vo_gpu: vulkan: generalize SPIR-V compiler

In addition to the built-in nvidia compiler, we now also support a
backend based on libshaderc. shaderc is sort of like glslang except it
has a C API and is available as a dynamic library.

The generated SPIR-V is now cached alongside the VkPipeline in the
cached_program. We use a special cache header to ensure validity of this
cache before passing it blindly to the vulkan implementation, since
passing invalid SPIR-V can cause all sorts of nasty things. It's also
designed to self-invalidate if the compiler gets better, by offering a
catch-all `int compiler_version` that implementations can use as a cache
invalidation marker.

1 files changed, 1 insertions, 0 deletions

diff --git a/video/out/gpu/context.h b/video/out/gpu/context.h
index f74087592d..78c0441cdf 100644
--- a/video/out/gpu/context.h
+++ b/video/out/gpu/context.h
@@ -22,6 +22,7 @@ struct ra_ctx {
     struct ra_ctx_opts opts;
     const struct ra_ctx_fns *fns;
     struct ra_swapchain *swapchain;
+    struct spirv_compiler *spirv;
 
     void *priv;
 };