summaryrefslogtreecommitdiffstats
path: root/widget/gtk/WindowSurfaceX11Image.cpp
blob: f83b64336cc2defe1b22189b28e6737ca0e57c6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
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