// Define inputs from application.
struct VertexIn
{
  float4 position : POSITION;       // Vertex in object-space
  float2 texCoords  : TEXCOORD0;    // Vertex's Texture Coordinates
};

// Define outputs from vertex shader.
struct Vertex
{
  float4 position   : POSITION;     // Vertex position in screen-space
  float4 color      : COLOR;        // Vertex color
  float2 texCoords  : TEXCOORD0;    // Vertex Texture Coordinates
  float depth       : TEXCOORD1;    // Vertex depth in eye space
};

Vertex main(VertexIn p_In,
            uniform float4 p_AmbientLight,          // Ambient light in scene
            uniform float4x4 p_ModelViewProjection  // Model view projection matrix
           )
{
    Vertex l_Out;
    
    // Transform vertex position into homogenous screen-space.
    l_Out.position = mul(p_ModelViewProjection, p_In.position);
    
    // Store depth
    l_Out.depth = l_Out.position.z;
    
    // Store ambient color
    l_Out.color = p_AmbientLight;
    
    // Pass texture coordinates to fragment shader
    l_Out.texCoords = p_In.texCoords;

    return l_Out;
}