Exercise 1

Fixed Function Diffuse Lighting and Vertex Shader Diffuse Lighting.

Example

float3 lightDirection = {0.5f, 0.5f, 0.0f };
float4 diffuseMaterialColor = {1.0f, 0.9f, 0.9f, 1.0f };

float4x4 worldMatrix;
float4x4 worldProjViewMatrix;

// Given: The application has set the matrices before calling this technique.

technique tec0 < string purpose = "Fixed Function Diffuse Lighting" ; >
{
    pass P0
    {
        MaterialDiffuse  = {diffuseMaterialColor};
        MaterialSpecular = {0.0f,0.0f,0.0f,0.0f};
        MaterialAmbient  = {0.0f,0.0f,0.0f,0.0f};
        
        LightType[0]      = DIRECTIONAL;
        LightDiffuse[0]   = {1.0f,1.0f,1.0f,1.0f};
        LightSpecular[0]  = {0.0f,0.0f,0.0f,0.0f}; 
        LightAmbient[0]   = {0.0f,0.0f,0.0f,0.0f};
        LightDirection[0] = {lightDirection};
        LightRange[0]     = 100000.0f;
        
        // Turn lighting on and use light zero
        LightEnable[0]    = TRUE;
        Lighting          = TRUE;
        
        // 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;
        
        // Z-buffering to be used
        ZEnable      = true;
        ZWriteEnable = true;
    }
}

technique tec1 < string purpose = "Vertex Shader Diffuse Lighting" ; >
{ 
    pass p0
    {
        // Load matrices
        VertexShaderConstant[0]  = (worldMatrix);
        VertexShaderConstant[4]  = (worldProjViewMatrix);      
		        
        // Material properties of object
        VertexShaderConstant[9]  = (1.0f,1.0f,1.0f,1.0f); 
        VertexShaderConstant[10] = (0.0f,0.0f,0.0f,0.0f);   
        VertexShaderConstant[11] = (0.0f,0.0f,0.0f,0.0f);   
        
        // Light Properties are input from the shader application
        // Diffuse
        VertexShaderConstant[13] = (1.0f,1.0f,1.0f,1.0f);   
        // Specular
        VertexShaderConstant[14] = (0.0f,0.0f,0.0f,0.0f);   
        // Ambient
        VertexShaderConstant[15] = (0.0f,0.0f,0.0f,0.0f);   
        VertexShaderConstant[16] = {lightDirection};                  
        
        // 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 =
        asm
        {
            vs_1_1            

            dcl_position v0
            dcl_normal   v3
            dcl_texcoord v7
            dcl_texcoord v8
			
            m4x4 oPos, v0, c4 // Transform point to projection space.
            m3x3 r0,v3,c0     // Transform normal to world space, 
			                  //   put result into r0.
            dp3  r0,r0,-c16   // Dot product against light, r0 now has lighting
                              //   constant in x, y, and z components (r,g,b).
            mul  r0,r0,c13    // Modulate against diffuse light color.
            mov oD0,r0        // Put into diffuse color output.
        };     
    }
}