Add spvfc CLI tool and GLSLCompiler public C++ API header

[Copilot]

Adds a command-line compiler (spvfc) that compiles GLSL/HLSL shaders directly to .spvf files and prints a human-readable reflection summary. Also extracts a proper public C++ API header from the previously header-less library.

GLSLCompiler.h (new)

• Moves ShaderLanguageType and CompileInfo out of glsl2spv.cpp into a public header
• SPVData / SPVParseData exposed as opaque handles; layouts remain private
• Includes SPVParseFlat.h — one include gives both the compiler API and the zero-dep flat-file loader
• vulkan_version / spv_version in CompileInfo changed from const members to plain uint32_t (assignable)

glsl2spv.cpp changes

• Three new extern "C" field accessors for the opaque SPVData handle: SPVDataGetResult, SPVDataGetLog, SPVDataGetDebugLog — also wired into GLSLCompilerInterface for dynamic-load callers
• Duplicate type definitions removed; #include "GLSLCompiler.h" replaces the old #include "SPVParseFlat.h"

spvfc.cpp (new)

Links against GLSLCompilerStatic. Per-file pipeline: extension → stage detection → CompileFromPath → ParseSPV → CreateShaderFlat → ShaderFlatLoad (for reflection printing) → write .spvf.

spvfc [options] <shader_file> [<shader_file2> ...]

  -o <file>       Output .spvf path  (single input only)
  -e <name>       Entry-point name   [default: main]
  -I <dir>        Add include search path  (repeatable; -I<dir> also OK)
  -D <macro>      Add preprocessor define  (-DMACRO=value also OK)
  --hlsl          Treat all inputs as HLSL
  --vulkan <ver>  Target Vulkan version: 1.0 (default)  1.1  1.2  1.3
  --spv    <ver>  Target SPIR-V version: 1.0 (default)  1.1 .. 1.6
  --no-output     Compile + reflect, skip writing .spvf
  --no-reflect    Suppress reflection text
  --quiet         Suppress informational messages

Sample reflection output:

=== Reflection: mesh.vert ===
Stage      : vertex (0x00000001)
Entry      : main
SPIR-V     : 4096 bytes (1024 words)

Stage Inputs (2):
  loc=0    vec3            inPosition
  loc=1    vec2            inTexCoord

uniform_buffer (1):
  set=0   binding=0    UboData

Push Constants (1):
  offset=0     size=64    Transform

CMakeLists.txt

• GLSLCompiler.h added to both library source lists
• New target: add_executable(spvfc spvfc.cpp) linked against GLSLCompilerStatic ${VULKAN_SPIRV_LIBS}

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.