Added SetLayerTransform to PPAPI

content/renderer/pepper/pepper_plugin_instance_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/pepper/pepper_plugin_instance_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bit_cast.h"
@@ skipping 1527 matching lines @@
 
 bool PepperPluginInstanceImpl::LoadTextInputInterface() {
   if (!plugin_textinput_interface_) {
     plugin_textinput_interface_ = static_cast<const PPP_TextInput_Dev*>(
         module_->GetPluginInterface(PPP_TEXTINPUT_DEV_INTERFACE));
   }
 
   return !!plugin_textinput_interface_;
 }
 
+void PepperPluginInstanceImpl::SetLayerTransform(gfx::Transform transform) {
+  transform_ = transform;
+  UpdateLayerTransform();
+}
+
 void PepperPluginInstanceImpl::UpdateLayerTransform() {
   if (!bound_graphics_2d_platform_ || !texture_layer_) {
     // Currently the transform is only applied for Graphics2D.
     return;
   }
   // Set the UV coordinates of the texture based on the size of the Graphics2D
   // context. By default a texture gets scaled to the size of the layer. But
   // if the size of the Graphics2D context doesn't match the size of the plugin
   // then it will be incorrectly stretched. This also affects how the plugin
   // is painted when it is being resized. If the Graphics2D contents are
   // stretched when a plugin is resized while waiting for a new frame from the
   // plugin to be rendered, then flickering behavior occurs as in
   // crbug.com/353453.
   gfx::SizeF graphics_2d_size_in_dip =
       gfx::ScaleSize(gfx::SizeF(bound_graphics_2d_platform_->Size()),
                      bound_graphics_2d_platform_->GetScale());
   gfx::Size plugin_size_in_dip(view_data_.rect.size.width,
                                view_data_.rect.size.height);
 
+  // Adding the SetLayerTransform from Graphics2D to the UV.
+  // If the transform_ is te identity matrix

[wjmaclean, 2016/04/13 14:47:19]

the

[alessandroa, 2016/04/21 15:39:21]

Done.

+  // then UV will be top_left (0,0) and
+  // lower_right (plugin_size_in_dip.width() / graphics_2d_size_in_dip.width(),
+  //             plugin_size_in_dip.height() / graphics_2d_size_in_dip.height())
+  gfx::PointF Translate = gfx::PointF(transform_.matrix().getFloat(0,3),

[wjmaclean, 2016/04/13 14:47:19]

Add a comment to warn the reader here that we're assuming the transform only
contains 2-D scale and 2-D translation.

Even better, add

DCHECK(transform.isScaleTranslate());

[alessandroa, 2016/04/21 15:39:21]

Nice one :)

+                                      transform_.matrix().getFloat(1,3));
+  float scale = transform_.matrix().getFloat(0,0);
+  gfx::PointF top_left = gfx::PointF(-1 *  Translate.x() / scale ,

[wjmaclean, 2016/04/13 14:47:18]

-Translate.x() ?

[alessandroa, 2016/04/21 15:39:21]

Done.

+                                     -1 * Translate.y() / scale);
+  gfx::PointF lower_right = gfx::PointF((1 / scale) * plugin_size_in_dip.width()
+                                        - 1 * Translate.x() / scale,

[wjmaclean, 2016/04/13 14:47:18]

Ditto. Also, even if you are using -1, you shouldn't write "- 1". Finally, use a
float literal, i.e. -1.f or -1.0f.

[alessandroa, 2016/04/21 15:39:21]

Acknowledged.

+                                       (1 / scale) * plugin_size_in_dip.height()
+                                       - 1 * Translate.y() / scale);
   texture_layer_->SetUV(
-      gfx::PointF(0.0f, 0.0f),
+      gfx::PointF(top_left.x() / graphics_2d_size_in_dip.width(),
+                  top_left.y() / graphics_2d_size_in_dip.height()),
       gfx::PointF(
-          plugin_size_in_dip.width() / graphics_2d_size_in_dip.width(),
-          plugin_size_in_dip.height() / graphics_2d_size_in_dip.height()));
+          lower_right.x() / graphics_2d_size_in_dip.width(),
+          lower_right.y() / graphics_2d_size_in_dip.height()));
 }
 
 bool PepperPluginInstanceImpl::PluginHasFocus() const {
   return flash_fullscreen_ || (has_webkit_focus_ && has_content_area_focus_);
 }
 
 void PepperPluginInstanceImpl::SendFocusChangeNotification() {
   // Keep a reference on the stack. RenderViewImpl::PepperFocusChanged may
   // remove the <embed> from the DOM, which will make the PepperWebPluginImpl
   // drop its reference, usually the last one. This is similar to possible
@@ skipping 1742 matching lines @@
 }
 
 void PepperPluginInstanceImpl::ConvertDIPToViewport(gfx::Rect* rect) const {
   rect->set_x(rect->x() / viewport_to_dip_scale_);
   rect->set_y(rect->y() / viewport_to_dip_scale_);
   rect->set_width(rect->width() / viewport_to_dip_scale_);
   rect->set_height(rect->height() / viewport_to_dip_scale_);
 }
 
 }  // namespace content