# convert ID3DXMatrixStack to DirectXMath

Is it right it convert ID3DXMatrixStack to DirectXMath like that:

#include <stack>
#include <iostream>
#include <DirectXMath.h>

class MatrixStack {
std::deque<DirectX::XMFLOAT4X4> m_MatrixStack;

public:
MatrixStack() {
DirectX::XMFLOAT4X4 identity;
DirectX::XMStoreFloat4x4(&identity, DirectX::XMMatrixIdentity());
m_MatrixStack.push_back(identity);
}
void Push() {
m_MatrixStack.push_back(m_MatrixStack.back());
}
void Pop() {
if (!m_MatrixStack.empty()) {
m_MatrixStack.pop_back();
}
}
void MultMatrix(DirectX::FXMMATRIX other) {
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), DirectX::XMMatrixMultiply(currentMatrix, other));
}
void MultMatrix(const DirectX::XMFLOAT4X4& other) {
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), DirectX::XMMatrixMultiply(currentMatrix, otherMatrix));
}
void MultMatrixLocal(DirectX::FXMMATRIX other) {
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), DirectX::XMMatrixMultiply(other, currentMatrix));
}
void MultMatrixLocal(const DirectX::XMFLOAT4X4& other) {
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), DirectX::XMMatrixMultiply(otherMatrix, currentMatrix));
}
DirectX::XMFLOAT4X4 identity;
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), DirectX::XMMatrixIdentity());
}
m_MatrixStack.back() = other;
}
DirectX::XMStoreFloat4x4(&m_MatrixStack.back(), other);
}
const DirectX::XMFLOAT4X4& GetTop() {
return m_MatrixStack.back();
}
void RotateAxis(const DirectX::XMFLOAT3& axis, float angle) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
currentMatrix,
DirectX::XMMatrixRotationAxis(axis3f, angle)
)
);
}
void RotateAxis(DirectX::FXMVECTOR axis, float angle) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
currentMatrix,
DirectX::XMMatrixRotationAxis(axis, angle)
)
);
}
void RotateAxisLocal(const DirectX::XMFLOAT3& axis, float angle) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
DirectX::XMMatrixRotationAxis(axis3f, angle),
currentMatrix
)
);
}
void RotateAxisLocal(const DirectX::FXMVECTOR& axis, float angle) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
DirectX::XMMatrixRotationAxis(axis, angle),
currentMatrix
)
);
}
void RotateYawPitchRoll(float yaw, float pitch, float roll) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
currentMatrix,
DirectX::XMMatrixRotationRollPitchYaw(pitch, yaw, roll)
)
);
}
void RotateYawPitchRollLocal(float yaw, float pitch, float roll) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
DirectX::XMMatrixRotationRollPitchYaw(pitch, yaw, roll),
currentMatrix
)
);
}
void Scale(float x, float y, float z) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
currentMatrix,
DirectX::XMMatrixScaling(x, y, z)
)
);
}
void ScaleLocal(float x, float y, float z) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
DirectX::XMMatrixScaling(x, y, z),
currentMatrix
)
);
}
void Translate(float x, float y, float z) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
currentMatrix,
DirectX::XMMatrixTranslation(x, y, z)
)
);
}
void TranslateLocal(float x, float y, float z) {
DirectX::XMStoreFloat4x4(
&m_MatrixStack.back(),
DirectX::XMMatrixMultiply(
DirectX::XMMatrixTranslation(x, y, z),
currentMatrix
)
);
}
};


Supplies a mechanism to enable matrices to be pushed onto and popped off of a matrix stack. Implementing a matrix stack is an efficient way to track matrices while traversing a transform hierarchy. Matrix stack to store transformations as matrices. Implementing a Scene Hierarchy A matrix stack simplifies the construction of hierarchical models, in which complicated objects are constructed from a series of simpler objects. A scene, or transform, hierarchy is usually represented by a tree data structure.Each node in the tree data structure contains a matrix.A particular matrix represents the change in coordinate systems from the node's parent to the node. For example, if you are modeling a human arm, you might implement the following hierarchy. In this hierarchy, the Body matrix places the body in the world.The UpperArm matrix contains the rotation of the shoulder, the LowerArm matrix contains the rotation of the elbow, and the Hand matrix contains the rotation of the wrist.To determine where the hand is relative to the world, you simply multiply all the matrices from Body down through Hand together. The previous hierarchy is overly simplistic, because each node has only one child.If you begin to model the hand in more detail, you will probably add fingersand a thumb. Each digit can be added to the hierarchy as children of Hand. If you traverse the complete graph of the arm in depth - first order-traversing as far down one path as possible before moving on to the next path—to draw the scene, you perform a sequence of segmented rendering.For example, to render the handand fingers, you implement the following pattern.

1. Push the Hand matrix onto the matrix stack.
2. Draw the hand.
3. Push the Thumb matrix onto the matrix stack.
4. Draw the thumb.
5. Pop the Thumb matrix off the stack.
6. Push the Finger 1 matrix onto the matrix stack.
7. Draw the first finger.
8. Pop the Finger 1 matrix off the stack.
9. Push the Finger 2 matrix onto the matrix stack.You continue in this manner until all the fingersand thumb are rendered.

After you have completed rendering the fingers, you would pop the Hand matrix off the stack. You can follow this basic process in code with the following examples.When you encounter a node during the depth - first search of the tree data structure, push the matrix onto the top of the matrix stack.

MatrixStack->Push();

MatrixStack->MultMatrix(pNode->matrix);

When you are finished with a node, pop the matrix off the top of the matrix stack.

MatrixStack->Pop();

In this way, the matrix on the top of the stack always represents the world - transform of the current node.Therefore, before drawing each node, you should set matrix.

// Adds a matrix to the stack.
// This method increments the count of items on the stack by 1, duplicating the current matrix.
// The stack will grow dynamically as more items are added.
void Push();

// Removes the current matrix from the top of the stack.
// Note that this method decrements the count of items on the stack by 1, effectively
// removing the current matrix from the top of the stack and promoting a matrix to the top of the
// stack. If the current count of items on the stack is 0, then this method returns without performing
// any action. If the current count of items on the stack is 1, then this method empties the stack.
void Pop();

// Determines the product of the current matrixand the given matrix.
// This method right-multiplies the given matrix to the current matrix (transformation is about the current world origin
// m_pstack[m_currentPos] = m_pstack[m_currentPos] * (*pMat);
// This method does not add an item to the stack, it replaces the current matrix with the product of the current matrix and the given matrix.
void MultMatrix(DirectX::FXMMATRIX other);

// Determines the product of the current matrixand the given matrix.
// This method right-multiplies the given matrix to the current matrix (transformation is about the current world origin
// m_pstack[m_currentPos] = m_pstack[m_currentPos] * (*pMat);
// This method does not add an item to the stack, it replaces the current matrix with the product of the current matrix and the given matrix.
void MultMatrix(const DirectX::XMFLOAT4X4& other);

// Determines the product of the given matrix and the current matrix.
// This method left-multiplies the given matrix to the current matrix (transformation is about the local origin of the object).
// m_pstack[m_currentPos] = (*pMat) * m_pstack[m_currentPos];
// This method does not add an item to the stack, it replaces the current matrix with the product of the given matrix and the current matrix.
void MultMatrixLocal(DirectX::FXMMATRIX other);

// Determines the product of the given matrix and the current matrix.
// This method left-multiplies the given matrix to the current matrix (transformation is about the local origin of the object).
// m_pstack[m_currentPos] = (*pMat) * m_pstack[m_currentPos];
// This method does not add an item to the stack, it replaces the current matrix with the product of the given matrix and the current matrix.
void MultMatrixLocal(const DirectX::XMFLOAT4X4& other);

// Loads identity in the current matrix.
// The identity matrix is a matrix in which all coefficients are 0.0 except the [1,1][2,2][3,3][4,4] coefficients,
// which are set to 1.0. The identity matrix is special in that when it is applied to vertices, they are unchanged.
// The identity matrix is used as the starting point for matrices that will modify vertex values to create rotations,
// translations, and any other transformations that can be represented by a 4x4 matrix.

// Loads the given matrix into the current matrix.

// Loads the given matrix into the current matrix.

// Retrieves the current matrix at the top of the stack.
// Note that this method does not remove the current matrix from the top of the stack; rather, it just returns the current matrix.
DirectX::XMFLOAT4X4& GetTop();

// Rotates (relative to world coordinate space) around an arbitrary axis.
// axis - arbitrary axis of rotation
// angle - Rotation angle about the arbitrary axis, in radians. Angles are measured counterclockwise when looking along the arbitrary axis toward the origin.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationAxis(&tmp, pV, angle);
// m_stack[m_currentPos] = m_stack[m_currentPos] * tmp;
// Because the rotation is right-multiplied to the matrix stack, the rotation is relative to world coordinate space.
void RotateAxis(const DirectX::XMFLOAT3& axis, float angle);

// Rotates (relative to world coordinate space) around an arbitrary axis.
// axis - arbitrary axis of rotation
// angle - Rotation angle about the arbitrary axis, in radians. Angles are measured counterclockwise when looking along the arbitrary axis toward the origin.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationAxis(&tmp, pV, angle);
// m_stack[m_currentPos] = m_stack[m_currentPos] * tmp;
// Because the rotation is right-multiplied to the matrix stack, the rotation is relative to world coordinate space.
void RotateAxis(DirectX::FXMVECTOR axis, float angle);

// Rotates (relative to the object's local coordinate space) around an arbitrary axis.
// axis - arbitrary axis of rotation
// angle - Rotation angle about the arbitrary axis, in radians. Angles are measured counterclockwise when looking along the arbitrary axis toward the origin.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationAxis(&tmp, pV, angle);
// m_stack[m_currentPos] = tmp * m_stack[m_currentPos];
// Because the rotation is left-multiplied to the matrix stack, the rotation is relative to the object's local coordinate space.
void RotateAxisLocal(const DirectX::XMFLOAT3& axis, float angle);

// Rotates (relative to the object's local coordinate space) around an arbitrary axis.
// axis - arbitrary axis of rotation
// angle - Rotation angle about the arbitrary axis, in radians. Angles are measured counterclockwise when looking along the arbitrary axis toward the origin.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationAxis(&tmp, pV, angle);
// m_stack[m_currentPos] = tmp * m_stack[m_currentPos];
// Because the rotation is left-multiplied to the matrix stack, the rotation is relative to the object's local coordinate space.
void RotateAxisLocal(const DirectX::FXMVECTOR& axis, float angle);

// Rotates around (relative to world coordinate space).
// The yaw around the y-axis in radians.
// The pitch around the x-axis in radians.
// The roll around the z-axis in radians.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationYawPitchRoll(&tmp, yaw, pitch, roll);
// m_stack[m_currentPos] = m_stack[m_currentPos] * tmp;
// Because the rotation is right-multiplied to the matrix stack, the rotation is relative to world coordinate space.
void RotateYawPitchRoll(float yaw, float pitch, float roll);

// Rotates around (relative to world coordinate space).
// The yaw around the y-axis in radians.
// The pitch around the x-axis in radians.
// The roll around the z-axis in radians.
// This method adds the rotation to the matrix stack with the computed rotation matrix similar to the following:
// D3DXMATRIX tmp;
// D3DXMatrixRotationYawPitchRoll(&tmp, yaw, pitch, roll);
// m_stack[m_currentPos] = tmp * m_stack[m_currentPos];
// Because the rotation is left-multiplied to the matrix stack, the rotation is relative to the object's local coordinate space.
void RotateYawPitchRollLocal(float yaw, float pitch, float roll);

// Scale the current matrix about the world coordinate origin.
// This method right-multiplies the current matrix with the computed scale matrix. The transformation is about the current world origin.
// D3DXMATRIX tmp;
// D3DXMatrixScaling(&tmp, x, y, z);
// m_stack[m_currentPos] = m_stack[m_currentPos] * tmp;
void Scale(float x, float y, float z);

// Scale the current matrix about the object origin.
// This method left-multiplies the current matrix with the computed scale matrix. The transformation is about the local origin of the object.
// D3DXMATRIX tmp;
// D3DXMatrixScaling(&tmp, x, y, z);
// m_stack[m_currentPos] = tmp * m_stack[m_currentPos];
void ScaleLocal(float x, float y, float z);

// Determines the product of the current matrix and the computed translation matrix determined by the given factors (x, y, and z)
// This method right-multiplies the current matrix with the computed translation matrix (transformation is about the current world origin).
// D3DXMATRIX tmp;
// D3DXMatrixTranslation(&tmp, x, y, z);
// m_stack[m_currentPos] = m_stack[m_currentPos] * tmp;
void Translate(float x, float y, float z);

// Determines the product of the computed translation matrix determined by the given factors (x, y, and z) and the current matrix.
// This method left-multiplies the current matrix with the computed translation matrix (transformation is about the local origin of the object).
// D3DXMATRIX tmp;
// D3DXMatrixTranslation(&tmp, x, y, z);
// m_stack[m_currentPos] = tmp * m_stack[m_currentPos];
void TranslateLocal(float x, float y, float z);

• It might be worth considering to replace deque with a vector – Greck May 14 at 11:11
• it would be better to add XM_CALLCONV for 32bit systems – Greck May 14 at 11:35