# I need some DirectX 11 code converted to DirectX 9

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i am not sure where to start on converting this camera code to directx 9 , would it be possible for someone todo it for me

void UpdateCamera()

{

// Rotate target around camera

/*camRotationMatrix = XMMatrixRotationRollPitchYaw(camPitch, camYaw, 0);

camTarget = XMVector3TransformCoord(DefaultForward, camRotationMatrix );

camTarget = XMVector3Normalize(camTarget);*/

/*XMMATRIX RotateYTempMatrix;

RotateYTempMatrix = XMMatrixRotationY(camYaw);

// Walk

camRight = XMVector3TransformCoord(DefaultRight, RotateYTempMatrix);

camForward = XMVector3TransformCoord(DefaultForward, RotateYTempMatrix);

camUp = XMVector3Cross(camForward, camRight);*/

/*// Free Cam

camRight = XMVector3TransformCoord(DefaultRight, camRotationMatrix);

camForward = XMVector3TransformCoord(DefaultForward, camRotationMatrix);

camUp = XMVector3Cross(camForward, camRight);*/

/*camPosition += moveLeftRight*camRight;

camPosition += moveBackForward*camForward;

moveLeftRight = 0.0f;

moveBackForward = 0.0f;

camTarget = camPosition + camTarget;*/

// Third Person Camera

// Set the cameras target to be looking at the character.

camTarget = charPosition;

// This line is because this lessons model was set to stand on the point (0,0,0) (my bad), and we

// don't want to just be looking at the models feet, so we move the camera's target vector up 5 units

camTarget = XMVectorSetY(camTarget, XMVectorGetY(camTarget)+5.0f);

// Unlike before, when we rotated the cameras target vector around the cameras position,

// we are now rotating the cameras position around it's target (which is the character)

// Rotate camera around target

camRotationMatrix = XMMatrixRotationRollPitchYaw(-camPitch, camYaw, 0);

camPosition = XMVector3TransformNormal(DefaultForward, camRotationMatrix );

camPosition = XMVector3Normalize(camPosition);

// Set our cameras position to rotate around the character. We need to add 5 to the characters

// position's y axis because i'm stupid and modeled the character in the 3d modeling program

// to be "standing" on (0,0,0), instead of centered around it ;) Well target her head here though

camPosition = (camPosition * charCamDist) + camTarget;

// We need to set our cameras forward and right vectors to lay

// in the worlds xz plane, since they are the vectors we will

// be using to determine the direction our character is running

camForward = XMVector3Normalize(camTarget - camPosition);    // Get forward vector based on target

camForward = XMVectorSetY(camForward, 0.0f);    // set forwards y component to 0 so it lays only on

// the xz plane

camForward = XMVector3Normalize(camForward);

// To get our camera's Right vector, we set it's x component to the negative z component from the

// camera's forward vector, and the z component to the camera forwards x component

camRight = XMVectorSet(-XMVectorGetZ(camForward), 0.0f, XMVectorGetX(camForward), 0.0f);

// Our camera does not "roll", so we can safely assume that the cameras right vector is always

// in the xz plane, so to get the up vector, we just get the normalized vector from the camera

// position to the cameras target, and cross it with the camera's Right vector

camUp =XMVector3Normalize(XMVector3Cross(XMVector3Normalize(camPosition - camTarget), camRight));

camView = XMMatrixLookAtLH( camPosition, camTarget, camUp );

}


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Where is the D3D 11 part?

The code is just about vector manipulation. MSDN has quite good documentation of each function. I think that those functions should work with D3D9 also.

Cheers!

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Indeed, you can use DirectXMath with D3D9. D3D9 doesn't care which math library you use.

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I just want D3DX functions in my source code so it looks neat

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Why can't you do it your self? Function names are similar with those of D3DX

XMMatrixRotationRollPitchYaw -> D3DXMatrixRotationRollPitchYaw

XMVector3TransformCoord -> D3DXVec3TransformCoord

XMVector3Normalize -> D3DXVec3Normalize


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because they only take 2 params, i know the return value is stored there but it just seems to be confusing me alot

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As i can see In D3DX first params is almost (if not always) an output value/parameter, the same thing it returns. Now it is removed and you just use returned value.

Although this confuses me too, shouldn't  here be Vec3TransformNormal instead Vec3TransformCoord since we are talking about directions?

// "dx11"
camTarget = XMVector3TransformCoord(DefaultForward, camRotationMatrix );

// "dx9"
D3DXVec3TransformCoord(&camTarget, &DefaultForward, &camRotationMatrix);

// although you could use return value if you need to fill some variable with same values as camTarget receives from this function
otherVec3 = *D3DXVec3TransformCoord(&camTarget, &DefaultForward, &camRotationMatrix);


// "dx11"
camRotationMatrix = XMMatrixRotationRollPitchYaw(camPitch, camYaw, 0);

// "dx9"
D3DXMatrixRotationRollPitchYaw(&camRotationMatrix, camPitch, camYaw, 0);

Edited by belfegor