ppapi/examples/gamepad/gamepad.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <algorithm>
   6 #include <cmath>
   7 #include <stdarg.h>
   8 #include <stdio.h>
   9
  10 #include "ppapi/c/ppb_gamepad.h"
  11 #include "ppapi/c/ppb_input_event.h"
  12 #include "ppapi/cpp/completion_callback.h"
  13 #include "ppapi/cpp/graphics_2d.h"
  14 #include "ppapi/cpp/image_data.h"
  15 #include "ppapi/cpp/input_event.h"
  16 #include "ppapi/cpp/instance.h"
  17 #include "ppapi/cpp/logging.h"
  18 #include "ppapi/cpp/module.h"
  19 #include "ppapi/cpp/rect.h"
  20 #include "ppapi/cpp/var.h"
  21 #include "ppapi/cpp/view.h"
  22 #include "ppapi/utility/completion_callback_factory.h"
  23
  24 void FillRect(pp::ImageData* image, int left, int top, int width, int height,
  25               uint32_t color) {
  26   for (int y = std::max(0, top);
  27        y < std::min(image->size().height() - 1, top + height);
  28        y++) {
  29     for (int x = std::max(0, left);
  30          x < std::min(image->size().width() - 1, left + width);
  31          x++)
  32       *image->GetAddr32(pp::Point(x, y)) = color;
  33   }
  34 }
  35
  36 class MyInstance : public pp::Instance {
  37  public:
  38   explicit MyInstance(PP_Instance instance)
  39       : pp::Instance(instance),
  40         width_(0),
  41         height_(0),
  42         callback_factory_(this),
  43         gamepad_(NULL) {
  44   }
  45   virtual ~MyInstance() {}
  46
  47   virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
  48     gamepad_ = reinterpret_cast<const PPB_Gamepad*>(
  49         pp::Module::Get()->GetBrowserInterface(PPB_GAMEPAD_INTERFACE));
  50     if (!gamepad_)
  51       return false;
  52     return true;
  53   }
  54
  55   virtual void DidChangeView(const pp::View& view) {
  56     pp::Rect rect = view.GetRect();
  57     if (rect.size().width() == width_ &&
  58         rect.size().height() == height_)
  59       return;  // We don't care about the position, only the size.
  60
  61     width_ = rect.size().width();
  62     height_ = rect.size().height();
  63
  64     device_context_ = pp::Graphics2D(this, pp::Size(width_, height_), false);
  65     if (!BindGraphics(device_context_))
  66       return;
  67
  68     Paint();
  69   }
  70
  71   void OnFlush(int32_t) {
  72     // This plugin continuously paints because it continously samples the
  73     // gamepad and paints its updated state.
  74     Paint();
  75   }
  76
  77  private:
  78   void Paint() {
  79     pp::ImageData image = PaintImage(device_context_.size());
  80     if (!image.is_null()) {
  81       device_context_.ReplaceContents(&image);
  82       device_context_.Flush(
  83           callback_factory_.NewCallback(&MyInstance::OnFlush));
  84     }
  85   }
  86
  87   pp::ImageData PaintImage(const pp::Size& size) {
  88     pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, true);
  89     if (image.is_null())
  90       return image;
  91
  92     PP_GamepadsSampleData gamepad_data;
  93     gamepad_->Sample(pp_instance(), &gamepad_data);
  94
  95     if (gamepad_data.length > 0 && gamepad_data.items[0].connected) {
  96       int width2 = size.width() / 2;
  97       int height2 = size.height() / 2;
  98       // Draw 2 axes
  99       for (size_t i = 0; i < gamepad_data.items[0].axes_length; i += 2) {
 100         int x = static_cast<int>(
 101             gamepad_data.items[0].axes[i + 0] * width2 + width2);
 102         int y = static_cast<int>(
 103             gamepad_data.items[0].axes[i + 1] * height2 + height2);
 104         uint32_t box_bgra = 0x80000000;  // Alpha 50%.
 105         FillRect(&image, x - 3, y - 3, 7, 7, box_bgra);
 106       }
 107
 108       for (size_t i = 0; i < gamepad_data.items[0].buttons_length; ++i) {
 109         float button_val = gamepad_data.items[0].buttons[i];
 110         uint32_t colour = static_cast<uint32_t>((button_val * 192) + 63) << 24;
 111         int x = static_cast<int>(i) * 8 + 10;
 112         int y = 10;
 113         FillRect(&image, x - 3, y - 3, 7, 7, colour);
 114       }
 115     }
 116     return image;
 117   }
 118
 119   int width_;
 120   int height_;
 121
 122   pp::CompletionCallbackFactory<MyInstance> callback_factory_;
 123
 124   const PPB_Gamepad* gamepad_;
 125
 126   pp::Graphics2D device_context_;
 127 };
 128
 129 // This object is the global object representing this plugin library as long
 130 // as it is loaded.
 131 class MyModule : public pp::Module {
 132  public:
 133   MyModule() : pp::Module() {}
 134   virtual ~MyModule() {}
 135
 136   // Override CreateInstance to create your customized Instance object.
 137   virtual pp::Instance* CreateInstance(PP_Instance instance) {
 138     return new MyInstance(instance);
 139   }
 140 };
 141
 142 namespace pp {
 143
 144 // Factory function for your specialization of the Module object.
 145 Module* CreateModule() {
 146   return new MyModule();
 147 }
 148
 149 }  // namespace pp