Implement RenderWidgetHostViewMac::CopyFromCompositingSurface.

This adds the support of the browser side thumbailing to Mac Chrome.

BUG=120001
TEST=Manually tested that thumbnails are properly generated on GPU composited pages with --enable-in-browser-thumbnailing.


Review URL: http://codereview.chromium.org/10022007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131710 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 111 insertions, 20 deletions

diff --git a/content/browser/renderer_host/compositing_iosurface_mac.h b/content/browser/renderer_host/compositing_iosurface_mac.h
index b81b286..6f0d8da 100644
--- a/content/browser/renderer_host/compositing_iosurface_mac.h
+++ b/content/browser/renderer_host/compositing_iosurface_mac.h
@@ -32,6 +32,12 @@ class CompositingIOSurfaceMac {
   // be white.
   void DrawIOSurface(NSView* view);
 
+  // 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|.
+  // 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);
+
   // Unref the IOSurface and delete the associated GL texture. If the GPU
   // process is no longer referencing it, this will delete the IOSurface.
   void UnrefIOSurface();
@@ -66,15 +72,17 @@ class CompositingIOSurfaceMac {
 
   // Counter-clockwise verts starting from upper-left corner (0, 0).
   struct SurfaceQuad {
-    void set_size(gfx::Size size) {
+    void set_size(gfx::Size vertex_size, gfx::Size texcoord_size) {
       // Texture coordinates are flipped vertically so they can be drawn on
       // a projection with a flipped y-axis (origin is top left).
-      float w = static_cast<float>(size.width());
-      float h = static_cast<float>(size.height());
-      verts_[0].set(0.0f, 0.0f, 0.0f, h);
-      verts_[1].set(0.0f, h, 0.0f, 0.0f);
-      verts_[2].set(w, h, w, 0.0f);
-      verts_[3].set(w, 0.0f, w, h);
+      float vw = static_cast<float>(vertex_size.width());
+      float vh = static_cast<float>(vertex_size.height());
+      float tw = static_cast<float>(texcoord_size.width());
+      float th = static_cast<float>(texcoord_size.height());
+      verts_[0].set(0.0f, 0.0f, 0.0f, th);
+      verts_[1].set(0.0f, vh, 0.0f, 0.0f);
+      verts_[2].set(vw, vh, tw, 0.0f);
+      verts_[3].set(vw, 0.0f, tw, th);
     }
     SurfaceVertex verts_[4];
   };
@@ -88,6 +96,8 @@ class CompositingIOSurfaceMac {
 
   void UnrefIOSurfaceWithContextCurrent();
 
+  void DrawQuad(const SurfaceQuad& quad);
+
   // Cached pointer to IOSurfaceSupport Singleton.
   IOSurfaceSupport* io_surface_support_;
 
diff --git a/content/browser/renderer_host/compositing_iosurface_mac.mm b/content/browser/renderer_host/compositing_iosurface_mac.mm
index 6b4a53d..f1754cf 100644
--- a/content/browser/renderer_host/compositing_iosurface_mac.mm
+++ b/content/browser/renderer_host/compositing_iosurface_mac.mm
@@ -136,15 +136,7 @@ void CompositingIOSurfaceMac::DrawIOSurface(NSView* view) {
     glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texture_); CHECK_GL_ERROR();
     glEnable(GL_TEXTURE_RECTANGLE_ARB); CHECK_GL_ERROR();
 
-    glEnableClientState(GL_VERTEX_ARRAY); CHECK_GL_ERROR();
-    glEnableClientState(GL_TEXTURE_COORD_ARRAY); CHECK_GL_ERROR();
-
-    glVertexPointer(2, GL_FLOAT, sizeof(SurfaceVertex), &quad_.verts_[0].x_);
-    glTexCoordPointer(2, GL_FLOAT, sizeof(SurfaceVertex), &quad_.verts_[0].tx_);
-    glDrawArrays(GL_QUADS, 0, 4); CHECK_GL_ERROR();
-
-    glDisableClientState(GL_VERTEX_ARRAY);
-    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+    DrawQuad(quad_);
 
     glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0); CHECK_GL_ERROR();
   }
@@ -154,6 +146,77 @@ void CompositingIOSurfaceMac::DrawIOSurface(NSView* view) {
   CGLSetCurrentContext(0);
 }
 
+bool CompositingIOSurfaceMac::CopyTo(const gfx::Size& dst_size, void* out) {
+  if (!MapIOSurfaceToTexture(io_surface_handle_))
+    return false;
+
+  CGLSetCurrentContext(cglContext_);
+  GLuint target = GL_TEXTURE_RECTANGLE_ARB;
+
+  GLuint dst_texture = 0;
+  glGenTextures(1, &dst_texture); CHECK_GL_ERROR();
+  glBindTexture(target, dst_texture); CHECK_GL_ERROR();
+
+  GLuint dst_framebuffer = 0;
+  glGenFramebuffersEXT(1, &dst_framebuffer); CHECK_GL_ERROR();
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, dst_framebuffer); CHECK_GL_ERROR();
+
+  glTexImage2D(target,
+               0,
+               GL_RGBA,
+               dst_size.width(),
+               dst_size.height(),
+               0,
+               GL_BGRA,
+               GL_UNSIGNED_INT_8_8_8_8_REV,
+               NULL); CHECK_GL_ERROR();
+  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
+                            GL_COLOR_ATTACHMENT0_EXT,
+                            target,
+                            dst_texture,
+                            0); CHECK_GL_ERROR();
+  glBindTexture(target, 0); CHECK_GL_ERROR();
+
+  glViewport(0, 0, dst_size.width(), dst_size.height());
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  glOrtho(0, dst_size.width(), 0, dst_size.height(), -1, 1);
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+
+  glDisable(GL_DEPTH_TEST);
+  glDisable(GL_BLEND);
+
+  glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+  // Draw only the color channels from the incoming texture.
+  glColorMask(true, true, true, false);
+
+  // Draw the color channels from the incoming texture.
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texture_); CHECK_GL_ERROR();
+  glEnable(GL_TEXTURE_RECTANGLE_ARB); CHECK_GL_ERROR();
+
+  SurfaceQuad quad;
+  quad.set_size(dst_size, io_surface_size_);
+  DrawQuad(quad);
+
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0); CHECK_GL_ERROR();
+
+  CGLFlushDrawable(cglContext_);
+
+  glReadPixels(0, 0, dst_size.width(), dst_size.height(),
+               GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, out);
+
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); CHECK_GL_ERROR();
+
+  glDeleteFramebuffersEXT(1, &dst_framebuffer);
+  glDeleteTextures(1, &dst_texture);
+
+  CGLSetCurrentContext(0);
+  return true;
+}
+
 bool CompositingIOSurfaceMac::MapIOSurfaceToTexture(
     uint64 io_surface_handle) {
   if (io_surface_.get() && io_surface_handle == io_surface_handle_)
@@ -176,7 +239,7 @@ bool CompositingIOSurfaceMac::MapIOSurfaceToTexture(
       io_surface_support_->IOSurfaceGetWidth(io_surface_),
       io_surface_support_->IOSurfaceGetHeight(io_surface_));
 
-  quad_.set_size(io_surface_size_);
+  quad_.set_size(io_surface_size_, io_surface_size_);
 
   GLenum target = GL_TEXTURE_RECTANGLE_ARB;
   glGenTextures(1, &texture_);
@@ -209,6 +272,18 @@ void CompositingIOSurfaceMac::UnrefIOSurface() {
   CGLSetCurrentContext(0);
 }
 
+void CompositingIOSurfaceMac::DrawQuad(const SurfaceQuad& quad) {
+  glEnableClientState(GL_VERTEX_ARRAY); CHECK_GL_ERROR();
+  glEnableClientState(GL_TEXTURE_COORD_ARRAY); CHECK_GL_ERROR();
+
+  glVertexPointer(2, GL_FLOAT, sizeof(SurfaceVertex), &quad.verts_[0].x_);
+  glTexCoordPointer(2, GL_FLOAT, sizeof(SurfaceVertex), &quad.verts_[0].tx_);
+  glDrawArrays(GL_QUADS, 0, 4); CHECK_GL_ERROR();
+
+  glDisableClientState(GL_VERTEX_ARRAY);
+  glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+}
+
 void CompositingIOSurfaceMac::UnrefIOSurfaceWithContextCurrent() {
   if (texture_) {
     glDeleteTextures(1, &texture_);
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 6ba515f..9f5a2de 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -796,9 +796,15 @@ BackingStore* RenderWidgetHostViewMac::AllocBackingStore(
 bool RenderWidgetHostViewMac::CopyFromCompositingSurface(
       const gfx::Size& size,
       skia::PlatformCanvas* output) {
-  // TODO(mazda): Implement this.
-  NOTIMPLEMENTED();
-  return false;
+  if (!compositing_iosurface_.get() ||
+      !compositing_iosurface_->HasIOSurface())
+    return false;
+
+  if (!output->initialize(size.width(), size.height(), true))
+    return false;
+
+  return compositing_iosurface_->CopyTo(
+      size, output->getTopDevice()->accessBitmap(true).getPixels());
 }
 
 void RenderWidgetHostViewMac::AsyncCopyFromCompositingSurface(