Graphics Reference
In-Depth Information
floating-point textures, shared exponent RGB 9-9-9-5 textures,
10-10-10-2 integer textures, and 8-bit-per-component signed
normalized textures.
• Non-power-of-2 textures (NPOT)—Textures can now be specified with
non-power-of-2 dimensions. This is useful in many situations, such as
when texturing from a video or camera feed that is captured/recorded
at a non-power-of-2 dimension.
• Texture level of detail (LOD) features—The texture LOD parameter
used to determine which mipmap to fetch from can now be
clamped. Additionally, the base and maximum mipmap level can
be clamped. These two features, in combination, make it possible to
stream mipmaps. As larger mipmap levels become available, the base
level can be increased and the LOD value can be smoothly increased
to provide smooth-looking streaming textures. This is very useful, for
example, when downloading texture mipmap data over a network
connection.
• Texture swizzles—A new texture object state was introduced to allow
independent control of where each channel (R, G, B, and A) of texture
data is mapped to in the shader.
• Immutable textures—Provide a mechanism for the application to
specify the format and size of a texture before loading it with data. In
doing so, the texture format becomes immutable and the OpenGL ES
driver can perform all consistency and memory checks up-front. This
can improve performance by allowing the driver to skip consistency
checks at draw time.
• Increased minimum sizes—All OpenGL ES 3.0 implementations are
required to support much larger texture resources than OpenGL ES
2.0. For example, the minimum supported 2D texture dimension in
OpenGL ES 2.0 was 64 but was increased to 2048 in OpenGL ES 3.0.
OpenGL ES 3.0 includes a major update to the OpenGL ES Shading
Language (ESSL; to v3.00) and new API features to support new shader
features:
• Program binaries—In OpenGL ES 2.0, it was possible to store shaders
in a binary format, but it was still required to link them into program
at runtime. In OpenGL ES 3.0, the entire linked program binary
(containing the vertex and fragment shader) can be stored in an
