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, 54 insertions, 0 deletions

diff --git a/video/out/vulkan/spirv_nvidia.c b/video/out/vulkan/spirv_nvidia.c
new file mode 100644
index 0000000000..6cc43a5619
--- /dev/null
+++ b/video/out/vulkan/spirv_nvidia.c
@@ -0,0 +1,54 @@
+#include "video/out/gpu/spirv.h"
+
+#include "common.h"
+#include "context.h"
+#include "utils.h"
+
+static bool nv_glsl_compile(struct spirv_compiler *spirv, void *tactx,
+                            enum glsl_shader type, const char *glsl,
+                            struct bstr *out_spirv)
+{
+    // The nvidia extension literally assumes your SPIRV is in fact valid GLSL
+    *out_spirv = bstr0(glsl);
+    return true;
+}
+
+static bool nv_glsl_init(struct ra_ctx *ctx)
+{
+    struct mpvk_ctx *vk = ra_vk_ctx_get(ctx);
+    if (!vk)
+        return false;
+
+    struct spirv_compiler *spv = ctx->spirv;
+    spv->required_ext = VK_NV_GLSL_SHADER_EXTENSION_NAME;
+    spv->glsl_version = 450; // impossible to query, so hard-code it..
+    spv->ra_caps = RA_CAP_NESTED_ARRAY;
+
+    // Make sure the extension is actually available, and fail gracefully
+    // if it isn't
+    VkExtensionProperties *props = NULL;
+    uint32_t extnum = 0;
+    VK(vkEnumerateDeviceExtensionProperties(vk->physd, NULL, &extnum, NULL));
+    props = talloc_array(NULL, VkExtensionProperties, extnum);
+    VK(vkEnumerateDeviceExtensionProperties(vk->physd, NULL, &extnum, props));
+
+    bool ret = true;
+    for (int e = 0; e < extnum; e++) {
+        if (strncmp(props[e].extensionName, spv->required_ext,
+                    VK_MAX_EXTENSION_NAME_SIZE) == 0)
+            goto done;
+    }
+
+error:
+    MP_VERBOSE(ctx, "Device doesn't support VK_NV_glsl_shader, skipping..\n");
+    ret = false;
+
+done:
+    talloc_free(props);
+    return ret;
+}
+
+const struct spirv_compiler_fns spirv_nvidia_builtin = {
+    .compile_glsl = nv_glsl_compile,
+    .init = nv_glsl_init,
+};