| // Copyright 2020 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. |
| |
| #ifndef ASH_HUD_DISPLAY_GRAPH_H_ |
| #define ASH_HUD_DISPLAY_GRAPH_H_ |
| |
| #include <vector> |
| |
| #include "ash/hud_display/hud_constants.h" |
| #include "base/containers/ring_buffer.h" |
| #include "third_party/skia/include/core/SkColor.h" |
| #include "ui/gfx/geometry/point.h" |
| #include "ui/gfx/geometry/rect.h" |
| |
| struct SkPoint; |
| |
| namespace gfx { |
| class Canvas; |
| } |
| |
| namespace ash { |
| namespace hud_display { |
| |
| class Graph { |
| public: |
| // Graph screen size (that is used in Layout()) should match (ring buffer |
| // size - 1) to prevent scaling, because RingBuffer always keeps one element |
| // unused. |
| using Data = base::RingBuffer<float, kHUDGraphWidth + 1>; |
| |
| enum class Baseline { |
| BASELINE_BOTTOM, // Positive values will be drawn from the bottom border |
| // up. |
| BASELINE_TOP, // Positive values will be drawn from the top border down. |
| }; |
| |
| // Whether to draw the graph as a filled polygon. |
| enum class Fill { |
| NONE, |
| SOLID, |
| }; |
| |
| enum class Style { |
| LINES, |
| SKYLINE, |
| }; |
| |
| // |max_data_points| must be less than the ring buffer size. |
| Graph(size_t max_data_points, |
| Baseline baseline, |
| Fill fill, |
| Style style, |
| SkColor color); |
| ~Graph(); |
| |
| Graph(const Graph&) = delete; |
| Graph& operator=(const Graph&) = delete; |
| |
| // |value| must be normalized to [0,1]. When graphs are drawn stacked, |
| // the full stack must be normalized. |
| // |unscaled_value| is used to label graph values to the user. |
| void AddValue(float value, float unscaled_value); |
| void Layout(const gfx::Rect& graph_bounds, const Graph* base); |
| void Draw(gfx::Canvas* canvas) const; |
| void UpdateLastValue(float value, float unscaled_value); |
| |
| const std::vector<SkPoint>& top_path() const { return top_path_; } |
| |
| // Returns number of data points displayed on the graph. |
| size_t max_data_points() const { return max_data_points_; } |
| |
| SkColor color() const { return color_; } |
| |
| // Returns value from |unscaled_data_|. |
| // |index| is always interpreted as "negative", i.e. "0" - current data, "1" |
| // - previous graph data, 2 - two steps "ago". I.e. it's number of graph |
| // points from the right graph edge. |
| float GetUnscaledValueAt(size_t index) const; |
| |
| // Returns true if |data_| is populated at the given index. |
| // |index| is always interpreted as "negative", i.e. "0" - current data, "1" |
| // - previous graph data, 2 - two steps ago. I.e. it's number of graph |
| // points from the right graph edge. |
| bool IsFilledIndex(size_t index) const; |
| |
| // Reset the data. |
| void Reset(); |
| |
| #if !defined(NDEBUG) |
| // Returns string representation os this object for debug. |
| std::string DebugDump(const std::string& name) const; |
| #endif |
| |
| private: |
| const Baseline baseline_; |
| const Fill fill_; |
| const Style style_; |
| const SkColor color_; |
| |
| // Result of last Layout() call. |
| gfx::Rect graph_bounds_; |
| |
| // Paths are measured from the top left corner. |
| // Partial graph is assumed to be right-justified. |
| // For BASELINE_BOTTOM |top_path_| has y values that are less than |
| // |bottom_path_|. (And opposite for the BASELINE_TOP.) |
| // Paths are calculated by Layout() from the |data_|. |
| std::vector<SkPoint> top_path_; |
| std::vector<SkPoint> bottom_path_; |
| // Bottom path style should follow base graph style. |
| Style bottom_path_style_ = Style::LINES; |
| |
| Data data_; |
| Data unscaled_data_; |
| size_t max_data_points_ = 0; |
| }; |
| |
| } // namespace hud_display |
| } // namespace ash |
| |
| #endif // ASH_HUD_DISPLAY_GRAPH_H_ |