summaryrefslogtreecommitdiffstats
path: root/gfx/thebes/gfxContext.cpp
blob: 6f097ce49f058e2711939df1ab50bf96aa9ff6b0 (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
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
/* -*- 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 <math.h>

#include "mozilla/Alignment.h"

#include "cairo.h"

#include "gfxContext.h"

#include "gfxMatrix.h"
#include "gfxUtils.h"
#include "gfxPattern.h"
#include "gfxPlatform.h"

#include "gfx2DGlue.h"
#include "mozilla/gfx/PathHelpers.h"
#include "mozilla/ProfilerLabels.h"
#include <algorithm>
#include "TextDrawTarget.h"

#if XP_WIN
#  include "gfxWindowsPlatform.h"
#  include "mozilla/gfx/DeviceManagerDx.h"
#endif

using namespace mozilla;
using namespace mozilla::gfx;

#ifdef DEBUG
#  define CURRENTSTATE_CHANGED() mAzureState.mContentChanged = true;
#else
#  define CURRENTSTATE_CHANGED()
#endif

PatternFromState::operator Pattern&() {
  const gfxContext::AzureState& state = mContext->mAzureState;

  if (state.pattern) {
    return *state.pattern->GetPattern(
        mContext->mDT,
        state.patternTransformChanged ? &state.patternTransform : nullptr);
  }

  mPattern = new (mColorPattern.addr()) ColorPattern(state.color);
  return *mPattern;
}

/* static */
UniquePtr<gfxContext> gfxContext::CreateOrNull(DrawTarget* aTarget) {
  if (!aTarget || !aTarget->IsValid()) {
    gfxCriticalNote << "Invalid target in gfxContext::CreateOrNull "
                    << hexa(aTarget);
    return nullptr;
  }

  return MakeUnique<gfxContext>(aTarget);
}

gfxContext::~gfxContext() {
  while (!mSavedStates.IsEmpty()) {
    Restore();
  }
  for (unsigned int c = 0; c < mAzureState.pushedClips.Length(); c++) {
    mDT->PopClip();
  }
}

mozilla::layout::TextDrawTarget* gfxContext::GetTextDrawer() const {
  if (mDT->GetBackendType() == BackendType::WEBRENDER_TEXT) {
    return static_cast<mozilla::layout::TextDrawTarget*>(&*mDT);
  }
  return nullptr;
}

void gfxContext::Save() {
  mSavedStates.AppendElement(mAzureState);
  mAzureState.pushedClips.Clear();
#ifdef DEBUG
  mAzureState.mContentChanged = false;
#endif
}

void gfxContext::Restore() {
#ifdef DEBUG
  // gfxContext::Restore is used to restore AzureState. We need to restore it
  // only if it was altered. The following APIs do change the content of
  // AzureState, a user should save the state before using them and restore it
  // after finishing painting:
  // 1. APIs to setup how to paint, such as SetColor()/SetAntialiasMode(). All
  //    gfxContext SetXXXX public functions belong to this category, except
  //    gfxContext::SetPath & gfxContext::SetMatrix.
  // 2. Clip functions, such as Clip() or PopClip(). You may call PopClip()
  //    directly instead of using gfxContext::Save if the clip region is the
  //    only thing that you altered in the target context.
  // 3. Function of setup transform matrix, such as Multiply() and
  //    SetMatrix(). Using gfxContextMatrixAutoSaveRestore is more recommended
  //    if transform data is the only thing that you are going to alter.
  //
  // You will hit the assertion message below if there is no above functions
  // been used between a pair of gfxContext::Save and gfxContext::Restore.
  // Considerate to remove that pair of Save/Restore if hitting that assertion.
  //
  // In the other hand, the following APIs do not alter the content of the
  // current AzureState, therefore, there is no need to save & restore
  // AzureState:
  // 1. constant member functions of gfxContext.
  // 2. Paint calls, such as Line()/Rectangle()/Fill(). Those APIs change the
  //    content of drawing buffer, which is not part of AzureState.
  // 3. Path building APIs, such as SetPath()/MoveTo()/LineTo()/NewPath().
  //    Surprisingly, path information is not stored in AzureState either.
  // Save current AzureState before using these type of APIs does nothing but
  // make performance worse.
  NS_ASSERTION(
      mAzureState.mContentChanged || mAzureState.pushedClips.Length() > 0,
      "The context of the current AzureState is not altered after "
      "Save() been called. you may consider to remove this pair of "
      "gfxContext::Save/Restore.");
#endif

  for (unsigned int c = 0; c < mAzureState.pushedClips.Length(); c++) {
    mDT->PopClip();
  }

  mAzureState = mSavedStates.PopLastElement();

  ChangeTransform(mAzureState.transform, false);
}

// drawing

void gfxContext::Fill(const Pattern& aPattern) {
  AUTO_PROFILER_LABEL("gfxContext::Fill", GRAPHICS);

  CompositionOp op = GetOp();

  if (mPathIsRect) {
    MOZ_ASSERT(!mTransformChanged);

    if (op == CompositionOp::OP_SOURCE) {
      // Emulate cairo operator source which is bound by mask!
      mDT->ClearRect(mRect);
      mDT->FillRect(mRect, aPattern, DrawOptions(1.0f));
    } else {
      mDT->FillRect(mRect, aPattern, DrawOptions(1.0f, op, mAzureState.aaMode));
    }
  } else {
    EnsurePath();
    mDT->Fill(mPath, aPattern, DrawOptions(1.0f, op, mAzureState.aaMode));
  }
}

// XXX snapToPixels is only valid when snapping for filled
// rectangles and for even-width stroked rectangles.
// For odd-width stroked rectangles, we need to offset x/y by
// 0.5...
void gfxContext::Rectangle(const gfxRect& rect, bool snapToPixels) {
  Rect rec = ToRect(rect);

  if (snapToPixels) {
    gfxRect newRect(rect);
    if (UserToDevicePixelSnapped(newRect, SnapOption::IgnoreScale)) {
      gfxMatrix mat = CurrentMatrixDouble();
      if (mat.Invert()) {
        // We need the user space rect.
        rec = ToRect(mat.TransformBounds(newRect));
      } else {
        rec = Rect();
      }
    }
  }

  if (!mPathBuilder && !mPathIsRect) {
    mPathIsRect = true;
    mRect = rec;
    return;
  }

  EnsurePathBuilder();

  mPathBuilder->MoveTo(rec.TopLeft());
  mPathBuilder->LineTo(rec.TopRight());
  mPathBuilder->LineTo(rec.BottomRight());
  mPathBuilder->LineTo(rec.BottomLeft());
  mPathBuilder->Close();
}

void gfxContext::SnappedClip(const gfxRect& rect) {
  Rect rec = ToRect(rect);

  gfxRect newRect(rect);
  if (UserToDevicePixelSnapped(newRect, SnapOption::IgnoreScale)) {
    gfxMatrix mat = CurrentMatrixDouble();
    if (mat.Invert()) {
      // We need the user space rect.
      rec = ToRect(mat.TransformBounds(newRect));
    } else {
      rec = Rect();
    }
  }

  Clip(rec);
}

bool gfxContext::UserToDevicePixelSnapped(gfxRect& rect,
                                          SnapOptions aOptions) const {
  if (mDT->GetUserData(&sDisablePixelSnapping)) {
    return false;
  }

  // if we're not at 1.0 scale, don't snap, unless we're
  // ignoring the scale.  If we're not -just- a scale,
  // never snap.
  const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a, b) (fabs((a) - (b)) < epsilon)
  Matrix mat = mAzureState.transform;
  if (!aOptions.contains(SnapOption::IgnoreScale) &&
      (!WITHIN_E(mat._11, 1.0) || !WITHIN_E(mat._22, 1.0) ||
       !WITHIN_E(mat._12, 0.0) || !WITHIN_E(mat._21, 0.0))) {
    return false;
  }
#undef WITHIN_E

  gfxPoint p1 = UserToDevice(rect.TopLeft());
  gfxPoint p2 = UserToDevice(rect.TopRight());
  gfxPoint p3 = UserToDevice(rect.BottomRight());

  // Check that the rectangle is axis-aligned. For an axis-aligned rectangle,
  // two opposite corners define the entire rectangle. So check if
  // the axis-aligned rectangle with opposite corners p1 and p3
  // define an axis-aligned rectangle whose other corners are p2 and p4.
  // We actually only need to check one of p2 and p4, since an affine
  // transform maps parallelograms to parallelograms.
  if (!(p2 == gfxPoint(p1.x, p3.y) || p2 == gfxPoint(p3.x, p1.y))) {
    return false;
  }

  if (aOptions.contains(SnapOption::PrioritizeSize)) {
    // Snap the dimensions of the rect, to minimize distortion; only after that
    // will we snap its position. In particular, this guarantees that a square
    // remains square after snapping, which may not be the case if each edge is
    // independently snapped to device pixels.

    // Use the same rounding approach as gfx::BasePoint::Round.
    rect.SizeTo(std::floor(rect.width + 0.5), std::floor(rect.height + 0.5));

    // Find the top-left corner based on the original center and the snapped
    // size, then snap this new corner to the grid.
    gfxPoint center = (p1 + p3) / 2;
    gfxPoint topLeft = center - gfxPoint(rect.width / 2.0, rect.height / 2.0);
    topLeft.Round();
    rect.MoveTo(topLeft);
  } else {
    p1.Round();
    p3.Round();
    rect.MoveTo(gfxPoint(std::min(p1.x, p3.x), std::min(p1.y, p3.y)));
    rect.SizeTo(gfxSize(std::max(p1.x, p3.x) - rect.X(),
                        std::max(p1.y, p3.y) - rect.Y()));
  }

  return true;
}

bool gfxContext::UserToDevicePixelSnapped(gfxPoint& pt,
                                          bool ignoreScale) const {
  if (mDT->GetUserData(&sDisablePixelSnapping)) {
    return false;
  }

  // if we're not at 1.0 scale, don't snap, unless we're
  // ignoring the scale.  If we're not -just- a scale,
  // never snap.
  const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a, b) (fabs((a) - (b)) < epsilon)
  Matrix mat = mAzureState.transform;
  if (!ignoreScale && (!WITHIN_E(mat._11, 1.0) || !WITHIN_E(mat._22, 1.0) ||
                       !WITHIN_E(mat._12, 0.0) || !WITHIN_E(mat._21, 0.0))) {
    return false;
  }
#undef WITHIN_E

  pt = UserToDevice(pt);
  pt.Round();
  return true;
}

void gfxContext::SetDash(const Float* dashes, int ndash, Float offset,
                         Float devPxScale) {
  CURRENTSTATE_CHANGED()

  mAzureState.dashPattern.SetLength(ndash);
  for (int i = 0; i < ndash; i++) {
    mAzureState.dashPattern[i] = dashes[i] * devPxScale;
  }
  mAzureState.strokeOptions.mDashLength = ndash;
  mAzureState.strokeOptions.mDashOffset = offset * devPxScale;
  mAzureState.strokeOptions.mDashPattern =
      ndash ? mAzureState.dashPattern.Elements() : nullptr;
}

bool gfxContext::CurrentDash(FallibleTArray<Float>& dashes,
                             Float* offset) const {
  if (mAzureState.strokeOptions.mDashLength == 0 ||
      !dashes.Assign(mAzureState.dashPattern, fallible)) {
    return false;
  }

  *offset = mAzureState.strokeOptions.mDashOffset;

  return true;
}

// clipping
void gfxContext::Clip(const Rect& rect) {
  AzureState::PushedClip clip = {nullptr, rect, mAzureState.transform};
  mAzureState.pushedClips.AppendElement(clip);
  mDT->PushClipRect(rect);
  NewPath();
}

void gfxContext::Clip(Path* aPath) {
  mDT->PushClip(aPath);
  AzureState::PushedClip clip = {aPath, Rect(), mAzureState.transform};
  mAzureState.pushedClips.AppendElement(clip);
}

void gfxContext::Clip() {
  if (mPathIsRect) {
    MOZ_ASSERT(!mTransformChanged);

    AzureState::PushedClip clip = {nullptr, mRect, mAzureState.transform};
    mAzureState.pushedClips.AppendElement(clip);
    mDT->PushClipRect(mRect);
  } else {
    EnsurePath();
    mDT->PushClip(mPath);
    AzureState::PushedClip clip = {mPath, Rect(), mAzureState.transform};
    mAzureState.pushedClips.AppendElement(clip);
  }
}

gfxRect gfxContext::GetClipExtents(ClipExtentsSpace aSpace) const {
  Rect rect = GetAzureDeviceSpaceClipBounds();

  if (rect.IsZeroArea()) {
    return gfxRect(0, 0, 0, 0);
  }

  if (aSpace == eUserSpace) {
    Matrix mat = mAzureState.transform;
    mat.Invert();
    rect = mat.TransformBounds(rect);
  }

  return ThebesRect(rect);
}

bool gfxContext::ExportClip(ClipExporter& aExporter) const {
  ForAllClips([&](const AzureState::PushedClip& aClip) -> void {
    gfx::Matrix transform = aClip.transform;
    transform.PostTranslate(-GetDeviceOffset());

    aExporter.BeginClip(transform);
    if (aClip.path) {
      aClip.path->StreamToSink(&aExporter);
    } else {
      aExporter.MoveTo(aClip.rect.TopLeft());
      aExporter.LineTo(aClip.rect.TopRight());
      aExporter.LineTo(aClip.rect.BottomRight());
      aExporter.LineTo(aClip.rect.BottomLeft());
      aExporter.Close();
    }
    aExporter.EndClip();
  });

  return true;
}

// rendering sources

bool gfxContext::GetDeviceColor(DeviceColor& aColorOut) const {
  if (mAzureState.pattern) {
    return mAzureState.pattern->GetSolidColor(aColorOut);
  }

  aColorOut = mAzureState.color;
  return true;
}

already_AddRefed<gfxPattern> gfxContext::GetPattern() const {
  RefPtr<gfxPattern> pat;

  if (mAzureState.pattern) {
    pat = mAzureState.pattern;
  } else {
    pat = new gfxPattern(mAzureState.color);
  }
  return pat.forget();
}

void gfxContext::Paint(Float alpha) const {
  AUTO_PROFILER_LABEL("gfxContext::Paint", GRAPHICS);

  Matrix mat = mDT->GetTransform();
  mat.Invert();
  Rect paintRect = mat.TransformBounds(Rect(Point(0, 0), Size(mDT->GetSize())));

  mDT->FillRect(paintRect, PatternFromState(this), DrawOptions(alpha, GetOp()));
}

#ifdef MOZ_DUMP_PAINTING
void gfxContext::WriteAsPNG(const char* aFile) {
  gfxUtils::WriteAsPNG(mDT, aFile);
}

void gfxContext::DumpAsDataURI() { gfxUtils::DumpAsDataURI(mDT); }

void gfxContext::CopyAsDataURI() { gfxUtils::CopyAsDataURI(mDT); }
#endif

void gfxContext::EnsurePath() {
  if (mPathBuilder) {
    mPath = mPathBuilder->Finish();
    mPathBuilder = nullptr;
  }

  if (mPath) {
    if (mTransformChanged) {
      Matrix mat = mAzureState.transform;
      mat.Invert();
      mat = mPathTransform * mat;
      mPathBuilder = mPath->TransformedCopyToBuilder(mat);
      mPath = mPathBuilder->Finish();
      mPathBuilder = nullptr;

      mTransformChanged = false;
    }
    return;
  }

  EnsurePathBuilder();
  mPath = mPathBuilder->Finish();
  mPathBuilder = nullptr;
}

void gfxContext::EnsurePathBuilder() {
  if (mPathBuilder && !mTransformChanged) {
    return;
  }

  if (mPath) {
    if (!mTransformChanged) {
      mPathBuilder = mPath->CopyToBuilder();
      mPath = nullptr;
    } else {
      Matrix invTransform = mAzureState.transform;
      invTransform.Invert();
      Matrix toNewUS = mPathTransform * invTransform;
      mPathBuilder = mPath->TransformedCopyToBuilder(toNewUS);
    }
    return;
  }

  DebugOnly<PathBuilder*> oldPath = mPathBuilder.get();

  if (!mPathBuilder) {
    mPathBuilder = mDT->CreatePathBuilder(FillRule::FILL_WINDING);

    if (mPathIsRect) {
      mPathBuilder->MoveTo(mRect.TopLeft());
      mPathBuilder->LineTo(mRect.TopRight());
      mPathBuilder->LineTo(mRect.BottomRight());
      mPathBuilder->LineTo(mRect.BottomLeft());
      mPathBuilder->Close();
    }
  }

  if (mTransformChanged) {
    // This could be an else if since this should never happen when
    // mPathBuilder is nullptr and mPath is nullptr. But this way we can
    // assert if all the state is as expected.
    MOZ_ASSERT(oldPath);
    MOZ_ASSERT(!mPathIsRect);

    Matrix invTransform = mAzureState.transform;
    invTransform.Invert();
    Matrix toNewUS = mPathTransform * invTransform;

    RefPtr<Path> path = mPathBuilder->Finish();
    if (!path) {
      gfxCriticalError()
          << "gfxContext::EnsurePathBuilder failed in PathBuilder::Finish";
    }
    mPathBuilder = path->TransformedCopyToBuilder(toNewUS);
  }

  mPathIsRect = false;
}

CompositionOp gfxContext::GetOp() const {
  if (mAzureState.op != CompositionOp::OP_SOURCE) {
    return mAzureState.op;
  }

  if (mAzureState.pattern) {
    if (mAzureState.pattern->IsOpaque()) {
      return CompositionOp::OP_OVER;
    } else {
      return CompositionOp::OP_SOURCE;
    }
  } else {
    if (mAzureState.color.a > 0.999) {
      return CompositionOp::OP_OVER;
    } else {
      return CompositionOp::OP_SOURCE;
    }
  }
}

/* SVG font code can change the transform after having set the pattern on the
 * context. When the pattern is set it is in user space, if the transform is
 * changed after doing so the pattern needs to be converted back into userspace.
 * We just store the old pattern transform here so that we only do the work
 * needed here if the pattern is actually used.
 * We need to avoid doing this when this ChangeTransform comes from a restore,
 * since the current pattern and the current transform are both part of the
 * state we know the new mAzureState's values are valid. But if we assume
 * a change they might become invalid since patternTransformChanged is part of
 * the state and might be false for the restored AzureState.
 */
void gfxContext::ChangeTransform(const Matrix& aNewMatrix,
                                 bool aUpdatePatternTransform) {
  if (aUpdatePatternTransform && (mAzureState.pattern) &&
      !mAzureState.patternTransformChanged) {
    mAzureState.patternTransform = GetDTTransform();
    mAzureState.patternTransformChanged = true;
  }

  if (mPathIsRect) {
    Matrix invMatrix = aNewMatrix;

    invMatrix.Invert();

    Matrix toNewUS = mAzureState.transform * invMatrix;

    if (toNewUS.IsRectilinear()) {
      mRect = toNewUS.TransformBounds(mRect);
      mRect.NudgeToIntegers();
    } else {
      mPathBuilder = mDT->CreatePathBuilder(FillRule::FILL_WINDING);

      mPathBuilder->MoveTo(toNewUS.TransformPoint(mRect.TopLeft()));
      mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.TopRight()));
      mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.BottomRight()));
      mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.BottomLeft()));
      mPathBuilder->Close();

      mPathIsRect = false;
    }

    // No need to consider the transform changed now!
    mTransformChanged = false;
  } else if ((mPath || mPathBuilder) && !mTransformChanged) {
    mTransformChanged = true;
    mPathTransform = mAzureState.transform;
  }

  mAzureState.transform = aNewMatrix;

  mDT->SetTransform(GetDTTransform());
}

Rect gfxContext::GetAzureDeviceSpaceClipBounds() const {
  Rect rect(mAzureState.deviceOffset.x + Float(mDT->GetRect().x),
            mAzureState.deviceOffset.y + Float(mDT->GetRect().y),
            Float(mDT->GetSize().width), Float(mDT->GetSize().height));
  ForAllClips([&](const AzureState::PushedClip& aClip) -> void {
    if (aClip.path) {
      rect.IntersectRect(rect, aClip.path->GetBounds(aClip.transform));
    } else {
      rect.IntersectRect(rect, aClip.transform.TransformBounds(aClip.rect));
    }
  });

  return rect;
}

template <typename F>
void gfxContext::ForAllClips(F&& aLambda) const {
  for (const auto& state : mSavedStates) {
    for (const auto& clip : state.pushedClips) {
      aLambda(clip);
    }
  }
  for (const auto& clip : mAzureState.pushedClips) {
    aLambda(clip);
  }
}