docs/MESA_window_pos.spec

   1 Name
   2
   3     MESA_window_pos
   4
   5 Name Strings
   6
   7     GL_MESA_window_pos
   8
   9 Contact
  10
  11     Brian Paul, brian.paul 'at' tungstengraphics.com
  12
  13 Status
  14
  15     Shipping (since Mesa version 1.2.8)
  16
  17 Version
  18
  19     $Id: MESA_window_pos.spec,v 1.4 2004/03/25 01:42:42 brianp Exp $
  20
  21 Number
  22
  23     197
  24
  25 Dependencies
  26
  27     OpenGL 1.0 is required.
  28     The extension is written against the OpenGL 1.2 Specification
  29
  30 Overview
  31
  32     In order to set the current raster position to a specific window
  33     coordinate with the RasterPos command, the modelview matrix, projection
  34     matrix and viewport must be set very carefully.  Furthermore, if the
  35     desired window coordinate is outside of the window's bounds one must
  36     rely on a subtle side-effect of the Bitmap command in order to circumvent
  37     frustum clipping.
  38
  39     This extension provides a set of functions to directly set the
  40     current raster position, bypassing the modelview matrix, the
  41     projection matrix and the viewport to window mapping.  Furthermore,
  42     clip testing is not performed.
  43
  44     This greatly simplifies the process of setting the current raster
  45     position to a specific window coordinate prior to calling DrawPixels,
  46     CopyPixels or Bitmap.
  47
  48 New Procedures and Functions
  49
  50     void WindowPos2dMESA(double x, double y)
  51     void WindowPos2fMESA(float x, float y)
  52     void WindowPos2iMESA(int x, int y)
  53     void WindowPos2sMESA(short x, short y)
  54     void WindowPos2ivMESA(const int *p)
  55     void WindowPos2svMESA(const short *p)
  56     void WindowPos2fvMESA(const float *p)
  57     void WindowPos2dvMESA(const double *p)
  58     void WindowPos3iMESA(int x, int y, int z)
  59     void WindowPos3sMESA(short x, short y, short z)
  60     void WindowPos3fMESA(float x, float y, float z)
  61     void WindowPos3dMESA(double x, double y, double z)
  62     void WindowPos3ivMESA(const int *p)
  63     void WindowPos3svMESA(const short *p)
  64     void WindowPos3fvMESA(const float *p)
  65     void WindowPos3dvMESA(const double *p)
  66     void WindowPos4iMESA(int x, int y, int z, int w)
  67     void WindowPos4sMESA(short x, short y, short z, short w)
  68     void WindowPos4fMESA(float x, float y, float z, float w)
  69     void WindowPos4dMESA(double x, double y, double z, double )
  70     void WindowPos4ivMESA(const int *p)
  71     void WindowPos4svMESA(const short *p)
  72     void WindowPos4fvMESA(const float *p)
  73     void WindowPos4dvMESA(const double *p)
  74
  75 New Tokens
  76
  77     none
  78
  79 Additions to Chapter 2 of the OpenGL 1.2 Specification (OpenGL Operation)
  80
  81   - (2.12, p. 41) Insert after third paragraph:
  82
  83       Alternately, the current raster position may be set by one of the
  84       WindowPosMESA commands:
  85
  86          void WindowPos{234}{sidf}MESA( T coords );
  87          void WindowPos{234}{sidf}vMESA( T coords );
  88
  89       WindosPos4MESA takes four values indicating x, y, z, and w.
  90       WindowPos3MESA (or WindowPos2MESA) is analaguos, but sets only
  91       x, y, and z with w implicitly set to 1 (or only x and y with z
  92       implicititly set to 0 and w implicitly set to 1).
  93
  94       WindowPosMESA operates like RasterPos except that the current modelview
  95       matrix, projection matrix and viewport parameters are ignored and the
  96       clip test operation always passes.  The current raster position values
  97       are directly set to the parameters passed to WindowPosMESA.  The current
  98       color, color index and texture coordinate update the current raster
  99       position's associated data.
 100
 101 Additions to the AGL/GLX/WGL Specifications
 102
 103     None
 104
 105 GLX Protocol
 106
 107     Not specified at this time.  However, a protocol message very similar
 108     to that of RasterPos is expected.
 109
 110 Errors
 111
 112     INVALID_OPERATION is generated if WindowPosMESA is called betweeen
 113     Begin and End.
 114
 115 New State
 116
 117     None.
 118
 119 New Implementation Dependent State
 120
 121     None.
 122
 123 Revision History
 124
 125   * Revision 1.0 - Initial specification
 126   * Revision 1.1 - Minor clean-up  (7 Jan 2000, Brian Paul)
 127