glshim ==== This is a shim providing OpenGL 1.x functionality to OpenGL ES accelerated cards. Most function of OpenGL up to 1.5 are supported, with some notable exceptions: * Reading of Depth or Stencil buffer will not work * GL_FEEDBACK mode is not implemented * OcclusionQuery is not implemented Some know limitations: * GL_SELECT as some limitation in its implementation (for exemple, current Depth buffer or binded texture are not taken into account) * NPOT texture are supported, but not with GL_REPEAT / GL_MIRRORED, only GL_CLAMP will work properly * Framebuffer use FRAMEBUFFER_OES extension (that must be present in the GLES 1.1 stack) * Multiple Color attachment on Framebuffer are not supported * Probably many other things ---- Compiling ---- *for Pandora* cmake . ; make GL *or for the Raspberry Pi* cmake . -DBCMHOST=1; make GL *or for the ODroid* cmake . -DODROID=1; make GL *or for Android* An Android.mk is provided that should compile with an NDK *or use ccmake* Alternatively, you can use the curses-bases ccmake to select wich platform to use interactively. ---- GLU ---- Standard GLU do works without any issues. But you can also find a GLES optimized version og GLU there https://github.com/lunixbochs/glues git clone git@github.com:lunixbochs/glues.git; git checkout glu; cmake .; make ---- Installation ---- Put lib/libGL.so.1 in your `LD_LIBRARY_PATH`. ---- Usage ---- There are many environnement variable to control glshim behavour. All are numeric, except LIBGL_VERSION that take a string. ##### LIBGL_FB Controls the Framebuffer output * 0 : Default, using standard x11 rendering * 1 : Use Framebuffer output (x11 bypassed, only fullscreen) * 2 : Use Framebuffer, but also an intermediary FBO ##### LIBGL_XREFRESH Debug helper in specific cases * 0 : Default, nothing special * 1 : xrefresh will be called on cleanup ##### LIBGL_STACKTRACE Automatic Backtrace log * 0 : Default, nothing special * 1 : stacktrace will be printed on crash ##### LIBGL_VSYNC VSync control * 0 : Default, nothing special * 1 : vsync enabled ##### LIBGL_RECYCLEFBO Recycling FBO special case (don't delete a created FBO, but recycle it if needed) * 0 : Default, nothing special * 1 : Recycling of FBO enabled ##### LIBGL_MIPMAP Handling of Manual and Automatic MIPMAP * 0 : Default, nothing special * 1 : AutoMipMap forced * 2 : guess AutoMipMap (based on manual mipmaping on textures) * 3 : ignore MipMap (mipmap creation / use entirely disabled) * 4 : ignore AutoMipMap on non-squared textures ##### LIBGL_TEXCOPY Make a local copy of every texture for easy glGetTexImage2D * 0 : Default, nothing special * 1 : Texture copy enabled ##### LIBGL_SHRINK Texture shrinking control * 0 : Default, nothing special * 1 : everything / 2 (using original algorithm for size reduction, all other shink mode use a refined algorithm) * 2 : only textures wich one size > 512 are / 2 * 3 : only textures wich one size > 256 are / 2 * 4 : only textures wich one size > 256 are / 2, and the one > 1024 are / 4 * 5 : only textures wich one size > 256 are resized to 256 (if possible, because only /2 and /4 exists), but empty texture are not shrinked * 6 : only textures wich one size > 128 are / 2, thoses >= 512 are resized to 256 (if possible, because only /2 and /4 exists), but empty texture are not shrinked * 7 : only textures wich one size > 512 are / 2, but empty texture are not shrinked * 8 : advertise a max texture size of 8192, but every texture wich one size > 2048 are shrinked to 2048 * 9 : advertise a max texture size of 8192, but every texture wich one size > 4096 are / 4 and the one > 512 are / 2, but empty texture are not shrinked * 10: advertise a max texture size of 8192, but every texture wich one size > 2048 are / 4 and the one > 512 are / 2, but empty texture are not shrinked ##### LIBGL_TEXDUMP Texture dump * 0 : Default, nothing special * 1 : Texture dump enabled ##### LIBGL_ALPHAHACK Experimental: enable Alpha test only when using texture that contains an alpha channel * 0 : Default, nothing special * 1 : Alpha Hack enabled ##### LIBGL_STREAM PANDORA only: enable Texture Streaming (works only on RGB textures) * 0 : Default, nothing special * 1 : Enabled on empty RGB textures * 2 : Enabled on all RGB textures ##### LIBGL_COPY Control the glCopyTex(Sub)Image2D hack (they are buggy on pandora and don't work most of the time) * 0 : Don't use native glCopyTex(Sub)Image2D, but a workaround function using FBO * 1 : No glCopyTexImage2D / glCopyTexSubImage2D hack, use native ones ##### LIBGL_NOLUMALPHA Control the availability of the LUMUNANCE_ALPHA format (can be buggy on Pandora model CC) * 0 : Default,GL_LUMINANCE_ALPHA is available and used if needed * 1 : GL_LUMINANCE_ALPHA hardware support disabled (a GL_RGBA texture will be used instead) ##### LIBGL_BLENDHACK Experimental: Change Blend GL_SRC_ALPHA, GL_ONE to GL_ONE, GL_ONE * 0 : Default, nothing special * 1 : Change Blend GL_SRC_ALPHA, GL_ONE to GL_ONE, GL_ONE (can be usefull for Xash3D engine) ##### LIBGL_VERSION Control the glGetString version. Overide version string (should be in the form of "1.x") ##### LIBGL_BATCH Experimental: Batch mode (fuse of contigous Display list, to limit Draw calls) * 0 : Default, only Draw list created during a glList are fused (i.e. contigous glBegin / glEnd inside a List) * 1 : Force a maximum of call to be batched (like if all was inside a big glList) * 2 : Disable Batch mode completly, no fuse of draw list ##### LIBGL_NOERROR Hack: glGetError() always return GL_NOERROR * 0 : Default, glGetError behave as it should * 1 : glGetError never fail.