float4 g_LightPosition;
float4x4 g_mView;
float4x4 g_mWorld;
float4x4 g_mProjection;
texture g_PlanetTexture;

sampler MeshTextureSampler = sampler_state
{
    texture = <g_PlanetTexture>;
    mipfilter = POINT;
    minfilter = LINEAR;
    magfilter = LINEAR;
};

struct VS_OUTPUT
{
	float4 Position : POSITION;
	float2 TextureUV : TEXCOORD0;
	float4 Color : COLOR0;
};

struct PS_OUTPUT
{
	float4 Color : COLOR;
};

VS_OUTPUT RenderSimplePlanetVS(float4 Pos : POSITION, float4 Normal : NORMAL, float2 Tex : TEXCOORD0, uniform bool bLit)
{
	VS_OUTPUT Output;
	float4x4 worldviewproj;
	float4 worldNormal;
	float4 p;
	float f;
	
	worldviewproj = mul(mul(g_mWorld, g_mView), g_mProjection);
	// turn the vertex normal to world space
	worldNormal = normalize(mul(Normal, g_mWorld));
	// turn the position to world space
	p = mul(Pos, g_mWorld);
	// get the actual position
	Output.Position = mul(Pos, worldviewproj);
	// Color is the light modifier of the vertex
	if (bLit)
	{
		f = max(0, dot(normalize(g_LightPosition - p), worldNormal));
		Output.Color.r = f;
		Output.Color.g = f;
		Output.Color.b = f;
	}
	else
	{
		Output.Color.r = 1.0f;
		Output.Color.g = 1.0f;
		Output.Color.b = 1.0f;
	}
	Output.Color.a = 1.0f;
	Output.TextureUV = Tex;

	return Output;
}

PS_OUTPUT RenderSimplePlanetPS(VS_OUTPUT In)
{
	PS_OUTPUT Output;
	
	Output.Color = tex2D(MeshTextureSampler, In.TextureUV) * In.Color;
	
	return Output;
}