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trampoline.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef FLUTTER_IMPELLER_TOOLKIT_GLVK_TRAMPOLINE_H_
6 #define FLUTTER_IMPELLER_TOOLKIT_GLVK_TRAMPOLINE_H_
7
8 #include "impeller/base/thread_safety.h"
9 #include "impeller/renderer/backend/vulkan/android/ahb_texture_source_vk.h"
10 #include "impeller/toolkit/egl/context.h"
11 #include "impeller/toolkit/egl/display.h"
12 #include "impeller/toolkit/egl/surface.h"
13 #include "impeller/toolkit/glvk/proc_table.h"
14
15 namespace impeller::glvk {
16
17 class AutoTrampolineContext;
18
19 //------------------------------------------------------------------------------
20 /// @brief An object used to interoperate between OpenGL and Vulkan.
21 ///
22 /// While these are not super expensive to create, they do manage an
23 /// internal EGL context as well as some OpenGL state. For this
24 /// reason, it is recommended that callers cache these for the
25 /// duration of the lifecycle of main rendering context.
26 ///
27 class Trampoline {
28 public:
29 //----------------------------------------------------------------------------
30 /// @brief Constructs a new trampoline. It is recommended that these
31 /// objects be cached and reused for all conversion operations.
32 ///
33 /// EGL contexts on already bound to the callers thread may become
34 /// unbound after a call to this method.
35 ///
36 Trampoline();
37
38 //----------------------------------------------------------------------------
39 /// @brief Destroys the trampoline. There are no threading restrictions.
40 /// EGL contexts on already bound to the callers thread may become
41 /// unbound after a call to this method.
42 ///
43 ~Trampoline();
44
45 Trampoline(const Trampoline&) = delete;
46
47 Trampoline& operator=(const Trampoline&) = delete;
48
49 //----------------------------------------------------------------------------
50 /// @brief Determines if this is a valid trampoline. There is no error
51 /// recovery mechanism if a trampoline cannot be constructed and
52 /// an invalid trampoline must be immediately discarded.
53 ///
54 /// @return True if valid, False otherwise.
55 ///
56 bool IsValid() const;
57
58 //----------------------------------------------------------------------------
59 /// @brief Describes an OpenGL texture along with information on how to
60 /// sample from it.
61 ///
62 struct GLTextureInfo {
63 //--------------------------------------------------------------------------
64 /// The OpenGL texture handle.
65 ///
66 GLuint texture = 0;
67 //--------------------------------------------------------------------------
68 /// The OpenGL texture target enum. For instance, GL_TEXTURE_2D or
69 /// GL_TEXTURE_EXTERNAL_OES.
70 ///
71 GLenum target = 0;
72 //--------------------------------------------------------------------------
73 /// A transformation applied to the texture coordinates in the form of (u,
74 /// v, 0, 1) when sampling from the texture.
75 ///
76 Matrix uv_transformation;
77 };
78
79 //----------------------------------------------------------------------------
80 /// @brief Perform a blit operation from the source OpenGL texture to a
81 /// target Vulkan texture.
82 ///
83 /// It is the callers responsibility to ensure that the EGL
84 /// context associated with the trampoline is already current
85 /// before making this call.
86 ///
87 /// It is also the responsibility of the caller to ensure that the
88 /// destination texture is the color-attachment-optimal layout.
89 /// Failure to ensure this will lead to validation error.
90 ///
91 /// @see `MakeCurrentContext`
92 ///
93 /// @param[in] src_texture The source OpenGL texture.
94 /// @param[in] dst_texture The destination Vulkan texture.
95 ///
96 /// @return True if the blit was successful, False otherwise.
97 ///
98 bool BlitTextureOpenGLToVulkan(const GLTextureInfo& src_texture,
99 const AHBTextureSourceVK& dst_texture) const;
100
101 //----------------------------------------------------------------------------
102 /// @brief Make the EGL context associated with this trampoline current
103 /// on the calling thread.
104 ///
105 /// @return The automatic trampoline context. The collection of this
106 /// context clears the threads EGL binding.
107 ///
108 [[nodiscard]] AutoTrampolineContext MakeCurrentContext() const;
109
110 private:
111 friend class AutoTrampolineContext;
112
113 std::unique_ptr<egl::Display> egl_display_;
114 std::unique_ptr<egl::Context> egl_context_;
115 std::unique_ptr<egl::Surface> egl_surface_;
116 std::unique_ptr<ProcTable> gl_;
117 GLuint program_ = GL_NONE;
118 GLint texture_uniform_location_ = 0;
119 GLint uv_transformation_location_ = 0;
120 bool is_valid_ = false;
121 };
122
123 //------------------------------------------------------------------------------
124 /// @brief An RAII object that makes the trampolines EGL context current
125 /// when constructed and clears the EGL binding on destruction.
126 ///
127 class AutoTrampolineContext final {
128 public:
129 //----------------------------------------------------------------------------
130 /// @brief Constructs a new instance and makes the trampolines EGL
131 /// context current on the calling thread.
132 ///
133 /// @param[in] trampoline The trampoline.
134 ///
135 explicit AutoTrampolineContext(const Trampoline& trampoline);
136
137 //----------------------------------------------------------------------------
138 /// @brief Destroys the object and clears the previous EGL binding.
139 ///
140 ~AutoTrampolineContext();
141
142 AutoTrampolineContext(const AutoTrampolineContext&) = delete;
143
144 AutoTrampolineContext& operator=(const AutoTrampolineContext&) = delete;
145
146 private:
147 const egl::Context* context_ = nullptr;
148 const egl::Surface* surface_ = nullptr;
149 };
150
151 } // namespace impeller::glvk
152
153 #endif // FLUTTER_IMPELLER_TOOLKIT_GLVK_TRAMPOLINE_H_
ahb_texture_source_vk.h
impeller::AHBTextureSourceVK
A texture source that wraps an instance of AHardwareBuffer.
Definition: ahb_texture_source_vk.h:32
impeller::egl::Context
An instance of an EGL context.
Definition: context.h:30
impeller::egl::Surface
An instance of an EGL surface. There is no ability to create surfaces directly. Instead,...
Definition: surface.h:18
impeller::glvk::AutoTrampolineContext
An RAII object that makes the trampolines EGL context current when constructed and clears the EGL bin...
Definition: trampoline.h:127
impeller::glvk::AutoTrampolineContext::~AutoTrampolineContext
~AutoTrampolineContext()
Destroys the object and clears the previous EGL binding.
Definition: trampoline.cc:326
impeller::glvk::AutoTrampolineContext::AutoTrampolineContext
AutoTrampolineContext(const Trampoline &trampoline)
Constructs a new instance and makes the trampolines EGL context current on the calling thread.
Definition: trampoline.cc:318
impeller::glvk::AutoTrampolineContext::operator=
AutoTrampolineContext & operator=(const AutoTrampolineContext &)=delete
impeller::glvk::AutoTrampolineContext::AutoTrampolineContext
AutoTrampolineContext(const AutoTrampolineContext &)=delete
impeller::glvk::Trampoline
An object used to interoperate between OpenGL and Vulkan.
Definition: trampoline.h:27
impeller::glvk::Trampoline::~Trampoline
~Trampoline()
Destroys the trampoline. There are no threading restrictions. EGL contexts on already bound to the ca...
Definition: trampoline.cc:153
impeller::glvk::Trampoline::BlitTextureOpenGLToVulkan
bool BlitTextureOpenGLToVulkan(const GLTextureInfo &src_texture, const AHBTextureSourceVK &dst_texture) const
Perform a blit operation from the source OpenGL texture to a target Vulkan texture.
Definition: trampoline.cc:197
impeller::glvk::Trampoline::operator=
Trampoline & operator=(const Trampoline &)=delete
impeller::glvk::Trampoline::Trampoline
Trampoline(const Trampoline &)=delete
impeller::glvk::Trampoline::IsValid
bool IsValid() const
Determines if this is a valid trampoline. There is no error recovery mechanism if a trampoline cannot...
Definition: trampoline.cc:161
impeller::glvk::Trampoline::MakeCurrentContext
AutoTrampolineContext MakeCurrentContext() const
Make the EGL context associated with this trampoline current on the calling thread.
Definition: trampoline.cc:313
impeller::glvk::Trampoline::Trampoline
Trampoline()
Constructs a new trampoline. It is recommended that these objects be cached and reused for all conver...
Definition: trampoline.cc:57
display.h
proc_table.h
impeller::glvk
Definition: proc_table.cc:9
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::glvk::Trampoline::GLTextureInfo
Describes an OpenGL texture along with information on how to sample from it.
Definition: trampoline.h:62
impeller::glvk::Trampoline::GLTextureInfo::uv_transformation
Matrix uv_transformation
Definition: trampoline.h:76
impeller::glvk::Trampoline::GLTextureInfo::texture
GLuint texture
Definition: trampoline.h:66
impeller::glvk::Trampoline::GLTextureInfo::target
GLenum target
Definition: trampoline.h:71
thread_safety.h
context.h
surface.h