1Name 2 3 MESA_window_pos 4 5Name Strings 6 7 GL_MESA_window_pos 8 9Contact 10 11 Brian Paul, brian.paul 'at' tungstengraphics.com 12 13Status 14 15 Shipping (since Mesa version 1.2.8) 16 17Version 18 19 20Number 21 22 197 23 24Dependencies 25 26 OpenGL 1.0 is required. 27 The extension is written against the OpenGL 1.2 Specification 28 29Overview 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 47New 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 74New Tokens 75 76 none 77 78Additions 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 implicitly 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 100Additions to the AGL/GLX/WGL Specifications 101 102 None 103 104GLX Protocol 105 106 Not specified at this time. However, a protocol message very similar 107 to that of RasterPos is expected. 108 109Errors 110 111 INVALID_OPERATION is generated if WindowPosMESA is called between 112 Begin and End. 113 114New State 115 116 None. 117 118New Implementation Dependent State 119 120 None. 121 122Revision History 123 124 * Revision 1.0 - Initial specification 125 * Revision 1.1 - Minor clean-up (7 Jan 2000, Brian Paul) 126 127