From bd57f345ed9dbed1d81683e48199626de2ea9044 Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Fri, 27 Jun 2025 10:18:39 -0700
Subject: Restructure project

---
 contrib/cgltf-tangents/cgltf_tangents.h | 67 +++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 contrib/cgltf-tangents/cgltf_tangents.h

(limited to 'contrib/cgltf-tangents/cgltf_tangents.h')

diff --git a/contrib/cgltf-tangents/cgltf_tangents.h b/contrib/cgltf-tangents/cgltf_tangents.h
new file mode 100644
index 0000000..79e3502
--- /dev/null
+++ b/contrib/cgltf-tangents/cgltf_tangents.h
@@ -0,0 +1,67 @@
+/*
+Copyright 2022 Marc Sunet
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+#ifndef CGLTF_TANGENTS_H_INCLUDED__
+#define CGLTF_TANGENTS_H_INCLUDED__
+
+#include <cgltf.h>
+
+/// A buffer that holds tangent vectors.
+///
+/// Tangent vectors are tightly packed in the array.
+///
+/// Tangent vectors have 4 coordinates: (X,Y,Z) for the vector, W for the sign.
+/// The usual rules of MikkTSpace apply, namely that the bitangent should be
+/// computed as:
+///
+///   bitangent = tangent.w * cross(normal, tangent.xyz);
+///
+/// Refer to the MikkTSpace documentation for more details.
+///
+/// The primitive pointer points to the mesh primitive for which the tangents in
+/// this buffer were computed. When your application loads mesh primitives, it
+/// can scan the cgltfTangetBuffer array outputed by cgltf_compute_tangents() to
+/// see whether tangents were computed for the mesh primitive.
+typedef struct cgltfTangentBuffer {
+  void* data;                 // X-coordinate of the first tangent vector.
+  cgltf_size size_bytes;      // Total Size of data in bytes.
+  cgltf_primitive* primitive; // The primitive these tangents belong to.
+} cgltfTangentBuffer;
+
+/// Compute tangent vectors for normal-mapped mesh primitives missing them.
+///
+/// cgltf_options can be zeroed out but must be non-null.
+///
+/// cgltf_data is the scene previously loaded by cgltf.
+///
+/// out_tangent_buffers is an output array of tangent buffers, one buffer per
+/// mesh primitive for which tangents were computed.
+///
+/// out_num_tangent_buffers is the number of tangent buffers in the output
+/// array.
+cgltf_result cgltf_compute_tangents(const cgltf_options*, const cgltf_data*,
+                                    cgltfTangentBuffer** out_tangent_buffers,
+                                    cgltf_size* out_num_tangent_buffers);
+
+#endif // CGLTF_TANGENTS_H_INCLUDED__
-- 
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