| '''OpenGL extension SUN.triangle_list |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.SUN.triangle_list to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| OpenGL has two chained triangle primitives, TRIANGLE_STRIP and |
| TRIANGLE_FAN. For multiple, consecutive triangle strips or |
| triangle fans, the overhead of Begin and End, or separate calls to |
| DrawArrays, can be significant depending on the number of triangles |
| per strip or fan. |
| |
| Many surface tessellators produce triangle strips with very few |
| triangles per strip before needing to restart a new strip. Even |
| sophisticated tessellators typically need to restart a new strip, |
| or switch from a triangle strip to a triangle fan, many times |
| within a single object. Such tessellators can often produce a more |
| efficient tessellation--one with fewer vertices--by mixing strips |
| and fans within the same object. The ability to switch from one to |
| the other without restarting the strip or fan yields even more |
| savings. Unfortunately, the overhead of switching from a triangle |
| strip to a triangle fan, or vice versa, can reduce, or even |
| eliminate the benefit gained from reducing the number of vertices. |
| |
| A new triangle list primitive, along with an associated replacement |
| code attribute, is defined by this extension to allow multiple |
| triangle strips and fans to be specified within the same Begin/End |
| pair or from a single call to DrawArrays. The triangle list |
| extension also provides the means to switch between triangle strips |
| and triangle fans with or without restarting the strip or fan. |
| |
| TRIANGLE_LIST is a new primitive type (i.e., new Begin mode) that |
| uses the ReplacementCodeSUN state attribute to determine whether the |
| current vertex replaces the oldest vertex, as in a triangle strip, |
| the middle vertex, as in a triangle fan, or restarts a new chained |
| triangle list. The first vertex of a new triangle list is |
| implicitly treated as a RESTART. The first three vertices complete |
| the first triangle, after which the replacement codes of the vertex |
| are used. The two vertices immediately following a |
| restart--including the implicit restart on the first vertex--are |
| ignored. The ReplacementCodeSUN attribute is part of the vertex |
| state, and is only used by the TRIANGLE_LIST primitive. |
| |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/SUN/triangle_list.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.SUN.triangle_list import * |
| from OpenGL.raw.GL.SUN.triangle_list import _EXTENSION_NAME |
|
|
| def glInitTriangleListSUN(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
| |
| glReplacementCodeuivSUN=wrapper.wrapper(glReplacementCodeuivSUN).setInputArraySize( |
| 'code', None |
| ) |
| |
| glReplacementCodeusvSUN=wrapper.wrapper(glReplacementCodeusvSUN).setInputArraySize( |
| 'code', None |
| ) |
| |
| glReplacementCodeubvSUN=wrapper.wrapper(glReplacementCodeubvSUN).setInputArraySize( |
| 'code', None |
| ) |
| |
| glReplacementCodePointerSUN=wrapper.wrapper(glReplacementCodePointerSUN).setInputArraySize( |
| 'pointer', None |
| ) |
| |
