Fix SOKOL_IMPL.

Author: WickedSmoke

viewer/src/platform/imgui_sokol_impl.cpp

@@ -1,5 +1,4 @@
 #include "sokol_app.h"
 #include "sokol_gfx.h"
-#define SOKOL_IMPL
 #include "imgui.h"
-#include "util/sokol_imgui.h"
+#include "util/sokol_imgui.h"

viewer/src/viewer.cpp

@@ -5,6 +5,7 @@
 #include "rive/shapes/paint/color.hpp"
 
 // Graphics and UI abstraction
+#define SOKOL_IMPL
 #include "sokol_app.h"
 #include "sokol_gfx.h"
 #include "sokol_glue.h"
@@ -217,4 +218,4 @@ sapp_desc sokol_main(int argc, char* argv[])
 #endif
         .width = 800, .height = 600, .icon.sokol_default = true, .gl_force_gles2 = true,
     };
-}
+}