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