Microsoft DirectX 8.1 (pixel shader versions 1.0, 1.1, 1.2, 1.3, 1.4)

mad

Multiply and add instruction. Sets the destination register to (src0 * src1) + src2.

mad dest, src0, src1, src2

Registers

Argument Description RegistersVersion
vn cn tn rn
dest Destination register x 1.0
x x 1.1, 1.2, 1.3
x 1.4
src0, src1, src2 Source register x x x x 1.0, 1.1, 1.2, 1.3
x x 1.4 phase 1
x x x 1.4 phase 2

To learn more about registers, see Registers.

Remarks

This instruction performs a multiply accumulate operation based on the following formula.

dest = src0 * src1 + src2

Example

This example is for illustration only. The C code accompanying the shader has not been optimized for performance. It can use helper functions from the Sample Framework. The sample framework is the foundation on which many of the samples are built.

 
// This example blends a diffuse color, a texture color and a constant color.

// The shader is shown below.
ps.1.0              // Version instruction.
tex t0              // Declare texture.
mad r0, v0, t0, v0  // Mix diffuse color and texture color.


// The following four images show the contents of the three source registers
// and the resulting output register. The output register shows the result of 
// the gradient in the center of the destination image, where the mid tones 
// appear. This is a result of adding the pixels from the center of src2 with 
// the pixel color created from the center of the product of src0*src1.



// Additional code loads a texture in texture stage 0.
LPDIRECT3DDEVICE8   m_pd3dDevice;   // initialize this pointer
LPDIRECT3DTEXTURE8  m_pTexture0;    // a pointer to the texture.
TCHAR               strPath[512] = "textureFile.jpg";

D3DUtil_CreateTexture( m_pd3dDevice, strPath, &m_pTexture0, D3DFMT_R5G6B5 );
m_pd3dDevice->SetTexture( 0, m_pTexture0 );