1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "ui/gfx/blit.h"
6
7 #include "base/logging.h"
8 #include "build/build_config.h"
9 #include "skia/ext/platform_canvas.h"
10 #include "ui/gfx/point.h"
11 #include "ui/gfx/rect.h"
12 #include "ui/gfx/vector2d.h"
13
14 #if defined(USE_CAIRO)
15 #if defined(OS_OPENBSD)
16 #include <cairo.h>
17 #elif defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
18 #include <cairo/cairo.h>
19 #endif
20 #endif
21
22 #if defined(OS_MACOSX)
23 #include "base/mac/scoped_cftyperef.h"
24 #endif
25
26 namespace gfx {
27
28 namespace {
29
30 // Returns true if the given canvas has any part of itself clipped out or
31 // any non-identity tranform.
HasClipOrTransform(const SkCanvas & canvas)32 bool HasClipOrTransform(const SkCanvas& canvas) {
33 if (!canvas.getTotalMatrix().isIdentity())
34 return true;
35
36 const SkRegion& clip_region = canvas.getTotalClip();
37 if (clip_region.isEmpty() || clip_region.isComplex())
38 return true;
39
40 // Now we know the clip is a regular rectangle, make sure it covers the
41 // entire canvas.
42 const SkBitmap& bitmap = skia::GetTopDevice(canvas)->accessBitmap(false);
43 const SkIRect& clip_bounds = clip_region.getBounds();
44 if (clip_bounds.fLeft != 0 || clip_bounds.fTop != 0 ||
45 clip_bounds.fRight != bitmap.width() ||
46 clip_bounds.fBottom != bitmap.height())
47 return true;
48
49 return false;
50 }
51
52 } // namespace
53
BlitContextToContext(NativeDrawingContext dst_context,const Rect & dst_rect,NativeDrawingContext src_context,const Point & src_origin)54 void BlitContextToContext(NativeDrawingContext dst_context,
55 const Rect& dst_rect,
56 NativeDrawingContext src_context,
57 const Point& src_origin) {
58 #if defined(OS_WIN)
59 BitBlt(dst_context, dst_rect.x(), dst_rect.y(),
60 dst_rect.width(), dst_rect.height(),
61 src_context, src_origin.x(), src_origin.y(), SRCCOPY);
62 #elif defined(OS_MACOSX)
63 // Only translations and/or vertical flips in the source context are
64 // supported; more complex source context transforms will be ignored.
65
66 // If there is a translation on the source context, we need to account for
67 // it ourselves since CGBitmapContextCreateImage will bypass it.
68 Rect src_rect(src_origin, dst_rect.size());
69 CGAffineTransform transform = CGContextGetCTM(src_context);
70 bool flipped = fabs(transform.d + 1) < 0.0001;
71 CGFloat delta_y = flipped ? CGBitmapContextGetHeight(src_context) -
72 transform.ty
73 : transform.ty;
74 src_rect.Offset(transform.tx, delta_y);
75
76 base::ScopedCFTypeRef<CGImageRef> src_image(
77 CGBitmapContextCreateImage(src_context));
78 base::ScopedCFTypeRef<CGImageRef> src_sub_image(
79 CGImageCreateWithImageInRect(src_image, src_rect.ToCGRect()));
80 CGContextDrawImage(dst_context, dst_rect.ToCGRect(), src_sub_image);
81 #elif defined(USE_CAIRO)
82 // Only translations in the source context are supported; more complex
83 // source context transforms will be ignored.
84 cairo_save(dst_context);
85 double surface_x = src_origin.x();
86 double surface_y = src_origin.y();
87 cairo_user_to_device(src_context, &surface_x, &surface_y);
88 cairo_set_source_surface(dst_context, cairo_get_target(src_context),
89 dst_rect.x()-surface_x, dst_rect.y()-surface_y);
90 cairo_rectangle(dst_context, dst_rect.x(), dst_rect.y(),
91 dst_rect.width(), dst_rect.height());
92 cairo_clip(dst_context);
93 cairo_paint(dst_context);
94 cairo_restore(dst_context);
95 #else
96 NOTIMPLEMENTED();
97 #endif
98 }
99
BlitContextToCanvas(SkCanvas * dst_canvas,const Rect & dst_rect,NativeDrawingContext src_context,const Point & src_origin)100 void BlitContextToCanvas(SkCanvas *dst_canvas,
101 const Rect& dst_rect,
102 NativeDrawingContext src_context,
103 const Point& src_origin) {
104 DCHECK(skia::SupportsPlatformPaint(dst_canvas));
105 BlitContextToContext(skia::BeginPlatformPaint(dst_canvas), dst_rect,
106 src_context, src_origin);
107 skia::EndPlatformPaint(dst_canvas);
108 }
109
BlitCanvasToContext(NativeDrawingContext dst_context,const Rect & dst_rect,SkCanvas * src_canvas,const Point & src_origin)110 void BlitCanvasToContext(NativeDrawingContext dst_context,
111 const Rect& dst_rect,
112 SkCanvas *src_canvas,
113 const Point& src_origin) {
114 DCHECK(skia::SupportsPlatformPaint(src_canvas));
115 BlitContextToContext(dst_context, dst_rect,
116 skia::BeginPlatformPaint(src_canvas), src_origin);
117 skia::EndPlatformPaint(src_canvas);
118 }
119
BlitCanvasToCanvas(SkCanvas * dst_canvas,const Rect & dst_rect,SkCanvas * src_canvas,const Point & src_origin)120 void BlitCanvasToCanvas(SkCanvas *dst_canvas,
121 const Rect& dst_rect,
122 SkCanvas *src_canvas,
123 const Point& src_origin) {
124 DCHECK(skia::SupportsPlatformPaint(dst_canvas));
125 DCHECK(skia::SupportsPlatformPaint(src_canvas));
126 BlitContextToContext(skia::BeginPlatformPaint(dst_canvas), dst_rect,
127 skia::BeginPlatformPaint(src_canvas), src_origin);
128 skia::EndPlatformPaint(src_canvas);
129 skia::EndPlatformPaint(dst_canvas);
130 }
131
ScrollCanvas(SkCanvas * canvas,const gfx::Rect & in_clip,const gfx::Vector2d & offset)132 void ScrollCanvas(SkCanvas* canvas,
133 const gfx::Rect& in_clip,
134 const gfx::Vector2d& offset) {
135 DCHECK(!HasClipOrTransform(*canvas)); // Don't support special stuff.
136 #if defined(OS_WIN)
137 // If we have a PlatformCanvas, we should use ScrollDC. Otherwise, fall
138 // through to the software implementation.
139 if (skia::SupportsPlatformPaint(canvas)) {
140 skia::ScopedPlatformPaint scoped_platform_paint(canvas);
141 HDC hdc = scoped_platform_paint.GetPlatformSurface();
142
143 RECT damaged_rect;
144 RECT r = in_clip.ToRECT();
145 ScrollDC(hdc, offset.x(), offset.y(), NULL, &r, NULL, &damaged_rect);
146 return;
147 }
148 #endif // defined(OS_WIN)
149 // For non-windows, always do scrolling in software.
150 // Cairo has no nice scroll function so we do our own. On Mac it's possible to
151 // use platform scroll code, but it's complex so we just use the same path
152 // here. Either way it will be software-only, so it shouldn't matter much.
153 SkBitmap& bitmap = const_cast<SkBitmap&>(
154 skia::GetTopDevice(*canvas)->accessBitmap(true));
155 SkAutoLockPixels lock(bitmap);
156
157 // We expect all coords to be inside the canvas, so clip here.
158 gfx::Rect clip = gfx::IntersectRects(
159 in_clip, gfx::Rect(0, 0, bitmap.width(), bitmap.height()));
160
161 // Compute the set of pixels we'll actually end up painting.
162 gfx::Rect dest_rect = gfx::IntersectRects(clip + offset, clip);
163 if (dest_rect.size().IsEmpty())
164 return; // Nothing to do.
165
166 // Compute the source pixels that will map to the dest_rect
167 gfx::Rect src_rect = dest_rect - offset;
168
169 size_t row_bytes = dest_rect.width() * 4;
170 if (offset.y() > 0) {
171 // Data is moving down, copy from the bottom up.
172 for (int y = dest_rect.height() - 1; y >= 0; y--) {
173 memcpy(bitmap.getAddr32(dest_rect.x(), dest_rect.y() + y),
174 bitmap.getAddr32(src_rect.x(), src_rect.y() + y),
175 row_bytes);
176 }
177 } else if (offset.y() < 0) {
178 // Data is moving up, copy from the top down.
179 for (int y = 0; y < dest_rect.height(); y++) {
180 memcpy(bitmap.getAddr32(dest_rect.x(), dest_rect.y() + y),
181 bitmap.getAddr32(src_rect.x(), src_rect.y() + y),
182 row_bytes);
183 }
184 } else if (offset.x() != 0) {
185 // Horizontal-only scroll. We can do it in either top-to-bottom or bottom-
186 // to-top, but have to be careful about the order for copying each row.
187 // Fortunately, memmove already handles this for us.
188 for (int y = 0; y < dest_rect.height(); y++) {
189 memmove(bitmap.getAddr32(dest_rect.x(), dest_rect.y() + y),
190 bitmap.getAddr32(src_rect.x(), src_rect.y() + y),
191 row_bytes);
192 }
193 }
194 }
195
196 } // namespace gfx
197