| '''OpenGL extension DFX.multisample |
| |
| This module customises the behaviour of the |
| OpenGL.raw.WGL.DFX.multisample to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| This extension provides a mechanism to antialias all GL primitives: |
| points, lines, polygons, bitmaps, and images. The technique is to |
| sample all primitives multiple times at each pixel. The color sample |
| values are resolved to a single, displayable color each time a pixel |
| is updated, so the antialiasing appears to be automatic at the |
| application level. Because each sample includes depth and stencil |
| information, the depth and stencil functions perform equivalently to |
| the single-sample mode. |
| |
| An additional buffer, called the multisample buffer, is added to the |
| framebuffer. Pixel sample values, including color, depth, and |
| stencil values, are stored in this buffer. When the framebuffer |
| includes a multisample buffer, it does not also include separate |
| depth or stencil buffers, even if the multisample buffer does not |
| store depth or stencil values. Color buffers (left/right, |
| front/back, and aux) do coexist with the multisample buffer, |
| however. |
| |
| Multisample antialiasing is most valuable for rendering polygons, |
| because it requires no sorting for hidden surface elimination, and |
| it correctly handles adjacent polygons, object silhouettes, and even |
| intersecting polygons. If only points or lines are being rendered, |
| the "smooth" antialiasing mechanism provided by the base GL may |
| result in a higher quality image. |
| |
| This extension is a subset of SGIS_multisample. It differs in these |
| key ways: |
| |
| * Fragment alpha values are not affected by the fragment sample mask |
| * The sample locations may or may not be fixed. Thus, there is no |
| support for rendering the scene multiple times with different |
| sample points. |
| * Fragment masks are not computed for images or for bitmasks. |
| |
| Because of these differences a new extension was created. However, |
| it is not expected that this extension will co-exist with |
| SGIS_multisample. Because of this and the fact that there are only |
| 32 push/pop bits the MULTISAMPLE_BIT_SGIS state value is the same as |
| MUTLISAMPLE_BIT_3DFX. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/DFX/multisample.txt |
| ''' |
| from OpenGL import platform, constant, arrays |
| from OpenGL import extensions, wrapper |
| import ctypes |
| from OpenGL.raw.WGL import _types, _glgets |
| from OpenGL.raw.WGL.DFX.multisample import * |
| from OpenGL.raw.WGL.DFX.multisample import _EXTENSION_NAME |
|
|
| def glInitMultisampleDFX(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
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| |
