Implement configurable frustum parameters

craigrmccown · Apr 1, 2023 · 2116b0c · 2116b0c
1 parent 4691910
commit 2116b0c
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Showing 4 changed files with 52 additions and 12 deletions.
diff --git a/apps/demo.cpp b/apps/demo.cpp
@@ -118,7 +118,7 @@ int main()
     mouse::listenForMovement(window);
 
     orc::Scene scene;
-    scene.GetCamera().SetPerspective(glm::radians(45.0f), (float)windowWidth/(float)windowHeight);
+    scene.GetCamera().SetAspectRatio((float)windowWidth/(float)windowHeight);
     scene.GetCamera().Translate(0, 0, 10);
 
     // This model is not checked into source control for practical reasons

diff --git a/libs/orc/examples/basic_usage.cpp b/libs/orc/examples/basic_usage.cpp
@@ -75,7 +75,7 @@ int main(int argc, char *argv[])
 
     // Create scene and position camera
     orc::Scene scene;
-    scene.GetCamera().SetPerspective(M_PI_4, windowWidth/windowHeight);
+    scene.GetCamera().SetAspectRatio(windowWidth/windowHeight);
     scene.GetCamera().Translate(6, 6, 12);
     scene.GetCamera().Rotate(M_PI_4/1.25, -M_PI_4/2.5, 0);
 

diff --git a/libs/orc/src/orc/camera.cpp b/libs/orc/src/orc/camera.cpp
@@ -2,7 +2,11 @@
 #include "camera.hpp"
 #include "visitor.hpp"
 
-const float defaultFieldOfView = glm::radians(45.0f), defaultAspectRatio = 16.0f/9.0f;
+const float
+    defaultFieldOfView = glm::radians(45.0f),
+    defaultAspectRatio = 16.0f/9.0f,
+    defaultNearClip = 0.1f,
+    defaultFarClip = 200.0f;
 
 static void copyVecToRow(const glm::vec3 &v, glm::mat4 &m, int r)
 {
@@ -20,8 +24,11 @@ namespace orc
     }
 
     Camera::Camera()
+        : fieldOfView(defaultFieldOfView)
+        , aspectRatio(defaultAspectRatio)
+        , nearClip(defaultNearClip)
+        , farClip(defaultFarClip)
     {
-        SetPerspective(defaultFieldOfView, defaultAspectRatio);
         ComputeMxs();
     }
 
@@ -30,23 +37,38 @@ namespace orc
         visitor.VisitCamera(this);
     }
 
-    void Camera::SetPerspective(float fieldOfView, float aspectRatio)
+    void Camera::SetFieldOfView(float fieldOfView)
     {
-        // TODO: Configurable frustum distances
-        projectionMx = glm::perspective(fieldOfView, aspectRatio, 0.1f, 100.0f);
+        this->fieldOfView = fieldOfView;
+    }
+
+    void Camera::SetAspectRatio(float aspectRatio)
+    {
+        this->aspectRatio = aspectRatio;
+    }
+
+    void Camera::SetClippingDistance(float near, float far)
+    {
+        if (near <= 0)
+        {
+            throw std::logic_error("Near clipping distance must be greater than 0");
+        }
+
+        nearClip = near;
+        farClip = far;
     }
 
     void Camera::ComputeMxs()
     {
         Node::ComputeMxs();
-        viewProjectionMx = projectionMx * GetViewMx();
+        viewProjectionMx = ComputeProjectionMx() * ComputeViewMx();
     }
 
     glm::mat4 Camera::GetViewProjectionMx() const {
         return viewProjectionMx;
     }
 
-    glm::mat4 Camera::GetViewMx() const
+    glm::mat4 Camera::ComputeViewMx() const
     {
         glm::vec3 pos = GetPosition();
         glm::vec3 up = GetUp();
@@ -80,4 +102,9 @@ namespace orc
 
         return viewMx;
     }
+
+    glm::mat4 Camera::ComputeProjectionMx() const
+    {
+        return glm::perspective(fieldOfView, aspectRatio, nearClip, farClip);
+    }
 }
diff --git a/libs/orc/src/orc/camera.hpp b/libs/orc/src/orc/camera.hpp
@@ -13,7 +13,19 @@ namespace orc
 
         void Dispatch(NodeVisitor &visitor) override;
 
-        void SetPerspective(float fieldOfView, float aspectRatio);
+        // Sets the camera's field of view angle, expressed in radians. Defaults
+        // to pi/4 (45 deg).
+        void SetFieldOfView(float fieldOfView);
+
+        // Sets the aspect ratio of the perspective projection. Usually this
+        // should be set to the screen's width/height. Defaults to 16/9,
+        // although this is rarely correct.
+        void SetAspectRatio(float aspectRatio);
+
+        // Sets the frustum distances of the camera. Distances that fall out of
+        // this range will be clipped. Near distance must be a non-zero,
+        // positive number
+        void SetClippingDistance(float near, float far);
 
         // See Node.ComputeMxs. Also computes the view-projection matrix.
         void ComputeMxs() override;
@@ -26,9 +38,10 @@ namespace orc
         Camera();
 
         private:
-        glm::mat4 projectionMx;
         glm::mat4 viewProjectionMx;
+        float fieldOfView, aspectRatio, nearClip, farClip;
 
-        glm::mat4 GetViewMx() const;
+        glm::mat4 ComputeViewMx() const;
+        glm::mat4 ComputeProjectionMx() const;
     };
 }