1 /*
2  Copyright (c) 2009-2011 Apple Inc.
3 
4  Permission is hereby granted, free of charge, to any person
5  obtaining a copy of this software and associated documentation files
6  (the "Software"), to deal in the Software without restriction,
7  including without limitation the rights to use, copy, modify, merge,
8  publish, distribute, sublicense, and/or sell copies of the Software,
9  and to permit persons to whom the Software is furnished to do so,
10  subject to the following conditions:
11 
12  The above copyright notice and this permission notice shall be
13  included in all copies or substantial portions of the Software.
14 
15  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
19  HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
20  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  DEALINGS IN THE SOFTWARE.
23 
24  Except as contained in this notice, the name(s) of the above
25  copyright holders shall not be used in advertising or otherwise to
26  promote the sale, use or other dealings in this Software without
27  prior written authorization.
28 */
29 
30 /* This should be removed once stereo hardware bugs are fixed
31  * <rdar://problem/6729006>
32  */
33 
34 #include <stdbool.h>
35 
36 #define GL_GLEXT_PROTOTYPES
37 #include <GL/gl.h>
38 #include <GL/glext.h>
39 
40 #include "glxclient.h"
41 #include "apple_glx_context.h"
42 #include "apple_xgl_api.h"
43 #include "main/glheader.h"
44 #include "glapitable.h"
45 
46 extern struct _glapi_table * __ogl_framework_api;
47 
48 /*
49  * These are special functions for stereoscopic support
50  * differences in MacOS X.
51  */
52 void
__applegl_glDrawBuffer(GLenum mode)53 __applegl_glDrawBuffer(GLenum mode)
54 {
55    struct glx_context * gc = __glXGetCurrentContext();
56 
57    if (gc != &dummyContext && apple_glx_context_uses_stereo(gc->driContext)) {
58       GLenum buf[2];
59       GLsizei n = 0;
60 
61       switch (mode) {
62       case GL_BACK:
63          buf[0] = GL_BACK_LEFT;
64          buf[1] = GL_BACK_RIGHT;
65          n = 2;
66          break;
67       case GL_FRONT:
68          buf[0] = GL_FRONT_LEFT;
69          buf[1] = GL_FRONT_RIGHT;
70          n = 2;
71          break;
72 
73       default:
74          buf[0] = mode;
75          n = 1;
76          break;
77       }
78 
79       __ogl_framework_api->DrawBuffers(n, buf);
80    }
81    else {
82       __ogl_framework_api->DrawBuffer(mode);
83    }
84 }
85 
86 
87 void
__applegl_glDrawBuffers(GLsizei n,const GLenum * bufs)88 __applegl_glDrawBuffers(GLsizei n, const GLenum * bufs)
89 {
90    struct glx_context * gc = __glXGetCurrentContext();
91 
92    if (gc != &dummyContext && apple_glx_context_uses_stereo(gc->driContext)) {
93       GLenum newbuf[n + 2];
94       GLsizei i, outi = 0;
95       bool have_back = false;
96       bool have_front = false;
97 
98       for (i = 0; i < n; ++i) {
99          if (GL_BACK == bufs[i]) {
100             have_back = true;
101          }
102          else if (GL_FRONT == bufs[i]) {
103             have_back = true;
104          }
105          else {
106             newbuf[outi++] = bufs[i];
107          }
108       }
109 
110       if (have_back) {
111          newbuf[outi++] = GL_BACK_LEFT;
112          newbuf[outi++] = GL_BACK_RIGHT;
113       }
114 
115       if (have_front) {
116          newbuf[outi++] = GL_FRONT_LEFT;
117          newbuf[outi++] = GL_FRONT_RIGHT;
118       }
119 
120       __ogl_framework_api->DrawBuffers(outi, newbuf);
121    }
122    else {
123       __ogl_framework_api->DrawBuffers(n, bufs);
124    }
125 }
126