| Flutter Impeller |

Public Member Functions | Public Attributes | List of all members
impeller::CapabilitiesGLES Class Referencefinal

The Vulkan layers and extensions wrangler. More...

`#include <capabilities_gles.h>`

Inheritance diagram for impeller::CapabilitiesGLES:

## Public Member Functions
| CapabilitiesGLES (const ProcTableGLES &gl)
| CapabilitiesGLES (const CapabilitiesGLES &)=delete
| CapabilitiesGLES (CapabilitiesGLES &&)=delete
CapabilitiesGLES & | operator= (const CapabilitiesGLES &)=delete
CapabilitiesGLES & | operator= (CapabilitiesGLES &&)=delete
size_t | GetMaxTextureUnits (ShaderStage stage) const
bool | IsANGLE () const
bool | SupportsOffscreenMSAA () const override
| Whether the context backend supports attaching offscreen MSAA color/stencil textures. More...
bool | SupportsImplicitResolvingMSAA () const override
| Whether the context backend supports multisampled rendering to the on-screen surface without requiring an explicit resolve of the MSAA color attachment. More...
bool | SupportsSSBO () const override
| Whether the context backend supports binding Shader Storage Buffer Objects (SSBOs) to pipelines. More...
bool | SupportsTextureToTextureBlits () const override
| Whether the context backend supports blitting from one texture region to another texture region (via the relevant `BlitPass::AddCopy` overloads). More...
bool | SupportsFramebufferFetch () const override
| Whether the context backend is able to support pipelines with shaders that read from the framebuffer (i.e. pixels that have been written by previous draw calls in the current render pass). More...
bool | SupportsCompute () const override
| Whether the context backend supports `ComputePass`. More...
bool | SupportsComputeSubgroups () const override
| Whether the context backend supports configuring `ComputePass` command subgroups. More...
bool | SupportsReadFromResolve () const override
| Whether the context backend supports binding the current `RenderPass` attachments. This is supported if the backend can guarantee that attachment textures will not be mutated until the render pass has fully completed. More...
bool | SupportsDecalSamplerAddressMode () const override
| Whether the context backend supports `SamplerAddressMode::Decal`. More...
bool | SupportsDeviceTransientTextures () const override
| Whether the context backend supports allocating `StorageMode::kDeviceTransient` (aka "memoryless") textures, which are temporary textures kept in tile memory for the duration of the `RenderPass` it's attached to. More...
PixelFormat | GetDefaultColorFormat () const override
| Returns a supported `PixelFormat` for textures that store 4-channel colors (red/green/blue/alpha). More...
PixelFormat | GetDefaultStencilFormat () const override
| Returns a supported `PixelFormat` for textures that store stencil information. May include a depth channel if a stencil-only format is not available. More...
PixelFormat | GetDefaultDepthStencilFormat () const override
| Returns a supported `PixelFormat` for textures that store both a stencil and depth component. This will never return a depth-only or stencil-only texture. Returns `PixelFormat::kUnknown` if no suitable depth+stencil format was found. More...
PixelFormat | GetDefaultGlyphAtlasFormat () const override
| Returns the default pixel format for the alpha bitmap glyph atlas. More...
Public Member Functions inherited from impeller::Capabilities
virtual | ~Capabilities ()

## Public Attributes
size_t | max_combined_texture_image_units = 8
size_t | max_cube_map_texture_size = 16
size_t | max_fragment_uniform_vectors = 16
size_t | max_renderbuffer_size = 1
size_t | max_texture_image_units = 8
ISize | max_texture_size = ISize{64, 64}
size_t | max_varying_vectors = 8
size_t | max_vertex_attribs = 8
size_t | max_vertex_texture_image_units = 0
size_t | max_vertex_uniform_vectors = 128
ISize | max_viewport_dims
size_t | num_compressed_texture_formats = 0
size_t | num_shader_binary_formats = 0

## Additional Inherited Members
Static Public Member Functions inherited from impeller::BackendCast< CapabilitiesGLES, Capabilities >
static CapabilitiesGLES & | Cast (Capabilities &base)
static const CapabilitiesGLES & | Cast (const Capabilities &base)
static CapabilitiesGLES * | Cast (Capabilities *base)
static const CapabilitiesGLES * | Cast (const Capabilities *base)
Protected Member Functions inherited from impeller::Capabilities
| Capabilities ()
| Capabilities (const Capabilities &)=delete
Capabilities & | operator= (const Capabilities &)=delete

## Detailed Description

The Vulkan layers and extensions wrangler.

Definition at line 23 of file capabilities_gles.h.

## Constructor & Destructor Documentation

## ◆ CapabilitiesGLES() [1/3]

impeller::CapabilitiesGLES::CapabilitiesGLES | ( | const ProcTableGLES & | gl | ) |
| explicit

Definition at line 25 of file capabilities_gles.cc.

25 {
26 {
27 GLint value = 0;
28 gl.GetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &value);
29 max_combined_texture_image_units = value;
30 }
31
32 {
33 GLint value = 0;
34 gl.GetIntegerv(GL_MAX_CUBE_MAP_TEXTURE_SIZE, &value);
35 max_cube_map_texture_size = value;
36 }
37
38 auto const desc = gl.GetDescription();
39
40 if (desc->IsES()) {
41 GLint value = 0;
42 gl.GetIntegerv(GL_MAX_FRAGMENT_UNIFORM_VECTORS, &value);
43 max_fragment_uniform_vectors = value;
44 }
45
46 {
47 GLint value = 0;
48 gl.GetIntegerv(GL_MAX_RENDERBUFFER_SIZE, &value);
49 max_renderbuffer_size = value;
50 }
51
52 {
53 GLint value = 0;
54 gl.GetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &value);
55 max_texture_image_units = value;
56 }
57
58 {
59 GLint value = 0;
60 gl.GetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
61 max_texture_size = ISize{value, value};
62 }
63
64 if (desc->IsES()) {
65 GLint value = 0;
66 gl.GetIntegerv(GL_MAX_VARYING_VECTORS, &value);
67 max_varying_vectors = value;
68 }
69
70 {
71 GLint value = 0;
72 gl.GetIntegerv(GL_MAX_VERTEX_ATTRIBS, &value);
73 max_vertex_attribs = value;
74 }
75
76 {
77 GLint value = 0;
78 gl.GetIntegerv(GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS, &value);
79 max_vertex_texture_image_units = value;
80 }
81
82 if (desc->IsES()) {
83 GLint value = 0;
84 gl.GetIntegerv(GL_MAX_VERTEX_UNIFORM_VECTORS, &value);
85 max_vertex_uniform_vectors = value;
86 }
87
88 {
89 GLint values[2] = {};
90 gl.GetIntegerv(GL_MAX_VIEWPORT_DIMS, values);
91 max_viewport_dims = ISize{values[0], values[1]};
92 }
93
94 {
95 GLint value = 0;
96 gl.GetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS, &value);
97 num_compressed_texture_formats = value;
98 }
99
100 if (desc->IsES()) {
101 GLint value = 0;
102 gl.GetIntegerv(GL_NUM_SHADER_BINARY_FORMATS, &value);
103 num_shader_binary_formats = value;
104 }
105
106 if (desc->IsES()) {
107 default_glyph_atlas_format_ = PixelFormat::kA8UNormInt;
108 } else {
109 default_glyph_atlas_format_ = PixelFormat::kR8UNormInt;
110 }
111
112 supports_framebuffer_fetch_ = desc->HasExtension(kFramebufferFetchExt);
113
114 if (desc->HasExtension(kTextureBorderClampExt) ||
115 desc->HasExtension(kNvidiaTextureBorderClampExt)) {
116 supports_decal_sampler_address_mode_ = true;
117 }
118
119 if (desc->HasExtension(kMultisampledRenderToTextureExt)) {
120 supports_implicit_msaa_ = true;
121
122 // We hard-code 4x MSAA, so let's make sure it's supported.
123 GLint value = 0;
124 gl.GetIntegerv(GL_MAX_SAMPLES_EXT, &value);
125 supports_offscreen_msaa_ = value >= 4;
126 }
127
128 is_angle_ = desc->IsANGLE();
129 }

References impeller::ProcTableGLES::GetDescription(), impeller::kA8UNormInt, impeller::kFramebufferFetchExt, impeller::kMultisampledRenderToTextureExt, impeller::kNvidiaTextureBorderClampExt, impeller::kR8UNormInt, impeller::kTextureBorderClampExt, max_combined_texture_image_units, max_cube_map_texture_size, max_fragment_uniform_vectors, max_renderbuffer_size, max_texture_image_units, max_texture_size, max_varying_vectors, max_vertex_attribs, max_vertex_texture_image_units, max_vertex_uniform_vectors, max_viewport_dims, num_compressed_texture_formats, and num_shader_binary_formats.

## ◆ CapabilitiesGLES() [2/3]

impeller::CapabilitiesGLES::CapabilitiesGLES | ( | const CapabilitiesGLES & |  | ) |
| delete

## ◆ CapabilitiesGLES() [3/3]

impeller::CapabilitiesGLES::CapabilitiesGLES | ( | CapabilitiesGLES && |  | ) |
| delete

## Member Function Documentation

## ◆ GetDefaultColorFormat()

PixelFormat impeller::CapabilitiesGLES::GetDefaultColorFormat | ( |  | ) | const
| override virtual

Returns a supported `PixelFormat` for textures that store 4-channel colors (red/green/blue/alpha).

Implements impeller::Capabilities.

Definition at line 184 of file capabilities_gles.cc.

184 {
185 return PixelFormat::kR8G8B8A8UNormInt;
186 }

References impeller::kR8G8B8A8UNormInt.

## ◆ GetDefaultDepthStencilFormat()

PixelFormat impeller::CapabilitiesGLES::GetDefaultDepthStencilFormat | ( |  | ) | const
| override virtual

Returns a supported `PixelFormat` for textures that store both a stencil and depth component. This will never return a depth-only or stencil-only texture. Returns `PixelFormat::kUnknown` if no suitable depth+stencil format was found.

Implements impeller::Capabilities.

Definition at line 192 of file capabilities_gles.cc.

192 {
193 return PixelFormat::kD24UnormS8Uint;
194 }

References impeller::kD24UnormS8Uint.

## ◆ GetDefaultGlyphAtlasFormat()

PixelFormat impeller::CapabilitiesGLES::GetDefaultGlyphAtlasFormat | ( |  | ) | const
| override virtual

Returns the default pixel format for the alpha bitmap glyph atlas.

       Some backends may use Red channel while others use grey. This
       should not have any impact

Implements impeller::Capabilities.

Definition at line 200 of file capabilities_gles.cc.

200 {
201 return default_glyph_atlas_format_;
202 }

## ◆ GetDefaultStencilFormat()

PixelFormat impeller::CapabilitiesGLES::GetDefaultStencilFormat | ( |  | ) | const
| override virtual

Returns a supported `PixelFormat` for textures that store stencil information. May include a depth channel if a stencil-only format is not available.

Implements impeller::Capabilities.

Definition at line 188 of file capabilities_gles.cc.

188 {
189 return PixelFormat::kS8UInt;
190 }

References impeller::kS8UInt.

## ◆ GetMaxTextureUnits()

size_t impeller::CapabilitiesGLES::GetMaxTextureUnits | ( | ShaderStage | stage | ) | const

Definition at line 131 of file capabilities_gles.cc.

131 {
132 switch (stage) {
133 case ShaderStage::kVertex:
134 return max_vertex_texture_image_units;
135 case ShaderStage::kFragment:
136 return max_texture_image_units;
137 case ShaderStage::kUnknown:
138 case ShaderStage::kCompute:
139 return 0u;
140 }
141 FML_UNREACHABLE();
142 }

References impeller::kCompute, impeller::kFragment, impeller::kUnknown, impeller::kVertex, max_texture_image_units, and max_vertex_texture_image_units.

## ◆ IsANGLE()

bool impeller::CapabilitiesGLES::IsANGLE | ( |  | ) | const

Definition at line 196 of file capabilities_gles.cc.

196 {
197 return is_angle_;
198 }

## ◆ operator=() [1/2]

CapabilitiesGLES& impeller::CapabilitiesGLES::operator= | ( | CapabilitiesGLES && |  | ) |
| delete

## ◆ operator=() [2/2]

CapabilitiesGLES& impeller::CapabilitiesGLES::operator= | ( | const CapabilitiesGLES & |  | ) |
| delete

## ◆ SupportsCompute()

bool impeller::CapabilitiesGLES::SupportsCompute | ( |  | ) | const
| override virtual

Whether the context backend supports `ComputePass`.

Implements impeller::Capabilities.

Definition at line 164 of file capabilities_gles.cc.

164 {
165 return false;
166 }

## ◆ SupportsComputeSubgroups()

bool impeller::CapabilitiesGLES::SupportsComputeSubgroups | ( |  | ) | const
| override virtual

Whether the context backend supports configuring `ComputePass` command subgroups.

Implements impeller::Capabilities.

Definition at line 168 of file capabilities_gles.cc.

168 {
169 return false;
170 }

## ◆ SupportsDecalSamplerAddressMode()

bool impeller::CapabilitiesGLES::SupportsDecalSamplerAddressMode | ( |  | ) | const
| override virtual

Whether the context backend supports `SamplerAddressMode::Decal`.

Implements impeller::Capabilities.

Definition at line 176 of file capabilities_gles.cc.

176 {
177 return supports_decal_sampler_address_mode_;
178 }

## ◆ SupportsDeviceTransientTextures()

bool impeller::CapabilitiesGLES::SupportsDeviceTransientTextures | ( |  | ) | const
| override virtual

Whether the context backend supports allocating `StorageMode::kDeviceTransient` (aka "memoryless") textures, which are temporary textures kept in tile memory for the duration of the `RenderPass` it's attached to.

This feature is especially useful for MSAA and stencils.

Implements impeller::Capabilities.

Definition at line 180 of file capabilities_gles.cc.

180 {
181 return false;
182 }

## ◆ SupportsFramebufferFetch()

bool impeller::CapabilitiesGLES::SupportsFramebufferFetch | ( |  | ) | const
| override virtual

Whether the context backend is able to support pipelines with shaders that read from the framebuffer (i.e. pixels that have been written by previous draw calls in the current render pass).

Example of reading from the first color attachment in a GLSL shader: ``` uniform subpassInput subpass_input;

out vec4 frag_color;

void main() { vec4 color = subpassLoad(subpass_input); // Invert the colors drawn to the framebuffer. frag_color = vec4(vec3(1) - color.rgb, color.a); } ```

Implements impeller::Capabilities.

Definition at line 160 of file capabilities_gles.cc.

160 {
161 return supports_framebuffer_fetch_;
162 }

## ◆ SupportsImplicitResolvingMSAA()

bool impeller::CapabilitiesGLES::SupportsImplicitResolvingMSAA | ( |  | ) | const
| override virtual

Whether the context backend supports multisampled rendering to the on-screen surface without requiring an explicit resolve of the MSAA color attachment.

Implements impeller::Capabilities.

Definition at line 148 of file capabilities_gles.cc.

148 {
149 return supports_implicit_msaa_;
150 }

## ◆ SupportsOffscreenMSAA()

bool impeller::CapabilitiesGLES::SupportsOffscreenMSAA | ( |  | ) | const
| override virtual

Whether the context backend supports attaching offscreen MSAA color/stencil textures.

Implements impeller::Capabilities.

Definition at line 144 of file capabilities_gles.cc.

144 {
145 return supports_offscreen_msaa_;
146 }

## ◆ SupportsReadFromResolve()

bool impeller::CapabilitiesGLES::SupportsReadFromResolve | ( |  | ) | const
| override virtual

Whether the context backend supports binding the current `RenderPass` attachments. This is supported if the backend can guarantee that attachment textures will not be mutated until the render pass has fully completed.

This is possible because many mobile graphics cards track `RenderPass` attachment state in intermediary tile memory prior to Storing the pass in the heap allocated attachments on DRAM. Metal's hazard tracking and Vulkan's barriers are granular enough to allow for safely accessing attachment textures prior to storage in the same `RenderPass`.

Implements impeller::Capabilities.

Definition at line 172 of file capabilities_gles.cc.

172 {
173 return false;
174 }

## ◆ SupportsSSBO()

bool impeller::CapabilitiesGLES::SupportsSSBO | ( |  | ) | const
| override virtual

Whether the context backend supports binding Shader Storage Buffer Objects (SSBOs) to pipelines.

Implements impeller::Capabilities.

Definition at line 152 of file capabilities_gles.cc.

152 {
153 return false;
154 }

## ◆ SupportsTextureToTextureBlits()

bool impeller::CapabilitiesGLES::SupportsTextureToTextureBlits | ( |  | ) | const
| override virtual

Whether the context backend supports blitting from one texture region to another texture region (via the relevant `BlitPass::AddCopy` overloads).

Implements impeller::Capabilities.

Definition at line 156 of file capabilities_gles.cc.

156 {
157 return false;
158 }

## Member Data Documentation

## ◆ max_combined_texture_image_units

size_t impeller::CapabilitiesGLES::max_combined_texture_image_units = 8

Definition at line 38 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_cube_map_texture_size

size_t impeller::CapabilitiesGLES::max_cube_map_texture_size = 16

Definition at line 41 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_fragment_uniform_vectors

size_t impeller::CapabilitiesGLES::max_fragment_uniform_vectors = 16

Definition at line 44 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_renderbuffer_size

size_t impeller::CapabilitiesGLES::max_renderbuffer_size = 1

Definition at line 47 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_texture_image_units

size_t impeller::CapabilitiesGLES::max_texture_image_units = 8

Definition at line 50 of file capabilities_gles.h.

Referenced by CapabilitiesGLES(), and GetMaxTextureUnits().

## ◆ max_texture_size

ISize impeller::CapabilitiesGLES::max_texture_size = ISize{64, 64}

Definition at line 53 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_varying_vectors

size_t impeller::CapabilitiesGLES::max_varying_vectors = 8

Definition at line 56 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_vertex_attribs

size_t impeller::CapabilitiesGLES::max_vertex_attribs = 8

Definition at line 59 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_vertex_texture_image_units

size_t impeller::CapabilitiesGLES::max_vertex_texture_image_units = 0

Definition at line 62 of file capabilities_gles.h.

Referenced by CapabilitiesGLES(), and GetMaxTextureUnits().

## ◆ max_vertex_uniform_vectors

size_t impeller::CapabilitiesGLES::max_vertex_uniform_vectors = 128

Definition at line 65 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ max_viewport_dims

ISize impeller::CapabilitiesGLES::max_viewport_dims

Definition at line 68 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ num_compressed_texture_formats

size_t impeller::CapabilitiesGLES::num_compressed_texture_formats = 0

Definition at line 71 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

## ◆ num_shader_binary_formats

size_t impeller::CapabilitiesGLES::num_shader_binary_formats = 0

Definition at line 74 of file capabilities_gles.h.

Referenced by CapabilitiesGLES().

The documentation for this class was generated from the following files:

- impeller/renderer/backend/gles/capabilities_gles.h
- impeller/renderer/backend/gles/capabilities_gles.cc

impeller::CapabilitiesGLES::max_vertex_attribs
size_t max_vertex_attribs
Definition: capabilities_gles.h:59
impeller::ISize
ISize64 ISize
Definition: size.h:140
impeller::CapabilitiesGLES::max_viewport_dims
ISize max_viewport_dims
Definition: capabilities_gles.h:68
impeller::PixelFormat::kS8UInt
@ kS8UInt
impeller::kMultisampledRenderToTextureExt
static const constexpr char * kMultisampledRenderToTextureExt
Definition: capabilities_gles.cc:22
impeller::ShaderStage::kUnknown
@ kUnknown
impeller::PixelFormat::kA8UNormInt
@ kA8UNormInt
impeller::PixelFormat::kR8UNormInt
@ kR8UNormInt
impeller::CapabilitiesGLES::max_fragment_uniform_vectors
size_t max_fragment_uniform_vectors
Definition: capabilities_gles.h:44
impeller::PixelFormat::kR8G8B8A8UNormInt
@ kR8G8B8A8UNormInt
impeller::kFramebufferFetchExt
static const constexpr char * kFramebufferFetchExt
Definition: capabilities_gles.cc:13
impeller::CapabilitiesGLES::max_cube_map_texture_size
size_t max_cube_map_texture_size
Definition: capabilities_gles.h:41
impeller::CapabilitiesGLES::max_vertex_uniform_vectors
size_t max_vertex_uniform_vectors
Definition: capabilities_gles.h:65
impeller::CapabilitiesGLES::max_combined_texture_image_units
size_t max_combined_texture_image_units
Definition: capabilities_gles.h:38
impeller::CapabilitiesGLES::max_vertex_texture_image_units
size_t max_vertex_texture_image_units
Definition: capabilities_gles.h:62
impeller::CapabilitiesGLES::max_texture_size
ISize max_texture_size
Definition: capabilities_gles.h:53
impeller::CapabilitiesGLES::max_texture_image_units
size_t max_texture_image_units
Definition: capabilities_gles.h:50
impeller::PixelFormat::kD24UnormS8Uint
@ kD24UnormS8Uint
impeller::ShaderStage::kFragment
@ kFragment
impeller::kNvidiaTextureBorderClampExt
static const constexpr char * kNvidiaTextureBorderClampExt
Definition: capabilities_gles.cc:18
impeller::CapabilitiesGLES::max_renderbuffer_size
size_t max_renderbuffer_size
Definition: capabilities_gles.h:47
impeller::CapabilitiesGLES::num_shader_binary_formats
size_t num_shader_binary_formats
Definition: capabilities_gles.h:74
impeller::ShaderStage::kVertex
@ kVertex
impeller::ShaderStage::kCompute
@ kCompute
impeller::kTextureBorderClampExt
static const constexpr char * kTextureBorderClampExt
Definition: capabilities_gles.cc:16
impeller::CapabilitiesGLES::num_compressed_texture_formats
size_t num_compressed_texture_formats
Definition: capabilities_gles.h:71
impeller::CapabilitiesGLES::max_varying_vectors
size_t max_varying_vectors
Definition: capabilities_gles.h:56