2 files changed, 97 insertions, 0 deletions

diff --git a/contrib/cgltf-tangents/test/CMakeLists.txt b/contrib/cgltf-tangents/test/CMakeLists.txt
new file mode 100644
index 0000000..422c950
--- /dev/null
+++ b/contrib/cgltf-tangents/test/CMakeLists.txt
@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.0)
+
+project (cgltf-test)
+
+add_executable(cgltf-test
+  main.c)
+
+target_link_libraries(cgltf-test
+  cgltf
+  cgltf-tangents
+  -lm)
diff --git a/contrib/cgltf-tangents/test/main.c b/contrib/cgltf-tangents/test/main.c
new file mode 100644
index 0000000..0d70008
--- /dev/null
+++ b/contrib/cgltf-tangents/test/main.c
@@ -0,0 +1,86 @@
+/*
+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.
+*/
+#include <cgltf_tangents.h>
+#define CGLTF_IMPLEMENTATION
+#include <cgltf.h>
+
+#include <stdio.h>
+
+void print_tangent_buffer(const cgltfTangentBuffer* buffer, int max_vectors) {
+  printf("Tangent buffer for primitive (%p) (%lu bytes):\n", buffer->primitive,
+         buffer->size_bytes);
+
+  const float* xyzw = (const float*)buffer->data;
+  const float* end = (const float*)(buffer->data + buffer->size_bytes);
+
+  for (int i = 0; i < max_vectors && xyzw < end; ++i, xyzw += 4) {
+    printf("(%3.2f, %3.2f, %3.2f, sign: %3.2f)\n", *xyzw, *(xyzw + 1),
+           *(xyzw + 2), *(xyzw + 3));
+  }
+  printf("--------------------");
+}
+
+void usage(const char* argv0) {
+  fprintf(stderr, "Usage: %s <glTF file path>\n", argv0);
+}
+
+int main(int argc, const char** argv) {
+  cgltf_options options = {0};
+  cgltf_data* data = NULL;
+
+  if (argc != 2) {
+    usage(argv[0]);
+    return 0;
+  }
+
+  const char* filepath = argv[1];
+
+  cgltf_result result = cgltf_parse_file(&options, filepath, &data);
+  if (result != cgltf_result_success) {
+    cgltf_free(data);
+    return 1;
+  }
+
+  // Must call cgltf_load_buffers() to load buffer data.
+  result = cgltf_load_buffers(&options, data, filepath);
+  if (result != cgltf_result_success) {
+    cgltf_free(data);
+    return 2;
+  }
+
+  cgltfTangentBuffer* tangent_buffers = 0;
+  cgltf_size num_tangent_buffers = 0;
+  cgltf_compute_tangents(&options, data, &tangent_buffers,
+                         &num_tangent_buffers);
+
+  // cgltf scene not needed beyond this point.
+  cgltf_free(data);
+
+  for (cgltf_size i = 0; i < num_tangent_buffers; ++i) {
+    print_tangent_buffer(tangent_buffers, 10);
+  }
+
+  return 0;
+}