1GLRASTERPOS(3G) OpenGL Manual GLRASTERPOS(3G)
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6 glRasterPos - specify the raster position for pixel operations
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9 void glRasterPos2s(GLshort x, GLshort y);
10 void glRasterPos2i(GLint x, GLint y);
12 void glRasterPos2f(GLfloat x, GLfloat y);
14 void glRasterPos2d(GLdouble x, GLdouble y);
16 void glRasterPos3s(GLshort x, GLshort y, GLshort z);
18 void glRasterPos3i(GLint x, GLint y, GLint z);
20 void glRasterPos3f(GLfloat x, GLfloat y, GLfloat z);
22 void glRasterPos3d(GLdouble x, GLdouble y, GLdouble z);
24 void glRasterPos4s(GLshort x, GLshort y, GLshort z, GLshort w);
26 void glRasterPos4i(GLint x, GLint y, GLint z, GLint w);
28 void glRasterPos4f(GLfloat x, GLfloat y, GLfloat z, GLfloat w);
30 void glRasterPos4d(GLdouble x, GLdouble y, GLdouble z, GLdouble w);
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34 x, y, z, w
35 Specify the x, y, z, and w object coordinates (if present) for the
36 raster position.
37
39 void glRasterPos2sv(const GLshort * v);
40 void glRasterPos2iv(const GLint * v);
42 void glRasterPos2fv(const GLfloat * v);
44 void glRasterPos2dv(const GLdouble * v);
46 void glRasterPos3sv(const GLshort * v);
48 void glRasterPos3iv(const GLint * v);
50 void glRasterPos3fv(const GLfloat * v);
52 void glRasterPos3dv(const GLdouble * v);
54 void glRasterPos4sv(const GLshort * v);
56 void glRasterPos4iv(const GLint * v);
58 void glRasterPos4fv(const GLfloat * v);
60 void glRasterPos4dv(const GLdouble * v);
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64 v
65 Specifies a pointer to an array of two, three, or four elements,
66 specifying x, y, z, and w coordinates, respectively.
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69 The GL maintains a 3D position in window coordinates. This position,
70 called the raster position, is used to position pixel and bitmap write
71 operations. It is maintained with subpixel accuracy. See glBitmap(),
72 glDrawPixels(), and glCopyPixels().
73 The current raster position consists of three window coordinates (x, y,
75 z), a clip coordinate value (w), an eye coordinate distance, a valid
76 bit, and associated color data and texture coordinates. The w
77 coordinate is a clip coordinate, because w is not projected to window
78 coordinates. glRasterPos4 specifies object coordinates x, y, z, and w
79 explicitly. glRasterPos3 specifies object coordinate x, y, and z
80 explicitly, while w is implicitly set to 1. glRasterPos2 uses the
81 argument values for x and y while implicitly setting z and w to 0 and
82 1.
83 The object coordinates presented by glRasterPos are treated just like
85 those of a glVertex() command: They are transformed by the current
86 modelview and projection matrices and passed to the clipping stage. If
87 the vertex is not culled, then it is projected and scaled to window
88 coordinates, which become the new current raster position, and the
89 GL_CURRENT_RASTER_POSITION_VALID flag is set. If the vertex is culled,
90 then the valid bit is cleared and the current raster position and
91 associated color and texture coordinates are undefined.
92 The current raster position also includes some associated color data
94 and texture coordinates. If lighting is enabled, then
95 GL_CURRENT_RASTER_COLOR (in RGBA mode) or GL_CURRENT_RASTER_INDEX (in
96 color index mode) is set to the color produced by the lighting
97 calculation (see glLight(), glLightModel(), and glShadeModel()). If
98 lighting is disabled, current color (in RGBA mode, state variable
99 GL_CURRENT_COLOR) or color index (in color index mode, state variable
100 GL_CURRENT_INDEX) is used to update the current raster color.
101 GL_CURRENT_RASTER_SECONDARY_COLOR (in RGBA mode) is likewise updated.
102 Likewise, GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of
104 GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture
105 generation functions (see glTexGen()). Finally, the distance from the
106 origin of the eye coordinate system to the vertex as transformed by
107 only the modelview matrix replaces GL_CURRENT_RASTER_DISTANCE.
108 Initially, the current raster position is (0, 0, 0, 1), the current
110 raster distance is 0, the valid bit is set, the associated RGBA color
111 is (1, 1, 1, 1), the associated color index is 1, and the associated
112 texture coordinates are (0, 0, 0, 1). In RGBA mode,
113 GL_CURRENT_RASTER_INDEX is always 1; in color index mode, the current
114 raster RGBA color always maintains its initial value.
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117 The raster position is modified by glRasterPos, glBitmap(), and
118 glWindowPos().
119 When the raster position coordinates are invalid, drawing commands that
121 are based on the raster position are ignored (that is, they do not
122 result in changes to GL state).
123 Calling glDrawElements() or glDrawRangeElements() may leave the current
125 color or index indeterminate. If glRasterPos is executed while the
126 current color or index is indeterminate, the current raster color or
127 current raster index remains indeterminate.
128 To set a valid raster position outside the viewport, first set a valid
130 raster position, then call glBitmap() with NULL as the bitmap
131 parameter.
132 When the ARB_imaging extension is supported, there are distinct raster
134 texture coordinates for each texture unit. Each texture unit's current
135 raster texture coordinates are updated by glRasterPos.
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138 GL_INVALID_OPERATION is generated if glRasterPos is executed between
139 the execution of glBegin() and the corresponding execution of glEnd().
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142 glGet() with argument GL_CURRENT_RASTER_POSITION
143 glGet() with argument GL_CURRENT_RASTER_POSITION_VALID
145 glGet() with argument GL_CURRENT_RASTER_DISTANCE
147 glGet() with argument GL_CURRENT_RASTER_COLOR
149 glGet() with argument GL_CURRENT_RASTER_SECONDARY_COLOR
151 glGet() with argument GL_CURRENT_RASTER_INDEX
153 glGet() with argument GL_CURRENT_RASTER_TEXTURE_COORDS
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157 glBitmap(), glCopyPixels(), glDrawArrays(), glDrawElements(),
158 glDrawRangeElements(), glDrawPixels(), glMultiTexCoord(), glTexCoord(),
159 glTexGen(), glVertex(), glWindowPos()
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162 Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
163 under the SGI Free Software B License. For details, see
164 http://oss.sgi.com/projects/FreeB/.
165
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