This is a sample of using Metal Shading Language in Unity Shaders.

##Prerequisites

Unity: 2017

Pretty much like GLSL snippets, Metal snippets should be surrounded with METALPROGRAM/ENDMETAL. Please note that you specify entry points for vertex program and fragment shader like for "normal" unity shaders:

#pragma vertex vert
#pragma fragment frag

To connect your shaders with Unity you need to mark vertex inputs, uniforms and textures. Please note that for uniforms only one (shared between vertex program and fragment shaders) uniform buffer is supported.

Use METAL_VERTEX_INPUT to mark vertex data. Arguments are: 0 for position, 1 - normal, 2 - color, 3-6 - uvs, 7 - tangent.

struct InputVP
{
	float4 pos METAL_VERTEX_INPUT(0);
	float2 uv  METAL_VERTEX_INPUT(3);
};

Use METAL_TEX_INPUT to mark used textures. Arguments are: first is metal type to use, second bind point and third texture property name.

fragment OutputFS frag(<...>, METAL_TEX_INPUT(texture2d<half, access::sample>, 0, _MainTex))

Use METAL_CONST_MATRIX and METAL_CONST_VECTOR to mark uniform declarations. Arguments are: METAL_CONST_VECTOR(type, dim, name) and METAL_CONST_MATRIX(type, rows, cols, name)

struct Globals
{
	METAL_CONST_MATRIX(float, 4,4, unity_ObjectToWorld);
	METAL_CONST_MATRIX(float, 4,4, unity_MatrixVP);
	METAL_CONST_VECTOR(half, 4, _Color);
};