impeller/aiks/canvas.h

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <deque>
#include <memory>
#include <optional>
#include <vector>

#include "flutter/fml/macros.h"
#include "impeller/aiks/image.h"
#include "impeller/aiks/paint.h"
#include "impeller/aiks/picture.h"
#include "impeller/entity/entity_pass.h"
#include "impeller/geometry/matrix.h"
#include "impeller/geometry/path.h"
#include "impeller/geometry/point.h"
#include "impeller/geometry/vector.h"
#include "impeller/geometry/vertices.h"
#include "impeller/renderer/sampler_descriptor.h"
#include "impeller/typographer/glyph_atlas.h"
#include "impeller/typographer/text_frame.h"

namespace impeller {

class Entity;

class Canvas {
 public:
  Canvas();

  ~Canvas();

  void Save();

  void SaveLayer(
      Paint paint,
      std::optional<Rect> bounds = std::nullopt,
      std::optional<Paint::ImageFilterProc> backdrop_filter = std::nullopt);

  bool Restore();

  size_t GetSaveCount() const;

  void RestoreToCount(size_t count);

  const Matrix& GetCurrentTransformation() const;

  void ResetTransform();

  void Transform(const Matrix& xformation);

  void Concat(const Matrix& xformation);

  void Translate(const Vector3& offset);

  void Scale(const Vector2& scale);

  void Scale(const Vector3& scale);

  void Skew(Scalar sx, Scalar sy);

  void Rotate(Radians radians);

  void DrawPath(Path path, Paint paint);

  void DrawPaint(Paint paint);

  void DrawRect(Rect rect, Paint paint);

  void DrawCircle(Point center, Scalar radius, Paint paint);

  void DrawImage(std::shared_ptr<Image> image,
                 Point offset,
                 Paint paint,
                 SamplerDescriptor sampler = {});

  void DrawImageRect(std::shared_ptr<Image> image,
                     Rect source,
                     Rect dest,
                     Paint paint,
                     SamplerDescriptor sampler = {});

  void ClipPath(
      Path path,
      Entity::ClipOperation clip_op = Entity::ClipOperation::kIntersect);

  void DrawShadow(Path path, Color color, Scalar elevation);

  void DrawPicture(Picture picture);

  void DrawTextFrame(TextFrame text_frame, Point position, Paint paint);

  void DrawVertices(Vertices vertices,
                    Entity::BlendMode blend_mode,
                    Paint paint);

  Picture EndRecordingAsPicture();

 private:
  std::unique_ptr<EntityPass> base_pass_;
  EntityPass* current_pass_ = nullptr;
  std::deque<CanvasStackEntry> xformation_stack_;

  void Initialize();

  void Reset();

  EntityPass& GetCurrentPass();

  size_t GetStencilDepth() const;

  void Save(bool create_subpass,
            Entity::BlendMode = Entity::BlendMode::kSourceOver);

  void RestoreClip();

  FML_DISALLOW_COPY_AND_ASSIGN(Canvas);
};

}  // namespace impeller