Exercise 2: Vertex Shader Diffuse Lighting

//
// Effect File Workshop Solution for Exercise 2
// Copyright (c) 2001 Microsoft Corporation. All rights reserved.
//

vector lhtR;	// Light direction from app
vector matD; 	// Object diffuse material color

matrix mWld;	// World
matrix mTot;	// Total

// Load model
string XFile = "f40.x";

// Background color
DWORD  BCLR = 0xff000000;

// No pixel shader
pixelshader pNIL; 

// Technique names for display in viewer window
string tec0 = "Solution 2: Vertex Shader Diffuse Lighting";


/////////////////////////////////////////////////////////////////////////////
///////        Exercise 2: Vertex Shader Diffuse Lighting          //////////
///////     Light the model taking both diffuse material and       //////////
///////     diffuse light source into consideration.               //////////
/////////////////////////////////////////////////////////////////////////////
technique tec0
{ 
    pass p0
    {
        //Load matrices
        VertexShaderConstant[0] = ; 	                // World Matrix
        VertexShaderConstant[4] = ;	            	// World*View*Proj Matrix
        
        //Material properties of object
        VertexShaderConstant[9]  = ;                  // Diffuse from object material diffuse
        VertexShaderConstant[10] = (0.0f,0.0f,0.0f,0.0f);   // Specular from constant color
        VertexShaderConstant[11] = (0.0f,0.0f,0.0f,0.0f);   // Ambient from constant color
        
        // Light Properties. lhtR is input from the shader app
        VertexShaderConstant[13] = (1.0f,0.9f,0.9f,1.0f);   // Diffuse
        VertexShaderConstant[14] = (0.0f,0.0f,0.0f,0.0f);   // Specular
        VertexShaderConstant[15] = (0.0f,0.0f,0.0f,0.0f);   // Ambient
        VertexShaderConstant[16] = ;	                // Light direction
        
        // Assign diffuse color to be used
        ColorOp[0]   = SelectArg1;
        ColorArg1[0] = Diffuse;
        AlphaOp[0]   = SelectArg1;
        AlphaArg1[0] = Diffuse;
        
        // Only one color being used
        ColorOp[1]   = Disable;
        AlphaOp[1]   = Disable;

        // Definition of the vertex shader, declarations then assembly
        VertexShader =
        decl
        {
            stream 0;
            float v0[3];        // Position
            float v3[3];        // Normal
            float v7[3];        // Texture Coord1
            float v8[3];        // Texture coord2
        }   
        asm
        {
            vs.1.1              // Version number

            m4x4 oPos, v0, c4   // Transform point to projection space
            
            dp3  r0,v3,-c16     // Dot product against untransformed light
                        
            mul  r0,r0,c13      // Modulate against diffuse light color
            mul  r0,r0,c9       // Modulate against diffuse material
            
            mov oD0,r0          // Put into Diffuse Color output
        };     
    }
}