opengl-registry

• opengl-registry Documentation
• opengl-registry on PyPI
• opengl-registry on Github

A tool for extracting information from the OpenGL API Registry.

The registry is currently located on github in the KhronosGroup organization: https://raw.githubusercontent.com/KhronosGroup/OpenGL-Registry/master/xml/gl.xml

Setting Up From Source

Clone the repo and enter the project directory. We assume the user will set up a virtualenv.

pip install -e .

This will install the package in editable mode meaning you can keep changing the source without having to install it for every change.

If you actually want to install the package and have no desire to modify its contents:

pip install .

Running Tests

We use tox for running tests covering py3.4, py3.6 and py3.7 with flake9 and coverage.

pip install -r tests/requirements.txt
# All environments
tox

# Specific environments
tox -e py36
tox -e py37
tox -e py38
tox -e py39
tox -e pep8

Building Docs

pip install -r docs/requirements.txt
python setup.py build_sphinx

Registry Info

The registry is simply a huge xml file usually named gl.xml containing information about enums and functions. These are then referenced in features (opengl/es versions) and extensions. This also includes required and removed enums and functions as the versions progress.

<registry>
    <!-- GL type definitions. -->
    <types>
        <type>typedef unsigned int <name>GLenum</name>;</type>
        <type>typedef unsigned char <name>GLboolean</name>;</type>
        ...
    </types>

    <!-- An attempt to group enums together (not critical information) -->
    <groups>
        <group name="CullFaceMode">
            <enum name="GL_BACK"/>
            <enum name="GL_FRONT"/>
            <enum name="GL_FRONT_AND_BACK"/>
        </group>
        ...
    </groups>

    <!-- Multiple enums blocks with the enum names and values. Can point to a group -->
    <enums namespace="GL" group="ContextProfileMask" type="bitmask">
        <enum value="0x00000001" name="GL_CONTEXT_CORE_PROFILE_BIT"/>
        <enum value="0x00000002" name="GL_CONTEXT_COMPATIBILITY_PROFILE_BIT"/>
    </enums>
    ...

    <!-- Details information about every GL function -->
    <commands namespace="GL">
        <command>
            <proto>void <name>glDrawArrays</name></proto>
            <param group="PrimitiveType"><ptype>GLenum</ptype> <name>mode</name></param>
            <param><ptype>GLint</ptype> <name>first</name></param>
            <param><ptype>GLsizei</ptype> <name>count</name></param>
            <glx type="render" opcode="193"/>
        </command>
        ...
    </command>

    <!-- Multiple feature blocks for each opengl version.
         These include the required and remove section
         referencing command names and enum names.

         Only including parts of GL 3.2 as it shows removal.
    -->
    <feature api="gl" name="GL_VERSION_1_1" number="1.1">...</feature>
    <feature api="gl" name="GL_VERSION_1_2" number="1.2">...</feature>
    <feature api="gl" name="GL_VERSION_1_3" number="1.3">...</feature>
    <feature api="gl" name="GL_VERSION_1_4" number="1.4">...</feature>
    <feature api="gl" name="GL_VERSION_1_5" number="1.5">...</feature>
    <feature api="gl" name="GL_VERSION_2_0" number="2.0">...</feature>
    <feature api="gl" name="GL_VERSION_2_1" number="2.1">...</feature>
    <feature api="gl" name="GL_VERSION_3_0" number="3.0">...</feature>
    <feature api="gl" name="GL_VERSION_3_1" number="3.1">...</feature>
    <feature api="gl" name="GL_VERSION_3_2" number="3.2">
        <require>
            <enum name="GL_CONTEXT_CORE_PROFILE_BIT"/>
            <enum name="GL_CONTEXT_COMPATIBILITY_PROFILE_BIT"/>
            <enum name="GL_LINES_ADJACENCY"/>
            <enum name="GL_LINE_STRIP_ADJACENCY"/>
            ...
        </require>
        <require comment="Reuse ARB_draw_elements_base_vertex">
            <command name="glDrawElementsBaseVertex"/>
            <command name="glDrawRangeElementsBaseVertex"/>
            <command name="glDrawElementsInstancedBaseVertex"/>
            <command name="glMultiDrawElementsBaseVertex"/>
        </require>
        <remove profile="core" comment="Compatibility-only GL 1.0 features removed from GL 3.2">
            <command name="glNewList"/>
            <command name="glEndList"/>
            <command name="glCallList"/>
            <command name="glCallLists"/>
            <command name="glDeleteLists"/>
            ...
        </remove>
        <remove profile="core" comment="Compatibility-only GL 1.1 features removed from GL 3.2">
            <enum name="GL_QUADS"/>
            <enum name="GL_POLYGON"/>
            ...
        </remove>
        ...
    </feature>
    <feature api="gl" name="GL_VERSION_3_3" number="3.3">...</feature>
    <feature api="gl" name="GL_VERSION_4_0" number="4.0">...</feature>
    <feature api="gl" name="GL_VERSION_4_1" number="4.1">...</feature>
    <feature api="gl" name="GL_VERSION_4_2" number="4.2">...</feature>
    <feature api="gl" name="GL_VERSION_4_3" number="4.3">...</feature>
    <feature api="gl" name="GL_VERSION_4_4" number="4.4">...</feature>
    <feature api="gl" name="GL_VERSION_4_5" number="4.5">...</feature>
    <feature api="gl" name="GL_VERSION_4_6" number="4.6">...</feature>
    <!-- There will also be feature blocks for gles -->

    <!-- Extension definitions are similar to features.
         The numer of extensions gathered here is staggering,
         but they can be filtered on the ``supported`` field
         to make it easier to handle.
    -->
    <extensions>
        <extension name="GL_EXT_debug_label" supported="gl|glcore|gles2">
            <require>
                <enum name="GL_PROGRAM_PIPELINE_OBJECT_EXT"/>
                <enum name="GL_PROGRAM_OBJECT_EXT"/>
                <enum name="GL_SHADER_OBJECT_EXT"/>
                <enum name="GL_BUFFER_OBJECT_EXT"/>
                <enum name="GL_QUERY_OBJECT_EXT"/>
                <enum name="GL_VERTEX_ARRAY_OBJECT_EXT"/>
                <command name="glLabelObjectEXT"/>
                <command name="glGetObjectLabelEXT"/>
            </require>
            <require comment="Depends on OpenGL ES 3.0">
                <enum name="GL_SAMPLER"/>
                <enum name="GL_TRANSFORM_FEEDBACK"/>
            </require>
        </extension>
        <extension name="GL_EXT_debug_marker" supported="gl|glcore|gles1|gles2">
            <require>
                <command name="glInsertEventMarkerEXT"/>
                <command name="glPushGroupMarkerEXT"/>
                <command name="glPopGroupMarkerEXT"/>
            </require>
        </extension>
        ...
    </extension>
</registry>