diff options
| -rw-r--r-- | native_client_sdk/src/examples/pi_generator/pi_generator.cc | 27 | ||||
| -rw-r--r-- | native_client_sdk/src/examples/pi_generator/pi_generator.h | 3 |
2 files changed, 21 insertions, 9 deletions
diff --git a/native_client_sdk/src/examples/pi_generator/pi_generator.cc b/native_client_sdk/src/examples/pi_generator/pi_generator.cc index 2b5766f..1106343f 100644 --- a/native_client_sdk/src/examples/pi_generator/pi_generator.cc +++ b/native_client_sdk/src/examples/pi_generator/pi_generator.cc @@ -81,7 +81,8 @@ PiGenerator::PiGenerator(PP_Instance instance) flush_pending_(false), quit_(false), thread_create_result_(0), - pi_(0.0) { + pi_(0.0), + device_scale_(1.0) { pthread_mutex_init(&pixel_buffer_mutex_, NULL); } @@ -98,13 +99,18 @@ PiGenerator::~PiGenerator() { } void PiGenerator::DidChangeView(const pp::View& view) { - pp::Rect position = view.GetRect(); - if (pixel_buffer_ && position.size() == pixel_buffer_->size()) - return; // Size didn't change, no need to update anything. - - // Create a new device context with the new size. + pp::Size size = view.GetRect().size(); + float device_scale = view.GetDeviceScale(); + size.set_width(static_cast<int>(size.width() * device_scale)); + size.set_height(static_cast<int>(size.height() * device_scale)); + if (pixel_buffer_ && size == pixel_buffer_->size() && + device_scale == device_scale_) + return; // Size and scale didn't change, no need to update anything. + + // Create a new device context with the new size and scale. DestroyContext(); - CreateContext(position.size()); + device_scale_ = device_scale; + CreateContext(size, device_scale_); // Delete the old pixel buffer and create a new one. ScopedMutexLock scoped_mutex(&pixel_buffer_mutex_); delete pixel_buffer_; @@ -164,7 +170,7 @@ void PiGenerator::Paint() { PostMessage(pi_estimate); } -void PiGenerator::CreateContext(const pp::Size& size) { +void PiGenerator::CreateContext(const pp::Size& size, float device_scale) { ScopedMutexLock scoped_mutex(&pixel_buffer_mutex_); if (!scoped_mutex.is_valid()) { return; @@ -172,6 +178,11 @@ void PiGenerator::CreateContext(const pp::Size& size) { if (IsContextValid()) return; graphics_2d_context_ = new pp::Graphics2D(this, size, false); + // Scale the contents of the graphics context down by the inverse of the + // device scale. This makes each pixel in the context represent a single + // physical pixel on the device when running on high-DPI displays. + // See pp::Graphics2D::SetScale for more details. + graphics_2d_context_->SetScale(1.0 / device_scale); if (!BindGraphics(*graphics_2d_context_)) { printf("Couldn't bind the device context\n"); } diff --git a/native_client_sdk/src/examples/pi_generator/pi_generator.h b/native_client_sdk/src/examples/pi_generator/pi_generator.h index 556b091..50f2dbd 100644 --- a/native_client_sdk/src/examples/pi_generator/pi_generator.h +++ b/native_client_sdk/src/examples/pi_generator/pi_generator.h @@ -83,7 +83,7 @@ class PiGenerator : public pp::Instance { private: // Create and initialize the 2D context used for drawing. - void CreateContext(const pp::Size& size); + void CreateContext(const pp::Size& size, float device_scale); // Destroy the 2D drawing context. void DestroyContext(); // Push the pixels to the browser, then attempt to flush the 2D context. If @@ -103,6 +103,7 @@ class PiGenerator : public pp::Instance { pthread_t compute_pi_thread_; int thread_create_result_; double pi_; + float device_scale_; // ComputePi() estimates Pi using Monte Carlo method and it is executed by a // separate thread created in SetWindow(). ComputePi() puts kMaxPointCount |