1GLRASTERPOS(3G) GLRASTERPOS(3G)
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6 glRasterPos2d, glRasterPos2f, glRasterPos2i, glRasterPos2s, glRaster‐
7 Pos3d, glRasterPos3f, glRasterPos3i, glRasterPos3s, glRasterPos4d,
8 glRasterPos4f, glRasterPos4i, glRasterPos4s, glRasterPos2dv, glRaster‐
9 Pos2fv, glRasterPos2iv, glRasterPos2sv, glRasterPos3dv, glRasterPos3fv,
10 glRasterPos3iv, glRasterPos3sv, glRasterPos4dv, glRasterPos4fv,
11 glRasterPos4iv, glRasterPos4sv - specify the raster position for pixel
12 operations
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16 void glRasterPos2d( GLdouble x,
17 GLdouble y )
18 void glRasterPos2f( GLfloat x,
19 GLfloat y )
20 void glRasterPos2i( GLint x,
21 GLint y )
22 void glRasterPos2s( GLshort x,
23 GLshort y )
24 void glRasterPos3d( GLdouble x,
25 GLdouble y,
26 GLdouble z )
27 void glRasterPos3f( GLfloat x,
28 GLfloat y,
29 GLfloat z )
30 void glRasterPos3i( GLint x,
31 GLint y,
32 GLint z )
33 void glRasterPos3s( GLshort x,
34 GLshort y,
35 GLshort z )
36 void glRasterPos4d( GLdouble x,
37 GLdouble y,
38 GLdouble z,
39 GLdouble w )
40 void glRasterPos4f( GLfloat x,
41 GLfloat y,
42 GLfloat z,
43 GLfloat w )
44 void glRasterPos4i( GLint x,
45 GLint y,
46 GLint z,
47 GLint w )
48 void glRasterPos4s( GLshort x,
49 GLshort y,
50 GLshort z,
51 GLshort w )
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53 delim $$
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56 x, y, z, w
57 Specify the $x$, $y$, $z$, and $w$ object coordinates (if
58 present) for the raster position.
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61 void glRasterPos2dv( const GLdouble *v )
62 void glRasterPos2fv( const GLfloat *v )
63 void glRasterPos2iv( const GLint *v )
64 void glRasterPos2sv( const GLshort *v )
65 void glRasterPos3dv( const GLdouble *v )
66 void glRasterPos3fv( const GLfloat *v )
67 void glRasterPos3iv( const GLint *v )
68 void glRasterPos3sv( const GLshort *v )
69 void glRasterPos4dv( const GLdouble *v )
70 void glRasterPos4fv( const GLfloat *v )
71 void glRasterPos4iv( const GLint *v )
72 void glRasterPos4sv( const GLshort *v )
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76 v Specifies a pointer to an array of two, three, or four elements,
77 specifying $x$, $y$, $z$, and $w$ coordinates, respectively.
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80 The GL maintains a 3D position in window coordinates. This position,
81 called the raster position, is used to position pixel and bitmap write
82 operations. It is maintained with subpixel accuracy. See glBitmap,
83 glDrawPixels, and glCopyPixels.
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85 The current raster position consists of three window coordinates ($x$,
86 $y$, $z$), a clip coordinate value ($w$), an eye coordinate distance, a
87 valid bit, and associated color data and texture coordinates. The $w$
88 coordinate is a clip coordinate, because $w$ is not projected to window
89 coordinates. glRasterPos4 specifies object coordinates $x$, $y$, $z$,
90 and $w$ explicitly. glRasterPos3 specifies object coordinate $x$, $y$,
91 and $z$ explicitly, while $w$ is implicitly set to 1. glRasterPos2
92 uses the argument values for $x$ and $y$ while implicitly setting $z$
93 and $w$ to 0 and 1.
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95 The object coordinates presented by glRasterPos are treated just like
96 those of a glVertex command: They are transformed by the current mod‐
97 elview and projection matrices and passed to the clipping stage. If
98 the vertex is not culled, then it is projected and scaled to window
99 coordinates, which become the new current raster position, and the
100 GL_CURRENT_RASTER_POSITION_VALID flag is set. If the vertex is culled,
101 then the valid bit is cleared and the current raster position and asso‐
102 ciated color and texture coordinates are undefined.
103
104 The current raster position also includes some associated color data
105 and texture coordinates. If lighting is enabled, then
106 GL_CURRENT_RASTER_COLOR (in RGBA mode) or GL_CURRENT_RASTER_INDEX (in
107 color index mode) is set to the color produced by the lighting calcula‐
108 tion (see glLight, glLightModel, and
109 glShadeModel). If lighting is disabled, current color (in RGBA mode,
110 state variable GL_CURRENT_COLOR) or color index (in color index mode,
111 state variable GL_CURRENT_INDEX) is used to update the current raster
112 color.
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114 Likewise, GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of
115 GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture
116 generation functions (see glTexGen). Finally, the distance from the
117 origin of the eye coordinate system to the vertex as transformed by
118 only the modelview matrix replaces GL_CURRENT_RASTER_DISTANCE.
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120 Initially, the current raster position is (0, 0, 0, 1), the current
121 raster distance is 0, the valid bit is set, the associated RGBA color
122 is (1, 1, 1, 1), the associated color index is 1, and the associated
123 texture coordinates are (0, 0, 0, 1). In RGBA mode,
124 GL_CURRENT_RASTER_INDEX is always 1; in color index mode, the current
125 raster RGBA color always maintains its initial value.
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128 The raster position is modified both by glRasterPos and by glBitmap.
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130 When the raster position coordinates are invalid, drawing commands that
131 are based on the raster position are ignored (that is, they do not
132 result in changes to GL state).
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134 Calling glDrawElements, or glDrawRangeElements may leave the current
135 color or index indeterminate. If glRasterPos is executed while the
136 current color or index is indeterminate, the current raster color or
137 current raster index remains indeterminate.
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139 To set a valid raster position outside the viewport, first set a valid
140 raster position, then call glBitmap with NULL as the bitmap parameter.
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142 When the GL_ARB_imaging extension is supported, there are distinct
143 raster texture coordinates for each texture unit. Each texture unit's
144 current raster texture coordinates are updated by glRasterPos.
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147 GL_INVALID_OPERATION is generated if glRasterPos is executed between
148 the execution of glBegin and the corresponding execution of glEnd.
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151 glGet with argument GL_CURRENT_RASTER_POSITION
152 glGet with argument GL_CURRENT_RASTER_POSITION_VALID
153 glGet with argument GL_CURRENT_RASTER_DISTANCE
154 glGet with argument GL_CURRENT_RASTER_COLOR
155 glGet with argument GL_CURRENT_RASTER_INDEX
156 glGet with argument GL_CURRENT_RASTER_TEXTURE_COORDS
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159 glBitmap(3G), glCopyPixels(3G), glDrawArrays(3G), glDrawElements(3G),
160 glDrawRangeElements(3G), glDrawPixels(3G), glTexCoord(3G),
161 glTexGen(3G), glVertex(3G)
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165 GLRASTERPOS(3G)