我正在尝试将相机运动系统实现到我当前正在处理的程序中。我无法弄清楚如何以非乱差单元移动相机,因此当我将相机移动时,它会"跳"到下一个位置。我该如何平稳地移动相机而不会跳跃。
摄像机控制功能:
void CameraControlls()
{
while (SDL_PollEvent(&e))
{
if (e.type == SDL_QUIT)
{
exit(0);
}
switch (e.type)
{
case SDL_KEYDOWN:
switch (e.key.keysym.sym)
{
case SDLK_w:
cam.MoveForward(0.3f);
break;
case SDLK_s:
cam.MoveBackward(0.3f);
break;
case SDLK_d:
cam.MoveRight(0.2f);
break;
case SDLK_a:
cam.MoveLeft(0.2f);
break;
case SDLK_ESCAPE:
exit(0);
break;
case SDLK_RIGHT:
cam.Yaw(-0.01f);
break;
case SDLK_LEFT:
cam.Yaw(0.01f);
break;
case SDLK_DOWN:
cam.Pitch(0.01f);
break;
case SDLK_UP:
cam.Pitch(-0.01f);
break;
}
}
}
}
相机结构:
struct Camera
{
public:
Camera(glm::vec3& pos, float fov, float aspect, float zNear, float zFar)
{
this->pos = pos;
this->forward = glm::vec3(0.0f, 0.0f, 1.0f);
this->up = glm::vec3(0.0f, 1.0f, 0.0f);
this->projection = glm::perspective(fov, aspect, zNear, zFar);
}
inline glm::mat4 GetViewProjection() const
{
return projection * glm::lookAt(pos, pos + forward, up);
}
void MoveBackward(float amt)
{
pos -= forward*amt;
}
void MoveForward(float amt)
{
pos += forward * amt;
}
void MoveRight(float amt)
{
pos -= glm::cross(up, forward) * amt;
}
void MoveLeft(float amt)
{
pos += glm::cross(up, forward) * amt;
}
void Pitch(float angle)
{
glm::vec3 right = glm::normalize(glm::cross(up, forward));
forward = glm::vec3(glm::normalize(glm::rotate(angle, right) * glm::vec4(forward, 0.0)));
up = glm::normalize(glm::cross(forward, right));
}
void Yaw(float angle)
{
static const glm::vec3 UP(0.0f, 1.0f, 0.0f);
glm::mat4 rotation = glm::rotate(angle, UP);
forward = glm::vec3(glm::normalize(rotation * glm::vec4(forward, 0.0)));
up = glm::vec3(glm::normalize(rotation * glm::vec4(up, 0.0)));
}
private:
glm::mat4 projection;
glm::vec3 pos;
glm::vec3 forward;
glm::vec3 up;
};
我想SDL的关键事件并非每个帧发射,因此您不应该直接从那里更改相机位置,因为相机不会更新每个帧。
我将创建一个布尔值变量move_forward,该变量是否为向前键
-
在关键事件中,您更新MOVE_FORWARD变量。
while (SDL_PollEvent(&e)) { .......... case SDL_KEYDOWN: switch (e.key.keysym.sym) { case SDLK_w: MOVE_FORWARD=true; break;
-
在您更新相机位置
的每个帧中if (MOVE_FORWARD){pos+=0.3}
这样,相机不仅在关键事件触发
时,相机会更新其位置您还可以避免使用SDL_GetKeyboardState(NULL)
而不是SDL_PollEvent(&e)
创建关键状态变量:
Uint8* keystate = SDL_GetKeyState(NULL);
if(keystate[SDL_SCANCODE_W])
{
pos+=0.3;
}