spine-runtimes/spine-xna/example-content/SpineEffect.fx

float4x4 World;
float4x4 View;
float4x4 Projection;

sampler TextureSampler : register(s0);

// TODO: add effect parameters here.

struct VertexShaderInput
{
    float4 Position : POSITION0;
	float4 Color : COLOR0;
	float4 TextureCoordinate : TEXCOORD0;
	float4 Color2 : COLOR1;
};

struct VertexShaderOutput
{
    float4 Position : POSITION0;
	float4 Color : COLOR0;
	float4 TextureCoordinate : TEXCOORD0;
	float4 Color2 : COLOR1;
};

VertexShaderOutput VertexShaderFunction(VertexShaderInput input)
{
    VertexShaderOutput output;

    float4 worldPosition = mul(input.Position, World);
    float4 viewPosition = mul(worldPosition, View);
    output.Position = mul(viewPosition, Projection);
	output.TextureCoordinate = input.TextureCoordinate;
	output.Color = input.Color;
	output.Color2 = input.Color2;

    return output;
}

float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0
{
	float4 texColor = tex2D(TextureSampler, input.TextureCoordinate);
	float alpha = texColor.a * input.Color.a;
	float4 output;
	output.a = alpha;
	output.rgb = ((texColor.a - 1.0) * input.Color2.a + 1.0 - texColor.rgb) * input.Color2.rgb + texColor.rgb * input.Color.rgb;

	return output;
}

technique Technique1
{
    pass Pass1
    {
        // TODO: set renderstates here.

        VertexShader = compile vs_2_0 VertexShaderFunction();
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}