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1 /*
2  * Copyright (C) 2010 Google Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are
6  * met:
7  *
8  *     * Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *     * Redistributions in binary form must reproduce the above
11  * copyright notice, this list of conditions and the following disclaimer
12  * in the documentation and/or other materials provided with the
13  * distribution.
14  *     * Neither the name of Google Inc. nor the names of its
15  * contributors may be used to endorse or promote products derived from
16  * this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "config.h"
32 #include "TransparencyWin.h"
33 
34 #include "AffineTransform.h"
35 #include "ImageBuffer.h"
36 
37 #include <gtest/gtest.h>
38 #include <windows.h>
39 
40 namespace WebCore {
41 
RECTToFloatRect(const RECT * rect)42 static FloatRect RECTToFloatRect(const RECT* rect)
43 {
44     return FloatRect(static_cast<float>(rect->left),
45                      static_cast<float>(rect->top),
46                      static_cast<float>(rect->right - rect->left),
47                      static_cast<float>(rect->bottom - rect->top));
48 }
49 
drawNativeRect(GraphicsContext * context,int x,int y,int w,int h)50 static void drawNativeRect(GraphicsContext* context,
51                            int x, int y, int w, int h)
52 {
53     SkCanvas* canvas = context->platformContext()->canvas();
54     HDC dc = skia::BeginPlatformPaint(canvas);
55 
56     RECT innerRc;
57     innerRc.left = x;
58     innerRc.top = y;
59     innerRc.right = x + w;
60     innerRc.bottom = y + h;
61     FillRect(dc, &innerRc,
62              reinterpret_cast<HBRUSH>(GetStockObject(BLACK_BRUSH)));
63 
64     skia::EndPlatformPaint(canvas);
65 }
66 
getPixelAt(GraphicsContext * context,int x,int y)67 static Color getPixelAt(GraphicsContext* context, int x, int y)
68 {
69     const SkBitmap& bitmap = context->platformContext()->canvas()->getTopDevice()->accessBitmap(false);
70     return Color(*reinterpret_cast<const RGBA32*>(bitmap.getAddr32(x, y)));
71 }
72 
73 // Resets the top layer's alpha channel to 0 for each pixel. This simulates
74 // Windows messing it up.
clearTopLayerAlphaChannel(GraphicsContext * context)75 static void clearTopLayerAlphaChannel(GraphicsContext* context)
76 {
77     SkBitmap& bitmap = const_cast<SkBitmap&>(context->platformContext()->canvas()->getTopDevice()->accessBitmap(false));
78     for (int y = 0; y < bitmap.height(); y++) {
79         uint32_t* row = bitmap.getAddr32(0, y);
80         for (int x = 0; x < bitmap.width(); x++)
81             row[x] &= 0x00FFFFFF;
82     }
83 }
84 
85 // Clears the alpha channel on the specified pixel.
clearTopLayerAlphaPixel(GraphicsContext * context,int x,int y)86 static void clearTopLayerAlphaPixel(GraphicsContext* context, int x, int y)
87 {
88     SkBitmap& bitmap = const_cast<SkBitmap&>(context->platformContext()->canvas()->getTopDevice()->accessBitmap(false));
89     *bitmap.getAddr32(x, y) &= 0x00FFFFFF;
90 }
91 
operator <<(std::ostream & out,const Color & c)92 static std::ostream& operator<<(std::ostream& out, const Color& c)
93 {
94     std::ios_base::fmtflags oldFlags = out.flags(std::ios_base::hex |
95                                                  std::ios_base::showbase);
96     out << c.rgb();
97     out.flags(oldFlags);
98     return out;
99 }
100 
TEST(TransparencyWin,NoLayer)101 TEST(TransparencyWin, NoLayer)
102 {
103     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(17, 16), ColorSpaceDeviceRGB));
104 
105     // KeepTransform
106     {
107         TransparencyWin helper;
108         helper.init(src->context(),
109                     TransparencyWin::NoLayer,
110                     TransparencyWin::KeepTransform,
111                     IntRect(1, 1, 14, 12));
112 
113         EXPECT_TRUE(src->context() == helper.context());
114         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
115         EXPECT_TRUE(IntRect(1, 1, 14, 12) == helper.drawRect());
116     }
117 
118     // Untransform is not allowed for NoLayer.
119 
120     // ScaleTransform
121     src->context()->save();
122     src->context()->scale(FloatSize(2.0, 0.5));
123     {
124         TransparencyWin helper;
125         helper.init(src->context(),
126                     TransparencyWin::NoLayer,
127                     TransparencyWin::ScaleTransform,
128                     IntRect(2, 2, 6, 6));
129         helper.composite();
130 
131         // The coordinate system should be based in the upper left of our box.
132         // It should be post-transformed.
133         EXPECT_TRUE(src->context() == helper.context());
134         EXPECT_TRUE(IntSize(12, 3) == helper.m_layerSize);
135         EXPECT_TRUE(IntRect(4, 1, 12, 3) == helper.drawRect());
136     }
137     src->context()->restore();
138 }
139 
TEST(TransparencyWin,WhiteLayer)140 TEST(TransparencyWin, WhiteLayer)
141 {
142     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
143 
144     // KeepTransform
145     {
146         TransparencyWin helper;
147         helper.init(src->context(),
148                     TransparencyWin::WhiteLayer,
149                     TransparencyWin::KeepTransform,
150                     IntRect(1, 1, 14, 12));
151         helper.composite();
152 
153         EXPECT_TRUE(src->context() != helper.context());
154         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
155         EXPECT_TRUE(IntRect(1, 1, 14, 12) == helper.drawRect());
156     }
157 
158     // Untransform
159     {
160         TransparencyWin helper;
161         helper.init(src->context(),
162                     TransparencyWin::WhiteLayer,
163                     TransparencyWin::Untransform,
164                     IntRect(1, 1, 14, 12));
165         helper.composite();
166 
167         EXPECT_TRUE(src->context() != helper.context());
168         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
169         EXPECT_TRUE(IntRect(0, 0, 14, 12) == helper.drawRect());
170     }
171 
172     // ScaleTransform
173     src->context()->save();
174     src->context()->scale(FloatSize(2.0, 0.5));
175     {
176         TransparencyWin helper;
177         helper.init(src->context(),
178                     TransparencyWin::WhiteLayer,
179                     TransparencyWin::ScaleTransform,
180                     IntRect(2, 2, 6, 6));
181         helper.composite();
182 
183         // The coordinate system should be based in the upper left of our box.
184         // It should be post-transformed.
185         EXPECT_TRUE(src->context() != helper.context());
186         EXPECT_TRUE(IntSize(12, 3) == helper.m_layerSize);
187         EXPECT_TRUE(IntRect(0, 0, 12, 3) == helper.drawRect());
188     }
189     src->context()->restore();
190 }
191 
TEST(TransparencyWin,TextComposite)192 TEST(TransparencyWin, TextComposite)
193 {
194     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
195 
196     // KeepTransform is the only valid transform mode for TextComposite.
197     {
198         TransparencyWin helper;
199         helper.init(src->context(),
200                     TransparencyWin::TextComposite,
201                     TransparencyWin::KeepTransform,
202                     IntRect(1, 1, 14, 12));
203         helper.composite();
204 
205         EXPECT_TRUE(src->context() != helper.context());
206         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
207         EXPECT_TRUE(IntRect(1, 1, 14, 12) == helper.drawRect());
208     }
209 }
210 
TEST(TransparencyWin,OpaqueCompositeLayer)211 TEST(TransparencyWin, OpaqueCompositeLayer)
212 {
213     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
214 
215     // KeepTransform
216     {
217         TransparencyWin helper;
218         helper.init(src->context(),
219                     TransparencyWin::OpaqueCompositeLayer,
220                     TransparencyWin::KeepTransform,
221                     IntRect(1, 1, 14, 12));
222         helper.composite();
223 
224         EXPECT_TRUE(src->context() != helper.context());
225         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
226         EXPECT_TRUE(IntRect(1, 1, 14, 12) == helper.drawRect());
227     }
228 
229     // KeepTransform with scroll applied.
230     src->context()->save();
231     src->context()->translate(0, -1);
232     {
233         TransparencyWin helper;
234         helper.init(src->context(),
235                     TransparencyWin::OpaqueCompositeLayer,
236                     TransparencyWin::KeepTransform,
237                     IntRect(1, 1, 14, 14));
238         helper.composite();
239 
240         EXPECT_TRUE(src->context() != helper.context());
241         EXPECT_TRUE(IntSize(14, 14) == helper.m_layerSize);
242         EXPECT_TRUE(IntRect(1, 1, 14, 14) == helper.drawRect());
243     }
244     src->context()->restore();
245 
246     // Untransform
247     {
248         TransparencyWin helper;
249         helper.init(src->context(),
250                     TransparencyWin::OpaqueCompositeLayer,
251                     TransparencyWin::Untransform,
252                     IntRect(1, 1, 14, 12));
253         helper.composite();
254 
255         EXPECT_TRUE(src->context() != helper.context());
256         EXPECT_TRUE(IntSize(14, 12) == helper.m_layerSize);
257         EXPECT_TRUE(IntRect(0, 0, 14, 12) == helper.drawRect());
258     }
259 
260     // ScaleTransform
261     src->context()->save();
262     src->context()->scale(FloatSize(2.0, 0.5));
263     {
264         TransparencyWin helper;
265         helper.init(src->context(),
266                     TransparencyWin::OpaqueCompositeLayer,
267                     TransparencyWin::ScaleTransform,
268                     IntRect(2, 2, 6, 6));
269         helper.composite();
270 
271         // The coordinate system should be based in the upper left of our box.
272         // It should be post-transformed.
273         EXPECT_TRUE(src->context() != helper.context());
274         EXPECT_TRUE(IntSize(12, 3) == helper.m_layerSize);
275         EXPECT_TRUE(IntRect(0, 0, 12, 3) == helper.drawRect());
276     }
277     src->context()->restore();
278 }
279 
TEST(TransparencyWin,WhiteLayerPixelTest)280 TEST(TransparencyWin, WhiteLayerPixelTest)
281 {
282     // Make a total transparent buffer, and draw the white layer inset by 1 px.
283     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
284 
285     {
286         TransparencyWin helper;
287         helper.init(src->context(),
288                     TransparencyWin::WhiteLayer,
289                     TransparencyWin::KeepTransform,
290                     IntRect(1, 1, 14, 14));
291 
292         // Coordinates should be in the original space, not the layer.
293         drawNativeRect(helper.context(), 3, 3, 1, 1);
294         clearTopLayerAlphaChannel(helper.context());
295         helper.composite();
296     }
297 
298     // The final image should be transparent around the edges for 1 px, white
299     // in the middle, with (3,3) (what we drew above) being opaque black.
300     EXPECT_EQ(Color(Color::transparent), getPixelAt(src->context(), 0, 0));
301     EXPECT_EQ(Color(Color::white), getPixelAt(src->context(), 2, 2));
302     EXPECT_EQ(Color(Color::black), getPixelAt(src->context(), 3, 3));
303     EXPECT_EQ(Color(Color::white), getPixelAt(src->context(), 4, 4));
304 }
305 
TEST(TransparencyWin,OpaqueCompositeLayerPixel)306 TEST(TransparencyWin, OpaqueCompositeLayerPixel)
307 {
308     Color red(0xFFFF0000), darkRed(0xFFBF0000);
309     Color green(0xFF00FF00);
310 
311     // Make a red bottom layer, followed by a half green next layer @ 50%.
312     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
313 
314     FloatRect fullRect(0, 0, 16, 16);
315     src->context()->fillRect(fullRect, red, ColorSpaceDeviceRGB);
316     src->context()->beginTransparencyLayer(0.5);
317     FloatRect rightHalf(8, 0, 8, 16);
318     src->context()->fillRect(rightHalf, green, ColorSpaceDeviceRGB);
319 
320     // Make a transparency layer inset by one pixel, and fill it inset by
321     // another pixel with 50% black.
322     {
323         TransparencyWin helper;
324         helper.init(src->context(),
325                     TransparencyWin::OpaqueCompositeLayer,
326                     TransparencyWin::KeepTransform,
327                     IntRect(1, 1, 14, 14));
328 
329         FloatRect inner(2, 2, 12, 12);
330         helper.context()->fillRect(inner, Color(0x7f000000), ColorSpaceDeviceRGB);
331         // These coordinates are relative to the layer, whish is inset by 1x1
332         // pixels from the top left. So we're actually clearing (2, 2) and
333         // (13,13), which are the extreme corners of the black area (and which
334         // we check below).
335         clearTopLayerAlphaPixel(helper.context(), 1, 1);
336         clearTopLayerAlphaPixel(helper.context(), 12, 12);
337         helper.composite();
338     }
339 
340     // Finish the compositing.
341     src->context()->endTransparencyLayer();
342 
343     // Check that we got the right values, it should be like the rectangle was
344     // drawn with half opacity even though the alpha channel got messed up.
345     EXPECT_EQ(red, getPixelAt(src->context(), 0, 0));
346     EXPECT_EQ(red, getPixelAt(src->context(), 1, 1));
347     EXPECT_EQ(darkRed, getPixelAt(src->context(), 2, 2));
348 
349     // The dark result is:
350     //   (black @ 50% atop green) @ 50% atop red = 0xFF804000
351     // which is 0xFFA02000 (Skia computes 0xFFA11F00 due to rounding).
352     Color darkGreenRed(0xFF803f00);
353     EXPECT_EQ(darkGreenRed, getPixelAt(src->context(), 13, 13));
354 
355     // 50% green on top of red = FF808000 (rounded to what Skia will produce).
356     Color greenRed(0xFF807F00);
357     EXPECT_EQ(greenRed, getPixelAt(src->context(), 14, 14));
358     EXPECT_EQ(greenRed, getPixelAt(src->context(), 15, 15));
359 }
360 
361 // Tests that translations are properly handled when using KeepTransform.
TEST(TransparencyWin,TranslateOpaqueCompositeLayer)362 TEST(TransparencyWin, TranslateOpaqueCompositeLayer)
363 {
364     // Fill with white.
365     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
366     Color white(0xFFFFFFFF);
367     FloatRect fullRect(0, 0, 16, 16);
368     src->context()->fillRect(fullRect, white, ColorSpaceDeviceRGB);
369 
370     // Scroll down by 8 (coordinate system goes up).
371     src->context()->save();
372     src->context()->translate(0, -8);
373 
374     Color red(0xFFFF0000);
375     Color green(0xFF00FF00);
376     {
377         // Make the transparency layer after translation will be @ (0, -8) with
378         // size 16x16.
379         TransparencyWin helper;
380         helper.init(src->context(),
381                     TransparencyWin::OpaqueCompositeLayer,
382                     TransparencyWin::KeepTransform,
383                     IntRect(0, 0, 16, 16));
384 
385         // Draw a red pixel at (15, 15). This should be the at (15, 7) after
386         // the transform.
387         FloatRect bottomRight(15, 15, 1, 1);
388         helper.context()->fillRect(bottomRight, green, ColorSpaceDeviceRGB);
389         helper.composite();
390     }
391 
392     src->context()->restore();
393 
394     // Check the pixel we wrote.
395     EXPECT_EQ(green, getPixelAt(src->context(), 15, 7));
396 }
397 
398 // Same as OpaqueCompositeLayer, but the canvas has a rotation applied. This
399 // tests that the propert transform is applied to the copied layer.
TEST(TransparencyWin,RotateOpaqueCompositeLayer)400 TEST(TransparencyWin, RotateOpaqueCompositeLayer)
401 {
402     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
403 
404     // The background is white.
405     Color white(0xFFFFFFFF);
406     FloatRect fullRect(0, 0, 16, 16);
407     src->context()->fillRect(fullRect, white, ColorSpaceDeviceRGB);
408 
409     // Rotate the image by 90 degrees. This matrix is the same as
410     // cw90.rotate(90); but avoids rounding errors. Rounding errors can cause
411     // Skia to think that !rectStaysRect() and it will fall through to path
412     // drawing mode, which in turn gives us antialiasing. We want no
413     // antialiasing or other rounding problems since we're testing exact pixel
414     // values.
415     src->context()->save();
416     AffineTransform cw90(0, 1, -1, 0, 0, 0);
417     src->context()->concatCTM(cw90);
418 
419     // Make a transparency layer consisting of a horizontal line of 50% black.
420     // Since the rotation is applied, this will actually be a vertical line
421     // down the middle of the image.
422     src->context()->beginTransparencyLayer(0.5);
423     FloatRect blackRect(0, -9, 16, 2);
424     Color black(0xFF000000);
425     src->context()->fillRect(blackRect, black, ColorSpaceDeviceRGB);
426 
427     // Now draw 50% red square.
428     {
429         // Create a transparency helper inset one pixel in the buffer. The
430         // coordinates are before transforming into this space, and maps to
431         // IntRect(1, 1, 14, 14).
432         TransparencyWin helper;
433         helper.init(src->context(),
434                     TransparencyWin::OpaqueCompositeLayer,
435                     TransparencyWin::Untransform,
436                     IntRect(1, -15, 14, 14));
437 
438         // Fill with red.
439         helper.context()->fillRect(helper.drawRect(), Color(0x7f7f0000), ColorSpaceDeviceRGB);
440         clearTopLayerAlphaChannel(helper.context());
441         helper.composite();
442     }
443 
444     // Finish the compositing.
445     src->context()->endTransparencyLayer();
446 
447     // Top corner should be the original background.
448     EXPECT_EQ(white, getPixelAt(src->context(), 0, 0));
449 
450     // Check the stripe down the middle, first at the top...
451     Color gray(0xFF808080);
452     EXPECT_EQ(white, getPixelAt(src->context(), 6, 0));
453     EXPECT_EQ(gray, getPixelAt(src->context(), 7, 0));
454     EXPECT_EQ(gray, getPixelAt(src->context(), 8, 0));
455     EXPECT_EQ(white, getPixelAt(src->context(), 9, 0));
456 
457     // ...now at the bottom.
458     EXPECT_EQ(white, getPixelAt(src->context(), 6, 15));
459     EXPECT_EQ(gray, getPixelAt(src->context(), 7, 15));
460     EXPECT_EQ(gray, getPixelAt(src->context(), 8, 15));
461     EXPECT_EQ(white, getPixelAt(src->context(), 9, 15));
462 
463     // Our red square should be 25% red over the top of those two.
464     Color redwhite(0xFFdfbfbf);
465     Color redgray(0xFF9f8080);
466     EXPECT_EQ(white, getPixelAt(src->context(), 0, 1));
467     EXPECT_EQ(redwhite, getPixelAt(src->context(), 1, 1));
468     EXPECT_EQ(redwhite, getPixelAt(src->context(), 6, 1));
469     EXPECT_EQ(redgray, getPixelAt(src->context(), 7, 1));
470     EXPECT_EQ(redgray, getPixelAt(src->context(), 8, 1));
471     EXPECT_EQ(redwhite, getPixelAt(src->context(), 9, 1));
472     EXPECT_EQ(redwhite, getPixelAt(src->context(), 14, 1));
473     EXPECT_EQ(white, getPixelAt(src->context(), 15, 1));
474 
475     // Complete the 50% transparent layer.
476     src->context()->restore();
477 }
478 
TEST(TransparencyWin,TranslateScaleOpaqueCompositeLayer)479 TEST(TransparencyWin, TranslateScaleOpaqueCompositeLayer)
480 {
481     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
482 
483     // The background is white on top with red on bottom.
484     Color white(0xFFFFFFFF);
485     FloatRect topRect(0, 0, 16, 8);
486     src->context()->fillRect(topRect, white, ColorSpaceDeviceRGB);
487     Color red(0xFFFF0000);
488     FloatRect bottomRect(0, 8, 16, 8);
489     src->context()->fillRect(bottomRect, red, ColorSpaceDeviceRGB);
490 
491     src->context()->save();
492 
493     // Translate left by one pixel.
494     AffineTransform left;
495     left.translate(-1, 0);
496 
497     // Scale by 2x.
498     AffineTransform scale;
499     scale.scale(2.0);
500     src->context()->concatCTM(scale);
501 
502     // Then translate up by one pixel (which will actually be 2 due to scaling).
503     AffineTransform up;
504     up.translate(0, -1);
505     src->context()->concatCTM(up);
506 
507     // Now draw 50% red square.
508     {
509         // Create a transparency helper inset one pixel in the buffer. The
510         // coordinates are before transforming into this space, and maps to
511         // IntRect(1, 1, 14, 14).
512         TransparencyWin helper;
513         helper.init(src->context(),
514                     TransparencyWin::OpaqueCompositeLayer,
515                     TransparencyWin::KeepTransform,
516                     IntRect(1, -15, 14, 14));
517 
518         // Fill with red.
519         helper.context()->fillRect(helper.drawRect(), Color(0x7f7f0000), ColorSpaceDeviceRGB);
520         clearTopLayerAlphaChannel(helper.context());
521         helper.composite();
522     }
523 }
524 
525 // Tests scale mode with no additional copy.
TEST(TransparencyWin,Scale)526 TEST(TransparencyWin, Scale)
527 {
528     // Create an opaque white buffer.
529     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
530     FloatRect fullBuffer(0, 0, 16, 16);
531     src->context()->fillRect(fullBuffer, Color::white, ColorSpaceDeviceRGB);
532 
533     // Scale by 2x.
534     src->context()->save();
535     AffineTransform scale;
536     scale.scale(2.0);
537     src->context()->concatCTM(scale);
538 
539     // Start drawing a rectangle from 1->4. This should get scaled to 2->8.
540     {
541         TransparencyWin helper;
542         helper.init(src->context(),
543                     TransparencyWin::NoLayer,
544                     TransparencyWin::ScaleTransform,
545                     IntRect(1, 1, 3, 3));
546 
547         // The context should now have the identity transform and the returned
548         // rect should be scaled.
549         EXPECT_TRUE(helper.context()->getCTM().isIdentity());
550         EXPECT_EQ(2, helper.drawRect().x());
551         EXPECT_EQ(2, helper.drawRect().y());
552         EXPECT_EQ(8, helper.drawRect().maxX());
553         EXPECT_EQ(8, helper.drawRect().maxY());
554 
555         // Set the pixel at (2, 2) to be transparent. This should be fixed when
556         // the helper goes out of scope. We don't want to call
557         // clearTopLayerAlphaChannel because that will actually clear the whole
558         // canvas (since we have no extra layer!).
559         SkBitmap& bitmap = const_cast<SkBitmap&>(helper.context()->platformContext()->canvas()->getTopDevice()->accessBitmap(false));
560         *bitmap.getAddr32(2, 2) &= 0x00FFFFFF;
561         helper.composite();
562     }
563 
564     src->context()->restore();
565 
566     // Check the pixel we previously made transparent, it should have gotten
567     // fixed back up to white.
568 
569     // The current version doesn't fixup transparency when there is no layer.
570     // This seems not to be necessary, so we don't bother, but if it becomes
571     // necessary, this line should be uncommented.
572     // EXPECT_EQ(Color(Color::white), getPixelAt(src->context(), 2, 2));
573 }
574 
575 // Tests scale mode with an additional copy for transparency. This will happen
576 // if we have a scaled textbox, for example. WebKit will create a new
577 // transparency layer, draw the text field, then draw the text into it, then
578 // composite this down with an opacity.
TEST(TransparencyWin,ScaleTransparency)579 TEST(TransparencyWin, ScaleTransparency)
580 {
581     // Create an opaque white buffer.
582     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
583     FloatRect fullBuffer(0, 0, 16, 16);
584     src->context()->fillRect(fullBuffer, Color::white, ColorSpaceDeviceRGB);
585 
586     // Make another layer (which duplicates how WebKit will make this). We fill
587     // the top half with red, and have the layer be 50% opaque.
588     src->context()->beginTransparencyLayer(0.5);
589     FloatRect topHalf(0, 0, 16, 8);
590     src->context()->fillRect(topHalf, Color(0xFFFF0000), ColorSpaceDeviceRGB);
591 
592     // Scale by 2x.
593     src->context()->save();
594     AffineTransform scale;
595     scale.scale(2.0);
596     src->context()->concatCTM(scale);
597 
598     // Make a layer inset two pixels (because of scaling, this is 2->14). And
599     // will it with 50% black.
600     {
601         TransparencyWin helper;
602         helper.init(src->context(),
603                     TransparencyWin::OpaqueCompositeLayer,
604                     TransparencyWin::ScaleTransform,
605                     IntRect(1, 1, 6, 6));
606 
607         helper.context()->fillRect(helper.drawRect(), Color(0x7f000000), ColorSpaceDeviceRGB);
608         clearTopLayerAlphaChannel(helper.context());
609         helper.composite();
610     }
611 
612     // Finish the layer.
613     src->context()->restore();
614     src->context()->endTransparencyLayer();
615 
616     Color redBackground(0xFFFF8080); // 50% red composited on white.
617     EXPECT_EQ(redBackground, getPixelAt(src->context(), 0, 0));
618     EXPECT_EQ(redBackground, getPixelAt(src->context(), 1, 1));
619 
620     // Top half (minus two pixel border) should be 50% gray atop opaque
621     // red = 0xFF804141. Then that's composited with 50% transparency on solid
622     // white = 0xFFC0A1A1.
623     Color darkRed(0xFFBF8080);
624     EXPECT_EQ(darkRed, getPixelAt(src->context(), 2, 2));
625     EXPECT_EQ(darkRed, getPixelAt(src->context(), 7, 7));
626 
627     // Bottom half (minus a two pixel border) should be a layer with 5% gray
628     // with another 50% opacity composited atop white.
629     Color darkWhite(0xFFBFBFBF);
630     EXPECT_EQ(darkWhite, getPixelAt(src->context(), 8, 8));
631     EXPECT_EQ(darkWhite, getPixelAt(src->context(), 13, 13));
632 
633     Color white(0xFFFFFFFF); // Background in the lower-right.
634     EXPECT_EQ(white, getPixelAt(src->context(), 14, 14));
635     EXPECT_EQ(white, getPixelAt(src->context(), 15, 15));
636 }
637 
TEST(TransparencyWin,Text)638 TEST(TransparencyWin, Text)
639 {
640     OwnPtr<ImageBuffer> src(ImageBuffer::create(IntSize(16, 16), ColorSpaceDeviceRGB));
641 
642     // Our text should end up 50% transparent blue-green.
643     Color fullResult(0x80008080);
644 
645     {
646         TransparencyWin helper;
647         helper.init(src->context(),
648                     TransparencyWin::TextComposite,
649                     TransparencyWin::KeepTransform,
650                     IntRect(0, 0, 16, 16));
651         helper.setTextCompositeColor(fullResult);
652 
653         // Write several different squares to simulate ClearType. These should
654         // all reduce to 2/3 coverage.
655         FloatRect pixel(0, 0, 1, 1);
656         helper.context()->fillRect(pixel, 0xFFFF0000, ColorSpaceDeviceRGB);
657         pixel.move(1.0f, 0.0f);
658         helper.context()->fillRect(pixel, 0xFF00FF00, ColorSpaceDeviceRGB);
659         pixel.move(1.0f, 0.0f);
660         helper.context()->fillRect(pixel, 0xFF0000FF, ColorSpaceDeviceRGB);
661         pixel.move(1.0f, 0.0f);
662         helper.context()->fillRect(pixel, 0xFF008080, ColorSpaceDeviceRGB);
663         pixel.move(1.0f, 0.0f);
664         helper.context()->fillRect(pixel, 0xFF800080, ColorSpaceDeviceRGB);
665         pixel.move(1.0f, 0.0f);
666         helper.context()->fillRect(pixel, 0xFF808000, ColorSpaceDeviceRGB);
667 
668         // Try one with 100% coverage (opaque black).
669         pixel.move(1.0f, 0.0f);
670         helper.context()->fillRect(pixel, 0xFF000000, ColorSpaceDeviceRGB);
671 
672         // Now mess with the alpha channel.
673         clearTopLayerAlphaChannel(helper.context());
674         helper.composite();
675     }
676 
677     Color oneThirdResult(0x55005555); // = fullResult * 2 / 3
678     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 0, 0));
679     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 1, 0));
680     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 2, 0));
681     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 3, 0));
682     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 4, 0));
683     EXPECT_EQ(oneThirdResult, getPixelAt(src->context(), 5, 0));
684     EXPECT_EQ(fullResult, getPixelAt(src->context(), 6, 0));
685     EXPECT_EQ(Color::transparent, getPixelAt(src->context(), 7, 0));
686 }
687 
688 } // namespace WebCore
689