1 /* Copyright (C) 2021 Wildfire Games.
2 * This file is part of 0 A.D.
4 * 0 A.D. is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
9 * 0 A.D. is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
19 * CCamera holds a view and a projection matrix. It also has a frustum
20 * which can be used to cull objects for rendering.
23 #ifndef INCLUDED_CAMERA
24 #define INCLUDED_CAMERA
26 #include "maths/BoundingBoxAligned.h"
27 #include "maths/Frustum.h"
28 #include "maths/Matrix3D.h"
44 // Represents camera viewport or frustum side in 3D space.
45 using Quad
= std::array
<CVector3D
, 4>;
47 enum class ProjectionType
57 CMatrix3D
& GetProjection() { return m_ProjMat
; }
58 const CMatrix3D
& GetProjection() const { return m_ProjMat
; }
59 CMatrix3D
GetViewProjection() const { return m_ProjMat
* m_Orientation
.GetInverse(); }
60 void SetProjection(const CMatrix3D
& matrix
);
61 void SetProjectionFromCamera(const CCamera
& camera
);
62 void SetOrthoProjection(float nearp
, float farp
, float scale
);
63 void SetPerspectiveProjection(float nearp
, float farp
, float fov
);
64 ProjectionType
GetProjectionType() const { return m_ProjType
; }
66 CMatrix3D
& GetOrientation() { return m_Orientation
; }
67 const CMatrix3D
& GetOrientation() const { return m_Orientation
; }
69 // Updates the frustum planes. Should be called
70 // everytime the view or projection matrices are
72 void UpdateFrustum(const CBoundingBoxAligned
& scissor
= CBoundingBoxAligned(CVector3D(-1.0f
, -1.0f
, -1.0f
), CVector3D(1.0f
, 1.0f
, 1.0f
)));
73 void ClipFrustum(const CPlane
& clipPlane
);
74 const CFrustum
& GetFrustum() const { return m_ViewFrustum
; }
76 void SetViewPort(const SViewPort
& viewport
);
77 const SViewPort
& GetViewPort() const { return m_ViewPort
; }
78 float GetAspectRatio() const;
80 float GetNearPlane() const { return m_NearPlane
; }
81 float GetFarPlane() const { return m_FarPlane
; }
82 float GetFOV() const { return m_FOV
; }
83 float GetOrthoScale() const { return m_OrthoScale
; }
85 // Returns a quad of view in camera space at given distance from camera.
86 void GetViewQuad(float dist
, Quad
& quad
) const;
88 // Builds a ray passing through the screen coordinate (px, py), calculates
89 // origin and direction of the ray.
90 void BuildCameraRay(int px
, int py
, CVector3D
& origin
, CVector3D
& dir
) const;
92 // General helpers that seem to fit here
94 // Get the screen-space coordinates corresponding to a given world-space position
95 void GetScreenCoordinates(const CVector3D
& world
, float& x
, float& y
) const;
97 // Get the point on the terrain corresponding to pixel (px,py) (or the mouse coordinates)
98 // The aboveWater parameter determines whether we want to stop at the water plane or also get underwater points
99 CVector3D
GetWorldCoordinates(int px
, int py
, bool aboveWater
=false) const;
100 // Get the point on the plane at height h corresponding to pixel (px,py)
101 CVector3D
GetWorldCoordinates(int px
, int py
, float h
) const;
102 // Get the point on the terrain (or water plane) the camera is pointing towards
103 CVector3D
GetFocus() const;
105 CBoundingBoxAligned
GetBoundsInViewPort(const CBoundingBoxAligned
& boundigBox
) const;
107 // Build an orientation matrix from camera position, camera focus point, and up-vector
108 void LookAt(const CVector3D
& camera
, const CVector3D
& focus
, const CVector3D
& up
);
110 // Build an orientation matrix from camera position, camera orientation, and up-vector
111 void LookAlong(const CVector3D
& camera
, CVector3D orientation
, CVector3D up
);
114 // This is the orientation matrix. The inverse of this
115 // is the view matrix
116 CMatrix3D m_Orientation
;
120 ProjectionType m_ProjType
= ProjectionType::CUSTOM
;
122 float m_NearPlane
= 0.0f
;
123 float m_FarPlane
= 0.0f
;
129 SViewPort m_ViewPort
;
131 CFrustum m_ViewFrustum
;
134 #endif // INCLUDED_CAMERA