[NaCl SDK] Add simple graphics2d example.

BUG=none
R=sbc@chromium.org, noelallen@chromium.org

Review URL: https://codereview.chromium.org/28613002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229587 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 294 insertions, 0 deletions

diff --git a/native_client_sdk/src/build_tools/sdk_files.list b/native_client_sdk/src/build_tools/sdk_files.list
index 9bcd608..3fea6cc 100644
--- a/native_client_sdk/src/build_tools/sdk_files.list
+++ b/native_client_sdk/src/build_tools/sdk_files.list
@@ -4,6 +4,7 @@ examples/api/audio/*
 examples/api/core/*
 examples/api/file_io/*
 examples/api/gamepad/*
+examples/api/graphics_2d/*
 examples/api/graphics_3d/*
 examples/api/input_event/*
 [win]examples/api/make.bat
diff --git a/native_client_sdk/src/examples/api/graphics_2d/example.dsc b/native_client_sdk/src/examples/api/graphics_2d/example.dsc
new file mode 100644
index 0000000..a9b31c77
--- /dev/null
+++ b/native_client_sdk/src/examples/api/graphics_2d/example.dsc
@@ -0,0 +1,17 @@
+{
+  'TOOLS': ['newlib', 'glibc', 'pnacl', 'win', 'linux'],
+  'TARGETS': [
+    {
+      'NAME' : 'graphics_2d',
+      'TYPE' : 'main',
+      'SOURCES' : [
+        'graphics_2d.cc',
+      ],
+      'LIBS': ['ppapi_cpp', 'ppapi', 'pthread']
+    }
+  ],
+  'DEST': 'examples/api',
+  'NAME': 'graphics_2d',
+  'TITLE': 'Graphics 2D',
+  'GROUP': 'API'
+}
diff --git a/native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc b/native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc
new file mode 100644
index 0000000..10b1609
--- /dev/null
+++ b/native_client_sdk/src/examples/api/graphics_2d/graphics_2d.cc
@@ -0,0 +1,253 @@
+// Copyright (c) 2013 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 <stdio.h>
+#include <stdlib.h>
+
+#include "ppapi/c/ppb_image_data.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/module.h"
+#include "ppapi/cpp/point.h"
+#include "ppapi/utility/completion_callback_factory.h"
+
+#ifdef WIN32
+#undef PostMessage
+// Allow 'this' in initializer list
+#pragma warning(disable : 4355)
+#endif
+
+namespace {
+
+static const int kMouseRadius = 20;
+
+uint8_t RandUint8(uint8_t min, uint8_t max) {
+  uint64_t r = rand();
+  uint8_t result = static_cast<uint8_t>(r * (max - min + 1) / RAND_MAX) + min;
+  return result;
+}
+
+uint32_t MakeColor(uint8_t r, uint8_t g, uint8_t b) {
+  uint8_t a = 255;
+  PP_ImageDataFormat format = pp::ImageData::GetNativeImageDataFormat();
+  if (format == PP_IMAGEDATAFORMAT_BGRA_PREMUL) {
+    return (a << 24) | (r << 16) | (g << 8) | b;
+  } else {
+    return (a << 24) | (b << 16) | (g << 8) | r;
+  }
+}
+
+}  // namespace
+
+
+class Graphics2DInstance : public pp::Instance {
+ public:
+  explicit Graphics2DInstance(PP_Instance instance)
+      : pp::Instance(instance),
+        callback_factory_(this),
+        mouse_down_(false),
+        buffer_(NULL) {}
+
+  ~Graphics2DInstance() {
+    delete[] buffer_;
+  }
+
+  virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
+    RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE);
+
+    unsigned int seed = 1;
+    srand(seed);
+    CreatePalette();
+    return true;
+  }
+
+  virtual void DidChangeView(const pp::View& view) {
+    pp::Size new_size = view.GetRect().size();
+    bool had_context = !context_.is_null();
+
+    if (!CreateContext(new_size)) {
+      // failed.
+      return;
+    }
+
+    if (!had_context) {
+      MainLoop(0);
+    }
+  }
+
+  virtual bool HandleInputEvent(const pp::InputEvent& event) {
+    if (!buffer_)
+      return true;
+
+    if (event.GetType() == PP_INPUTEVENT_TYPE_MOUSEDOWN ||
+        event.GetType() == PP_INPUTEVENT_TYPE_MOUSEMOVE) {
+      pp::MouseInputEvent mouse_event(event);
+
+      if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_NONE)
+        return true;
+
+      mouse_ = mouse_event.GetPosition();
+      mouse_down_ = true;
+    }
+
+    if (event.GetType() == PP_INPUTEVENT_TYPE_MOUSEUP) {
+      mouse_down_ = false;
+    }
+
+    return true;
+  }
+
+ private:
+  void CreatePalette() {
+    for (int i = 0; i < 64; ++i) {
+      // Black -> Red
+      palette_[i] = MakeColor(i * 2, 0, 0);
+      palette_[i + 64] = MakeColor(128 + i * 2, 0, 0);
+      // Red -> Yellow
+      palette_[i + 128] = MakeColor(255, i * 4, 0);
+      // Yellow -> White
+      palette_[i + 192] = MakeColor(255, 255, i * 4);
+    }
+  }
+
+  bool CreateContext(const pp::Size& new_size) {
+    const bool kIsAlwaysOpaque = true;
+    context_ = pp::Graphics2D(this, new_size, kIsAlwaysOpaque);
+    if (!BindGraphics(context_)) {
+      fprintf(stderr, "Unable to bind 2d context!\n");
+      context_ = pp::Graphics2D();
+      return false;
+    }
+
+    // Create an ImageData object we can draw to that is the same size as the
+    // Graphics2D context.
+    const bool kInitToZero = true;
+    PP_ImageDataFormat format = pp::ImageData::GetNativeImageDataFormat();
+    image_data_ = pp::ImageData(this, format, new_size, kInitToZero);
+
+    // Allocate a buffer of palette entries of the same size.
+    buffer_ = new uint8_t[new_size.width() * new_size.height()];
+
+    return true;
+  }
+
+  void Update() {
+    // Old-school fire technique cribbed from
+    // http://ionicsolutions.net/2011/12/30/demo-fire-effect/
+    UpdateCoals();
+    DrawMouse();
+    UpdateFlames();
+  }
+
+  void UpdateCoals() {
+    const pp::Size& size = image_data_.size();
+    int width = size.width();
+    int height = size.height();
+    size_t span = 0;
+
+    // Draw two rows of random values at the bottom.
+    for (int y = height - 2; y < height; ++y) {
+      size_t offset = y * width;
+      for (int x = 0; x < width; ++x) {
+        // On a random chance, draw some longer strips of brighter colors.
+        if (span || RandUint8(1, 4) == 1) {
+          if (!span)
+            span = RandUint8(10, 20);
+          buffer_[offset + x] = RandUint8(128, 255);
+          span--;
+        } else {
+          buffer_[offset + x] = RandUint8(32, 96);
+        }
+      }
+    }
+  }
+
+  void UpdateFlames() {
+    const pp::Size& size = image_data_.size();
+    int width = size.width();
+    int height = size.height();
+    for (int y = 1; y < height - 1; ++y) {
+      size_t offset = y * width;
+      for (int x = 1; x < width - 1; ++x) {
+        int sum = 0;
+        sum += buffer_[offset - width + x - 1];
+        sum += buffer_[offset - width + x + 1];
+        sum += buffer_[offset         + x - 1];
+        sum += buffer_[offset         + x + 1];
+        sum += buffer_[offset + width + x - 1];
+        sum += buffer_[offset + width + x];
+        sum += buffer_[offset + width + x + 1];
+        buffer_[offset - width + x] = sum / 7;
+      }
+    }
+  }
+
+  void DrawMouse() {
+    if (!mouse_down_)
+      return;
+
+    const pp::Size& size = image_data_.size();
+    int width = size.width();
+    int height = size.height();
+
+    // Draw a circle at the mouse position.
+    int radius = kMouseRadius;
+    int cx = mouse_.x();
+    int cy = mouse_.y();
+    int minx = cx - radius <= 0 ? 1 : cx - radius;
+    int maxx = cx + radius >= width ? width - 1 : cx + radius;
+    int miny = cy - radius <= 0 ? 1 : cy - radius;
+    int maxy = cy + radius >= height ? height - 1 : cy + radius;
+    for (int y = miny; y < maxy; ++y) {
+      for (int x = minx; x < maxx; ++x) {
+        if ((x - cx) * (x - cx) + (y - cy) * (y - cy) < radius * radius) {
+          buffer_[y * width + x] = RandUint8(192, 255);
+        }
+      }
+    }
+  }
+
+  void Paint() {
+    const pp::Size& size = image_data_.size();
+    uint32_t* data = static_cast<uint32_t*>(image_data_.data());
+    uint32_t num_pixels = size.width() * size.height();
+    size_t offset = 0;
+    for (uint32_t i = 0; i < num_pixels; ++i) {
+      data[offset] = palette_[buffer_[offset]];
+      offset++;
+    }
+    context_.PaintImageData(image_data_, pp::Point());
+  }
+
+  void MainLoop(int32_t) {
+    Update();
+    Paint();
+    context_.Flush(
+        callback_factory_.NewCallback(&Graphics2DInstance::MainLoop));
+  }
+
+  pp::CompletionCallbackFactory<Graphics2DInstance> callback_factory_;
+  pp::Graphics2D context_;
+  pp::ImageData image_data_;
+  pp::Point mouse_;
+  bool mouse_down_;
+  uint8_t* buffer_;
+  uint32_t palette_[256];
+};
+
+class Graphics2DModule : public pp::Module {
+ public:
+  Graphics2DModule() : pp::Module() {}
+  virtual ~Graphics2DModule() {}
+
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new Graphics2DInstance(instance);
+  }
+};
+
+namespace pp {
+Module* CreateModule() { return new Graphics2DModule(); }
+}  // namespace pp
diff --git a/native_client_sdk/src/examples/api/graphics_2d/index.html b/native_client_sdk/src/examples/api/graphics_2d/index.html
new file mode 100644
index 0000000..f667472
--- /dev/null
+++ b/native_client_sdk/src/examples/api/graphics_2d/index.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<!--
+Copyright (c) 2012 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.
+-->
+<head>
+  <meta http-equiv="Pragma" content="no-cache">
+  <meta http-equiv="Expires" content="-1">
+  <title>{{title}}</title>
+  <script type="text/javascript" src="common.js"></script>
+</head>
+<body data-width="500" data-height="500" {{attrs}}>
+  <h1>{{title}}</h1>
+  <h2>Status: <code id="statusField">NO-STATUS</code></h2>
+  <p>The Graphics2D example demonstrates a simple flame effect.</p>
+  <p>Click and hold to add a flame.</p>
+  <!-- The NaCl plugin will be embedded inside the element with id "listener".
+      See common.js.-->
+  <div id="listener"></div>
+</body>
+</html>