The current target is OpenGL 4.6 Core. The generator does not emit OpenGL ES or mix extension entry points into the core API. gl.xml is the authoritative generation input; the retained gl.h is reference material only.

Usage

Start the interactive CLI:

dotnet run --project tools/StgSharp.GenerateGL/StgSharp.GenerateGL.csproj

Common commands:

summary
find glBindBuffer
show command glBindBuffer
target summary
families list Vertex
families show VertexAttributeP
generate
list files
preview OpenGLFunction.v4_1.g.cs

Generate directly into an existing directory:

dotnet run --project tools/StgSharp.GenerateGL/StgSharp.GenerateGL.csproj -- generate src/StgSharp.Graphics/OpenGL/Generated

Without a directory, generate retains its output in the current CLI session. With a directory:

the directory must already exist and be writable;
each file is staged in the destination directory before replacing its target;
an existing file is replaced only when its first line is // <auto-generated>;
unrelated and obsolete generated files are not deleted.

Use a directory dedicated to generated source files.

Pipeline

gl.xml
  -> lossless XML and registry models
  -> desktop OpenGL 4.6 Core projection
  -> function-family and scalar/vector relation analysis
  -> managed API filters
  -> C# naming and signature validation
  -> in-memory generated file set
  -> preview or directory output

The target projection removes GLES and ARB/NV/EXT extension entry points. It retains only commands and constants present in the target Core Profile.

Generated files:

glconst.cs: core constants;
OpenglContext.g.cs: the function-pointer table with native names and ABI types;
glContextShadow.g.cs: an identically ordered nint table used while loading native entry points;
OpenGLFunction.Base.g.cs: APIs introduced through OpenGL 3.2 and retained in the target profile;
OpenGLFunction.v3_3.g.cs through OpenGLFunction.v4_6.g.cs: APIs introduced by each later core version.

OpenglContext intentionally remains close to the C ABI. Overloads, Span<T>, GlHandle, and managed naming exist only in the OpenGLFunction layer.

Overload rules

The generator merges a family only when it can validate the resulting signatures. Every managed method retains a reference to its original gl* command.

Native C API	Generated API
`glUniform1f` through `glUniform4f`	Scalar `Uniform(...)` overloads
`glUniformi`, `glUniformui`, and `glUniform*d`	Merged into `Uniform(...)` by C# parameter type
`glProgramUniform*`	Merged into `ProgramUniform(...)` by the same rules
`glUniform1*v`	`Uniform(..., ReadOnlySpan<T>)`
`glUniform4*v`	`Uniform(..., ReadOnlySpan<Vec4<T>>)`
`glUniform2v` and `glUniform3v`	Omitted because `Vec2` and `Vec3` storage is not a tightly packed C array
`glUniformMatrix4fv`	`Uniform(..., GraphicsMatrix)` and matrix-span overloads
Other matrix sizes and double matrices	Omitted because only the graphics-oriented 4x4 float layout is defined
`glGetBooleanv`, `glGetFloatv`, `glGetIntegerv`, and related queries	`GetValue(..., Span<T>)`
`glVertexAttrib1f/2f/3f/4f` and equivalent scalar forms	`VertexAttribute(...)`; component count is expressed by the parameter list
`glVertexAttribfv/iv/...` with a scalar equivalent	Omitted instead of exposing a duplicate C-style pointer entry point
`glVertexAttrib4N*`	`VertexAttributeNormalized(...)`
`glVertexAttribI*`	`VertexAttributeInteger(...)`
`glVertexAttribL*`	`VertexAttributeDouble(...)`; `L` does not mean C# `long`
`glVertexAttribP1ui` through `P4ui`	`VertexAttributePacked1(...)` through `Packed4(...)`; the width prevents signature collisions
`glGetVertexAttribI` and `L`	`GetVertexAttributeInteger(...)` and `GetVertexAttributeDouble(...)`
`glScissorIndexed` and `glScissorIndexedv`	`ScissorIndexed(...)` overloads

Function families are inferred from common name prefixes, shape suffixes, type suffixes, and vector forms. Candidates are checked against:

the gl.xml <vecequiv> relation;
parameter len, kind, and native types;
scalar T versus const T* relationships;
uniqueness of the final C# signature.

If incomplete type mapping causes two methods to collapse to the same C# signature, the generator conservatively restores their normalized native names instead of emitting uncompilable overloads.

Renaming rules

Safe lexical normalization applies to all public methods:

OpenGL spelling	C# spelling
`Framebuffer` / `framebuffer`	`FrameBuffer` / `frameBuffer`
`Renderbuffer` / `renderbuffer`	`RenderBuffer` / `renderBuffer`
`Internalformat` / `internalformat`	`InternalFormat` / `internalFormat`
`Attrib` / `attrib`	`Attribute` / `attribute`
`Frag`	`Fragment`
`attribindex`	`attributeIndex`
`bindingindex`	`bindingIndex`
`relativeoffset`	`relativeOffset`
`pname`	`pName`
`xoffset` / `yoffset` / `zoffset`	`xOffset` / `yOffset` / `zOffset`
`vaobj`	`vertexArray`

Families that represent distinct semantics receive explicit names:

Native family	Managed family
`TexParameter*`	`TextureParameter(...)`
DSA `TextureParameter*`	`NamedTextureParameter(...)`
`TexParameterI*`	`TextureParameterInteger(...)`
DSA `TextureParameterI*`	`NamedTextureParameterInteger(...)`
`SamplerParameterI*`	`SamplerParameterInteger(...)`
`GetnUniform*`	Merged into `GetUniform(...)` when signatures permit
`VertexAttribI/L/P/N`	Expanded to `Integer/Double/Packed/Normalized`

Renaming never changes the native target. For example, VertexAttributeInteger(...) still calls __context->glVertexAttribI*.

Type rules

gl.xml typedefs map to equivalent C# ABI types; the generator does not emit separate type aliases;
a GLuint is converted to GlHandle only when object class and parameter semantics identify it as an object handle;
handle arrays use Span<GlHandle> or ReadOnlySpan<GlHandle>;
OpenGLFunction stores an OpenglContext* and forwards through __context->glFunction(...);
unknown-length arrays, complex outputs, multiple indirection, and void* remain pointers.

A T* alone does not determine whether a managed API should use Span<T>, ReadOnlySpan<T>, out T, or a return value. Future pointer improvements should be implemented as family-specific filters validated with len, parameter direction, and OpenGL state semantics.

Documentation comments

Every generated public method contains:

its original C API declaration;
a <seealso> link to the corresponding docs.gl OpenGL 4 page or family page.

The generator does not emit <param> or <returns> elements and does not copy docs.gl content.

Source layout

Registry/: the gl.xml object model and Core Profile projection;
Analysis/: function families, name shapes, and scalar/vector relations;
Generation/: type mapping, API filters, signature planning, and file generation;
Naming/: C# identifier and semantic-family naming policies;
XmlCli.cs, RegistryCli.cs, and FunctionFamilyCli.cs: interactive inspection;
GenerateCli.cs: in-memory preview and protected directory output.