1GLCLEAR(3G) [FIXME: manual] GLCLEAR(3G)
2
3
4
6 glClear - clear buffers to preset values
7
9 void glClear(GLbitfield mask);
10
12 mask
13 Bitwise OR of masks that indicate the buffers to be cleared. The
14 three masks are GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, and
15 GL_STENCIL_BUFFER_BIT.
16
18 glClear sets the bitplane area of the window to values previously
19 selected by glClearColor, glClearDepth, and glClearStencil. Multiple
20 color buffers can be cleared simultaneously by selecting more than one
21 buffer at a time using glDrawBuffer().
22
23 The pixel ownership test, the scissor test, dithering, and the buffer
24 writemasks affect the operation of glClear. The scissor box bounds the
25 cleared region. Alpha function, blend function, logical operation,
26 stenciling, texture mapping, and depth-buffering are ignored by
27 glClear.
28
29 glClear takes a single argument that is the bitwise OR of several
30 values indicating which buffer is to be cleared.
31
32 The values are as follows:
33
34 GL_COLOR_BUFFER_BIT
35 Indicates the buffers currently enabled for color writing.
36
37 GL_DEPTH_BUFFER_BIT
38 Indicates the depth buffer.
39
40 GL_STENCIL_BUFFER_BIT
41 Indicates the stencil buffer.
42
43 The value to which each buffer is cleared depends on the setting of the
44 clear value for that buffer.
45
47 If a buffer is not present, then a glClear directed at that buffer has
48 no effect.
49
51 GL_INVALID_VALUE is generated if any bit other than the three defined
52 bits is set in mask.
53
55 glGet() with argument GL_DEPTH_CLEAR_VALUE
56
57 glGet() with argument GL_COLOR_CLEAR_VALUE
58
59 glGet() with argument GL_STENCIL_CLEAR_VALUE
60
62 ┌─────────┬───────────────────────────────────────────────────────────────────────┐
63 │ │ OpenGL Version │
64 ├─────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤
65 │Function │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │
66 │/ │ │ │ │ │ │ │ │ │ │ │ │ │
67 │Feature │ │ │ │ │ │ │ │ │ │ │ │ │
68 │Name │ │ │ │ │ │ │ │ │ │ │ │ │
69 ├─────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
70 │glClear │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
71 └─────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
72
74 glClearColor, glClearDepth, glClearStencil, glColorMask(),
75 glDepthMask(), glDrawBuffer(), glScissor(), glStencilMask()
76
78 Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014
79 Khronos Group. This document is licensed under the SGI Free Software B
80 License. For details, see http://oss.sgi.com/projects/FreeB/.
81
83 Copyright © 1991-2006 Silicon Graphics, Inc.
84 Copyright © 2010-2014 Khronos Group
85
86
87
88[FIXME: source] 03/06/2019 GLCLEAR(3G)