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renderer/vulkan: revert built-in SPV precompile until cross-shader bug found 

Even with image_vert + image_frag runtime-compiled while the
other 7 used precompiled SPV, kitty images still rendered at
full-window size. That rules out the SPV bytes for those two
shaders specifically — the bug is some cross-shader interaction
the precompile path triggers that runtime glslang doesn't.

Hypotheses worth chasing later:
  - Auto-map binding numbers depend on glslang TLS state. Build-
    time spawns a fresh process per shader → fresh state each
    time. Runtime compiles 9 sequentially → shared TLS pool
    accumulates assignments. Final bindings/locations could
    diverge in ways that affect a specific pipeline's draw.
  - ProcessDeferred's SetupBuiltinSymbolTable might cache cross-
    compile and produce different inlined builtins between
    "fresh process" and "Nth call in same process".
  - The std140 layout we verified matches IS correct — host
    Globals struct ↔ SPV decorate offsets line up. So it's not
    a UBO layout mismatch.

Going back to all-runtime Module.init via glslang. ~5 MB
heaptrack-only leak comes back; user-visible image rendering
correctness restored.

VulkanSpv.zig + src/vulkan_spvgen.zig + the build step stay in
the tree (small build overhead, no runtime cost since the
generated module isn't imported). A future investigation can
turn it back on by adding back the @import("vulkan_spv") + 9
Module.initFromSpirv calls once we understand the cross-shader
issue.

Co-Authored-By: claude-flow <ruv@ruv.net>
pull/12846/head
Nathan 2026-05-26 15:02:23 -05:00
parent 99d26181ed
commit de590c2a25
1 changed files with 31 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
src/renderer/vulkan/shaders.zig
View File

@ -30,19 +30,11 @@ const DescriptorPool = vulkan.DescriptorPool;
const Pipeline = @import("Pipeline.zig");
const math = @import("../../math.zig");
/// Build-time-precompiled SPIR-V blobs for the 9 built-in
/// shaders. Generated by `src/build/VulkanSpv.zig`. Each decl
/// is `[]const u32` backed by a comptime-aligned u8 array
/// (align(@alignOf(u32))) so the underlying storage is on a
/// 4-byte boundary — Module.initFromSpirv can consume the
/// slices directly without alignment surgery.
///
/// Skipping the runtime glslang call path for built-ins
/// eliminates the per-process TPoolAllocator high-water-mark
/// leak that the first-surface compile otherwise leaves
/// behind (~5 MB heaptrack delta). Custom (user) shaders still
/// go through glslang at runtime via shadertoy.spirvFromGlsl.
const vulkan_spv = @import("vulkan_spv");
// Build-time-precompiled SPIR-V blobs are generated by
// `src/build/VulkanSpv.zig` and exposed as the `vulkan_spv`
// module — currently UNUSED at runtime; see the long
// explanation in `Shaders.init` for why we went back to
// runtime glslang compilation for built-ins.
const log = std.log.scoped(.vulkan);
@ -920,16 +912,33 @@ pub const Shaders = struct {
// runtime via shadertoy.spirvFromGlsl, and the per-frame
// shadertoy post-pipeline below still allocates via
// `alloc`, so the parameter is still load-bearing.
// All built-ins runtime-compiled via glslang. The build-
// time SPV precompile path (commits c921c4b2e / 99d26181e)
// saves ~5 MB of TPoolAllocator leak per heaptrack but
// somehow corrupts kitty image rendering (images fill the
// whole window). The diagnostic in 7c045d694... showed
// even runtime-compiling image_vert + image_frag while
// leaving the other 7 precompiled DIDN'T fix it — so the
// bug isn't local to those shaders' SPV, it's some cross-
// shader interaction (descriptor binding cross-talk?
// ProcessDeferred state divergence between fresh-process
// build-time vs sequential-compile runtime?) we don't
// understand yet.
//
// VulkanSpv.zig + src/vulkan_spvgen.zig + the generated
// vulkan_spv import stay in tree so a future investigation
// can flip the swap back on. ~5 MB cosmetic leak is the
// wrong trade-off vs visibly broken images.
var modules: Modules = .{
.bg_color_frag = try Module.initFromSpirv(device, vulkan_spv.bg_color_frag, .fragment),
.bg_image_frag = try Module.initFromSpirv(device, vulkan_spv.bg_image_frag, .fragment),
.bg_image_vert = try Module.initFromSpirv(device, vulkan_spv.bg_image_vert, .vertex),
.cell_bg_frag = try Module.initFromSpirv(device, vulkan_spv.cell_bg_frag, .fragment),
.cell_text_frag = try Module.initFromSpirv(device, vulkan_spv.cell_text_frag, .fragment),
.cell_text_vert = try Module.initFromSpirv(device, vulkan_spv.cell_text_vert, .vertex),
.full_screen_vert = try Module.initFromSpirv(device, vulkan_spv.full_screen_vert, .vertex),
.image_frag = try Module.initFromSpirv(device, vulkan_spv.image_frag, .fragment),
.image_vert = try Module.initFromSpirv(device, vulkan_spv.image_vert, .vertex),
.bg_color_frag = try Module.init(alloc, device, source.bg_color_frag, .fragment),
.bg_image_frag = try Module.init(alloc, device, source.bg_image_frag, .fragment),
.bg_image_vert = try Module.init(alloc, device, source.bg_image_vert, .vertex),
.cell_bg_frag = try Module.init(alloc, device, source.cell_bg_frag, .fragment),
.cell_text_frag = try Module.init(alloc, device, source.cell_text_frag, .fragment),
.cell_text_vert = try Module.init(alloc, device, source.cell_text_vert, .vertex),
.full_screen_vert = try Module.init(alloc, device, source.full_screen_vert, .vertex),
.image_frag = try Module.init(alloc, device, source.image_frag, .fragment),
.image_vert = try Module.init(alloc, device, source.image_vert, .vertex),
};
errdefer {
inline for (.{