From 62012e3c68ea1e39aaf50045c863f0b90c29065f Mon Sep 17 00:00:00 2001
From: Camilla Berglund <elmindreda@glfw.org>
Date: Tue, 8 Nov 2016 22:44:59 +0100
Subject: [PATCH] OSMesa: Add fallback to OSMesaCreateContextExt

---
 src/osmesa_context.c | 72 ++++++++++++++++++++++++++++++--------------
 src/osmesa_context.h |  3 ++
 2 files changed, 52 insertions(+), 23 deletions(-)

diff --git a/src/osmesa_context.c b/src/osmesa_context.c
index 65fb6e92..852d4e54 100644
--- a/src/osmesa_context.c
+++ b/src/osmesa_context.c
@@ -120,6 +120,7 @@ GLFWbool _glfwInitOSMesa(void)
 #elif defined(__CYGWIN__)
         "libOSMesa-8.so",
 #else
+        "libOSMesa.so.8",
         "libOSMesa.so.6",
 #endif
         NULL
@@ -141,6 +142,8 @@ GLFWbool _glfwInitOSMesa(void)
         return GLFW_FALSE;
     }
 
+    _glfw.osmesa.CreateContextExt = (PFNOSMESACREATECONTEXTEXTPROC)
+        _glfw_dlsym(_glfw.osmesa.handle, "OSMesaCreateContextExt");
     _glfw.osmesa.CreateContextAttribs = (PFNOSMESACREATECONTEXTATTRIBSPROC)
         _glfw_dlsym(_glfw.osmesa.handle, "OSMesaCreateContextAttribs");
     _glfw.osmesa.DestroyContext = (PFNOSMESADESTROYCONTEXTPROC)
@@ -154,7 +157,7 @@ GLFWbool _glfwInitOSMesa(void)
     _glfw.osmesa.GetProcAddress = (PFNOSMESAGETPROCADDRESSPROC)
         _glfw_dlsym(_glfw.osmesa.handle, "OSMesaGetProcAddress");
 
-    if (!_glfw.osmesa.CreateContextAttribs ||
+    if (!_glfw.osmesa.CreateContextExt ||
         !_glfw.osmesa.DestroyContext ||
         !_glfw.osmesa.MakeCurrent ||
         !_glfw.osmesa.GetColorBuffer ||
@@ -192,37 +195,60 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
                                   const _GLFWfbconfig* fbconfig)
 {
     OSMesaContext share = NULL;
-    int index = 0, attribs[40];
+    const int accumBits = fbconfig->accumRedBits +
+                          fbconfig->accumGreenBits +
+                          fbconfig->accumBlueBits +
+                          fbconfig->accumAlphaBits;
 
     if (ctxconfig->share)
         share = ctxconfig->share->context.osmesa.handle;
 
-    setAttrib(OSMESA_FORMAT, OSMESA_RGBA);
-    setAttrib(OSMESA_DEPTH_BITS, fbconfig->depthBits);
-    setAttrib(OSMESA_STENCIL_BITS, fbconfig->stencilBits);
-    setAttrib(OSMESA_ACCUM_BITS, fbconfig->accumRedBits +
-                                 fbconfig->accumGreenBits +
-                                 fbconfig->accumBlueBits +
-                                 fbconfig->accumAlphaBits);
+    if (OSMesaCreateContextAttribs)
+    {
+        int index = 0, attribs[40];
 
-    if (ctxconfig->profile == GLFW_OPENGL_CORE_PROFILE)
-    {
-        setAttrib(OSMESA_PROFILE, OSMESA_CORE_PROFILE);
+        setAttrib(OSMESA_FORMAT, OSMESA_RGBA);
+        setAttrib(OSMESA_DEPTH_BITS, fbconfig->depthBits);
+        setAttrib(OSMESA_STENCIL_BITS, fbconfig->stencilBits);
+        setAttrib(OSMESA_ACCUM_BITS, accumBits);
+
+        if (ctxconfig->profile == GLFW_OPENGL_CORE_PROFILE)
+        {
+            setAttrib(OSMESA_PROFILE, OSMESA_CORE_PROFILE);
+        }
+        else if (ctxconfig->profile == GLFW_OPENGL_COMPAT_PROFILE)
+        {
+            setAttrib(OSMESA_PROFILE, OSMESA_COMPAT_PROFILE);
+        }
+
+        if (ctxconfig->major != 1 || ctxconfig->minor != 0)
+        {
+            setAttrib(OSMESA_CONTEXT_MAJOR_VERSION, ctxconfig->major);
+            setAttrib(OSMESA_CONTEXT_MINOR_VERSION, ctxconfig->minor);
+        }
+
+        setAttrib(0, 0);
+
+        window->context.osmesa.handle =
+            OSMesaCreateContextAttribs(attribs, share);
     }
-    else if (ctxconfig->profile == GLFW_OPENGL_COMPAT_PROFILE)
+    else
     {
-        setAttrib(OSMESA_PROFILE, OSMESA_COMPAT_PROFILE);
+        if (ctxconfig->profile)
+        {
+            _glfwInputError(GLFW_VERSION_UNAVAILABLE,
+                            "OSMesa: OpenGL profiles unavailable");
+            return GLFW_FALSE;
+        }
+
+        window->context.osmesa.handle =
+            OSMesaCreateContextExt(OSMESA_RGBA,
+                                   fbconfig->depthBits,
+                                   fbconfig->stencilBits,
+                                   accumBits,
+                                   share);
     }
 
-    if (ctxconfig->major != 1 || ctxconfig->minor != 0)
-    {
-        setAttrib(OSMESA_CONTEXT_MAJOR_VERSION, ctxconfig->major);
-        setAttrib(OSMESA_CONTEXT_MINOR_VERSION, ctxconfig->minor);
-    }
-
-    setAttrib(0, 0);
-
-    window->context.osmesa.handle = OSMesaCreateContextAttribs(attribs, share);
     if (window->context.osmesa.handle == NULL)
     {
         _glfwInputError(GLFW_VERSION_UNAVAILABLE,
diff --git a/src/osmesa_context.h b/src/osmesa_context.h
index 2dbac9dd..5b49b054 100644
--- a/src/osmesa_context.h
+++ b/src/osmesa_context.h
@@ -43,11 +43,13 @@ typedef void* OSMesaContext;
 typedef void (*OSMESAproc)();
 
 typedef OSMesaContext (* PFNOSMESACREATECONTEXTATTRIBSPROC)(const int*,OSMesaContext);
+typedef OSMesaContext (* PFNOSMESACREATECONTEXTEXTPROC)(GLenum,GLint,GLint,GLint,OSMesaContext);
 typedef void (* PFNOSMESADESTROYCONTEXTPROC)(OSMesaContext);
 typedef int (* PFNOSMESAMAKECURRENTPROC)(OSMesaContext,void*,int,int,int);
 typedef int (* PFNOSMESAGETCOLORBUFFERPROC)(OSMesaContext,int*,int*,int*,void**);
 typedef int (* PFNOSMESAGETDEPTHBUFFERPROC)(OSMesaContext,int*,int*,int*,void**);
 typedef GLFWglproc (* PFNOSMESAGETPROCADDRESSPROC)(const char*);
+#define OSMesaCreateContextExt _glfw.osmesa.CreateContextExt
 #define OSMesaCreateContextAttribs _glfw.osmesa.CreateContextAttribs
 #define OSMesaDestroyContext _glfw.osmesa.DestroyContext
 #define OSMesaMakeCurrent _glfw.osmesa.MakeCurrent
@@ -76,6 +78,7 @@ typedef struct _GLFWlibraryOSMesa
 {
     void*           handle;
 
+    PFNOSMESACREATECONTEXTEXTPROC     CreateContextExt;
     PFNOSMESACREATECONTEXTATTRIBSPROC CreateContextAttribs;
     PFNOSMESADESTROYCONTEXTPROC       DestroyContext;
     PFNOSMESAMAKECURRENTPROC          MakeCurrent;