UUSL Semantics

Redefined UUSL semantics allows you to create unified input\output shader structures for both graphics APIs.

Vertex shader semantics contain necessary input and output data for shader. You should initialize variables first and then use them.

Here is an example of vertex shader input and output structures:

// Input vertex data
STRUCT(VERTEX_IN)
	INIT_ATTRIBUTE(float4,0,POSITION)	// Vertex position
	INIT_ATTRIBUTE(float4,1,TEXCOORD0)	// Vertex texcoord (uv)
	INIT_ATTRIBUTE(float4,2,TEXCOORD1)	// Vertex basis tangent
	INIT_ATTRIBUTE(float4,3,TEXCOORD2)	// Vertex color
END

// Our output vertex data
STRUCT(VERTEX_OUT)
	INIT_POSITION		// Out projected position
	INIT_OUT(float4,0)	// Texcoord (uv)
	INIT_OUT(float3,1)	// Vertex direction
END

Use the following pre-defined variables to use the input\output vertex shader semantics:

Fragment shader semantics contain necessary input and output data for shader. You should initialize variables first and then use them.

To use the variables in the code, use the following variables:

Here is a simple example of using the variable in the main function of the shader:

MAIN_BEGIN(FRAGMENT_OUT,FRAGMENT_IN)
	
	float4 texcoord = IN_DATA(0);

	/* ... other code ... */
END

Unified shader semantics allows you to create single structure for both vertex and fragment shaders. It facilities the work with vertex and fragment shaders input/output structure by using single structure for both shaders: this structure will be output for vertex shader and input for fragment shader respectively.

You can write vertex and fragment shader in a single file with .shader extension. In this case, in the material you should specify this .shader file for both shader stages.

<materials version="2.0" editable="0">
	<material name="mesh_base" editable="0" parameters_prefix="m" defines="VERTEX_ATTRIBUTE_GEOMETRY">
		<!-- ... -->
		<shader pass="auxiliary" object="mesh_static"
				auxiliary="1"
				defines="BASE_AUXILIARY"
				vertex="core/shaders/mesh/auxiliary/auxiliary.shader"
				fragment="core/shaders/mesh/auxiliary/auxiliary.shader"/>
		<!-- ... -->
	</material>
</materials>

IF statement

//input struct
STRUCT(FRAGMENT_IN)
/* ... */
	#ifdef ALPHA_FADE && USE_ALPHA_FADE
		INIT_DATA(float,1,DATA_ALPHA_FADE)
	#endif
/* ... */
END

//main functions
MAIN_SHADOW_BEGIN(FRAGMENT_OUT,FRAGMENT_IN)
/* ... */
	IF_DATA(DATA_ALPHA_FADE)
		//code to execute if the data is not null
		texture2DAlphaFadeDiscard(DATA_ALPHA_FADE,IN_POSITION.xy);
	ENDIF
/* ... */
MAIN_SHADOW_END