| | '''OpenGL extension ARB.draw_instanced |
| | |
| | This module customises the behaviour of the |
| | OpenGL.raw.GL.ARB.draw_instanced to provide a more |
| | Python-friendly API |
| | |
| | Overview (from the spec) |
| | |
| | A common use case in GL for some applications is to be able to |
| | draw the same object, or groups of similar objects that share |
| | vertex data, primitive count and type, multiple times. This |
| | extension provides a means of accelerating such use cases while |
| | restricting the number of API calls, and keeping the amount of |
| | duplicate data to a minimum. |
| | |
| | This extension introduces two draw calls which are conceptually |
| | equivalent to a series of draw calls. Each conceptual call in |
| | this series is considered an "instance" of the actual draw call. |
| | |
| | This extension also introduces a read-only built-in variable to |
| | GLSL which contains the "instance ID." This variable initially |
| | contains 0, but increases by one after each conceptual draw call. |
| | |
| | By using the instance ID or multiples thereof as an index into |
| | a uniform array containing transform data, vertex shaders can |
| | draw multiple instances of an object with a single draw call. |
| | |
| | The official definition of this extension is available here: |
| | http://www.opengl.org/registry/specs/ARB/draw_instanced.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.ARB.draw_instanced import * |
| | from OpenGL.raw.GL.ARB.draw_instanced import _EXTENSION_NAME |
| |
|
| | def glInitDrawInstancedARB(): |
| | '''Return boolean indicating whether this extension is available''' |
| | from OpenGL import extensions |
| | return extensions.hasGLExtension( _EXTENSION_NAME ) |
| |
|
| | |
| | glDrawElementsInstancedARB=wrapper.wrapper(glDrawElementsInstancedARB).setInputArraySize( |
| | 'indices', None |
| | ) |
| | |
