vkd3d-utils: Allow writing log output via a custom callback.

When using PE vkd3d through Wine, debug output may be swallowed by writing to
Win32 stderr. Avoid this by providing a way to hook up vkd3d log output to Wine
output.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Giovanni Mascellani <gmascellani@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

include/vkd3d_utils.h

@@ -75,6 +75,21 @@ VKD3D_UTILS_API HRESULT WINAPI D3DPreprocess(const void *data, SIZE_T size, cons
         const D3D_SHADER_MACRO *defines, ID3DInclude *include,
         ID3DBlob **shader, ID3DBlob **error_messages);
 
+/**
+ * Set a callback to be called when vkd3d-utils outputs debug logging.
+ *
+ * If NULL, or if this function has not been called, libvkd3d-utils will print
+ * all enabled log output to stderr.
+ *
+ * Calling this function will also set the log callback for libvkd3d and
+ * libvkd3d-shader.
+ *
+ * \param callback Callback function to set.
+ *
+ * \since 1.4
+ */
+VKD3D_UTILS_API void vkd3d_utils_set_log_callback(PFN_vkd3d_log callback);
+
 #ifdef __cplusplus
 }
 #endif  /* __cplusplus */

libs/vkd3d-utils/vkd3d_utils.map

@@ -15,6 +15,7 @@ global:
     vkd3d_create_event;
     vkd3d_destroy_event;
     vkd3d_signal_event;
+    vkd3d_utils_set_log_callback;
     vkd3d_wait_event;
 
 local: *;

libs/vkd3d-utils/vkd3d_utils_main.c

@@ -536,3 +536,9 @@ HRESULT WINAPI D3DCreateBlob(SIZE_T data_size, ID3DBlob **blob)
     }
     return hr;
 }
+
+void vkd3d_utils_set_log_callback(PFN_vkd3d_log callback)
+{
+    vkd3d_set_log_callback(callback);
+    vkd3d_dbg_set_log_callback(callback);
+}