[Remoting Android] Cursor & Cursor Feedback for OpenGL Renderer

remoting/client/gl_cursor_feedback.cc

+// Copyright 2016 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 "remoting/client/gl_cursor_feedback.h"
+
+#include <math.h>
+#include <array>
+
+#include "base/logging.h"
+#include "remoting/base/util.h"
+#include "remoting/client/gl_canvas.h"
+#include "remoting/client/gl_math.h"
+#include "remoting/client/gl_render_layer.h"
+#include "skia/include/core/SkCanvas.h"
+#include "skia/include/core/SkColor.h"
+#include "skia/include/core/SkImageInfo.h"
+#include "skia/include/core/SkPaint.h"
+#include "skia/include/core/SkSurface.h"
+#include "skia/include/effects/SkGradientShader.h"
+
+namespace {
+
+const int kTextureId = 2;
+const int kColorRingsCount = 4;
+const int kFeedbackTexturePixelDiameter = 256;
+const float kAnimationDurationMs = 220.f;
+
+// RGBA8888 colors. From inside to outside.
+const SkColor kFeedbackRingColors[kColorRingsCount] = {
+    SkColorSetARGB(0, 0, 0, 0),  // transparent black
+    SkColorSetARGB(0xff, 0xff, 0xff, 0xff),  // white
+    SkColorSetARGB(0xff, 0, 0, 0),  // black
+    SkColorSetARGB(0, 0, 0, 0),  // transparent black
+};
+
+const float kFeedbackRadiusStops[kColorRingsCount] = {0.0f, 0.8f, 0.9f, 1.0f};
+
+}  // namespace
+
+namespace remoting {
+
+GlCursorFeedback::GlCursorFeedback() {}
+
+GlCursorFeedback::~GlCursorFeedback() {}
+
+void GlCursorFeedback::SetCanvas(GlCanvas* canvas) {
+  if (!canvas) {
+    layer_.reset();
+    return;
+  }
+  layer_.reset(new GlRenderLayer(kTextureId, canvas));
+  layer_->SetTexture(GetFeedbackTexture(), kFeedbackTexturePixelDiameter,
+                     kFeedbackTexturePixelDiameter);
+}
+
+void GlCursorFeedback::StartAnimation(float normalized_x,
+                                      float normalized_y,
+                                      float normalized_width,
+                                      float normalized_height) {
+  max_width_ = normalized_width;
+  max_height_ = normalized_height;
+  cursor_x_ = normalized_x;
+  cursor_y_ = normalized_y;
+  animation_start_time_ = base::TimeTicks::Now();
+}
+
+bool GlCursorFeedback::Draw() {
+  if (!layer_ || animation_start_time_.is_null()) {
+    return false;
+  }
+  float progress =
+      (base::TimeTicks::Now() - animation_start_time_).InMilliseconds() /
+      kAnimationDurationMs;
+  if (progress > 1) {
+    animation_start_time_ = base::TimeTicks();
+    return false;
+  }
+  float width = progress * max_width_;
+  float height = progress * max_height_;
+  std::array<float, 8> positions;
+  FillRectangleVertexPositions(&positions, cursor_x_ - width / 2,
+                               cursor_y_ - height / 2, width, height);
+  layer_->SetVertexPositions(positions);
+  layer_->Draw(1.f - progress);
+  return true;
+}
+
+// static
+const uint8_t* GlCursorFeedback::GetFeedbackTexture() {
+  if (texture_initialized_) {
+    return texture_;
+  }
+  SkImageInfo image_info = SkImageInfo::Make(
+      kFeedbackTexturePixelDiameter, kFeedbackTexturePixelDiameter,
+      SkColorType::kRGBA_8888_SkColorType, SkAlphaType::kPremul_SkAlphaType);
+  sk_sp<SkSurface> surface(SkSurface::MakeRasterDirect(
+      image_info, texture_,
+      kFeedbackTexturePixelDiameter * kBytesPerPixelRGB32));
+  SkCanvas* canvas = surface->getCanvas();
+
+  SkPaint paint;
+  int radius = kFeedbackTexturePixelDiameter / 2;
+  paint.setShader(SkGradientShader::MakeRadial(
+      SkPoint::Make(radius, radius), radius, kFeedbackRingColors,
+      kFeedbackRadiusStops, kColorRingsCount,
+      SkShader::TileMode::kClamp_TileMode));
+  canvas->drawPaint(paint);
+
+  texture_initialized_ = true;
+  return texture_;
+}
+
+// static
+uint8_t GlCursorFeedback::texture_[kFeedbackTexturePixelDiameter *
+                                   kFeedbackTexturePixelDiameter *
+                                   kBytesPerPixelRGB32];
+
+// static
+bool GlCursorFeedback::texture_initialized_ = false;

[Sergey Ulanov, 2016/07/20 18:06:11]

this flag doesn't have to be a class member. It can be a static variable defined
in the .cc file.

[Sergey Ulanov, 2016/07/20 18:06:11]

Please use base::Singleton<> to make initialization of this singleton simpler.

[Yuwei, 2016/07/20 22:56:48]

Done.

+
+}  // namespace remoting