Support copying a partial rectangle region from the compositing surface on Mac.

This CL also made RenderWidgetHostView::MacCopyFromCompositingSurface support HiDPI.

BUG=118571
TEST=Manual


Review URL: https://chromiumcodereview.appspot.com/10835014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148690 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/compositing_iosurface_mac.h

@@ -15,6 +15,10 @@
 
 class IOSurfaceSupport;
 
+namespace gfx {
+class Rect;
+}
+
 namespace content {
 
 // This class manages an OpenGL context and IOSurface for the accelerated
@@ -35,10 +39,14 @@ class CompositingIOSurfaceMac {
   void DrawIOSurface(NSView* view, float scale_factor);
 
   // Copy the data of the "live" OpenGL texture referring to this IOSurfaceRef
-  // into |out|. The image data is transformed so that it fits in |dst_size|.
+  // into |out|. The copied region is specified with |src_pixel_subrect| and
+  // the data is transformed so that it fits in |dst_pixel_size|.
+  // |src_pixel_subrect| and |dst_pixel_size| are not in DIP but in pixel.
   // Caller must ensure that |out| is allocated with the size no less than
-  // |4 * dst_size.width() * dst_size.height()| bytes.
-  bool CopyTo(const gfx::Size& dst_size, void* out);
+  // |4 * dst_pixel_size.width() * dst_pixel_size.height()| bytes.
+  bool CopyTo(const gfx::Rect& src_pixel_subrect,
+              const gfx::Size& dst_pixel_size,
+              void* out);
 
   // Unref the IOSurface and delete the associated GL texture. If the GPU
   // process is no longer referencing it, this will delete the IOSurface.
@@ -65,7 +73,6 @@ class CompositingIOSurfaceMac {
   // Vertex structure for use in glDraw calls.
   struct SurfaceVertex {
     SurfaceVertex() : x_(0.0f), y_(0.0f), tx_(0.0f), ty_(0.0f) { }
-    // Currently the texture coords are always the same as vertex coords.
     void set(float x, float y, float tx, float ty) {
       x_ = x;
       y_ = y;
@@ -76,6 +83,10 @@ class CompositingIOSurfaceMac {
       x_ = x;
       y_ = y;
     }
+    void set_texcoord(float tx, float ty) {
+      tx_ = tx;
+      ty_ = ty;
+    }
     float x_;
     float y_;
     float tx_;
@@ -102,6 +113,14 @@ class CompositingIOSurfaceMac {
       verts_[2].set_position(x2, y2);
       verts_[3].set_position(x2, y1);
     }
+    void set_texcoord_rect(float tx1, float ty1, float tx2, float ty2) {
+      // Texture coordinates are flipped vertically so they can be drawn on
+      // a projection with a flipped y-axis (origin is top left).
+      verts_[0].set_texcoord(tx1, ty2);
+      verts_[1].set_texcoord(tx1, ty1);
+      verts_[2].set_texcoord(tx2, ty1);
+      verts_[3].set_texcoord(tx2, ty2);
+    }
     SurfaceVertex verts_[4];
   };
 

content/browser/renderer_host/compositing_iosurface_mac.mm

@@ -12,6 +12,7 @@
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 #include "content/public/browser/browser_thread.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
+#include "ui/gfx/rect.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_switches.h"
@@ -303,7 +304,10 @@ void CompositingIOSurfaceMac::DrawIOSurface(NSView* view, float scale_factor) {
   CGLSetCurrentContext(0);
 }
 
-bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
+bool CompositingIOSurfaceMac::CopyTo(
+      const gfx::Rect& src_pixel_subrect,
+      const gfx::Size& dst_pixel_size,
+      void* out) {
   if (!MapIOSurfaceToTexture(io_surface_handle_))
     return false;
 
@@ -321,8 +325,8 @@ bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
   glTexImage2D(target,
                0,
                GL_RGBA,
-               dst_size.width(),
-               dst_size.height(),
+               dst_pixel_size.width(),
+               dst_pixel_size.height(),
                0,
                GL_BGRA,
                GL_UNSIGNED_INT_8_8_8_8_REV,
@@ -334,11 +338,11 @@ bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
                             0); CHECK_GL_ERROR();
   glBindTexture(target, 0); CHECK_GL_ERROR();
 
-  glViewport(0, 0, dst_size.width(), dst_size.height());
+  glViewport(0, 0, dst_pixel_size.width(), dst_pixel_size.height());
 
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
-  glOrtho(0, dst_size.width(), 0, dst_size.height(), -1, 1);
+  glOrtho(0, dst_pixel_size.width(), 0, dst_pixel_size.height(), -1, 1);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
 
@@ -353,7 +357,9 @@ bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texture_);
 
   SurfaceQuad quad;
-  quad.set_size(dst_size, pixel_io_surface_size_);
+  quad.set_rect(0.0f, 0.0f, dst_pixel_size.width(), dst_pixel_size.height());
+  quad.set_texcoord_rect(src_pixel_subrect.x(), src_pixel_subrect.y(),
+                         src_pixel_subrect.right(), src_pixel_subrect.bottom());
   DrawQuad(quad);
 
   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0); CHECK_GL_ERROR();
@@ -361,7 +367,7 @@ bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
 
   CGLFlushDrawable(cglContext_);
 
-  glReadPixels(0, 0, dst_size.width(), dst_size.height(),
+  glReadPixels(0, 0, dst_pixel_size.width(), dst_pixel_size.height(),
                GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, out);
 
   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); CHECK_GL_ERROR();

content/browser/renderer_host/render_widget_host_impl.cc

@@ -503,12 +503,12 @@ void RenderWidgetHostImpl::CopyFromBackingStore(
   if (view_ && is_accelerated_compositing_active_) {
     TRACE_EVENT0("browser",
         "RenderWidgetHostImpl::CopyFromBackingStore::FromCompositingSurface");
-#if defined(USE_AURA) || defined(OS_LINUX)
+#if defined(USE_AURA) || defined(OS_LINUX) || defined(OS_MACOSX)
     gfx::Rect copy_rect = src_subrect.IsEmpty() ?
         gfx::Rect(view_->GetViewBounds().size()) : src_subrect;
 #else
     // Just passes an empty rect to CopyFromCompositingSurface on non-Aura Win
-    // and Mac because copying a partial rectangle is not supported.
+    // because copying a partial rectangle is not supported.
     gfx::Rect copy_rect;
 #endif
     view_->CopyFromCompositingSurface(copy_rect,

content/browser/renderer_host/render_widget_host_view_mac.mm

@@ -822,22 +822,22 @@ void RenderWidgetHostViewMac::CopyFromCompositingSurface(
     const base::Callback<void(bool)>& callback,
     skia::PlatformCanvas* output) {
   base::ScopedClosureRunner scoped_callback_runner(base::Bind(callback, false));
-  // TODO(mazda): Support copying a partial rectangle from the compositing
-  // surface with |src_subrect| (http://crbug.com/118571).
-  if (!src_subrect.IsEmpty()) {
-    NOTIMPLEMENTED();
-    return;
-  }
-
   if (!compositing_iosurface_.get() ||
       !compositing_iosurface_->HasIOSurface())
     return;
 
-  if (!output->initialize(dst_size.width(), dst_size.height(), true))
+  float scale = ScaleFactor(cocoa_view_);
+  gfx::Size dst_pixel_size = dst_size.Scale(scale);
+  if (!output->initialize(
+      dst_pixel_size.width(), dst_pixel_size.height(), true))
     return;
 
+  gfx::Rect src_pixel_subrect(src_subrect.origin().Scale(scale),
+                              src_subrect.size().Scale(scale));
   const bool result = compositing_iosurface_->CopyTo(
-      dst_size, output->getTopDevice()->accessBitmap(true).getPixels());
+      src_pixel_subrect,
+      dst_pixel_size,
+      output->getTopDevice()->accessBitmap(true).getPixels());
   scoped_callback_runner.Release();
   callback.Run(result);
 }