mad

Multiplies and adds sources.

mad dest, src0, src1, src2

Registers

dest

Destination register.

src0

Input source register.

src1

Input source register.

src2

Input source register.

To learn more about registers, see Registers.

Remarks

The following code fragment shows the operations performed.

dest.x = src0.x * src1.x + src2.x;
dest.y = src0.y * src1.y + src2.y;
dest.z = src0.z * src1.z + src2.z;
dest.w = src0.w * src1.w + src2.w;

Example

// This example combines three colors.

vs.1.0
m4x4 oPos, v0, c0	; transform vertices by view/projection matrix

mov r0, c4	    	; green
mov r1, c6		; off white
mov r2, c7	    	; gray
mad r3, r0, r1, r2	         ; combine all three colors
mov oD0, r3

// The resultant vertex color is a combination of all three colors. 
// The mad instruction multiplies green and off-white to produce a 
// slightly darker shade of green. Then gray is added to the result 
// which yields a shade of green that has non-zero red and blue 
// components. The resulting shade is shown below.

// Additional code is used to initialize the constant registers. 

D3DXMATRIX mat, matView, matProj;
D3DXMatrixMultiply(&mat, &matView, &matProj);
D3DXMatrixTranspose(&mat, &mat);
// set C0 with the view and projection matrix
m_pd3dDevice->SetVertexShaderConstant(0, &mat, 4);

// set register c4
float color[4] = {0, 1, 0, 0};
m_pd3dDevice->SetVertexShaderConstant(4, &color, 1);

// set register c6
float colorOffWhite[] = {0.9f, 0.9f, 0.9f, 0.9f};
m_pd3dDevice->SetVertexShaderConstant(6, &colorOffWhite, 1);

// set register c7
float colorGray[] = {0.5f, 0.5f, 0.5f, 0.5f};
m_pd3dDevice->SetVertexShaderConstant(7, &colorGray, 1);

// The c0 register is loaded with the view and projection matrix using the 
// m4x4 instruction (the m4x4 instruction also uses the c1, c2 and c3 
// registers). The last three methods set the constant color registers 
// c4, c6 and c7.