• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1Name
2
3    3DFX_tbuffer
4
5Name Strings
6
7    GL_3DFX_tbuffer
8
9Contact
10
11    Paula Womack, 3dfx Interactive (paulaw 'at' 3dfx.com)
12
13Status
14
15    Complete
16
17Version
18
19    Date: April 13, 2000; Revision: 1.0
20
21Number
22
23    208
24
25Dependencies
26
27    OpenGL 1.1 is required.
28    Either SGIS_multisample or 3DFX_multisample is required.
29    This specification is written against OpenGL 1.2.
30
31Overview
32
33    This extension allows a write mask to be defined for the fragment
34    mask which is created during multisample rendering. This can be used
35    to create effects such as motion blur and depth of field.
36
37IP Status
38
39    3DFX has filed for patent protection for some of the techniques
40    described in this extension document.
41
42Issues
43
44    None.
45
46New Procedures and Functions
47
48    void TbufferMask3DFX(uint mask);
49
50New Tokens
51
52    None.
53
54Additions to Chapter 2 of the 1.2 Specification (OpenGL Operation)
55
56    None
57
58Additions to Chapter 3 of the 1.2 Specification (Rasterization)
59
60    The value of TBUFFER_WRITE_MASK_3DFX is specified by calling
61    TbufferMask3DFX, with mask set to the desired mask value. If
62    multisample rendering is enabled then the n least significant bits
63    of TBUFFER_WRITE_MASK_3DFX are bitwise ANDed with the fragment
64    sample mask, where n is equal to SAMPLES_3DFX.
65
66Additions to 3.3.2 Point Multisample Rasterization:
67
68    Following the sentence "Mask bits that correspond to sample points
69    that intersect the circular region are 1, other mask bits are 0."
70    add "The fragment mask thus computed, is then bitwise ANDed with the
71    SAMPLES_3DFX least significant bits of TBUFFER_WRITE_MASK_3DFX.
72
73Additions to 3.4.4 Line Multisample Rasterization:
74
75    Following the sentence "Mask bits that correspond to sample points
76    that intersect a retained rectangle are 1, other mask bits are 0."
77    add "The fragment mask thus computed, is then bitwise ANDed with the
78    SAMPLES_3DFX least significant bits of TBUFFER_WRITE_MASK_3DFX.
79
80Additions to 3.5.6 Polygon Multisample Rasterization:
81
82    Following the sentence "Mask bits that correspond to sample points
83    that satisfy the point sampling criteria are 1, other mask bits are
84    0." add "The fragment mask thus computed, is then bitwise ANDed with
85    the SAMPLES_3DFX least significant bits of TBUFFER_WRITE_MASK_3DFX.
86
87Additions to Chapter 4 of the 1.2 Specification (Per-Fragment Operations and
88the Frame Buffer)
89
90    None
91
92Additions to Chapter 5 of the 1.2 Specification (Special Functions)
93
94    None
95
96Additions to Chapter 6 of the 1.2 Specification (State and State Requests)
97
98    An additional group of multisample state variables is defined by the
99    SGIS_multitexture and 3DFX_multitexture extensions. When PushAttrib
100    is called with bit MULTISAMPLE_BIT_SGIS or MULTISAMPLE_BIT_3DFX set,
101    the multisample group of state variables is pushed onto the
102    attribute stack. When PopAttrib is called, these state variables are
103    restored to their previous values if they were pushed. This
104    extension adds state to the multisample group of state variables.
105
106Additions to the GLX Specification
107
108    None.
109
110Errors
111
112    INVALID_OPERATION is generated if TbufferWriteMask3DFX is called
113    between the execution of Begin and the execution of the
114    corresponding End.
115
116New State
117
118    Get Value		    Get Command Type	Initial Value	Attribute
119    ---------		    ----------- ----	-------------	---------
120    TBUFFER_WRITE_MASK_3DFX GetIntegerv Z+	1's		multisample
121
122Revision History
123