[ ...  2, 3, 6,  // Front top triangle        3, 5, 7,  // Right side bottom triangle        3, 1, 5,  // Right side top triangle            ... ] // ⟾ Index Buffer

     [ YZX, Z,   Y,   0.0,
       Z,   ZY,  X,   0.0,
       Y,   X,   XYZ, 0.0,
       X,   Y,   Z,   W    ]

// A vertex shader is executed for every vertex in the Scene.
// This is written in "CG" a high-level shading language by NVIDIA.
void vertexShader( in  float3 InPosition   : POSITION,
                   in  float3 InNormal     : NORMAL,
                   in  float2 InTexCoord   : TEXCOORD1,
                   out float4 OutPosition  : POSITION,
                   out float3 OutNormal    : TEXCOORD0,
                   out float2 OutTexCoord  : TEXCOORD1) {
    
    // Execute view space transformation.
    float3 position = TransformPoint(InPosition, CameraProjectionMatrix);

    // Return vertex data.
    OutPosition = transformedPosition;
    OutTexCoord = InTexCoord;
    OutNormal = normalize(InNormal);
}

// A fragment shader is executed for every fragment of a triangle,
// calculating the color of its pixel based on texture and light.
float4 fragmentShader( float3 InNormal    : TEXCOORD0,
                       float2 InTexCoord  : TEXCOORD1) : COLOR {

    // Texture sampling by interpolated texture coordinate.
    float4 texel = tex2D(texture, InTexCoord);

    // Calculate light color: Ambient light.
    float3 light = ambientLightColor;
    // Add directional light based on interpolated normal.
    light += (max(dot(-lightDirection, InNormal), 0.0) * lightColor);

    // Add light to texture color.
    return texel * float4(light, 1.0);
}