| Flutter Impeller |

capabilities.h
Go to the documentation of this file.
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_RENDERER_CAPABILITIES_H_
6 #define FLUTTER_IMPELLER_RENDERER_CAPABILITIES_H_
7
8 #include <memory>
9
10 #include "impeller/core/formats.h"
11
12 namespace impeller {
13
14 class Capabilities {
15 public:
16 virtual ~Capabilities();
17
18 /// @brief Whether the context backend supports attaching offscreen MSAA
19 /// color/stencil textures.
20 virtual bool SupportsOffscreenMSAA() const = 0;
21
22 /// @brief Whether the context backend supports multisampled rendering to
23 /// the on-screen surface without requiring an explicit resolve of
24 /// the MSAA color attachment.
25 virtual bool SupportsImplicitResolvingMSAA() const = 0;
26
27 /// @brief Whether the context backend supports binding Shader Storage Buffer
28 /// Objects (SSBOs) to pipelines.
29 virtual bool SupportsSSBO() const = 0;
30
31 /// @brief Whether the context backend supports blitting from one texture
32 /// region to another texture region (via the relevant
33 /// `BlitPass::AddCopy` overloads).
34 virtual bool SupportsTextureToTextureBlits() const = 0;
35
36 /// @brief Whether the context backend is able to support pipelines with
37 /// shaders that read from the framebuffer (i.e. pixels that have been
38 /// written by previous draw calls in the current render pass).
39 ///
40 /// Example of reading from the first color attachment in a GLSL
41 /// shader:
42 /// ```
43 /// uniform subpassInput subpass_input;
44 ///
45 /// out vec4 frag_color;
46 ///
47 /// void main() {
48 /// vec4 color = subpassLoad(subpass_input);
49 /// // Invert the colors drawn to the framebuffer.
50 /// frag_color = vec4(vec3(1) - color.rgb, color.a);
51 /// }
52 /// ```
53 virtual bool SupportsFramebufferFetch() const = 0;
54
55 /// @brief Whether the context backend supports `ComputePass`.
56 virtual bool SupportsCompute() const = 0;
57
58 /// @brief Whether the context backend supports configuring `ComputePass`
59 /// command subgroups.
60 virtual bool SupportsComputeSubgroups() const = 0;
61
62 /// @brief Whether the context backend supports binding the current
63 /// `RenderPass` attachments. This is supported if the backend can
64 /// guarantee that attachment textures will not be mutated until the
65 /// render pass has fully completed.
66 ///
67 /// This is possible because many mobile graphics cards track
68 /// `RenderPass` attachment state in intermediary tile memory prior to
69 /// Storing the pass in the heap allocated attachments on DRAM.
70 /// Metal's hazard tracking and Vulkan's barriers are granular enough
71 /// to allow for safely accessing attachment textures prior to storage
72 /// in the same `RenderPass`.
73 virtual bool SupportsReadFromResolve() const = 0;
74
75 /// @brief Whether the context backend supports `SamplerAddressMode::Decal`.
76 virtual bool SupportsDecalSamplerAddressMode() const = 0;
77
78 /// @brief Whether the context backend supports allocating
79 /// `StorageMode::kDeviceTransient` (aka "memoryless") textures, which
80 /// are temporary textures kept in tile memory for the duration of the
81 /// `RenderPass` it's attached to.
82 ///
83 /// This feature is especially useful for MSAA and stencils.
84 virtual bool SupportsDeviceTransientTextures() const = 0;
85
86 /// @brief Returns a supported `PixelFormat` for textures that store
87 /// 4-channel colors (red/green/blue/alpha).
88 virtual PixelFormat GetDefaultColorFormat() const = 0;
89
90 /// @brief Returns a supported `PixelFormat` for textures that store stencil
91 /// information. May include a depth channel if a stencil-only format
92 /// is not available.
93 virtual PixelFormat GetDefaultStencilFormat() const = 0;
94
95 /// @brief Returns a supported `PixelFormat` for textures that store both a
96 /// stencil and depth component. This will never return a depth-only
97 /// or stencil-only texture.
98 /// Returns `PixelFormat::kUnknown` if no suitable depth+stencil
99 /// format was found.
100 virtual PixelFormat GetDefaultDepthStencilFormat() const = 0;
101
102 /// @brief Returns the default pixel format for the alpha bitmap glyph atlas.
103 ///
104 /// Some backends may use Red channel while others use grey. This
105 /// should not have any impact
106 virtual PixelFormat GetDefaultGlyphAtlasFormat() const = 0;
107
108 protected:
109 Capabilities();
110
111 Capabilities(const Capabilities&) = delete;
112
113 Capabilities& operator=(const Capabilities&) = delete;
114 };
115
116 class CapabilitiesBuilder {
117 public:
118 CapabilitiesBuilder();
119
120 ~CapabilitiesBuilder();
121
122 CapabilitiesBuilder& SetSupportsOffscreenMSAA(bool value);
123
124 CapabilitiesBuilder& SetSupportsSSBO(bool value);
125
126 CapabilitiesBuilder& SetSupportsTextureToTextureBlits(bool value);
127
128 CapabilitiesBuilder& SetSupportsFramebufferFetch(bool value);
129
130 CapabilitiesBuilder& SetSupportsCompute(bool value);
131
132 CapabilitiesBuilder& SetSupportsComputeSubgroups(bool value);
133
134 CapabilitiesBuilder& SetSupportsReadFromResolve(bool value);
135
136 CapabilitiesBuilder& SetDefaultColorFormat(PixelFormat value);
137
138 CapabilitiesBuilder& SetDefaultStencilFormat(PixelFormat value);
139
140 CapabilitiesBuilder& SetDefaultDepthStencilFormat(PixelFormat value);
141
142 CapabilitiesBuilder& SetSupportsDecalSamplerAddressMode(bool value);
143
144 CapabilitiesBuilder& SetSupportsDeviceTransientTextures(bool value);
145
146 CapabilitiesBuilder& SetDefaultGlyphAtlasFormat(PixelFormat value);
147
148 std::unique_ptr<Capabilities> Build();
149
150 private:
151 bool supports_offscreen_msaa_ = false;
152 bool supports_ssbo_ = false;
153 bool supports_texture_to_texture_blits_ = false;
154 bool supports_framebuffer_fetch_ = false;
155 bool supports_compute_ = false;
156 bool supports_compute_subgroups_ = false;
157 bool supports_read_from_resolve_ = false;
158 bool supports_decal_sampler_address_mode_ = false;
159 bool supports_device_transient_textures_ = false;
160 std::optional<PixelFormat> default_color_format_ = std::nullopt;
161 std::optional<PixelFormat> default_stencil_format_ = std::nullopt;
162 std::optional<PixelFormat> default_depth_stencil_format_ = std::nullopt;
163 std::optional<PixelFormat> default_glyph_atlas_format_ = std::nullopt;
164
165 CapabilitiesBuilder(const CapabilitiesBuilder&) = delete;
166
167 CapabilitiesBuilder& operator=(const CapabilitiesBuilder&) = delete;
168 };
169
170 } // namespace impeller
171
172 #endif // FLUTTER_IMPELLER_RENDERER_CAPABILITIES_H_
impeller::CapabilitiesBuilder::CapabilitiesBuilder
CapabilitiesBuilder()
impeller::CapabilitiesBuilder::Build
std::unique_ptr< Capabilities > Build()
Definition: capabilities.cc:212
impeller::Capabilities::SupportsReadFromResolve
virtual bool SupportsReadFromResolve() const =0
Whether the context backend supports binding the current RenderPass attachments. This is supported if...
impeller::Capabilities::SupportsOffscreenMSAA
virtual bool SupportsOffscreenMSAA() const =0
Whether the context backend supports attaching offscreen MSAA color/stencil textures.
impeller::Capabilities::SupportsDeviceTransientTextures
virtual bool SupportsDeviceTransientTextures() const =0
Whether the context backend supports allocating StorageMode::kDeviceTransient (aka "memoryless") text...
formats.h
impeller::CapabilitiesBuilder
Definition: capabilities.h:116
impeller::PixelFormat
PixelFormat
The Pixel formats supported by Impeller. The naming convention denotes the usage of the component,...
Definition: formats.h:99
impeller::Capabilities
Definition: capabilities.h:14
impeller::CapabilitiesBuilder::SetSupportsSSBO
CapabilitiesBuilder & SetSupportsSSBO(bool value)
Definition: capabilities.cc:142
impeller::CapabilitiesBuilder::SetSupportsCompute
CapabilitiesBuilder & SetSupportsCompute(bool value)
Definition: capabilities.cc:159
impeller::CapabilitiesBuilder::SetDefaultDepthStencilFormat
CapabilitiesBuilder & SetDefaultDepthStencilFormat(PixelFormat value)
Definition: capabilities.cc:182
impeller::CapabilitiesBuilder::SetDefaultGlyphAtlasFormat
CapabilitiesBuilder & SetDefaultGlyphAtlasFormat(PixelFormat value)
Definition: capabilities.cc:206
impeller::Capabilities::SupportsImplicitResolvingMSAA
virtual bool SupportsImplicitResolvingMSAA() const =0
Whether the context backend supports multisampled rendering to the on-screen surface without requirin...
impeller::CapabilitiesBuilder::SetSupportsFramebufferFetch
CapabilitiesBuilder & SetSupportsFramebufferFetch(bool value)
Definition: capabilities.cc:153
impeller::CapabilitiesBuilder::~CapabilitiesBuilder
~CapabilitiesBuilder()
impeller::CapabilitiesBuilder::SetSupportsComputeSubgroups
CapabilitiesBuilder & SetSupportsComputeSubgroups(bool value)
Definition: capabilities.cc:164
impeller::Capabilities::Capabilities
Capabilities()
impeller::CapabilitiesBuilder::SetSupportsTextureToTextureBlits
CapabilitiesBuilder & SetSupportsTextureToTextureBlits(bool value)
Definition: capabilities.cc:147
impeller::Capabilities::operator=
Capabilities & operator=(const Capabilities &)=delete
impeller::Capabilities::GetDefaultGlyphAtlasFormat
virtual PixelFormat GetDefaultGlyphAtlasFormat() const =0
Returns the default pixel format for the alpha bitmap glyph atlas.
impeller::Capabilities::GetDefaultStencilFormat
virtual PixelFormat GetDefaultStencilFormat() const =0
Returns a supported PixelFormat for textures that store stencil information. May include a depth chan...
impeller::CapabilitiesBuilder::SetDefaultColorFormat
CapabilitiesBuilder & SetDefaultColorFormat(PixelFormat value)
Definition: capabilities.cc:170
impeller::CapabilitiesBuilder::SetDefaultStencilFormat
CapabilitiesBuilder & SetDefaultStencilFormat(PixelFormat value)
Definition: capabilities.cc:176
impeller::Capabilities::~Capabilities
virtual ~Capabilities()
impeller::CapabilitiesBuilder::SetSupportsDecalSamplerAddressMode
CapabilitiesBuilder & SetSupportsDecalSamplerAddressMode(bool value)
Definition: capabilities.cc:194
impeller::Capabilities::SupportsComputeSubgroups
virtual bool SupportsComputeSubgroups() const =0
Whether the context backend supports configuring ComputePass command subgroups.
impeller::CapabilitiesBuilder::SetSupportsDeviceTransientTextures
CapabilitiesBuilder & SetSupportsDeviceTransientTextures(bool value)
Definition: capabilities.cc:200
impeller::Capabilities::GetDefaultColorFormat
virtual PixelFormat GetDefaultColorFormat() const =0
Returns a supported PixelFormat for textures that store 4-channel colors (red/green/blue/alpha).
impeller::Capabilities::SupportsDecalSamplerAddressMode
virtual bool SupportsDecalSamplerAddressMode() const =0
Whether the context backend supports SamplerAddressMode::Decal.
impeller::Capabilities::SupportsFramebufferFetch
virtual bool SupportsFramebufferFetch() const =0
Whether the context backend is able to support pipelines with shaders that read from the framebuffer ...
impeller::Capabilities::SupportsSSBO
virtual bool SupportsSSBO() const =0
Whether the context backend supports binding Shader Storage Buffer Objects (SSBOs) to pipelines.
impeller
Definition: aiks_blend_unittests.cc:18
impeller::CapabilitiesBuilder::SetSupportsReadFromResolve
CapabilitiesBuilder & SetSupportsReadFromResolve(bool value)
Definition: capabilities.cc:188
impeller::Capabilities::SupportsTextureToTextureBlits
virtual bool SupportsTextureToTextureBlits() const =0
Whether the context backend supports blitting from one texture region to another texture region (via ...
impeller::CapabilitiesBuilder::SetSupportsOffscreenMSAA
CapabilitiesBuilder & SetSupportsOffscreenMSAA(bool value)
Definition: capabilities.cc:137
impeller::Capabilities::GetDefaultDepthStencilFormat
virtual PixelFormat GetDefaultDepthStencilFormat() const =0
Returns a supported PixelFormat for textures that store both a stencil and depth component....
impeller::Capabilities::SupportsCompute
virtual bool SupportsCompute() const =0
Whether the context backend supports ComputePass.