renderdiff: allow for explicit (compile-time) linking of osmesa (#8301)

If the shared osmesa lib is not found, then we assume that the library has been compile-time linked via the linker. This is to accommodate build frameworks where compile-time linking is preferred.
google · Dec 12, 2024 · aaac6e7 · aaac6e7
1 parent 2cc375e
commit aaac6e7
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Showing 2 changed files with 18 additions and 9 deletions.
diff --git a/filament/backend/src/opengl/platforms/PlatformOSMesa.cpp b/filament/backend/src/opengl/platforms/PlatformOSMesa.cpp
@@ -64,10 +64,14 @@ struct OSMesaAPI {
                 break;
             }
         }
-        FILAMENT_CHECK_PRECONDITION(mLib)
-                << "Unable to dlopen libOSMesa to create a software GL context";
+        if (mLib) {
+            OSMesaGetProcAddress = (GetProcAddressFunc) dlsym(mLib, "OSMesaGetProcAddress");
+        } else {
+            OSMesaGetProcAddress = (GetProcAddressFunc) dlsym(RTLD_LOCAL, "OSMesaGetProcAddress");
+        }
 
-        OSMesaGetProcAddress = (GetProcAddressFunc) dlsym(mLib, "OSMesaGetProcAddress");
+        FILAMENT_CHECK_PRECONDITION(OSMesaGetProcAddress)
+                << "Unable to against libOSMesa to create a software GL context";
 
         OSMesaCreateContext = (CreateContextFunc) OSMesaGetProcAddress("OSMesaCreateContext");
         OSMesaDestroyContext =
@@ -76,7 +80,9 @@ struct OSMesaAPI {
     }
 
     ~OSMesaAPI() {
-        dlclose(mLib);
+        if (mLib) {
+            dlclose(mLib);
+        }
     }
 private:
     void* mLib = nullptr;

diff --git a/libs/bluegl/src/BlueGLLinuxOSMesa.cpp b/libs/bluegl/src/BlueGLLinuxOSMesa.cpp
@@ -38,12 +38,13 @@ bool initBinder() {
         }
     }
     if (!g_driver.library) {
-        return false;
+        // The library has been linked explicitly during compile.
+        g_driver.OSMesaGetProcAddress = (ProcAddressFunc) dlsym(RTLD_LOCAL, "OSMesaGetProcAddress");
+    } else {
+        g_driver.OSMesaGetProcAddress =
+                (ProcAddressFunc) dlsym(g_driver.library, "OSMesaGetProcAddress");
     }
 
-    g_driver.OSMesaGetProcAddress = (ProcAddressFunc)
-            dlsym(g_driver.library, "OSMesaGetProcAddress");
-
     return g_driver.OSMesaGetProcAddress;
 }
 
@@ -52,7 +53,9 @@ void* loadFunction(const char* name) {
 }
 
 void shutdownBinder() {
-    dlclose(g_driver.library);
+    if (g_driver.library) {
+        dlclose(g_driver.library);
+    }
     memset(&g_driver, 0, sizeof(g_driver));
 }