ShaderCompiler::HlslEmitter class
#include <Utilities/ShaderCompiler/Hlsl.h>

Transforms an already-lowered modern-GLSL stage source into HLSL (Shader Model 4/5).

Public types

enum class Dialect { Hlsl, Cg }
Which member of the HLSL/Cg dialect family to emit.

Public static functions

static auto Transform(StringView modernSource, bool vertexStage, const StageReflection& reflection, String& out, Diagnostic& diag, Dialect dialect = Dialect::Hlsl, std::int32_t maxBatchSize = 0) -> bool

Enum documentation

enum class ShaderCompiler::HlslEmitter::Dialect

Which member of the HLSL/Cg dialect family to emit.

Cg targets the PS Vita's sceGxm backend, whose shaders are compiled on the console by SceShaccCg. It is the same language family - floatN, mul(), lerp/frac/ddx and TEXCOORD<i> interpolant semantics are shared, which is why it lives here instead of in an emitter of its own - and differs only in the places listed below:

  • Entry points are both named main (VSMain/PSMain in HLSL)
  • System semantics: POSITION for the clip position, WPOS for the fragment position and COLOR for the colour output, instead of SV_Position/SV_Target
  • Uniforms are plain uniform declarations (there is no cbuffer); the samplers are combined sampler2D/sampler3D objects carrying the GXM TEXUNIT<n> semantic, sampled with tex2D()/tex2Dlod() instead of Texture2D + SamplerState + .Sample()
  • There is no vertex-ID or instance-ID input at all - the GXM parameter semantics are the fixed-function-era Cg set - so a stage still referencing gl_VertexID/gl_InstanceID after VertexIdRewrite has run is rejected with a diagnostic rather than mis-emitted

Function documentation

static bool ShaderCompiler::HlslEmitter::Transform(StringView modernSource, bool vertexStage, const StageReflection& reflection, String& out, Diagnostic& diag, Dialect dialect = Dialect::Hlsl, std::int32_t maxBatchSize = 0)

Transforms modernSource (as produced by ShaderParser::BuildStageSource) into HLSL, writing the result to out. vertexStage selects the vertex-vs-fragment lowering; reflection supplies texture-unit register assignments and the batched instance-block stride (for the emitted array size). Returns false and fills diag when the source uses a construct the emitter does not handle.

maxBatchSize caps the BATCH_SIZE baked into a batched shader. Zero, the default, means the only bound is the 64 KB uniform block the desktop and Vita tiers have. The PlayStation 3 needs a far smaller one: its batched instance array reaches the vertex program through constant registers rather than a bindable buffer, so --emit-rsx passes the batch its backend supports.