1GLBITMAP(3G)                     OpenGL Manual                    GLBITMAP(3G)
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NAME

6       glBitmap - draw a bitmap
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C SPECIFICATION

9       void glBitmap(GLsizei width, GLsizei height, GLfloat xorig,
10                     GLfloat yorig, GLfloat xmove, GLfloat ymove,
11                     const GLubyte * bitmap);
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PARAMETERS

14       width, height
15           Specify the pixel width and height of the bitmap image.
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17       xorig, yorig
18           Specify the location of the origin in the bitmap image. The origin
19           is measured from the lower left corner of the bitmap, with right
20           and up being the positive axes.
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22       xmove, ymove
23           Specify the x and y offsets to be added to the current raster
24           position after the bitmap is drawn.
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26       bitmap
27           Specifies the address of the bitmap image.
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DESCRIPTION

30       A bitmap is a binary image. When drawn, the bitmap is positioned
31       relative to the current raster position, and frame buffer pixels
32       corresponding to 1's in the bitmap are written using the current raster
33       color or index. Frame buffer pixels corresponding to 0's in the bitmap
34       are not modified.
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36       glBitmap takes seven arguments. The first pair specifies the width and
37       height of the bitmap image. The second pair specifies the location of
38       the bitmap origin relative to the lower left corner of the bitmap
39       image. The third pair of arguments specifies x and y offsets to be
40       added to the current raster position after the bitmap has been drawn.
41       The final argument is a pointer to the bitmap image itself.
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43       If a non-zero named buffer object is bound to the
44       GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer()) while a bitmap image
45       is specified, bitmap is treated as a byte offset into the buffer
46       object's data store.
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48       The bitmap image is interpreted like image data for the glDrawPixels()
49       command, with width and height corresponding to the width and height
50       arguments of that command, and with type set to GL_BITMAP and format
51       set to GL_COLOR_INDEX. Modes specified using glPixelStore() affect the
52       interpretation of bitmap image data; modes specified using
53       glPixelTransfer() do not.
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55       If the current raster position is invalid, glBitmap is ignored.
56       Otherwise, the lower left corner of the bitmap image is positioned at
57       the window coordinates
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59       x w = x r - x o
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61       y w = y r - y o
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63       where x r y r is the raster position and x o y o is the bitmap origin.
64       Fragments are then generated for each pixel corresponding to a 1 (one)
65       in the bitmap image. These fragments are generated using the current
66       raster z coordinate, color or color index, and current raster texture
67       coordinates. They are then treated just as if they had been generated
68       by a point, line, or polygon, including texture mapping, fogging, and
69       all per-fragment operations such as alpha and depth testing.
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71       After the bitmap has been drawn, the x and y coordinates of the current
72       raster position are offset by xmove and ymove. No change is made to the
73       z coordinate of the current raster position, or to the current raster
74       color, texture coordinates, or index.
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NOTES

77       To set a valid raster position outside the viewport, first set a valid
78       raster position inside the viewport, then call glBitmap with NULL as
79       the bitmap parameter and with xmove and ymove set to the offsets of the
80       new raster position. This technique is useful when panning an image
81       around the viewport.
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ERRORS

84       GL_INVALID_VALUE is generated if width or height is negative.
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86       GL_INVALID_OPERATION is generated if a non-zero buffer object name is
87       bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object's data
88       store is currently mapped.
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90       GL_INVALID_OPERATION is generated if a non-zero buffer object name is
91       bound to the GL_PIXEL_UNPACK_BUFFER target and the data would be
92       unpacked from the buffer object such that the memory reads required
93       would exceed the data store size.
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95       GL_INVALID_OPERATION is generated if glBitmap is executed between the
96       execution of glBegin() and the corresponding execution of glEnd().
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ASSOCIATED GETS

99       glGet() with argument GL_CURRENT_RASTER_POSITION
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101       glGet() with argument GL_CURRENT_RASTER_COLOR
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103       glGet() with argument GL_CURRENT_RASTER_SECONDARY_COLOR
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105       glGet() with argument GL_CURRENT_RASTER_DISTANCE
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107       glGet() with argument GL_CURRENT_RASTER_INDEX
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109       glGet() with argument GL_CURRENT_RASTER_TEXTURE_COORDS
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111       glGet() with argument GL_CURRENT_RASTER_POSITION_VALID
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113       glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING
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SEE ALSO

116       glBindBuffer(), glDrawPixels(), glPixelStore(), glPixelTransfer(),
117       glRasterPos(), glWindowPos()
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120       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
121       under the SGI Free Software B License. For details, see
122       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

125       opengl.org
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129opengl.org                        07/13/2018                      GLBITMAP(3G)
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