I need help rotating my arm sprite towards the mouse coordinates.
My mouse coordinates are set to be POINT MousePos
Here is my transformation code:
static float rotation;
D3DXVECTOR2 spriteCentre=D3DXVECTOR2(2.0f,5.0f);
D3DXMatrixTransformation2D(&mat,NULL,0.0,&scaling,&spriteCentre,rotation,&trans);
float Rotation is how much the sprite will rotate, in radian.
Please help me out on this one.
PS:If you don't know this code, you can write your own.
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C++ DirectX9.
MSVC++ 2010 Express.
Windows 7.
I'm not expert in this but I think you have to explain better what you are trying to accomplish.
You wan't a sprite to point towards the mouse pointer?
If that is the case you would probably need a algorithm to calculate it. It would depend on the location of the sprite as much as of the mouse pointer.
Let´s say the rotation 0 is straight up then that should be the case when it has the same X as mouse and Y is bigger.
The math here would be, assuming:
pos is position of sprite
mouse is position of mouse
I'm not expert in this but I think you have to explain better what you are trying to accomplish.
You wan't a sprite to point towards the mouse pointer?
If that is the case you would probably need a algorithm to calculate it. It would depend on the location of the sprite as much as of the mouse pointer.
Let´s say the rotation 0 is straight up then that should be the case when it has the same X as mouse and Y is bigger.
The math here would be, assuming:
pos is position of sprite
mouse is position of mouse
DeltaY = mouse.Y - pos.Y
DeltaX = mouse.X - pos.X
rotation = tan^-1(DeltaY / DeltaX)
This is basic and I might be off.
I'll explain better:
my character's arm is an individual sprite, I want it to rotate towards the mouse, so when you move the mouse the arm follows so that you are able to aim.
I tried to do
DeltaY = MousePos.y - pos_y;
DeltaX = MousePos.x - pos_x;
rotation = tan^-1(DeltaY / DeltaX);
But got the error "Expression must have (pointer-to-) function type" and "term does not evaluate to a function taking 1 arguments"
This was for the "-1" in this line "rotation = tan^-1(DeltaY / DeltaX);"
But got the error "Expression must have (pointer-to-) function type" and "term does not evaluate to a function taking 1 arguments"
This was for the "-1" in this line "rotation = tan^-1(DeltaY / DeltaX);"
My example was just pure math not code syntax
Buckeye has already explained the syntax you would need. Did it otherwise work as I explained? I wasn't sure just a rough guess.
But got the error "Expression must have (pointer-to-) function type" and "term does not evaluate to a function taking 1 arguments"
This was for the "-1" in this line "rotation = tan^-1(DeltaY / DeltaX);"
My example was just pure math not code syntax
Buckeye has already explained the syntax you would need. Did it otherwise work as I explained? I wasn't sure just a rough guess.
