15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <algorithm> 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <deque> 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <string> 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/graphics_2d.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/image_data.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/instance.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/module.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/var.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/cpp/var_array_buffer.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ppapi/utility/completion_callback_factory.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef WIN32 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#undef min 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#undef max 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#undef PostMessage 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Allow 'this' in initializer list 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#pragma warning(disable : 4355) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Disable warning about behaviour of array initialization. 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#pragma warning(disable : 4351) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace { 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const uint32_t kBlue = 0xff4040ffu; 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const uint32_t kBlack = 0xff000000u; 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const size_t kHistogramSize = 256u; 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 36b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles)class VarArrayBufferInstance : public pp::Instance { 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 38b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) explicit VarArrayBufferInstance(PP_Instance instance) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : pp::Instance(instance), 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) callback_factory_(this), 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) flushing_(false), 42c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) histogram_() {} 43b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) virtual ~VarArrayBufferInstance() {} 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Handler for messages coming in from the browser via postMessage(). The 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// @a var_message can contain anything: a JSON string; a string that encodes 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// method names and arguments; etc. 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// In this case, we only handle <code>pp::VarArrayBuffer</code>s. When we 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// receive one, we compute and display a histogram based on its contents. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// @param[in] var_message The message posted by the browser. 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void HandleMessage(const pp::Var& var_message) { 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (var_message.is_array_buffer()) { 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::VarArrayBuffer buffer(var_message); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ComputeHistogram(buffer); 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DrawHistogram(); 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Create and return a blank (all-black) <code>pp::ImageData</code> of the 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// given <code>size</code>. 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::ImageData MakeBlankImageData(const pp::Size& size) { 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const bool init_to_zero = false; 66c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) pp::ImageData image_data = 67c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) pp::ImageData(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, init_to_zero); 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t* image_buffer = static_cast<uint32_t*>(image_data.data()); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (int i = 0; i < size.GetArea(); ++i) 70c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) image_buffer[i] = kBlack; 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return image_data; 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Draw a bar of the appropriate height based on <code>value</code> at 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// <code>column</code> in <code>image_data</code>. <code>value</code> must be 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// in the range [0, 1]. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void DrawBar(uint32_t column, double value, pp::ImageData* image_data) { 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) assert((value >= 0.0) && (value <= 1.0)); 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t* image_buffer = static_cast<uint32_t*>(image_data->data()); 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint32_t image_height = image_data->size().height(); 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint32_t image_width = image_data->size().width(); 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) assert(column < image_width); 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int bar_height = static_cast<int>(value * image_height); 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (int i = 0; i < bar_height; ++i) { 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t row = image_height - 1 - i; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) image_buffer[row * image_width + column] = kBlue; 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void PaintAndFlush(pp::ImageData* image_data) { 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) assert(!flushing_); 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) graphics_2d_context_.ReplaceContents(image_data); 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) graphics_2d_context_.Flush( 94b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) callback_factory_.NewCallback(&VarArrayBufferInstance::DidFlush)); 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) flushing_ = true; 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// The callback that gets invoked when a flush completes. This is bound to a 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// <code>CompletionCallback</code> and passed as a parameter to 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// <code>Flush</code>. 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void DidFlush(int32_t error_code) { 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) flushing_ = false; 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If there are no images in the queue, we're done for now. 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (paint_queue_.empty()) 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Otherwise, pop the next image off the queue and draw it. 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::ImageData image_data = paint_queue_.front(); 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) paint_queue_.pop_front(); 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PaintAndFlush(&image_data); 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void DidChangeView(const pp::View& view) { 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (size_ != view.GetRect().size()) { 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_ = view.GetRect().size(); 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const bool is_always_opaque = true; 116c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) graphics_2d_context_ = 117c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) pp::Graphics2D(this, view.GetRect().size(), is_always_opaque); 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) BindGraphics(graphics_2d_context_); 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The images in our queue are the wrong size, so we won't paint them. 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We'll only draw the most recently computed histogram. 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) paint_queue_.clear(); 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DrawHistogram(); 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Compute and normalize a histogram based on the given VarArrayBuffer. 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void ComputeHistogram(pp::VarArrayBuffer& buffer) { 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::fill_n(histogram_, kHistogramSize, 0.0); 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t buffer_size = buffer.ByteLength(); 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (buffer_size == 0) 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* buffer_data = static_cast<uint8_t*>(buffer.Map()); 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (uint32_t i = 0; i < buffer_size; ++i) 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) histogram_[buffer_data[i]] += 1.0; 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Normalize. 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) double max = *std::max_element(histogram_, histogram_ + kHistogramSize); 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (uint32_t i = 0; i < kHistogramSize; ++i) 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) histogram_[i] /= max; 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Draw the current histogram_ in to an pp::ImageData, then paint and flush 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// that image. If we're already waiting on a flush, push it on to 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// <code>paint_queue_</code> to paint later. 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void DrawHistogram() { 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::ImageData image_data = MakeBlankImageData(size_); 146c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) for (int i = 0; i < std::min(static_cast<int>(kHistogramSize), 147c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) image_data.size().width()); 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ++i) { 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DrawBar(i, histogram_[i], &image_data); 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!flushing_) 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PaintAndFlush(&image_data); 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) paint_queue_.push_back(image_data); 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::Graphics2D graphics_2d_context_; 159b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) pp::CompletionCallbackFactory<VarArrayBufferInstance> callback_factory_; 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// A queue of images to paint. We must maintain a queue because we can not 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// call pp::Graphics2D::Flush while a Flush is already pending. 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::deque<pp::ImageData> paint_queue_; 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// The size of our rectangle in the DOM, as of the last time DidChangeView 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// was called. 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pp::Size size_; 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// true iff we are flushing. 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool flushing_; 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// Stores the most recent histogram so that we can re-draw it if we get 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// resized. 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) double histogram_[kHistogramSize]; 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 177b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles)class VarArrayBufferModule : public pp::Module { 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 179b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) VarArrayBufferModule() : pp::Module() {} 180b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) virtual ~VarArrayBufferModule() {} 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual pp::Instance* CreateInstance(PP_Instance instance) { 183b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles) return new VarArrayBufferInstance(instance); 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace pp { 188b2df76ea8fec9e32f6f3718986dba0d95315b29cTorne (Richard Coles)Module* CreateModule() { return new VarArrayBufferModule(); } 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace pp 190