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capabilities.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_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 Whether the primitive type TriangleFan is supported by the backend.
87 virtual bool SupportsTriangleFan() const = 0;
88
89 /// @brief Returns a supported `PixelFormat` for textures that store
90 /// 4-channel colors (red/green/blue/alpha).
91 virtual PixelFormat GetDefaultColorFormat() const = 0;
92
93 /// @brief Returns a supported `PixelFormat` for textures that store stencil
94 /// information. May include a depth channel if a stencil-only format
95 /// is not available.
96 virtual PixelFormat GetDefaultStencilFormat() const = 0;
97
98 /// @brief Returns a supported `PixelFormat` for textures that store both a
99 /// stencil and depth component. This will never return a depth-only
100 /// or stencil-only texture.
101 /// Returns `PixelFormat::kUnknown` if no suitable depth+stencil
102 /// format was found.
103 virtual PixelFormat GetDefaultDepthStencilFormat() const = 0;
104
105 /// @brief Returns the default pixel format for the alpha bitmap glyph atlas.
106 ///
107 /// Some backends may use Red channel while others use grey. This
108 /// should not have any impact
109 virtual PixelFormat GetDefaultGlyphAtlasFormat() const = 0;
110
111 /// @brief Return the maximum size of a render pass attachment.
112 ///
113 /// Note that this may be smaller than the maximum allocatable texture size.
114 virtual ISize GetMaximumRenderPassAttachmentSize() const = 0;
115
116 protected:
117 Capabilities();
118
119 Capabilities(const Capabilities&) = delete;
120
121 Capabilities& operator=(const Capabilities&) = delete;
122 };
123
124 class CapabilitiesBuilder {
125 public:
126 CapabilitiesBuilder();
127
128 ~CapabilitiesBuilder();
129
130 CapabilitiesBuilder& SetSupportsOffscreenMSAA(bool value);
131
132 CapabilitiesBuilder& SetSupportsSSBO(bool value);
133
134 CapabilitiesBuilder& SetSupportsTextureToTextureBlits(bool value);
135
136 CapabilitiesBuilder& SetSupportsFramebufferFetch(bool value);
137
138 CapabilitiesBuilder& SetSupportsCompute(bool value);
139
140 CapabilitiesBuilder& SetSupportsComputeSubgroups(bool value);
141
142 CapabilitiesBuilder& SetSupportsReadFromResolve(bool value);
143
144 CapabilitiesBuilder& SetDefaultColorFormat(PixelFormat value);
145
146 CapabilitiesBuilder& SetDefaultStencilFormat(PixelFormat value);
147
148 CapabilitiesBuilder& SetDefaultDepthStencilFormat(PixelFormat value);
149
150 CapabilitiesBuilder& SetSupportsDecalSamplerAddressMode(bool value);
151
152 CapabilitiesBuilder& SetSupportsDeviceTransientTextures(bool value);
153
154 CapabilitiesBuilder& SetDefaultGlyphAtlasFormat(PixelFormat value);
155
156 CapabilitiesBuilder& SetSupportsTriangleFan(bool value);
157
158 CapabilitiesBuilder& SetMaximumRenderPassAttachmentSize(ISize size);
159
160 std::unique_ptr<Capabilities> Build();
161
162 private:
163 bool supports_offscreen_msaa_ = false;
164 bool supports_ssbo_ = false;
165 bool supports_texture_to_texture_blits_ = false;
166 bool supports_framebuffer_fetch_ = false;
167 bool supports_compute_ = false;
168 bool supports_compute_subgroups_ = false;
169 bool supports_read_from_resolve_ = false;
170 bool supports_decal_sampler_address_mode_ = false;
171 bool supports_device_transient_textures_ = false;
172 bool supports_triangle_fan_ = false;
173 std::optional<PixelFormat> default_color_format_ = std::nullopt;
174 std::optional<PixelFormat> default_stencil_format_ = std::nullopt;
175 std::optional<PixelFormat> default_depth_stencil_format_ = std::nullopt;
176 std::optional<PixelFormat> default_glyph_atlas_format_ = std::nullopt;
177 std::optional<ISize> default_maximum_render_pass_attachment_size_ =
178 std::nullopt;
179
180 CapabilitiesBuilder(const CapabilitiesBuilder&) = delete;
181
182 CapabilitiesBuilder& operator=(const CapabilitiesBuilder&) = delete;
183 };
184
185 } // namespace impeller
186
187 #endif // FLUTTER_IMPELLER_RENDERER_CAPABILITIES_H_
impeller::CapabilitiesBuilder::CapabilitiesBuilder
CapabilitiesBuilder()
impeller::CapabilitiesBuilder::Build
std::unique_ptr< Capabilities > Build()
Definition: capabilities.cc:238
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...
impeller::Capabilities::GetMaximumRenderPassAttachmentSize
virtual ISize GetMaximumRenderPassAttachmentSize() const =0
Return the maximum size of a render pass attachment.
impeller::CapabilitiesBuilder
Definition: capabilities.h:124
formats.h
impeller::CapabilitiesBuilder::SetSupportsTriangleFan
CapabilitiesBuilder & SetSupportsTriangleFan(bool value)
Definition: capabilities.cc:227
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::TSize
Definition: size.h:19
impeller::CapabilitiesBuilder::SetSupportsSSBO
CapabilitiesBuilder & SetSupportsSSBO(bool value)
Definition: capabilities.cc:157
impeller::CapabilitiesBuilder::SetSupportsCompute
CapabilitiesBuilder & SetSupportsCompute(bool value)
Definition: capabilities.cc:174
impeller::CapabilitiesBuilder::SetDefaultDepthStencilFormat
CapabilitiesBuilder & SetDefaultDepthStencilFormat(PixelFormat value)
Definition: capabilities.cc:197
impeller::CapabilitiesBuilder::SetMaximumRenderPassAttachmentSize
CapabilitiesBuilder & SetMaximumRenderPassAttachmentSize(ISize size)
Definition: capabilities.cc:232
impeller::CapabilitiesBuilder::SetDefaultGlyphAtlasFormat
CapabilitiesBuilder & SetDefaultGlyphAtlasFormat(PixelFormat value)
Definition: capabilities.cc:221
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:168
impeller::CapabilitiesBuilder::~CapabilitiesBuilder
~CapabilitiesBuilder()
impeller::CapabilitiesBuilder::SetSupportsComputeSubgroups
CapabilitiesBuilder & SetSupportsComputeSubgroups(bool value)
Definition: capabilities.cc:179
impeller::Capabilities::Capabilities
Capabilities()
impeller::CapabilitiesBuilder::SetSupportsTextureToTextureBlits
CapabilitiesBuilder & SetSupportsTextureToTextureBlits(bool value)
Definition: capabilities.cc:162
impeller::Capabilities::operator=
Capabilities & operator=(const Capabilities &)=delete
impeller::Capabilities::SupportsTriangleFan
virtual bool SupportsTriangleFan() const =0
Whether the primitive type TriangleFan is supported by the backend.
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:185
impeller::CapabilitiesBuilder::SetDefaultStencilFormat
CapabilitiesBuilder & SetDefaultStencilFormat(PixelFormat value)
Definition: capabilities.cc:191
impeller::Capabilities::~Capabilities
virtual ~Capabilities()
impeller::CapabilitiesBuilder::SetSupportsDecalSamplerAddressMode
CapabilitiesBuilder & SetSupportsDecalSamplerAddressMode(bool value)
Definition: capabilities.cc:209
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:215
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: allocation.cc:12
impeller::CapabilitiesBuilder::SetSupportsReadFromResolve
CapabilitiesBuilder & SetSupportsReadFromResolve(bool value)
Definition: capabilities.cc:203
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:152
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.