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