easy-gl › Capabilities

Capabilities

Populated automatically by Device::initialize(). Provides read-only access to the GL context information, supported features and implementation limits.

Accessing capabilities

const auto& caps = device.capabilities();
const auto& info = caps.context_info();

std::cout << "Vendor:   "   << info.vendor             << '\n';
std::cout << "Renderer: "   << info.renderer           << '\n';
std::cout << "Version:  "   << info.version_string     << '\n';
std::cout << "GLSL:     "   << info.shading_language_version << '\n';
std::cout << "API kind: "   << (caps.is_opengl() ? "OpenGL" : "OpenGL ES") << '\n';
std::cout << "GL >= 4.1: " << caps.is_at_least(4, 1) << '\n';

Feature checks

if (caps.supports(easygl::Feature::ComputeShader)) { ... }
if (caps.supports(easygl::Feature::AnisotropicFiltering)) { ... }

Extension check

if (caps.supports_extension("GL_ARB_bindless_texture")) {
    // use bindless textures
}

Implementation limits

int maxTexUnits  = caps.get_limit("MAX_COMBINED_TEXTURE_IMAGE_UNITS");
int maxUboSize   = caps.get_limit("MAX_UNIFORM_BLOCK_SIZE");
int maxComputeX  = caps.get_limit("MAX_COMPUTE_WORK_GROUP_SIZE_X");

Feature enum reference

Feature	Minimum GL	Description
`VertexArrayObject`	3.0	VAO support
`Shader`	2.0	Programmable shaders
`Program`	2.0	Linked shader programs
`Buffer`	1.5	VBOs
`BasicRendering`	1.0	Draw calls, clear
`DebugOutput`	4.3 / KHR_debug	GL debug callback
`ComputeShader`	4.3	Compute shaders
`GeometryShader`	3.2	Geometry shaders
`TessellationShader`	4.0	Tessellation stages
`Texture3D`	1.2	3D texture targets
`TextureFloat`	3.0 / ARB_texture_float	Float internal formats
`TextureRG`	3.0 / ARB_texture_rg	Red/RG-only formats
`SamplerObject`	3.3	Sampler objects
`Instancing`	3.1	Instanced draw calls
`UniformBufferObject`	3.1	UBOs
`FramebufferObject`	3.0	FBOs
`Multisampling`	3.2	MSAA
`DrawBuffers`	2.0	MRT
`MapBuffer`	1.5	Buffer mapping
`DirectStateAccess`	4.5	DSA calls
`TextureCompression`	1.3	Compressed texture formats
`AnisotropicFiltering`	EXT_texture_filter_anisotropic	Anisotropic filtering

Method reference

Method	Description
`context_info()`	Returns ContextInfo struct.
`supports(Feature)`	True if the feature is available.
`supports_extension(name)`	True if the named extension is present.
`get_limit(name)`	Return a named implementation limit as int.
`is_opengl()`	True if desktop OpenGL context.
`is_opengles()`	True if OpenGL ES context.
`is_at_least(major, minor)`	True if context version ≥ major.minor.