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diff --git a/mesalib/docs/README.CYGWIN b/mesalib/docs/README.CYGWIN deleted file mode 100644 index 58d5af3e2..000000000 --- a/mesalib/docs/README.CYGWIN +++ /dev/null @@ -1,256 +0,0 @@ - - Mesa Cygwin/X11 Information - - -WARNING -======= - -If you installed X11 (packages xorg-x11-devel and xorg-x11-bin-dlls ) with the -latest setup.exe from Cygwin the GL (Mesa) libraries and include are already -installed in /usr/X11R6. - -The following will explain how to "replace" them. - -Installation -============ - -How to compile Mesa on Cygwin/X11 systems: - -1. Shared libs: - type 'make cygwin-sl'. - - When finished, the Mesa DLL will be in the Mesa-x.y/lib/ and - Mesa-x.y/bin directories. - - -2. Static libs: - type 'make cygwin-static'. - When finished, the Mesa libraries will be in the Mesa-x.y/lib/ directory. - -Header and library files: - After you've compiled Mesa and tried the demos I recommend the following - procedure for "installing" Mesa. - - Copy the Mesa include/GL directory to /usr/X11R6/include: - cp -a include/GL /usr/X11R6/include - - Copy the Mesa library files to /usr/X11R6/lib: - cp -a lib/* /usr/X11R6ocal/lib - - Copy the Mesa bin files (used by the DLL stuff) to /usr/X11R6/bin: - cp -a lib/cyg* /usr/X11R6/bin - -Xt/Motif widgets: - If you want to use Mesa or OpenGL in your Xt/Motif program you can build - the widgets found in either the widgets-mesa or widgets-sgi directories. - The former were written for Mesa and the later are the original SGI - widgets. Look in those directories for more information. - For the Motif widgets you must have downloaded the lesstif package. - - -Using the library -================= - -Configuration options: - The file src/mesa/main/config.h has many parameters which you can adjust - such as maximum number of lights, clipping planes, maximum texture size, - etc. In particular, you may want to change DEPTH_BITS from 16 to 32 - if a 16-bit depth buffer isn't precise enough for your application. - - -Shared libraries: - If you compile shared libraries (Win32 DLLS) you may have to set an - environment variable to specify where the Mesa libraries are located. - Set the PATH variable to include /your-dir/Mesa-2.6/bin. - Otherwise, when you try to run a demo it may fail with a message saying - that one or more DLL couldn't be found. - - -Xt/Motif Widgets: - Two versions of the Xt/Motif OpenGL drawing area widgets are included: - - widgets-sgi/ SGI's stock widgets - widgets-mesa/ Mesa-tuned widgets - - Look in those directories for details - - -Togl: - Togl is an OpenGL/Mesa widget for Tcl/Tk. - See http://togl.sourceforge.net for more information. - - - -X Display Modes: - Mesa supports RGB(A) rendering into almost any X visual type and depth. - - The glXChooseVisual function tries its best to pick an appropriate visual - for the given attribute list. However, if this doesn't suit your needs - you can force Mesa to use any X visual you want (any supported by your - X server that is) by setting the MESA_RGB_VISUAL and MESA_CI_VISUAL - environment variables. When an RGB visual is requested, glXChooseVisual - will first look if the MESA_RGB_VISUAL variable is defined. If so, it - will try to use the specified visual. Similarly, when a color index - visual is requested, glXChooseVisual will look for the MESA_CI_VISUAL - variable. - - The format of accepted values is: <visual-class> <depth> - Here are some examples: - - using the C-shell: - % setenv MESA_RGB_VISUAL "TrueColor 8" // 8-bit TrueColor - % setenv MESA_CI_VISUAL "PseudoColor 12" // 12-bit PseudoColor - % setenv MESA_RGB_VISUAL "PseudoColor 8" // 8-bit PseudoColor - - using the KornShell: - $ export MESA_RGB_VISUAL="TrueColor 8" - $ export MESA_CI_VISUAL="PseudoColor 12" - $ export MESA_RGB_VISUAL="PseudoColor 8" - - -Double buffering: - Mesa can use either an X Pixmap or XImage as the backbuffer when in - double buffer mode. Using GLX, the default is to use an XImage. The - MESA_BACK_BUFFER environment variable can override this. The valid - values for MESA_BACK_BUFFER are: Pixmap and XImage (only the first - letter is checked, case doesn't matter). - - A pixmap is faster when drawing simple lines and polygons while an - XImage is faster when Mesa has to do pixel-by-pixel rendering. If you - need depth buffering the XImage will almost surely be faster. Exper- - iment with the MESA_BACK_BUFFER variable to see which is faster for - your application. - - -Colormaps: - When using Mesa directly or with GLX, it's up to the application writer - to create a window with an appropriate colormap. The aux, tk, and GLUT - toolkits try to minimize colormap "flashing" by sharing colormaps when - possible. Specifically, if the visual and depth of the window matches - that of the root window, the root window's colormap will be shared by - the Mesa window. Otherwise, a new, private colormap will be allocated. - - When sharing the root colormap, Mesa may be unable to allocate the colors - it needs, resulting in poor color quality. This can happen when a - large number of colorcells in the root colormap are already allocated. - To prevent colormap sharing in aux, tk and GLUT, define the environment - variable MESA_PRIVATE_CMAP. The value isn't significant. - - -Gamma correction: - To compensate for the nonlinear relationship between pixel values - and displayed intensities, there is a gamma correction feature in - Mesa. Some systems, such as Silicon Graphics, support gamma - correction in hardware (man gamma) so you won't need to use Mesa's - gamma facility. Other systems, however, may need gamma adjustment - to produce images which look correct. If in the past you thought - Mesa's images were too dim, read on. - - Gamma correction is controlled with the MESA_GAMMA environment - variable. Its value is of the form "Gr Gg Gb" or just "G" where - Gr is the red gamma value, Gg is the green gamma value, Gb is the - blue gamma value and G is one gamma value to use for all three - channels. Each value is a positive real number typically in the - range 1.0 to 2.5. The defaults are all 1.0, effectively disabling - gamma correction. Examples using csh: - - % setenv MESA_GAMMA "2.3 2.2 2.4" // separate R,G,B values - % setenv MESA_GAMMA "2.0" // same gamma for R,G,B - - The demos/gamma.c program may help you to determine reasonable gamma - value for your display. With correct gamma values, the color intensities - displayed in the top row (drawn by dithering) should nearly match those - in the bottom row (drawn as grays). - - Alex De Bruyn reports that gamma values of 1.6, 1.6 and 1.9 work well - on HP displays using the HP-ColorRecovery technology. - - Mesa implements gamma correction with a lookup table which translates - a "linear" pixel value to a gamma-corrected pixel value. There is a - small performance penalty. Gamma correction only works in RGB mode. - Also be aware that pixel values read back from the frame buffer will - not be "un-corrected" so glReadPixels may not return the same data - drawn with glDrawPixels. - - For more information about gamma correction see: - http://www.inforamp.net/~poynton/notes/colour_and_gamma/GammaFAQ.html - - -Overlay Planes - - Overlay planes in the frame buffer are supported by Mesa but require - hardware and X server support. To determine if your X server has - overlay support you can test for the SERVER_OVERLAY_VISUALS property: - - xprop -root | grep SERVER_OVERLAY_VISUALS - - -HPCR glClear(GL_COLOR_BUFFER_BIT) dithering - - If you set the MESA_HPCR_CLEAR environment variable then dithering - will be used when clearing the color buffer. This is only applicable - to HP systems with the HPCR (Color Recovery) system. - - -Extensions -========== - There are three Mesa-specific GLX extensions at this time. - - GLX_MESA_pixmap_colormap - - This extension adds the GLX function: - - GLXPixmap glXCreateGLXPixmapMESA( Display *dpy, XVisualInfo *visual, - Pixmap pixmap, Colormap cmap ) - - It is an alternative to the standard glXCreateGLXPixmap() function. - Since Mesa supports RGB rendering into any X visual, not just True- - Color or DirectColor, Mesa needs colormap information to convert RGB - values into pixel values. An X window carries this information but a - pixmap does not. This function associates a colormap to a GLX pixmap. - See the xdemos/glxpixmap.c file for an example of how to use this - extension. - - GLX_MESA_release_buffers - - Mesa associates a set of ancillary (depth, accumulation, stencil and - alpha) buffers with each X window it draws into. These ancillary - buffers are allocated for each X window the first time the X window - is passed to glXMakeCurrent(). Mesa, however, can't detect when an - X window has been destroyed in order to free the ancillary buffers. - - The best it can do is to check for recently destroyed windows whenever - the client calls the glXCreateContext() or glXDestroyContext() - functions. This may not be sufficient in all situations though. - - The GLX_MESA_release_buffers extension allows a client to explicitly - deallocate the ancillary buffers by calling glxReleaseBuffersMESA() - just before an X window is destroyed. For example: - - #ifdef GLX_MESA_release_buffers - glXReleaseBuffersMESA( dpy, window ); - #endif - XDestroyWindow( dpy, window ); - - This extension is new in Mesa 2.0. - - GLX_MESA_copy_sub_buffer - - This extension adds the glXCopySubBufferMESA() function. It works - like glXSwapBuffers() but only copies a sub-region of the window - instead of the whole window. - - This extension is new in Mesa version 2.6 - - - -Summary of X-related environment variables: - MESA_RGB_VISUAL - specifies the X visual and depth for RGB mode (X only) - MESA_CI_VISUAL - specifies the X visual and depth for CI mode (X only) - MESA_BACK_BUFFER - specifies how to implement the back color buffer (X only) - MESA_PRIVATE_CMAP - force aux/tk libraries to use private colormaps (X only) - MESA_GAMMA - gamma correction coefficients (X only) - - ----------------------------------------------------------------------- -README.CYGWIN - lassauge April 2004 - based on README.X11 |