Name MESA_window_pos Name Strings GL_MESA_window_pos Contact Brian Paul, brian.paul 'at' tungstengraphics.com Status Shipping (since Mesa version 1.2.8) Version $Id: MESA_window_pos.spec,v 1.1.1.1 2006/11/25 18:49:29 matthieu Exp $ Number 197 Dependencies OpenGL 1.0 is required. The extension is written against the OpenGL 1.2 Specification Overview In order to set the current raster position to a specific window coordinate with the RasterPos command, the modelview matrix, projection matrix and viewport must be set very carefully. Furthermore, if the desired window coordinate is outside of the window's bounds one must rely on a subtle side-effect of the Bitmap command in order to circumvent frustum clipping. This extension provides a set of functions to directly set the current raster position, bypassing the modelview matrix, the projection matrix and the viewport to window mapping. Furthermore, clip testing is not performed. This greatly simplifies the process of setting the current raster position to a specific window coordinate prior to calling DrawPixels, CopyPixels or Bitmap. New Procedures and Functions void WindowPos2dMESA(double x, double y) void WindowPos2fMESA(float x, float y) void WindowPos2iMESA(int x, int y) void WindowPos2sMESA(short x, short y) void WindowPos2ivMESA(const int *p) void WindowPos2svMESA(const short *p) void WindowPos2fvMESA(const float *p) void WindowPos2dvMESA(const double *p) void WindowPos3iMESA(int x, int y, int z) void WindowPos3sMESA(short x, short y, short z) void WindowPos3fMESA(float x, float y, float z) void WindowPos3dMESA(double x, double y, double z) void WindowPos3ivMESA(const int *p) void WindowPos3svMESA(const short *p) void WindowPos3fvMESA(const float *p) void WindowPos3dvMESA(const double *p) void WindowPos4iMESA(int x, int y, int z, int w) void WindowPos4sMESA(short x, short y, short z, short w) void WindowPos4fMESA(float x, float y, float z, float w) void WindowPos4dMESA(double x, double y, double z, double ) void WindowPos4ivMESA(const int *p) void WindowPos4svMESA(const short *p) void WindowPos4fvMESA(const float *p) void WindowPos4dvMESA(const double *p) New Tokens none Additions to Chapter 2 of the OpenGL 1.2 Specification (OpenGL Operation) - (2.12, p. 41) Insert after third paragraph: Alternately, the current raster position may be set by one of the WindowPosMESA commands: void WindowPos{234}{sidf}MESA( T coords ); void WindowPos{234}{sidf}vMESA( T coords ); WindosPos4MESA takes four values indicating x, y, z, and w. WindowPos3MESA (or WindowPos2MESA) is analaguos, but sets only x, y, and z with w implicitly set to 1 (or only x and y with z implicititly set to 0 and w implicitly set to 1). WindowPosMESA operates like RasterPos except that the current modelview matrix, projection matrix and viewport parameters are ignored and the clip test operation always passes. The current raster position values are directly set to the parameters passed to WindowPosMESA. The current color, color index and texture coordinate update the current raster position's associated data. Additions to the AGL/GLX/WGL Specifications None GLX Protocol Not specified at this time. However, a protocol message very similar to that of RasterPos is expected. Errors INVALID_OPERATION is generated if WindowPosMESA is called betweeen Begin and End. New State None. New Implementation Dependent State None. Revision History * Revision 1.0 - Initial specification * Revision 1.1 - Minor clean-up (7 Jan 2000, Brian Paul)