// 3D world rendering shader
// Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com

// Vertex input data
struct VertexData
{
	float3 pos		  : POSITION;
	float4 color	  : COLOR0;
	float2 uv		    : TEXCOORD0;
	float3 normal   : NORMAL; //mxd
};

// Pixel input data
struct PixelData
{
	float4 pos		: POSITION;
	float4 color	: COLOR0;
	float2 uv		  : TEXCOORD0;
};

//mxd
// Pixel input data for light pass
struct LitPixelData
{
	float4 pos		  : POSITION;
	float4 color	  : COLOR0;
	float2 uv		    : TEXCOORD0;
	float3 pos_w    : TEXCOORD1; //mxd. pixel position in world space
	float3 normal   : TEXCOORD2; //mxd. normal
};

// Modulation color
float4 modulatecolor;

// Highlight color
float4 highlightcolor;

// Matrix for final transformation
float4x4 worldviewproj;

//mxd
float4x4 world;
float4 vertexColor;
//light
float4 lightPosAndRadius;
float4 lightColor; //also used as fog color
//fog
float4 cameraPos;  //w is set to fade factor (distance, at wich fog color completely overrides pixel color)

// Texture input
texture texture1;

// Filter settings
dword minfiltersettings;
dword magfiltersettings;
dword mipfiltersettings;
float maxanisotropysetting;

// Texture sampler settings
sampler2D texturesamp = sampler_state
{
	Texture = <texture1>;
	MagFilter = magfiltersettings;
	MinFilter = minfiltersettings;
	MipFilter = mipfiltersettings;
	MipMapLodBias = 0.0f;
	MaxAnisotropy = maxanisotropysetting;
};

// Vertex shader
PixelData vs_main(VertexData vd) {
	PixelData pd;
	// Fill pixel data input
	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
	pd.color = vd.color;
	pd.uv = vd.uv;
	// Return result
	return pd;
}

//mxd. same as vs_main, but uses vertexColor var instead of actual vertex color. used in models rendering
PixelData vs_customvertexcolor(VertexData vd) {
	PixelData pd;
	// Fill pixel data input
	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
	pd.color = vertexColor;
	pd.color.a = 1.0f;
	pd.uv = vd.uv;
	// Return result
	return pd;
}

LitPixelData vs_customvertexcolor_fog(VertexData vd) {
	LitPixelData pd;
	// Fill pixel data input
	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
	pd.pos_w = mul(float4(vd.pos, 1.0f), world);
	pd.color = vertexColor;
	pd.color.a = 1.0f;
	pd.uv = vd.uv;
	pd.normal = vd.normal;
	// Return result
	return pd;
}

//mxd. light pass vertex shader
LitPixelData vs_lightpass(VertexData vd) {
	LitPixelData pd;
	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
	//pd.pos_w = mul(vd.pos, (float3x3)world);
	pd.pos_w = mul(float4(vd.pos, 1.0f), world);
	pd.color = vd.color;
	pd.uv = vd.uv;
	pd.normal = vd.normal;

	// Return result
	return pd;
}

// Normal pixel shader
float4 ps_main(PixelData pd) : COLOR
{
	float4 tcolor = tex2D(texturesamp, pd.uv);
	return tcolor * pd.color * modulatecolor;
}

// Full-bright pixel shader
float4 ps_fullbright(PixelData pd) : COLOR
{
	float4 tcolor = tex2D(texturesamp, pd.uv);
	tcolor.a *= pd.color.a;
	
	// Blend texture color and modulation color
	return tcolor * modulatecolor;
}

// Normal pixel shader with highlight
float4 ps_main_highlight(PixelData pd) : COLOR
{
	float4 tcolor = tex2D(texturesamp, pd.uv);
	
	// Blend texture color, vertex color and modulation color
	float4 ncolor = tcolor * pd.color * modulatecolor;
	float4 hcolor = float4(highlightcolor.rgb, ncolor.a);
	
	//return lerp(ncolor, hcolor, highlightcolor.a);
	return float4(hcolor.rgb * highlightcolor.a + (ncolor.rgb - 0.4f * highlightcolor.a), ncolor.a + 0.25f); //tcolor.a
}

// Full-bright pixel shader with highlight
float4 ps_fullbright_highlight(PixelData pd) : COLOR
{
	float4 tcolor = tex2D(texturesamp, pd.uv);
	
	// Blend texture color and modulation color
	float4 ncolor = tcolor * modulatecolor;
	float4 hcolor = float4(highlightcolor.rgb, ncolor.a);
	
	//return lerp(ncolor, hcolor, highlightcolor.a);
	return float4(hcolor.rgb * highlightcolor.a + (ncolor.rgb - 0.4f * highlightcolor.a), ncolor.a + 0.25f); //tcolor.a
}

//mxd. This adds fog color to current pixel color
float4 getFogColor(LitPixelData pd, float4 color){
   float fogdist = max(16.0f, distance(pd.pos_w, cameraPos.xyz));
   float fogfactor = min(1.0f, fogdist / cameraPos.w);
   //float fogfactor = exp2(cameraPos.w * fogdist);
   if(fogfactor == 1.0f) //texture color completly replaced by fog color
	   return float4(lightColor.rgb, color.a);
   return float4(lightColor.rgb * fogfactor + color.rgb * (1.0f - fogfactor), color.a);
}

//mxd. Shaders with fog calculation
// Normal pixel shader
float4 ps_main_fog(LitPixelData pd) : COLOR {
	float4 tcolor = tex2D(texturesamp, pd.uv);
	return getFogColor(pd, tcolor * pd.color * modulatecolor);
}

// Normal pixel shader with highlight
float4 ps_main_highlight_fog(LitPixelData pd) : COLOR {
	float4 tcolor = tex2D(texturesamp, pd.uv);
	
	// Blend texture color, vertex color and modulation color
	float4 ncolor = tcolor * pd.color * modulatecolor;
	float4 hcolor = float4(highlightcolor.rgb, ncolor.a);
  return getFogColor(pd, float4(hcolor.rgb * highlightcolor.a + (ncolor.rgb - 0.4f * highlightcolor.a), ncolor.a + 0.25f)); //tcolor.a
}

//mxd: used to draw bounding boxes
float4 ps_constant_color(PixelData pd) : COLOR {
	return vertexColor;
}

//mxd. dynamic light pixel shader pass, dood!
float4 ps_lightpass(LitPixelData pd) : COLOR {
	  //is face facing away from light source?
	  if(dot(pd.normal, (lightPosAndRadius.xyz - pd.pos_w)) < -0.1f) // (lightPosAndRadius.xyz - pd.pos_w) == direction from light to current pixel
		  clip(-1);

	  //is pixel in light range?
	  float dist = distance(pd.pos_w, lightPosAndRadius.xyz);
	  if(dist > lightPosAndRadius.w)
		  clip(-1);
	  
	  //is pixel tranparent?
	  float4 tcolor = tex2D(texturesamp, pd.uv);
	  if(tcolor.a == 0.0f)
		  clip(-1);

	  //if it is - calculate color at current pixel
	  float4 lightColorMod = float4(0.0f, 0.0f, 0.0f, 0.0f);

	  lightColorMod.rgb = lightColor.rgb * max(lightPosAndRadius.w - dist, 0.0f) / lightPosAndRadius.w;
	  if(lightColorMod.r > 0.0f || lightColorMod.g > 0.0f || lightColorMod.b > 0.0f){
		  lightColorMod.rgb *= lightColor.a;
		  if(lightColor.a > 0.4f) //Normal, vavoom or negative light
			  return tcolor * lightColorMod;
		  return lightColorMod; //Additive light
	  }
	  clip(-1);
	  return lightColorMod; //should never get here
}

// Technique for shader model 2.0
technique SM20 {
	// Normal
	pass p0 {
		VertexShader = compile vs_2_0 vs_main();
		PixelShader = compile ps_2_0 ps_main();
	}
	
	// Full brightness mode
	pass p1 {
		VertexShader = compile vs_2_0 vs_main();
		PixelShader = compile ps_2_0 ps_fullbright();
	}

	// Normal with highlight
	pass p2 {
		VertexShader = compile vs_2_0 vs_main();
		PixelShader = compile ps_2_0 ps_main_highlight();
	}
	
	// Full brightness mode with highlight
	pass p3 {
		VertexShader = compile vs_2_0 vs_main();
		PixelShader = compile ps_2_0 ps_fullbright_highlight();
	}
	
	//mxd. same as p0-p3, but using vertexColor variable
	// Normal
	pass p4 {
		VertexShader = compile vs_2_0 vs_customvertexcolor();
		PixelShader = compile ps_2_0 ps_main();
	}
	
	pass p5 {} //mxd. need this only to maintain offset
	
	// Normal with highlight
	pass p6 {
		VertexShader = compile vs_2_0 vs_customvertexcolor();
		PixelShader = compile ps_2_0 ps_main_highlight();
	}

	pass p7 {} //mxd. need this only to maintain offset
	
	//mxd. same as p0-p3, but with fog calculation
	 // Normal
	pass p8 {
		VertexShader = compile vs_2_0 vs_lightpass();
		PixelShader = compile ps_2_0 ps_main_fog();
	}
	
	pass p9 {} //mxd. need this only to maintain offset

	// Normal with highlight
	pass p10 {
		VertexShader = compile vs_2_0 vs_lightpass();
		PixelShader = compile ps_2_0 ps_main_highlight_fog();
	}

	pass p11 {} //mxd. need this only to maintain offset
	
	//mxd. same as p4-p7, but with fog calculation
	// Normal
	pass p12 {
		VertexShader = compile vs_2_0 vs_customvertexcolor_fog();
		PixelShader = compile ps_2_0 ps_main_fog();
	}

	pass p13 {} //mxd. need this only to maintain offset
	
	// Normal with highlight
	pass p14 {
		VertexShader = compile vs_2_0 vs_customvertexcolor_fog();
		PixelShader = compile ps_2_0 ps_main_highlight_fog();
	}


	pass p15 {} //mxd. need this only to maintain offset
	
	//mxd. Just fills everything with vertexColor. Used in ThingCage rendering.
	pass p16 {
		VertexShader = compile vs_2_0 vs_customvertexcolor();
		PixelShader  = compile ps_2_0 ps_constant_color();
	}
	
	//mxd. Light pass
	pass p17 {
		VertexShader = compile vs_2_0 vs_lightpass();
		PixelShader  = compile ps_2_0 ps_lightpass();
		AlphaBlendEnable = true;
	}
}