feat Make camera and model instance more abstract

* src/camera.cpp src/camera.hpp: Remove the camera as Vector3D and
Rotation3D are going to replace it.
* src/model.cpp: Add draw command as instances do not exist anymore.
* src/model/instance.cpp src/model/instance.hpp: Remove the instance as
Vector3D and Rotation3D are going to replace it.

1 files changed, 113 insertions, 0 deletions

diff --git a/src/rotation3d.cpp b/src/rotation3d.cpp
new file mode 100644
index 0000000..d95947b
--- /dev/null
+++ b/src/rotation3d.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2022 Frederico de Oliveira Linhares
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "rotation3d.hpp"
+
+#include "vector3d.hpp"
+
+namespace
+{
+inline float
+pitch_limit(float pitch)
+{
+  if(pitch > M_PI/2) pitch = M_PI/2;
+  else if (pitch < -(M_PI/2)) pitch = -(M_PI/2);
+
+  return pitch;
+}
+
+}
+
+void
+cg_free_rotation3d(mrb_state *mrb, void* obj)
+{
+  auto ptr = static_cast<std::shared_ptr<glm::vec3>*>(obj);
+
+  ptr->~shared_ptr();
+  mrb_free(mrb, ptr);
+}
+
+const struct mrb_data_type cg_rotation3d_type = {
+  "CG_Rotation3D", cg_free_rotation3d};
+
+static mrb_value
+cg_cRotation3D_initialize(mrb_state *mrb, mrb_value self)
+{
+  mrb_float pitch, yaw, roll;
+  std::shared_ptr<glm::vec3> *ptr;
+
+  mrb_get_args(mrb, "fff", &pitch, &yaw, &roll);
+  ptr = (std::shared_ptr<glm::vec3>*)DATA_PTR(self);
+  if(ptr) mrb_free(mrb, ptr);
+  ptr = (std::shared_ptr<glm::vec3>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<glm::vec3>));
+
+  new(ptr)std::shared_ptr<glm::vec3>(
+    std::make_shared<glm::vec3>(pitch_limit(pitch), yaw, roll));
+
+  mrb_data_init(self, ptr, &cg_rotation3d_type);
+  return self;
+}
+
+// Rotation when there is a up direction (ex.: Earth).
+static mrb_value
+cg_cRotation3D_rotate(mrb_state *mrb, mrb_value self)
+{
+  mrb_float pitch, yaw;
+  auto *ptr = (std::shared_ptr<glm::vec3>*)DATA_PTR(self);
+
+  mrb_get_args(mrb, "ff", &pitch, &yaw);
+
+  (*ptr)->x = pitch_limit((*ptr)->x + pitch);
+  (*ptr)->y += yaw;
+
+  return self;
+}
+
+// Rotation when there is a up direction (ex.: space without gravity).
+static mrb_value
+cg_cRotation3D_baseless_rotation(mrb_state *mrb, mrb_value self)
+{
+  mrb_float x, y;
+
+  // TODO
+
+  return self;
+}
+
+void
+cg_rotation3d_init(mrb_state *mrb)
+{
+  struct RClass *cg_m, *cg_cRotation3D;
+
+  cg_m = mrb_module_get(mrb, "CandyGear");
+  cg_cRotation3D = mrb_define_class_under(
+    mrb, cg_m, "Rotation3D", mrb->object_class);
+  MRB_SET_INSTANCE_TT(cg_cRotation3D, MRB_TT_DATA);
+  mrb_define_method(
+    mrb, cg_cRotation3D, "initialize", cg_cRotation3D_initialize,
+    MRB_ARGS_REQ(3));
+
+  mrb_define_method(
+    mrb, cg_cRotation3D, "pitch", cg_cVector3D_get_x, MRB_ARGS_NONE());
+  mrb_define_method(
+    mrb, cg_cRotation3D, "yaw", cg_cVector3D_get_y, MRB_ARGS_NONE());
+  mrb_define_method(
+    mrb, cg_cRotation3D, "roll", cg_cVector3D_get_z, MRB_ARGS_NONE());
+
+  mrb_define_method(
+    mrb, cg_cRotation3D, "rotate", cg_cRotation3D_rotate, MRB_ARGS_REQ(2));
+}