DirectX11 学习笔记7 - 支持自由移动的摄像机

如今将又一次制定一个camera摄像机。能够自由移动。

比方前进 后退，上游 下潜。 各个方向渲染之类的。

首先设置按键。

这个时候须要在

XWindow.h 里面

bool XWindow::frame()
{
	//推断是否按下ESC键
	if(x_input->isKeyDown(VK_ESCAPE))
		return false;
	//假设A,S,D,W,Q,E,Z,X,C键按下。移动摄像机
	if(GetAsyncKeyState('W') & 0x8000)    //前后
		x_graphics->x_camera->walk(-0.1f);
	if(GetAsyncKeyState('S') & 0x8000)
		x_graphics->x_camera->walk(0.1f);
	if(GetAsyncKeyState('A') & 0x8000)    //左右
		x_graphics->x_camera->strafe(-0.1f);
	if(GetAsyncKeyState('D') & 0x8000)
		x_graphics->x_camera->strafe(0.1f);
	//if(GetAsyncKeyState('Q') & 0x8000)    //上下
	//	x_graphics->x_camera->fly(-0.1f);
	//if(GetAsyncKeyState('E') & 0x8000)
	//	x_graphics->x_camera->fly(0.1f);
	//if(GetAsyncKeyState('Z') & 0x8000)
	//	x_graphics->x_camera->pitch(PI/180);
	//if(GetAsyncKeyState('X') & 0x8000)
	//	x_graphics->x_camera->yaw(PI/180);
	//if(GetAsyncKeyState('C') & 0x8000)
	//	x_graphics->x_camera->roll(PI/180);

	//动画。旋转摄像机
	//x_graphics->x_camera->roll(PI/180);

	//開始渲染
	return x_graphics->frame();
}

加入一些按键。假设报错的话， 可能是x_camera 在XGraphics.h 类里面是私有的，能够设置成公有

private:
	bool render();
public:
	XCamera *x_camera;//摄像机
private:
	XD3Device *x_d3d;//3D设备
	XModel *x_model;//模型
	XShader *x_shader;//渲染器
	HWND hwnd;

然后非常easy吧

然后就是改动摄像机了

先上代码再解说吧

#pragma once
#include <xnamath.h>
class XCamera
{
public:
	enum CameraType { LANDOBJECT, AIRCRAFT };
	XCamera();
	void strafe(float units); // l左右
	//void fly(float units);    // 上下
	void walk(float units);   // 前后

	//void pitch(float angle); // 旋转view坐标系right向量
	//void yaw(float angle);   // 旋转up向量
	//void roll(float angle);  // 旋转look向量

	void getViewMatrix(XMMATRIX& V);
	void setCameraType(CameraType cameraType);
	void getPosition(XMFLOAT3* pos);
	void setPosition(XMFLOAT3* pos); 

	void getRight(XMFLOAT3* right);
	void getUp(XMFLOAT3* up);
	void getLook(XMFLOAT3* look);
private:
	CameraType _cameraType;
	XMFLOAT3 _right,_up,_look,_pos;
};
XCamera::XCamera()
{
	_cameraType=AIRCRAFT;
	_pos=XMFLOAT3(0.0f, 0.0f, -10.0f);
	_right=XMFLOAT3(1.0f,0.0f,0.0f);
	_up=XMFLOAT3(0.0f,1.0f,0.0f);
	_look=XMFLOAT3(0.0f,0.0f,1.0f);
}
void XCamera::getPosition(XMFLOAT3* pos)
{
	*pos = _pos;
}

void XCamera::setPosition(XMFLOAT3* pos)
{
	_pos = *pos;
}

void XCamera::getRight(XMFLOAT3* right)
{
	*right = _right;
}

void XCamera::getUp(XMFLOAT3* up)
{
	*up = _up;
}

void XCamera::getLook(XMFLOAT3* look)
{
	*look = _look;
}

//行走，沿着摄像机观察方向的移动
void XCamera::walk(float units)
{
	XMVECTOR vpos,vlook;
	vpos=XMLoadFloat3(&_pos);
	vlook=XMLoadFloat3(&_look);
	// 仅在x,z平面移动
	if( _cameraType == LANDOBJECT )
	{
		vpos += XMVectorSet(_look.x, 0.0f, _look.z,0)*units;
	}
	if( _cameraType == AIRCRAFT )
		vpos += vlook * units;
	XMStoreFloat3(&_pos,vpos);
}

//扫视。是指保持观察方向不变，沿向量right方向从一边平移到还有一边
void XCamera::strafe(float units)
{
	XMVECTOR vpos,vright;
	vpos=XMLoadFloat3(&_pos);
	vright=XMLoadFloat3(&_right);
	// 仅在x,z平面移动
	if( _cameraType == LANDOBJECT )
		vpos += XMVectorSet(_right.x, 0.0f, _right.z,0.0f) * units;

	if( _cameraType == AIRCRAFT )
		vpos += vright * units;
	XMStoreFloat3(&_pos,vpos);
}/*
//飞行模式，升降，指沿着向量up方向的移动
void XCamera::fly(float units)
{
	// 仅在y轴移动
	if( _cameraType == LANDOBJECT )
		_pos.y += units;

	if( _cameraType == AIRCRAFT )
		_pos += _up * units;
}

void XCamera::pitch(float angle)
{
	XMMATRIX T;
	T=XMMatrixRotationAxis( _right, angle);

	// 绕着right向量。旋转up和look
	_up=XMVector3TransformCoord(_up,_up, T);
	_look=XMVector3TransformCoord(_look, T);
}

void XCamera::yaw(float angle)
{
	D3DXMATRIX T;

	//对LANDOBJECT,总是绕着(0,1,0)旋转。

if( _cameraType == LANDOBJECT )
		T=XMMatrixRotationY(angle);

	//对于aircraft,绕着up向量旋转
	if( _cameraType == AIRCRAFT )
		T=XMMatrixRotationAxis(_up, angle);

	// 绕着up或者y轴，旋转right和look
	_right=XMVector3TransformCoord(_right, T);
	_look=XMVector3TransformCoord(_look, T);
}

void XCamera::roll(float angle)
{
	//仅仅对aircraft模式才左roll旋转
	if( _cameraType == AIRCRAFT )
	{
		D3DXMATRIX T;
		T=XMMatrixRotationAxis(_look, angle);

		// 绕着look向量，旋转up和right
		_right=XMVector3TransformCoord(_right, T);
		_up=XMVector3TransformCoord(_up, T);
	}
}
*/
void XCamera::getViewMatrix(XMMATRIX &V)
{
	XMVECTOR vlook,vup,vright,vpos;
	vpos=XMLoadFloat3(&_pos);
	vlook=XMLoadFloat3(&_look);
	vup=XMLoadFloat3(&_up);
	vright=XMLoadFloat3(&_right);
	// 保持view局部坐标系，各轴的彼此正交
	vlook=XMVector3Normalize(vlook);
	// look X right
	vup=XMVector3Cross(vlook, vright);
	vup=XMVector3Normalize(vup);

	vright=XMVector3Cross(vup, vlook);
	vright=XMVector3Normalize(vright);
	V=XMMatrixLookAtLH( vpos,vlook, vup);
	// 生成view矩阵:
	//float x = -D3DXVec3Dot(&_right, &_pos);
	//float y = -D3DXVec3Dot(&_up, &_pos);
	//float z = -D3DXVec3Dot(&_look, &_pos);

	//(*V)(0,0) = _right.x; (*V)(0, 1) = _up.x; (*V)(0, 2) = _look.x; (*V)(0, 3) = 0.0f;
	//(*V)(1,0) = _right.y; (*V)(1, 1) = _up.y; (*V)(1, 2) = _look.y; (*V)(1, 3) = 0.0f;
	//(*V)(2,0) = _right.z; (*V)(2, 1) = _up.z; (*V)(2, 2) = _look.z; (*V)(2, 3) = 0.0f;
	//(*V)(3,0) = x;        (*V)(3, 1) = y;     (*V)(3, 2) = z;       (*V)(3, 3) = 1.0f;
}

void XCamera::setCameraType(CameraType cameraType)
{
	_cameraType = cameraType;
}

凝视掉的地方是一个坑。为什么呢。

以下就要讲XMVECTOR 和XMFloat3的差别

前者是向量。后者就是一个点结构

前者支持各种运算。

差 点  乘 加减

后者 仅仅能赋值啊什么的。

是不是特别奇怪。

由于XMVECTOR

看源代码

// Vector intrinsic: Four 32 bit floating point components aligned on a 16 byte
// boundary and mapped to hardware vector registers
#if defined(_XM_SSE_INTRINSICS_) && !defined(_XM_NO_INTRINSICS_)
typedef __m128 XMVECTOR;
#else

128位懂了吧。不能随便玩， 不然会报错 涉及到对齐问题

上节说了。全局变量和局部变量能够用XMVECTOR 可是类变量不建议用

偏偏这个摄像机是类变量。

作死啊。仅仅有设成XMFloat3了

看源代码

// 3D Vector; 32 bit floating point components
typedef struct _XMFLOAT3
{
    FLOAT x;
    FLOAT y;
    FLOAT z;

#ifdef __cplusplus

    _XMFLOAT3() {};
    _XMFLOAT3(FLOAT _x, FLOAT _y, FLOAT _z) : x(_x), y(_y), z(_z) {};
    _XMFLOAT3(CONST FLOAT *pArray);

    _XMFLOAT3& operator= (CONST _XMFLOAT3& Float3);

#endif // __cplusplus

32位的 仅仅能赋值 怎么玩 怎么玩

上面摄像机类加凝视了的函数是之前悲剧了的，我以为Float能够做运算。结果悲剧了。

后来查了一下。 能够用一个转换

XMVECTOR vpos,vright;
	vpos=XMLoadFloat3(&_pos);
	vright=XMLoadFloat3(&_right);
	// 仅在x,z平面移动
	if( _cameraType == LANDOBJECT )
		vpos += XMVectorSet(_right.x, 0.0f, _right.z,0.0f) * units;

	if( _cameraType == AIRCRAFT )
		vpos += vright * units;
	XMStoreFloat3(&_pos,vpos);

看懂了吗 看懂了吗。 先load 把float装到vector局部变量  然后进行运算

运算完毕后  再store

是不是非常烦

是不是

没办法。

眼下我仅仅会这样弄。你嫌烦 直接全局变量吧。

或者回归dx10math.h

废话不说 效果图。

仅仅改了walk函数。 其它自己改改吧，锻炼下自己

//(*V)(0,0) = _right.x; (*V)(0, 1) = _up.x; (*V)(0, 2) = _look.x; (*V)(0, 3) = 0.0f;
	//(*V)(1,0) = _right.y; (*V)(1, 1) = _up.y; (*V)(1, 2) = _look.y; (*V)(1, 3) = 0.0f;
	//(*V)(2,0) = _right.z; (*V)(2, 1) = _up.z; (*V)(2, 2) = _look.z; (*V)(2, 3) = 0.0f;
	//(*V)(3,0) = x;        (*V)(3, 1) = y;     (*V)(3, 2) = z;       (*V)(3, 3) = 1.0f;

对了还有上面这个。原教程是直接这样算的一个矩阵，麻烦吧。

麻烦吧。 懂不起含义了吧 快看龙书就懂了。

懂了之后怎么办。还敲这么多？？

V=XMMatrixLookAtLH( vpos,vlook, vup);

一句话搞定。就不要造轮子了

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