| Name |
| |
| EXT_clip_volume_hint |
| |
| Name Strings |
| |
| GL_EXT_clip_volume_hint |
| |
| Version |
| |
| Microsoft revision 1.00, April 17, 1996 (hockl) |
| $Date: 1999/12/28 01:40:35 $ $Revision: 1.4 $ |
| |
| Number |
| |
| 79 |
| |
| Dependencies |
| |
| None. |
| |
| Overview |
| |
| EXT_clip_volume_hint provides a mechanism for applications to |
| indicate that they do not require clip volume clipping for |
| primitives. It allows applications to maximize performance in |
| situations where they know that clipping is unnecessary. |
| EXT_clip_volume_hint is only an indication, though, and |
| implementations are free to ignore it. |
| |
| New Procedures and Functions |
| |
| None. |
| |
| New Tokens |
| |
| Accepted by the target parameter of Hint and the pname parameter of |
| GetBooleanv, GetDoublev, GetFloatv and GetIntegerv: |
| CLIP_VOLUME_CLIPPING_HINT_EXT 0x80F0 |
| |
| Additions to Chapter 2 of the GL Specification (OpenGL Operation) |
| |
| Before the last paragraph of Section 2.11, 'Clipping,' the following |
| text is added: |
| |
| The EXT_clip_volume_hint extension can be used to indicate that |
| a primitive falls inside the current clip volume. In this case, |
| an implementation might not clip the primitive to the clip |
| volume, and the behavior of the GL is undefined if the primitive |
| extends beyond the clip volume. |
| |
| In the fourth (clipping) paragraph of Section 2.12, 'Current Raster |
| Position,' the following text is added before the last sentence |
| "Figure 2.7 summarizes..." |
| |
| Raster position clipping is not affected by the |
| CLIP_VOLUME_CLIPPING_HINT_EXT hint in the EXT_clip_volume_hint |
| extension. |
| |
| Additions to Chapter 3 of the GL Specification (Rasterization) |
| |
| None. |
| |
| Additions to Chapter 4 of the GL Specification (Per-Fragment |
| Operations and the Framebuffer) |
| |
| None. |
| |
| Additions to Chapter 5 of the GL Specification (Special Functions) |
| |
| Section 5.6, 'Hints,' should be changed to add the following |
| hint description: |
| |
| CLIP_VOLUME_CLIPPING_HINT_EXT, indicating whether clipping to |
| the clip volume is necessary. |
| |
| Additions to Chapter 6 of the GL Specification (State and State |
| Requests) |
| |
| In table 6.18, 'Hints,' the following entry is added: |
| |
| CLIP_VOLUME_CLIPPING_HINT_EXT|Z3|GetIntegerv|DONT_CARE| |
| Clip volume clipping hint|5.6|hint |
| |
| Revision History |
| ---------------- |
| Original draft, revision 0.9, March 1, 1996 (drewb) |
| Created. |
| Minor revision, revision 0.91, March 8, 1996 (drewb) |
| Hint revision, revision 0.95, April 12, 1996 (drewb) |
| Changed from Enable-based to Hint-based. Clarified |
| behavior of RasterPos. |
| More revision, revision 0.96, April 16, 1996 (hockl) |
| Changed extension and enumerant names. Added robustness. |
| Changed it to have no effect on RasterPos. |
| More revision, revision 1.00, April 17, 1996 (hockl) |
| Removed robustness requirement. |
| |