Get windowless plugins working when accelerated compositing is turned on.

content/renderer/webplugin_delegate_proxy.cc

Index: content/renderer/webplugin_delegate_proxy.cc
===================================================================
--- content/renderer/webplugin_delegate_proxy.cc	(revision 166499)
+++ content/renderer/webplugin_delegate_proxy.cc	(working copy)
@@ -48,6 +48,7 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
+#include "ui/gfx/skia_util.h"
 #include "webkit/glue/webkit_glue.h"
 #include "webkit/plugins/npapi/webplugin.h"
 #include "webkit/plugins/plugin_constants.h"
@@ -402,6 +403,7 @@
         (silverlight && LowerCaseEqualsASCII(arg_names[i], "background") &&
          SilverlightColorIsTransparent(arg_values[i]))) {
       transparent_ = true;
+      RenderThread::Get()->RecordUserMetrics("Plugin_Transparent");
     }
   }
   params.load_manually = load_manually;
@@ -409,8 +411,7 @@
   plugin_ = plugin;
 
   result = false;
-  IPC::Message* msg = new PluginMsg_Init(instance_id_, params, &result);
-  Send(msg);
+  Send(new PluginMsg_Init(instance_id_, params, &result));
 
   if (!result)
     LOG(ERROR) << "PluginMsg_Init returned false";
@@ -668,6 +669,12 @@
           ResetWindowlessBitmaps();
           return;
         }
+
+        if (needs_background_store &&
+            render_view_->is_accelerated_compositing_active()) {
+          // Better than grabage...
+          background_store_.canvas->drawColor(SK_ColorWHITE);

[piman, 2012/11/09 19:27:03]

How about writing transparent pixels? If the plugin is transparent, you have a
shot at compositing it correctly.

[jam, 2012/11/09 22:50:24]

Thanks, actually trying this out shows that NPAPI Flash and Silverlight now
support transparency correctly and don't need the page text to be present :)
This means we don't need any of this code, so I've gone ahead and purged it.

+        }
       }
     }
   }
@@ -762,40 +769,28 @@
   if (!front_buffer_canvas())
     return;
 
-  // We're using the native OS APIs from here on out.
-  if (!skia::SupportsPlatformPaint(canvas)) {
-    // TODO(alokp): Implement this path.
-    // This block will only get hit with --enable-accelerated-drawing flag.
-    // With accelerated canvas, we do not have a bitmap that can be provided
-    // to the plugin for compositing. We may have to implement a solution
-    // described in crbug.com/12586.
-    DLOG(WARNING) << "Could not paint plugin";
-    return;
-  }
-  skia::ScopedPlatformPaint scoped_platform_paint(canvas);
-  gfx::NativeDrawingContext context =
-      scoped_platform_paint.GetPlatformSurface();
-
   gfx::Rect offset_rect = rect;
   offset_rect.Offset(-plugin_rect_.x(), -plugin_rect_.y());
-  gfx::Rect canvas_rect = offset_rect;
-#if defined(OS_MACOSX)
-  // The canvases are flipped relative to the context, so flip the rect too.
-  FlipRectVerticallyWithHeight(&canvas_rect, plugin_rect_.height());
-#endif
 
   bool background_changed = false;
-  if (background_store_.canvas.get() && BackgroundChanged(context, rect)) {
+  if (background_store_.canvas.get() && BackgroundChanged(canvas, rect) &&
+      // When accelerated compositing is used we don't have access to the
+      // page data under the plugin. This might result in painting glitches,
+      // but there's nothing we can do about that. This is mostly mitigiated

[piman, 2012/11/09 19:27:03]

typo: mitigated

+      // by the fact that this is only for NPAPI plugins, and for Flash we use
+      // Pepper.
+      !render_view_->is_accelerated_compositing_active()) {
     background_changed = true;
-    BlitContextToCanvas(background_store_.canvas.get(), canvas_rect,
-                        context, rect.origin());
+    SkIRect src_rect = gfx::RectToSkIRect(rect);
+    background_store_.canvas->drawBitmapRect(
+        canvas->getDevice()->accessBitmap(false),
+        &src_rect, gfx::RectToSkRect(offset_rect));

[jam, 2012/11/09 19:02:25]

btw I found that somehow this isn't working on Linux. any idea? On Win/Mac this
works fine by copying the current page's data to the background canvas. On
Linux, this seems to not do anything.

[piman, 2012/11/09 19:27:03]

I'm not sure specifically, but I was going to mention that we want to check what
happens for recording canvas (either with --enable-per-tile-painting or
--enable-accelerated-drawing). They don't give you (directly) access to the
underlying pixels.
It may be related, but I don't think it's on by default on linux though.

   }
 
   // transport_store_painted_ is really a bounding box, so in principle this
   // check could falsely indicate that we don't need to paint offset_rect, but
   // in practice it works fine.
-  if (background_changed ||
-      !transport_store_painted_.Contains(offset_rect)) {
+  if (background_changed || !transport_store_painted_.Contains(offset_rect)) {
     Send(new PluginMsg_Paint(instance_id_, offset_rect));
     // Since the plugin is not blocked on the renderer in this context, there is
     // a chance that it will begin repainting the back-buffer before we complete
@@ -805,20 +800,15 @@
     UpdateFrontBuffer(offset_rect, false);
   }
 
-#if defined(OS_MACOSX)
-  // The canvases are flipped relative to the context, so flip the context's
-  // coordinate space so that the blit unflips the content.
-  CGContextSaveGState(context);
-  CGContextScaleCTM(context, 1, -1);
-  rect.set_y(-rect.bottom());
-#endif
-  BlitCanvasToContext(context,
-                      rect,
-                      front_buffer_canvas(),
-                      offset_rect.origin());
-#if defined(OS_MACOSX)
-  CGContextRestoreGState(context);
-#endif
+  const SkBitmap& bitmap =
+      front_buffer_canvas()->getDevice()->accessBitmap(false);
+  SkPaint paint;
+  paint.setXfermodeMode(SkXfermode::kSrcATop_Mode);
+  SkIRect src_rect = gfx::RectToSkIRect(offset_rect);
+  canvas->drawBitmapRect(bitmap,
+                         &src_rect,
+                         gfx::RectToSkRect(rect),
+                         &paint);
 
   if (invalidate_pending_) {
     // Only send the PaintAck message if this paint is in response to an
@@ -829,154 +819,26 @@
   }
 }
 
-bool WebPluginDelegateProxy::BackgroundChanged(
-    gfx::NativeDrawingContext context,
-    const gfx::Rect& rect) {
-#if defined(OS_ANDROID)
-  NOTIMPLEMENTED();
-#else
-#if defined(OS_WIN)

[piman, 2012/11/09 19:27:03]

Awesome thanks for removing this horrible per-platform code.

-  HBITMAP hbitmap = static_cast<HBITMAP>(GetCurrentObject(context, OBJ_BITMAP));
-  if (hbitmap == NULL) {
-    NOTREACHED();
-    return true;
-  }
+bool WebPluginDelegateProxy::BackgroundChanged(SkCanvas* canvas,
+                                               const gfx::Rect& rect) {
+  const SkMatrix& matrix = canvas->getTotalMatrix();
+  const SkBitmap& page = canvas->getDevice()->accessBitmap(false);
+  const SkBitmap& background =
+      background_store_.canvas->getDevice()->accessBitmap(false);
+  CHECK(page.bytesPerPixel() == background.bytesPerPixel());
+  int row_byte_size = rect.width() * page.bytesPerPixel();

[piman, 2012/11/09 19:27:03]

This can get tricky with CSS transforms, in particular 3D ones. I think we need
extra clipping (once transformed, the rect may be outside the page bounds). See
e.g. crbug.com/137623

+  for (int y = rect.y(); y < rect.bottom(); y++) {
+    SkPoint result;
+    matrix.mapXY(SkIntToScalar(rect.x()), SkIntToScalar(y), &result);
+    uint32_t* page_row_start = page.getAddr32(result.x(), result.y());
 
-  BITMAP bitmap = { 0 };
-  int result = GetObject(hbitmap, sizeof(bitmap), &bitmap);
-  if (!result) {
-    NOTREACHED();
-    return true;
-  }
-
-  XFORM xf;
-  if (!GetWorldTransform(context, &xf)) {
-    NOTREACHED();
-    return true;
-  }
-
-  // The damaged rect that we're given can be larger than the bitmap, so
-  // intersect their rects first.
-  gfx::Rect bitmap_rect(static_cast<int>(-xf.eDx), static_cast<int>(-xf.eDy),
-                        bitmap.bmWidth, bitmap.bmHeight);
-  gfx::Rect check_rect = gfx::IntersectRects(rect, bitmap_rect);
-  int row_byte_size = check_rect.width() * (bitmap.bmBitsPixel / 8);
-  for (int y = check_rect.y(); y < check_rect.bottom(); y++) {
-    char* hdc_row_start = static_cast<char*>(bitmap.bmBits) +
-        (y + static_cast<int>(xf.eDy)) * bitmap.bmWidthBytes +
-        (check_rect.x() + static_cast<int>(xf.eDx)) * (bitmap.bmBitsPixel / 8);
-
     // getAddr32 doesn't use the translation units, so we have to subtract
     // the plugin origin from the coordinates.
-    uint32_t* canvas_row_start =
-        background_store_.canvas->getDevice()->accessBitmap(true).getAddr32(
-            check_rect.x() - plugin_rect_.x(), y - plugin_rect_.y());
-    if (memcmp(hdc_row_start, canvas_row_start, row_byte_size) != 0)
+    uint32_t* background_row_start = background.getAddr32(
+        rect.x() - plugin_rect_.x(), y - plugin_rect_.y());
+    if (memcmp(page_row_start, background_row_start, row_byte_size) != 0)
       return true;
   }
-#else
-#if defined(OS_MACOSX)
-  // If there is a translation on the content area context, we need to account
-  // for it; the context may be a subset of the full content area with a
-  // transform that makes the coordinates work out.
-  CGAffineTransform transform = CGContextGetCTM(context);
-  bool flipped = fabs(transform.d + 1) < 0.0001;
-  CGFloat context_offset_x = -transform.tx;
-  CGFloat context_offset_y = flipped ? transform.ty -
-                                           CGBitmapContextGetHeight(context)
-                                     : -transform.ty;
-  gfx::Rect full_content_rect(context_offset_x, context_offset_y,
-                              CGBitmapContextGetWidth(context),
-                              CGBitmapContextGetHeight(context));
-#else
-  cairo_surface_t* page_surface = cairo_get_target(context);
-  DCHECK_EQ(cairo_surface_get_type(page_surface), CAIRO_SURFACE_TYPE_IMAGE);
-  DCHECK_EQ(cairo_image_surface_get_format(page_surface), CAIRO_FORMAT_ARGB32);
-
-  // Transform context coordinates into surface coordinates.
-  double page_x_double = 0;
-  double page_y_double = 0;
-  cairo_device_to_user(context, &page_x_double, &page_y_double);
-  gfx::Rect full_content_rect(static_cast<int>(page_x_double),
-                              static_cast<int>(page_y_double),
-                              cairo_image_surface_get_width(page_surface),
-                              cairo_image_surface_get_height(page_surface));
-#endif
-  // According to comments in the Windows code, the damage rect that we're given
-  // may project outside the image, so intersect their rects.
-  gfx::Rect content_rect = gfx::IntersectRects(rect, full_content_rect);
-
-#if defined(OS_MACOSX)
-  const unsigned char* page_bytes = static_cast<const unsigned char*>(
-      CGBitmapContextGetData(context));
-  int page_stride = CGBitmapContextGetBytesPerRow(context);
-  int page_start_x = content_rect.x() - context_offset_x;
-  int page_start_y = content_rect.y() - context_offset_y;
-
-  skia::ScopedPlatformPaint scoped_platform_paint(
-      background_store_.canvas.get());
-  CGContextRef bg_context = scoped_platform_paint.GetPlatformSurface();
-
-  DCHECK_EQ(CGBitmapContextGetBitsPerPixel(context),
-            CGBitmapContextGetBitsPerPixel(bg_context));
-  const unsigned char* bg_bytes = static_cast<const unsigned char*>(
-      CGBitmapContextGetData(bg_context));
-  int full_bg_width = CGBitmapContextGetWidth(bg_context);
-  int full_bg_height = CGBitmapContextGetHeight(bg_context);
-  int bg_stride = CGBitmapContextGetBytesPerRow(bg_context);
-  int bg_last_row = CGBitmapContextGetHeight(bg_context) - 1;
-
-  int bytes_per_pixel = CGBitmapContextGetBitsPerPixel(context) / 8;
-#else
-  cairo_surface_flush(page_surface);
-  const unsigned char* page_bytes = cairo_image_surface_get_data(page_surface);
-  int page_stride = cairo_image_surface_get_stride(page_surface);
-  int page_start_x = content_rect.x() - static_cast<int>(page_x_double);
-  int page_start_y = content_rect.y() - static_cast<int>(page_y_double);
-
-  skia::ScopedPlatformPaint scoped_platform_paint(
-      background_store_.canvas.get());
-  cairo_surface_t* bg_surface =cairo_get_target(
-      scoped_platform_paint.GetPlatformSurface());
-  DCHECK_EQ(cairo_surface_get_type(bg_surface), CAIRO_SURFACE_TYPE_IMAGE);
-  DCHECK_EQ(cairo_image_surface_get_format(bg_surface), CAIRO_FORMAT_ARGB32);
-  cairo_surface_flush(bg_surface);
-  const unsigned char* bg_bytes = cairo_image_surface_get_data(bg_surface);
-  int full_bg_width = cairo_image_surface_get_width(bg_surface);
-  int full_bg_height = cairo_image_surface_get_height(bg_surface);
-  int bg_stride = cairo_image_surface_get_stride(bg_surface);
-
-  int bytes_per_pixel = 4;  // ARGB32 = 4 bytes per pixel.
-#endif
-
-  int damage_width = content_rect.width();
-  int damage_height = content_rect.height();
-
-  int bg_start_x = rect.x() - plugin_rect_.x();
-  int bg_start_y = rect.y() - plugin_rect_.y();
-  // The damage rect is supposed to have been intersected with the plugin rect;
-  // double-check, since if it hasn't we'll walk off the end of the buffer.
-  DCHECK_LE(bg_start_x + damage_width, full_bg_width);
-  DCHECK_LE(bg_start_y + damage_height, full_bg_height);
-
-  int bg_x_byte_offset = bg_start_x * bytes_per_pixel;
-  int page_x_byte_offset = page_start_x * bytes_per_pixel;
-  for (int row = 0; row < damage_height; ++row) {
-    int page_offset = page_stride * (page_start_y + row) + page_x_byte_offset;
-    int bg_y = bg_start_y + row;
-#if defined(OS_MACOSX)
-    // The background buffer is upside down relative to the content.
-    bg_y = bg_last_row - bg_y;
-#endif
-    int bg_offset = bg_stride * bg_y + bg_x_byte_offset;
-    if (memcmp(page_bytes + page_offset,
-               bg_bytes + bg_offset,
-               damage_width * bytes_per_pixel) != 0)
-      return true;
-  }
-#endif
-#endif  // OS_ANDROID
-
   return false;
 }