Implement Vector4, Vector4i, Projection

Implement built-in classes Vector4, Vector4i and Projection.

* Two versions of Vector4 (float and integer).
* A Projection class, which is a 4x4 matrix specialized in projection types.

These types have been requested for a long time, but given they were very corner case they were not added before.
Because in Godot 4, reimplementing parts of the rendering engine is now possible, access to these types (heavily used by the rendering code) becomes a necessity.

**Q**: Why Projection and not Matrix4?
**A**: Godot does not use Matrix2, Matrix3, Matrix4x3, etc. naming convention because, within the engine, these types always have a *purpose*. As such, Godot names them: Transform2D, Transform3D or Basis. In this case, this 4x4 matrix is _always_ used as a _Projection_, hence the naming.

4 files changed, 8 insertions, 8 deletions

diff --git a/servers/xr/xr_interface.cpp b/servers/xr/xr_interface.cpp
index 0808b1fd7b..4b9ea40223 100644
--- a/servers/xr/xr_interface.cpp
+++ b/servers/xr/xr_interface.cpp
@@ -195,7 +195,7 @@ RID XRInterface::get_vrs_texture() {
 			uint8_t *data_ptr = data.ptrw();
 
 			// Our near and far don't matter much for what we're doing here, but there are some interfaces that will remember this as the near and far and may fail as a result...
-			CameraMatrix cm = get_projection_for_view(i, aspect, 0.1, 1000.0);
+			Projection cm = get_projection_for_view(i, aspect, 0.1, 1000.0);
 			Vector3 center = cm.xform(Vector3(0.0, 0.0, 999.0));
 
 			Vector2i view_center;
diff --git a/servers/xr/xr_interface.h b/servers/xr/xr_interface.h
index b4eb4694f6..f11458f1cc 100644
--- a/servers/xr/xr_interface.h
+++ b/servers/xr/xr_interface.h
@@ -31,7 +31,7 @@
 #ifndef XR_INTERFACE_H
 #define XR_INTERFACE_H
 
-#include "core/math/camera_matrix.h"
+#include "core/math/projection.h"
 #include "core/os/thread_safe.h"
 #include "servers/xr_server.h"
 
@@ -119,7 +119,7 @@ public:
 	virtual uint32_t get_view_count() = 0; /* returns the view count we need (1 is monoscopic, 2 is stereoscopic but can be more) */
 	virtual Transform3D get_camera_transform() = 0; /* returns the position of our camera for updating our camera node. For monoscopic this is equal to the views transform, for stereoscopic this should be an average */
 	virtual Transform3D get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) = 0; /* get each views transform */
-	virtual CameraMatrix get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) = 0; /* get each view projection matrix */
+	virtual Projection get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) = 0; /* get each view projection matrix */
 	virtual RID get_vrs_texture(); /* obtain VRS texture */
 
 	// note, external color/depth/vrs texture support will be added here soon.
diff --git a/servers/xr/xr_interface_extension.cpp b/servers/xr/xr_interface_extension.cpp
index 94953c69a9..7395cd5ad4 100644
--- a/servers/xr/xr_interface_extension.cpp
+++ b/servers/xr/xr_interface_extension.cpp
@@ -258,12 +258,12 @@ Transform3D XRInterfaceExtension::get_transform_for_view(uint32_t p_view, const
 	return Transform3D();
 }
 
-CameraMatrix XRInterfaceExtension::get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) {
-	CameraMatrix cm;
+Projection XRInterfaceExtension::get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) {
+	Projection cm;
 	PackedFloat64Array arr;
 
 	if (GDVIRTUAL_CALL(_get_projection_for_view, p_view, p_aspect, p_z_near, p_z_far, arr)) {
-		ERR_FAIL_COND_V_MSG(arr.size() != 16, CameraMatrix(), "Projection matrix must contain 16 floats");
+		ERR_FAIL_COND_V_MSG(arr.size() != 16, Projection(), "Projection matrix must contain 16 floats");
 		real_t *m = (real_t *)cm.matrix;
 		for (int i = 0; i < 16; i++) {
 			m[i] = arr[i];
@@ -271,7 +271,7 @@ CameraMatrix XRInterfaceExtension::get_projection_for_view(uint32_t p_view, doub
 		return cm;
 	}
 
-	return CameraMatrix();
+	return Projection();
 }
 
 RID XRInterfaceExtension::get_vrs_texture() {
diff --git a/servers/xr/xr_interface_extension.h b/servers/xr/xr_interface_extension.h
index 7174b412c5..09dd70aca0 100644
--- a/servers/xr/xr_interface_extension.h
+++ b/servers/xr/xr_interface_extension.h
@@ -100,7 +100,7 @@ public:
 	virtual uint32_t get_view_count() override;
 	virtual Transform3D get_camera_transform() override;
 	virtual Transform3D get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) override;
-	virtual CameraMatrix get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) override;
+	virtual Projection get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) override;
 	virtual RID get_vrs_texture() override;
 
 	GDVIRTUAL0R(Size2, _get_render_target_size);