src/video/quartz/SDL_QuartzGL.m
author Sam Lantinga
Sun, 16 May 2004 18:06:27 +0000
changeset 890 416158ec61a0
parent 857 ce05e92d909b
child 900 c3c8739f7844
permissions -rw-r--r--
Date: Sat, 10 Apr 2004 10:05:46 +0200
From: Christian Walther
Subject: [SDL] OpenGL Accumulation Buffer on Mac OS X

Is there a reason for not having OpenGL accumulation buffer support in
SDL 1.2.7 (and as far as I have checked also in the current CVS) on Mac OS
X?

Maybe I am doing something wrong, but it seems very easy to add (at least
it works for for me in 10.3.3) - just add

if ( this->gl_config.accum_red_size + this->gl_config.accum_green_size + this->gl_config.accum_blue_size + this->gl_config.accum_alpha_size > 0) {
attr[i++] = NSOpenGLPFAAccumSize;
attr[i++] = this->gl_config.accum_red_size + this->gl_config.accum_green_size + this->gl_config.accum_blue_size + this->gl_config.accum_alpha_size;
}

to QZ_SetupOpenGL() in SDL_QuartzGL.m
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2003  Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #include "SDL_QuartzVideo.h"
    24 
    25 /*
    26  * GL_ARB_Multisample is supposed to be available in 10.1, according to Apple:
    27  *
    28  *   http://developer.apple.com/opengl/extensions.html#GL_ARB_multisample
    29  *
    30  *  ...but it isn't in the system headers, according to Sam:
    31  *
    32  *   http://www.libsdl.org/pipermail/sdl/2003-December/058335.html
    33  *
    34  * These are normally enums and not #defines in the system headers.
    35  *
    36  *   --ryan.
    37  */
    38 #if (MAC_OS_X_VERSION_MAX_ALLOWED < 1020)
    39 #define NSOpenGLPFASampleBuffers ((NSOpenGLPixelFormatAttribute) 55)
    40 #define NSOpenGLPFASamples ((NSOpenGLPixelFormatAttribute) 56)
    41 #endif
    42 
    43 
    44 @implementation NSOpenGLContext (CGLContextAccess)
    45 - (CGLContextObj) cglContext;
    46 {
    47     return _contextAuxiliary;
    48 }
    49 @end
    50 
    51 /* OpenGL helper functions (used internally) */
    52 
    53 int QZ_SetupOpenGL (_THIS, int bpp, Uint32 flags) {
    54 
    55     NSOpenGLPixelFormatAttribute attr[32];
    56     NSOpenGLPixelFormat *fmt;
    57     int i = 0;
    58     int colorBits = bpp;
    59 
    60     if ( flags & SDL_FULLSCREEN ) {
    61 
    62         attr[i++] = NSOpenGLPFAFullScreen;
    63     }
    64     /* In windowed mode, the OpenGL pixel depth must match device pixel depth */
    65     else if ( colorBits != device_bpp ) {
    66 
    67         colorBits = device_bpp;
    68     }
    69 
    70     attr[i++] = NSOpenGLPFAColorSize;
    71     attr[i++] = colorBits;
    72 
    73     attr[i++] = NSOpenGLPFADepthSize;
    74     attr[i++] = this->gl_config.depth_size;
    75 
    76     if ( this->gl_config.double_buffer ) {
    77         attr[i++] = NSOpenGLPFADoubleBuffer;
    78     }
    79 
    80     if ( this->gl_config.stereo ) {
    81         attr[i++] = NSOpenGLPFAStereo;
    82     }
    83 
    84     if ( this->gl_config.stencil_size != 0 ) {
    85         attr[i++] = NSOpenGLPFAStencilSize;
    86         attr[i++] = this->gl_config.stencil_size;
    87     }
    88 
    89     if ( (this->gl_config.accum_red_size +
    90           this->gl_config.accum_green_size +
    91           this->gl_config.accum_blue_size +
    92           this->gl_config.accum_alpha_size) > 0 ) {
    93         attr[i++] = NSOpenGLPFAAccumSize;
    94         attr[i++] = this->gl_config.accum_red_size + this->gl_config.accum_green_size + this->gl_config.accum_blue_size + this->gl_config.accum_alpha_size;
    95     }
    96 
    97     if ( this->gl_config.multisamplebuffers != 0 ) {
    98         attr[i++] = NSOpenGLPFASampleBuffers;
    99         attr[i++] = this->gl_config.multisamplebuffers;
   100     }
   101 
   102     if ( this->gl_config.multisamplesamples != 0 ) {
   103         attr[i++] = NSOpenGLPFASamples;
   104         attr[i++] = this->gl_config.multisamplesamples;
   105     }
   106 
   107     attr[i++] = NSOpenGLPFAScreenMask;
   108     attr[i++] = CGDisplayIDToOpenGLDisplayMask (display_id);
   109     attr[i] = 0;
   110 
   111     fmt = [ [ NSOpenGLPixelFormat alloc ] initWithAttributes:attr ];
   112     if (fmt == nil) {
   113         SDL_SetError ("Failed creating OpenGL pixel format");
   114         return 0;
   115     }
   116 
   117     gl_context = [ [ NSOpenGLContext alloc ] initWithFormat:fmt
   118                                                shareContext:nil];
   119 
   120     if (gl_context == nil) {
   121         SDL_SetError ("Failed creating OpenGL context");
   122         return 0;
   123     }
   124 
   125     /*
   126      * Wisdom from Apple engineer in reference to UT2003's OpenGL performance:
   127      *  "You are blowing a couple of the internal OpenGL function caches. This
   128      *  appears to be happening in the VAO case.  You can tell OpenGL to up
   129      *  the cache size by issuing the following calls right after you create
   130      *  the OpenGL context.  The default cache size is 16."    --ryan.
   131      */
   132 
   133     #ifndef GLI_ARRAY_FUNC_CACHE_MAX
   134     #define GLI_ARRAY_FUNC_CACHE_MAX 284
   135     #endif
   136 
   137     #ifndef GLI_SUBMIT_FUNC_CACHE_MAX
   138     #define GLI_SUBMIT_FUNC_CACHE_MAX 280
   139     #endif
   140 
   141     {
   142         long cache_max = 64;
   143         CGLContextObj ctx = [ gl_context cglContext ];
   144         CGLSetParameter (ctx, GLI_SUBMIT_FUNC_CACHE_MAX, &cache_max);
   145         CGLSetParameter (ctx, GLI_ARRAY_FUNC_CACHE_MAX, &cache_max);
   146     }
   147 
   148     /* End Wisdom from Apple Engineer section. --ryan. */
   149 
   150     /* Convince SDL that the GL "driver" is loaded */
   151     this->gl_config.driver_loaded = 1;
   152 
   153     [ fmt release ];
   154 
   155     return 1;
   156 }
   157 
   158 void QZ_TearDownOpenGL (_THIS) {
   159 
   160     [ NSOpenGLContext clearCurrentContext ];
   161     [ gl_context clearDrawable ];
   162     [ gl_context release ];
   163 }
   164 
   165 
   166 /* SDL OpenGL functions */
   167 
   168 int    QZ_GL_LoadLibrary    (_THIS, const char *location) {
   169     this->gl_config.driver_loaded = 1;
   170     return 1;
   171 }
   172 
   173 void*  QZ_GL_GetProcAddress (_THIS, const char *proc) {
   174 
   175     /* We may want to cache the bundleRef at some point */
   176     CFBundleRef bundle;
   177     CFURLRef bundleURL = CFURLCreateWithFileSystemPath (kCFAllocatorDefault,
   178                                                         CFSTR("/System/Library/Frameworks/OpenGL.framework"), kCFURLPOSIXPathStyle, true);
   179 
   180     CFStringRef functionName = CFStringCreateWithCString
   181         (kCFAllocatorDefault, proc, kCFStringEncodingASCII);
   182 
   183     void *function;
   184 
   185     bundle = CFBundleCreate (kCFAllocatorDefault, bundleURL);
   186     assert (bundle != NULL);
   187 
   188     function = CFBundleGetFunctionPointerForName (bundle, functionName);
   189 
   190     CFRelease ( bundleURL );
   191     CFRelease ( functionName );
   192     CFRelease ( bundle );
   193 
   194     return function;
   195 }
   196 
   197 int    QZ_GL_GetAttribute   (_THIS, SDL_GLattr attrib, int* value) {
   198 
   199     GLenum attr = 0;
   200 
   201     QZ_GL_MakeCurrent (this);
   202 
   203     switch (attrib) {
   204         case SDL_GL_RED_SIZE: attr = GL_RED_BITS;   break;
   205         case SDL_GL_BLUE_SIZE: attr = GL_BLUE_BITS;  break;
   206         case SDL_GL_GREEN_SIZE: attr = GL_GREEN_BITS; break;
   207         case SDL_GL_ALPHA_SIZE: attr = GL_ALPHA_BITS; break;
   208         case SDL_GL_DOUBLEBUFFER: attr = GL_DOUBLEBUFFER; break;
   209         case SDL_GL_DEPTH_SIZE: attr = GL_DEPTH_BITS;  break;
   210         case SDL_GL_STENCIL_SIZE: attr = GL_STENCIL_BITS; break;
   211         case SDL_GL_ACCUM_RED_SIZE: attr = GL_ACCUM_RED_BITS; break;
   212         case SDL_GL_ACCUM_GREEN_SIZE: attr = GL_ACCUM_GREEN_BITS; break;
   213         case SDL_GL_ACCUM_BLUE_SIZE: attr = GL_ACCUM_BLUE_BITS; break;
   214         case SDL_GL_ACCUM_ALPHA_SIZE: attr = GL_ACCUM_ALPHA_BITS; break;
   215         case SDL_GL_STEREO: attr = GL_STEREO; break;
   216         case SDL_GL_MULTISAMPLEBUFFERS: attr = GL_SAMPLE_BUFFERS_ARB; break;
   217         case SDL_GL_MULTISAMPLESAMPLES: attr = GL_SAMPLES_ARB; break;
   218         case SDL_GL_BUFFER_SIZE:
   219         {
   220             GLint bits = 0;
   221             GLint component;
   222 
   223             /* there doesn't seem to be a single flag in OpenGL for this! */
   224             glGetIntegerv (GL_RED_BITS, &component);   bits += component;
   225             glGetIntegerv (GL_GREEN_BITS,&component);  bits += component;
   226             glGetIntegerv (GL_BLUE_BITS, &component);  bits += component;
   227             glGetIntegerv (GL_ALPHA_BITS, &component); bits += component;
   228 
   229             *value = bits;
   230         }
   231         return 0;
   232     }
   233 
   234     glGetIntegerv (attr, (GLint *)value);
   235     return 0;
   236 }
   237 
   238 int    QZ_GL_MakeCurrent    (_THIS) {
   239     [ gl_context makeCurrentContext ];
   240     return 0;
   241 }
   242 
   243 void   QZ_GL_SwapBuffers    (_THIS) {
   244     [ gl_context flushBuffer ];
   245 }