[PATCH 3/3] include: Document the feature flags compile option.

[Conor McCarthy]

From: Conor McCarthy

---
 include/vkd3d_shader.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/vkd3d_shader.h b/include/vkd3d_shader.h
index 2f4478a79..a4eb3252d 100644
--- a/include/vkd3d_shader.h
+++ b/include/vkd3d_shader.h
@@ -199,7 +199,14 @@ enum vkd3d_shader_compile_option_fragment_coordinate_origin
 /** Advertises feature availability. \since 1.11 */
 enum vkd3d_shader_compile_option_feature_flags
 {
+    /** Enable 64-bit integer support for SPIR-V targets. This flag must be set
+     *  for sources which use 64-bit integers, and should only be set if the
+     *  target environment supports the shaderInt64 feature. */
     VKD3D_SHADER_COMPILE_OPTION_FEATURE_INT64         = 0x00000001,
+    /** Enable 64-bit floating point support for SPIR-V targets. This flag must
+     *  be set for sources which use 64-bit floating point values with API
+     *  version 1.11 or greater, and should only be set if the target
+     *  environment supports the shaderFloat64 feature. */
     VKD3D_SHADER_COMPILE_OPTION_FEATURE_FLOAT64       = 0x00000002,

VKD3D_FORCE_32_BIT_ENUM(VKD3D_SHADER_COMPILE_OPTION_FEATURE_FLAGS),