| | '''OpenGL extension APPLE.float_pixels |
| | |
| | This module customises the behaviour of the |
| | OpenGL.raw.GL.APPLE.float_pixels to provide a more |
| | Python-friendly API |
| | |
| | Overview (from the spec) |
| | |
| | This extensions adds texture types, texture internal formats and |
| | color buffers composed of both 32 bit and 16 floating point numbers. |
| | 16 bit floats (half float) are very similar to the IEEE |
| | single-precision floating-point standard, except that it has only 5 |
| | exponent bits and 10 mantissa bits. All floating point numbers are |
| | clamped to the limits of the range representable by their respective |
| | format. |
| | |
| | Specifically, APPLE_float_pixels adds four pieces of functionality |
| | to OpenGL. First, it provides an HALF_APPLE texture type allowing |
| | clients to pass textures in the half float format. Second, it adds |
| | 12 additional sized internal formats to allow OpenGL to process and |
| | maintain texture data in the requested format if possible. Next, it |
| | provides the COLOR_FLOAT_APPLE pixel format to allow creation of |
| | floating point and half float color buffers. Lastly, it provides an |
| | additional query to allow clients to verify that they have a |
| | floating point color buffer. |
| | |
| | The HALF_APPLE texture type allows clients to use source textures |
| | composed of half float color components. This constant is use in |
| | the type parameter in DrawPixels, ReadPixels and texturing commands |
| | with a corresponding GL half data type, which corresponds to a 16 |
| | bit half float, and has no special interpretation. |
| | |
| | Clients can use the 12 additional (6 floating point and 6 half |
| | float) sized internal texture formats to specify the mapping of R, |
| | G, B and A values to texture components, as they would with any |
| | other sized internal texture format. Note, as is the standard |
| | practice with OpenGL, implementations should map the sized internal |
| | texture R, G, B and A values to internal components with memory |
| | allocations as close as possible to those specified in the sized |
| | internal format. |
| | |
| | Floating point color buffers are created by specifying the |
| | appropriate color floating point pixel format attribute for the |
| | windowing system API in use by the client. Both 128 bit and 64 bit |
| | floating point color buffers can be supported, the former with full |
| | 32 bit floating point components and the latter with 16 bit half |
| | float components. |
| | |
| | Additionally, clients can query to see if they have a floating point |
| | color buffer using GetBooleanv with COLOR_FLOAT_APPLE as the get |
| | value. The number of bits per color buffer component can be |
| | determined in the usual manner. |
| | |
| | The official definition of this extension is available here: |
| | http://www.opengl.org/registry/specs/APPLE/float_pixels.txt |
| | ''' |
| | from OpenGL import platform, constant, arrays |
| | from OpenGL import extensions, wrapper |
| | import ctypes |
| | from OpenGL.raw.GL import _types, _glgets |
| | from OpenGL.raw.GL.APPLE.float_pixels import * |
| | from OpenGL.raw.GL.APPLE.float_pixels import _EXTENSION_NAME |
| |
|
| | def glInitFloatPixelsAPPLE(): |
| | '''Return boolean indicating whether this extension is available''' |
| | from OpenGL import extensions |
| | return extensions.hasGLExtension( _EXTENSION_NAME ) |
| |
|
| |
|
| | |
