Pepper gamepad support

ppapi/examples/gamepad/gamepad.cc

+// Copyright (c) 2011 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 <cmath>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "ppapi/c/dev/ppb_console_dev.h"
+#include "ppapi/c/dev/ppb_gamepad_dev.h"
+#include "ppapi/c/ppb_input_event.h"
+#include "ppapi/cpp/completion_callback.h"
+#include "ppapi/cpp/graphics_2d.h"
+#include "ppapi/cpp/image_data.h"
+#include "ppapi/cpp/input_event.h"
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/logging.h"
+#include "ppapi/cpp/module.h"
+#include "ppapi/cpp/rect.h"
+#include "ppapi/cpp/var.h"
+
+void FlushCallback(void* data, int32_t result);
+
+void FillRect(pp::ImageData* image, int left, int top, int width, int height,
+              uint32_t color) {
+  for (int y = std::max(0, top);
+       y < std::min(image->size().height() - 1, top + height);
+       y++) {
+    for (int x = std::max(0, left);
+         x < std::min(image->size().width() - 1, left + width);
+         x++)
+      *image->GetAddr32(pp::Point(x, y)) = color;
+  }
+}
+
+class MyInstance : public pp::Instance {
+ public:
+  explicit MyInstance(PP_Instance instance)
+      : pp::Instance(instance),
+        width_(0),
+        height_(0),
+        pending_paint_(false),
+        waiting_for_flush_completion_(false),
+        callback_factory_(this),
+        console_(NULL),
+        gamepad_(NULL) {
+  }
+  virtual ~MyInstance() {}
+
+  virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
+    console_ = reinterpret_cast<const PPB_Console_Dev*>(
+        pp::Module::Get()->GetBrowserInterface(PPB_CONSOLE_DEV_INTERFACE));
+    if (!console_)
+      return false;
+
+    gamepad_ = reinterpret_cast<const PPB_Gamepad_Dev*>(
+        pp::Module::Get()->GetBrowserInterface(PPB_GAMEPAD_DEV_INTERFACE));
+    if (!gamepad_)
+      return false;
+
+    RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE |

[brettw, 2012/01/06 23:36:44]

It looks like you don't ever actually use the input events, so I'd remove this
line.

+                       PP_INPUTEVENT_CLASS_KEYBOARD);
+    return true;
+  }
+
+  virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {

[brettw, 2012/01/06 23:36:44]

Would you mind using the new version of DidChangeView (the one that takes a
const View& as an arg)?

+    if (position.size().width() == width_ &&
+        position.size().height() == height_)
+      return;  // We don't care about the position, only the size.
+
+    width_ = position.size().width();
+    height_ = position.size().height();
+
+    device_context_ = pp::Graphics2D(this, pp::Size(width_, height_), false);
+    if (!BindGraphics(device_context_))
+      return;
+
+    Paint();
+  }
+
+  void OnFlush() {
+    Paint();
+  }
+
+ private:
+  void Paint() {
+    pp::ImageData image = PaintImage(device_context_.size());
+    if (!image.is_null()) {
+      device_context_.ReplaceContents(&image);
+      device_context_.Flush(pp::CompletionCallback(&FlushCallback, this));

[brettw, 2012/01/06 23:36:44]

Here you should say
callback_factory_.NewRequiredCallback(&MyInstance::OnFlush) instead (you'll have
to add an int32_t result param to OnFlush. Then you can delete your
FlushCallback function.

+    } else {
+      printf("NullImage\n");
+    }
+  }
+
+  pp::ImageData PaintImage(const pp::Size& size) {
+    pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, false);
+    if (image.is_null())
+      return image;
+
+    PP_GamepadsData_Dev gamepad_data;
+    gamepad_->SampleGamepads(pp_instance(), &gamepad_data);
+
+    int width2 = size.width() / 2;
+    int height2 = size.height() / 2;
+    // Draw 2 axes
+    for (int i = 0; i < 4; i += 2) {
+      int x = static_cast<int>(
+          gamepad_data.items[0].axes[i + 0] * width2 + width2);
+      int y = static_cast<int>(
+          gamepad_data.items[0].axes[i + 1] * height2 + height2);
+      uint32_t box_bgra = 0x80ff0000;  // Alpha 50%.
+      FillRect(&image, x - 3, y - 3, 7, 7, box_bgra);
+    }
+    return image;
+  }
+
+  int width_;
+  int height_;
+
+  bool pending_paint_;
+  bool waiting_for_flush_completion_;
+
+  pp::CompletionCallbackFactory<MyInstance> callback_factory_;
+
+  const PPB_Console_Dev* console_;
+  const PPB_Gamepad_Dev* gamepad_;
+
+  pp::Graphics2D device_context_;
+};
+
+void FlushCallback(void* data, int32_t result) {
+  static_cast<MyInstance*>(data)->OnFlush();
+}
+
+// This object is the global object representing this plugin library as long
+// as it is loaded.
+class MyModule : public pp::Module {
+ public:
+  MyModule() : pp::Module() {}
+  virtual ~MyModule() {}
+
+  // Override CreateInstance to create your customized Instance object.
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new MyInstance(instance);
+  }
+};
+
+namespace pp {
+
+// Factory function for your specialization of the Module object.
+Module* CreateModule() {
+  return new MyModule();
+}
+
+}  // namespace pp
+