f;
+      alphas += SHAPED_IMAGE_SURFACE_BPP;
+
+      gchar maskByte = maskBytes[x >> 3];
+      bool maskBit = (maskByte & (1 << (x & 7))) != 0;
+
+      if (maskBit != newBit) {
+        return true;
+      }
+    }
+    aImageData += stride;
+  }
+
+  return false;
+}
+
+static void UpdateMaskBits(gchar* aMaskBits, int32_t aMaskWidth,
+                           int32_t aMaskHeight, const nsIntRect& aRect,
+                           uint8_t* aImageData) {
+  int32_t stride = aMaskWidth * SHAPED_IMAGE_SURFACE_BPP;
+  int32_t x, y, xMax = aRect.XMost(), yMax = aRect.YMost();
+  int32_t maskBytesPerRow = GetBitmapStride(aMaskWidth);
+  for (y = aRect.y; y < yMax; y++) {
+    gchar* maskBytes = aMaskBits + y * maskBytesPerRow;
+    uint8_t* alphas = aImageData;
+    for (x = aRect.x; x < xMax; x++) {
+      bool newBit = *(alphas + SHAPED_IMAGE_SURFACE_ALPHA_INDEX) > 0x7f;
+      alphas += SHAPED_IMAGE_SURFACE_BPP;
+
+      gchar mask = 1 << (x & 7);
+      gchar maskByte = maskBytes[x >> 3];
+      // Note: '-newBit' turns 0 into 00...00 and 1 into 11...11
+      maskBytes[x >> 3] = (maskByte & ~mask) | (-newBit & mask);
+    }
+    aImageData += stride;
+  }
+}
+
+void WindowSurfaceX11Image::ResizeTransparencyBitmap(int aWidth, int aHeight) {
+  int32_t actualSize =
+      GetBitmapStride(mTransparencyBitmapWidth) * mTransparencyBitmapHeight;
+  int32_t newSize = GetBitmapStride(aWidth) * aHeight;
+
+  if (actualSize < newSize) {
+    delete[] mTransparencyBitmap;
+    mTransparencyBitmap = new gchar[newSize];
+  }
+
+  mTransparencyBitmapWidth = aWidth;
+  mTransparencyBitmapHeight = aHeight;
+}
+
+void WindowSurfaceX11Image::ApplyTransparencyBitmap() {
+  gfx::IntSize size = mWindowSurface->GetSize();
+  bool maskChanged = true;
+
+  if (!mTransparencyBitmap) {
+    mTransparencyBitmapWidth = size.width;
+    mTransparencyBitmapHeight = size.height;
+
+    int32_t byteSize =
+        GetBitmapStride(mTransparencyBitmapWidth) * mTransparencyBitmapHeight;
+    mTransparencyBitmap = new gchar[byteSize];
+  } else {
+    bool sizeChanged = (size.width != mTransparencyBitmapWidth ||
+                        size.height != mTransparencyBitmapHeight);
+
+    if (sizeChanged) {
+      ResizeTransparencyBitmap(size.width, size.height);
+    } else {
+      maskChanged = ChangedMaskBits(
+          mTransparencyBitmap, mTransparencyBitmapWidth,
+          mTransparencyBitmapHeight, nsIntRect(0, 0, size.width, size.height),
+          (uint8_t*)mImageSurface->Data());
+    }
+  }
+
+  if (maskChanged) {
+    UpdateMaskBits(mTransparencyBitmap, mTransparencyBitmapWidth,
+                   mTransparencyBitmapHeight,
+                   nsIntRect(0, 0, size.width, size.height),
+                   (uint8_t*)mImageSurface->Data());
+
+    // We use X11 calls where possible, because GDK handles expose events
+    // for shaped windows in a way that's incompatible with us (Bug 635903).
+    // It doesn't occur when the shapes are set through X.
+    Display* xDisplay = mWindowSurface->XDisplay();
+    Window xDrawable = mWindowSurface->XDrawable();
+    Pixmap maskPixmap = XCreateBitmapFromData(
+        xDisplay, xDrawable, mTransparencyBitmap, mTransparencyBitmapWidth,
+        mTransparencyBitmapHeight);
+    XShapeCombineMask(xDisplay, xDrawable, ShapeBounding, 0, 0, maskPixmap,
+                      ShapeSet);
+    XFreePixmap(xDisplay, maskPixmap);
+  }
+}
+
+void WindowSurfaceX11Image::Commit(
+    const LayoutDeviceIntRegion& aInvalidRegion) {
+  RefPtr<gfx::DrawTarget> dt = gfx::Factory::CreateDrawTargetForCairoSurface(
+      mWindowSurface->CairoSurface(), mWindowSurface->GetSize());
+  RefPtr<gfx::SourceSurface> surf =
+      gfx::Factory::CreateSourceSurfaceForCairoSurface(
+          mImageSurface->CairoSurface(), mImageSurface->GetSize(),
+          mImageSurface->Format());
+  if (!dt || !surf) {
+    return;
+  }
+
+  gfx::IntRect bounds = aInvalidRegion.GetBounds().ToUnknownRect();
+  if (bounds.IsEmpty()) {
+    return;
+  }
+
+  if (mIsShaped) {
+    ApplyTransparencyBitmap();
+  }
+
+  uint32_t numRects = aInvalidRegion.GetNumRects();
+  if (numRects == 1) {
+    dt->CopySurface(surf, bounds, bounds.TopLeft());
+  } else {
+    AutoTArray<IntRect, 32> rects;
+    rects.SetCapacity(numRects);
+    for (auto iter = aInvalidRegion.RectIter(); !iter.Done(); iter.Next()) {
+      rects.AppendElement(iter.Get().ToUnknownRect());
+    }
+    dt->PushDeviceSpaceClipRects(rects.Elements(), rects.Length());
+
+    dt->DrawSurface(surf, gfx::Rect(bounds), gfx::Rect(bounds),
+                    DrawSurfaceOptions(),
+                    DrawOptions(1.0f, CompositionOp::OP_SOURCE));
+
+    dt->PopClip();
+  }
+}
+
+}  // namespace widget
+}  // namespace mozilla