third person camera

include/view.h

@@ -2,26 +2,41 @@
 
 namespace view {
   struct view_state {
-    XMVECTOR up;
+    // positions
     XMVECTOR eye;
-    XMVECTOR forward;
-    XMVECTOR direction;
     XMVECTOR at;
-    XMVECTOR normal;
+
+    // vectors
+    XMVECTOR up;
+    XMVECTOR forward;
+    XMVECTOR normal; // cross(forward, up)
+    XMVECTOR direction; // rotationaxis(forward, pitch)
+
+    // angles
     float fov;
     float pitch;
 
+    // transforms
     XMMATRIX projection_transform;
     XMMATRIX view_transform;
     XMMATRIX transform;
+
+    // transform views
     XMFLOAT4X4 float_transform;
   };
 
-
   extern view_state state;
 
-  void apply_translation(float forward, float strafe, float elevation);
+  namespace first_person {
-  void apply_yaw_pitch(float delta_yaw, float delta_pitch);
+    void apply_transform(float forward, float strafe, float elevation,
+                         float delta_yaw, float delta_pitch);
+  }
+
+  namespace third_person {
+    void apply_transform(float forward, float strafe, float elevation,
+                         float delta_yaw, float delta_pitch);
+  }
+
   void apply_fov(float delta);
   void update_transforms();
   void load();

main.lua

@@ -27,8 +27,6 @@ void update(float time);
 end
 
 local update = function(time)
-   test.update(time)
-
    for joystick_index, joystick in ipairs(joysticks) do
       if joystick_index > 8 then
          break
@@ -64,6 +62,8 @@ local update = function(time)
    local left = love.keyboard.isDown("left")
    local right = love.keyboard.isDown("right")
    test.update_keyboard(up, down, left, right);
+
+   test.update(time)
 end
 
 local draw = function()

src/non_block.cpp

@@ -112,7 +112,7 @@ namespace non_block {
     glEnable(GL_DEPTH_TEST);
     glDepthFunc(GL_GREATER);
 
-    XMVECTOR offset = view::state.eye + view::state.forward * 4.0f;
+    XMVECTOR offset = view::state.at;
     XMMATRIX world_transform = XMMatrixTranslationFromVector(offset);
     XMMATRIX transform = world_transform * view::state.transform;
     XMFLOAT4X4 float_world_transform;

src/test.cpp

@@ -665,9 +665,9 @@ light_parameters lighting = {
 
 void update_keyboard(int up, int down, int left, int right)
 {
-  float forward = (0.1f * up + -0.1f * down);
+  //float forward = (0.1f * up + -0.1f * down);
-  float strafe = (-0.1f * left + 0.1f * right);
+  //float strafe = (-0.1f * left + 0.1f * right);
-  view::apply_translation(forward, strafe, 0);
+  //view::third_person::apply_translation(forward, strafe, 0);
 }
 
 const int max_joysticks = 8;
@@ -680,11 +680,13 @@ void update_joystick(int joystick_index,
                      int leftshoulder, int rightshoulder,
                      int start)
 {
-  float forward = -ly;
+  float forward = -ly * 0.5;
-  float strafe = lx;
+  float strafe = lx * 0.5;
-  float elevation = tl - tr;
+  float elevation = (tl - tr) * 0.5;
-  view::apply_yaw_pitch(rx * -0.035, ry * -0.035);
+  float delta_yaw = rx * -0.035;
-  view::apply_translation(forward, strafe, elevation);
+  float delta_pitch = ry * -0.035;
+  view::third_person::apply_transform(forward, strafe, elevation,
+                                      delta_yaw, delta_pitch);
   view::apply_fov(0.01 * up + -0.01 * down);
 
   lighting.quadratic += 0.01 * a + -0.01 * b;

src/view.cpp

@@ -6,7 +6,7 @@
 constexpr bool third_person = false;
 
 namespace view {
-  view_state state;
+  view_state state = {};
 
   static inline XMMATRIX current_projection()
   {
@@ -20,29 +20,57 @@ namespace view {
 
   static inline XMMATRIX current_view()
   {
-    state.at = XMVectorAdd(state.eye, state.direction);
-
     XMMATRIX view = XMMatrixLookAtRH(state.eye, state.at, state.up);
     return view;
   }
 
-  void apply_translation(float forward, float strafe, float elevation)
+  static inline float clamp_pitch(float delta_pitch)
   {
-    state.eye += state.forward * forward + state.normal * strafe + state.up * elevation;
+    float pitch = state.pitch + delta_pitch;
+    if (pitch > 1.57f) pitch = 1.57f;
+    if (pitch < -1.57f) pitch = -1.57f;
+    return pitch;
   }
 
-  void apply_yaw_pitch(float delta_yaw, float delta_pitch)
+  static inline XMVECTOR get_normal()
   {
-    XMMATRIX mrz = XMMatrixRotationZ(delta_yaw);
+    return XMVector3NormalizeEst(XMVector3Cross(state.forward, state.up));
-    state.forward = XMVector3Transform(state.forward, mrz);
+  }
-    state.normal = XMVector3NormalizeEst(XMVector3Cross(state.forward, state.up));
-
-    state.pitch += delta_pitch;
-    if (state.pitch > 1.57f) state.pitch = 1.57f;
-    if (state.pitch < -1.57f) state.pitch = -1.57f;
 
+  static inline XMVECTOR get_direction()
+  {
     XMMATRIX mrn = XMMatrixRotationAxis(state.normal, state.pitch);
-    state.direction = XMVector3Transform(state.forward, mrn);
+    return XMVector3Transform(state.forward, mrn);
+  }
+
+  namespace first_person {
+    void apply_transform(float forward, float strafe, float elevation,
+                         float delta_yaw, float delta_pitch)
+    {
+      state.pitch = clamp_pitch(delta_pitch);
+
+      state.forward = XMVector3Transform(state.forward, XMMatrixRotationZ(delta_yaw));
+      state.normal = get_normal(); // on forward change
+      state.direction = get_direction(); // on forward/normal/pitch change
+
+      state.eye += state.forward * forward + state.normal * strafe + state.up * elevation;
+      state.at = state.eye + state.direction * 4;
+    }
+  }
+
+  namespace third_person {
+    void apply_transform(float forward, float strafe, float elevation,
+                         float delta_yaw, float delta_pitch)
+    {
+      state.pitch = clamp_pitch(delta_pitch);
+
+      state.forward = XMVector3Transform(state.forward, XMMatrixRotationZ(delta_yaw));
+      state.normal = get_normal(); // on forward change
+      state.direction = get_direction(); // on forward/normal/pitch change
+
+      state.at += state.forward * forward + state.normal * strafe + state.up * elevation;
+      state.eye = state.at - state.direction * 4;
+    }
   }
 
   void apply_fov(float delta)
@@ -64,13 +92,16 @@ namespace view {
   void load()
   {
     state.up = XMVectorSet(0.0f, 0.0f, 1.0f, 0.0f);
-    state.eye = XMVectorSet(-55.5f, 48.25f, 50.0f, 1);
-    state.forward = XMVector3Normalize(XMVectorSet(-0.63, 0.78, 0, 0));
-    state.direction = state.forward;
-    state.normal = XMVector3Normalize(XMVector3Cross(state.forward, state.up));
 
     state.fov = 1.5;
-
     state.pitch = 0;
+
+    state.forward = XMVector3Normalize(XMVectorSet(-0.63, 0.78, 0, 0));
+    state.normal = get_normal(); // on forward change
+    state.direction = get_direction(); // on forward/normal/pitch change
+
+    // position
+    state.eye = XMVectorSet(-55.5f, 48.25f, 50.0f, 1);
+    state.at = state.eye + state.direction * 4;
   }
 }