| '''OpenGL extension NV.read_buffer |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GLES2.NV.read_buffer to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| Unextended OpenGL ES 2.0 only supports using ReadPixels to read from |
| the default color buffer of the currently-bound framebuffer. |
| However, it is useful for debugging to be able to read from |
| non-default color buffers. Particularly, when the NV_draw_buffers |
| extension is supported, each framebuffer may contain multiple color |
| buffers. This extension provides a mechanism to select which color |
| buffer to read from. |
| |
| This document describes two extensions to allow an implementation to |
| support a subset of the total functionality. |
| |
| The NV_read_buffer extension adds the command ReadBufferNV, which is |
| used to select which color buffer of the currently-bound framebuffer |
| to use as the source for subsequent calls to ReadPixels, |
| CopyTexImage2D, and CopyTexSubImage2D. If the system-provided |
| framebuffer is bound, then ReadBufferNV accepts value BACK. If a |
| user-created FBO is bound, then ReadBufferNV accepts COLOR_ATTACHMENT0. |
| Additionally, if the NV_draw_buffers extension is supported, |
| ReadBufferNV accepts COLOR_ATTACHMENTn_NV (n is 0 to 15). |
| |
| The NV_read_buffer_front extension requires NV_read_buffer and adds |
| the ability to select the system-provided FRONT color buffer as the |
| source for read operations when the system-provided framebuffer is |
| bound and contains both a front and back buffer. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/NV/read_buffer.txt |
| ''' |
| from OpenGL import platform, constant, arrays |
| from OpenGL import extensions, wrapper |
| import ctypes |
| from OpenGL.raw.GLES2 import _types, _glgets |
| from OpenGL.raw.GLES2.NV.read_buffer import * |
| from OpenGL.raw.GLES2.NV.read_buffer import _EXTENSION_NAME |
|
|
| def glInitReadBufferNV(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
