Merge pull request #108853 from aaronfranke/gltf-accessor

GLTF: Move accessor encoding functions to GLTFAccessor
This commit is contained in:
Thaddeus Crews
2025-11-13 12:33:38 -06:00
6 changed files with 1003 additions and 1246 deletions

File diff suppressed because it is too large Load Diff

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@ -108,8 +108,6 @@ public:
private:
void _build_parent_hierarchy(Ref<GLTFState> p_state);
double _filter_number(double p_float);
void _round_min_max_components(Vector<double> &r_type_min, Vector<double> &r_type_max);
String _get_component_type_name(const GLTFAccessor::GLTFComponentType p_component_type);
int _get_component_type_size(const GLTFAccessor::GLTFComponentType p_component_type);
Error _parse_scenes(Ref<GLTFState> p_state);
@ -134,7 +132,6 @@ private:
void _compute_node_heights(Ref<GLTFState> p_state);
Error _parse_buffers(Ref<GLTFState> p_state, const String &p_base_path);
Error _parse_buffer_views(Ref<GLTFState> p_state);
GLTFAccessor::GLTFAccessorType _get_accessor_type_from_str(const String &p_string);
Error _parse_accessors(Ref<GLTFState> p_state);
Error _decode_buffer_view(Ref<GLTFState> p_state, double *p_dst,
const GLTFBufferViewIndex p_buffer_view,
@ -183,11 +180,6 @@ private:
const GLTFAccessorIndex p_accessor,
Variant::Type p_variant_type,
GLTFAccessor::GLTFAccessorType p_accessor_type);
GLTFAccessorIndex _encode_accessor_as_variant(Ref<GLTFState> p_state,
Vector<Variant> p_attribs,
Variant::Type p_variant_type,
GLTFAccessor::GLTFAccessorType p_accessor_type,
GLTFAccessor::GLTFComponentType p_component_type = GLTFAccessor::COMPONENT_TYPE_SINGLE_FLOAT);
Error _parse_meshes(Ref<GLTFState> p_state);
Error _serialize_textures(Ref<GLTFState> p_state);
Error _serialize_texture_samplers(Ref<GLTFState> p_state);
@ -230,59 +222,6 @@ private:
T _interpolate_track(const Vector<double> &p_times, const Vector<T> &p_values,
const float p_time,
const GLTFAnimation::Interpolation p_interp);
GLTFAccessorIndex _encode_accessor_as_quaternions(Ref<GLTFState> p_state,
const Vector<Quaternion> p_attribs,
const bool p_for_vertex);
GLTFAccessorIndex _encode_accessor_as_weights(Ref<GLTFState> p_state,
const Vector<Color> p_attribs,
const bool p_for_vertex);
GLTFAccessorIndex _encode_accessor_as_joints(Ref<GLTFState> p_state,
const Vector<Color> p_attribs,
const bool p_for_vertex);
GLTFAccessorIndex _encode_accessor_as_floats(Ref<GLTFState> p_state,
const Vector<double> p_attribs,
const bool p_for_vertex);
GLTFAccessorIndex _encode_accessor_as_vec2(Ref<GLTFState> p_state,
const Vector<Vector2> p_attribs,
const bool p_for_vertex);
void _calc_accessor_vec2_min_max(int p_i, const int64_t p_element_count, Vector<double> &p_type_max, Vector2 p_attribs, Vector<double> &p_type_min) {
if (p_i == 0) {
for (int64_t type_i = 0; type_i < p_element_count; type_i++) {
p_type_max.write[type_i] = p_attribs[(p_i * p_element_count) + type_i];
p_type_min.write[type_i] = p_attribs[(p_i * p_element_count) + type_i];
}
}
for (int64_t type_i = 0; type_i < p_element_count; type_i++) {
p_type_max.write[type_i] = MAX(p_attribs[(p_i * p_element_count) + type_i], p_type_max[type_i]);
p_type_min.write[type_i] = MIN(p_attribs[(p_i * p_element_count) + type_i], p_type_min[type_i]);
p_type_max.write[type_i] = _filter_number(p_type_max.write[type_i]);
p_type_min.write[type_i] = _filter_number(p_type_min.write[type_i]);
}
}
GLTFAccessorIndex _encode_accessor_as_vec3(Ref<GLTFState> p_state,
const Vector<Vector3> p_attribs,
const bool p_for_vertex);
GLTFAccessorIndex _encode_sparse_accessor_as_vec3(Ref<GLTFState> p_state, const Vector<Vector3> p_attribs, const Vector<Vector3> p_reference_attribs, const float p_reference_multiplier, const bool p_for_vertex, const GLTFAccessorIndex p_reference_accessor);
GLTFAccessorIndex _encode_accessor_as_color(Ref<GLTFState> p_state,
const Vector<Color> p_attribs,
const bool p_for_vertex);
void _calc_accessor_min_max(int p_i, const int64_t p_element_count, Vector<double> &p_type_max, Vector<double> p_attribs, Vector<double> &p_type_min);
GLTFAccessorIndex _encode_accessor_as_ints(Ref<GLTFState> p_state,
const Vector<int32_t> p_attribs,
const bool p_for_vertex,
const bool p_for_indices);
GLTFAccessorIndex _encode_accessor_as_xform(Ref<GLTFState> p_state,
const Vector<Transform3D> p_attribs,
const bool p_for_vertex);
Error _encode_accessor_into_buffer_view(Ref<GLTFState> p_state, const double *p_src,
const int64_t p_count, const GLTFAccessor::GLTFAccessorType p_accessor_type,
const GLTFAccessor::GLTFComponentType p_component_type, const bool p_normalized,
const int64_t p_byte_offset, const bool p_for_vertex,
GLTFBufferViewIndex &r_buffer_view, const bool p_for_indices = false);
Error _encode_accessors(Ref<GLTFState> p_state);
Error _encode_buffer_views(Ref<GLTFState> p_state);

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@ -230,6 +230,150 @@ void GLTFAccessor::set_sparse_values_byte_offset(int64_t p_sparse_values_byte_of
// Trivial helper functions.
void GLTFAccessor::_calculate_min_and_max(const PackedFloat64Array &p_numbers) {
const int64_t vector_size = _get_vector_size();
ERR_FAIL_COND(vector_size <= 0 || p_numbers.size() % vector_size != 0);
min.resize(vector_size);
max.resize(vector_size);
// Initialize min and max with the first vector element values.
for (int64_t in_vec = 0; in_vec < vector_size; in_vec++) {
min.write[in_vec] = p_numbers[in_vec];
max.write[in_vec] = p_numbers[in_vec];
}
// Iterate over the rest of the vectors.
for (int64_t which_vec = vector_size; which_vec < p_numbers.size(); which_vec += vector_size) {
for (int64_t in_vec = 0; in_vec < vector_size; in_vec++) {
min.write[in_vec] = MIN(p_numbers[which_vec + in_vec], min[in_vec]);
max.write[in_vec] = MAX(p_numbers[which_vec + in_vec], max[in_vec]);
}
}
// 3.6.2.5: For floating-point components, JSON-stored minimum and maximum values represent single precision
// floats and SHOULD be rounded to single precision before usage to avoid any potential boundary mismatches.
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#accessors-bounds
if (component_type == GLTFAccessor::COMPONENT_TYPE_SINGLE_FLOAT) {
for (int64_t i = 0; i < min.size(); i++) {
min.write[i] = (double)(float)min[i];
max.write[i] = (double)(float)max[i];
}
}
}
void GLTFAccessor::_determine_pad_skip(int64_t &r_skip_every, int64_t &r_skip_bytes) const {
// 3.6.2.4. Accessors of matrix type have data stored in column-major order. The start of each column MUST be aligned to 4-byte boundaries.
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#data-alignment
switch (component_type) {
case GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE: {
if (accessor_type == GLTFAccessor::TYPE_MAT2) {
r_skip_every = 2;
r_skip_bytes = 2;
}
if (accessor_type == GLTFAccessor::TYPE_MAT3) {
r_skip_every = 3;
r_skip_bytes = 1;
}
} break;
case GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT: {
if (accessor_type == GLTFAccessor::TYPE_MAT3) {
r_skip_every = 6;
r_skip_bytes = 2;
}
} break;
default: {
} break;
}
}
int64_t GLTFAccessor::_determine_padded_byte_count(int64_t p_raw_byte_size) const {
// 3.6.2.4. Accessors of matrix type have data stored in column-major order. The start of each column MUST be aligned to 4-byte boundaries.
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#data-alignment
switch (component_type) {
case GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE: {
if (accessor_type == GLTFAccessor::TYPE_MAT2) {
return p_raw_byte_size * 2;
}
if (accessor_type == GLTFAccessor::TYPE_MAT3) {
return p_raw_byte_size * 4 / 3;
}
} break;
case GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT: {
if (accessor_type == GLTFAccessor::TYPE_MAT3) {
return p_raw_byte_size * 4 / 3;
}
} break;
default: {
} break;
}
return p_raw_byte_size;
}
PackedFloat64Array GLTFAccessor::_filter_numbers(const PackedFloat64Array &p_numbers) const {
PackedFloat64Array filtered_numbers = p_numbers;
for (int64_t i = 0; i < p_numbers.size(); i++) {
const double num = p_numbers[i];
if (!Math::is_finite(num)) {
// 3.6.2.2. "Values of NaN, +Infinity, and -Infinity MUST NOT be present."
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#accessor-data-types
filtered_numbers.set(i, 0.0);
} else if (component_type == GLTFAccessor::COMPONENT_TYPE_SINGLE_FLOAT) {
filtered_numbers.set(i, (double)(float)num);
}
}
return filtered_numbers;
}
String GLTFAccessor::_get_component_type_name(const GLTFComponentType p_component) {
// These names are only for debugging and printing error messages, glTF uses the numeric values.
switch (p_component) {
case GLTFAccessor::COMPONENT_TYPE_NONE:
return "None";
case GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE:
return "Byte";
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE:
return "UByte";
case GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT:
return "Short";
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT:
return "UShort";
case GLTFAccessor::COMPONENT_TYPE_SIGNED_INT:
return "Int";
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT:
return "UInt";
case GLTFAccessor::COMPONENT_TYPE_SINGLE_FLOAT:
return "Float";
case GLTFAccessor::COMPONENT_TYPE_DOUBLE_FLOAT:
return "Double";
case GLTFAccessor::COMPONENT_TYPE_HALF_FLOAT:
return "Half";
case GLTFAccessor::COMPONENT_TYPE_SIGNED_LONG:
return "Long";
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_LONG:
return "ULong";
}
return "<Error>";
}
GLTFAccessor::GLTFComponentType GLTFAccessor::_get_indices_component_type_for_size(const int64_t p_size) {
ERR_FAIL_COND_V(p_size < 0, GLTFAccessor::COMPONENT_TYPE_NONE);
// 3.7.2.1. indices accessor MUST NOT contain the maximum possible value for the component type used
// (i.e., 255 for unsigned bytes, 65535 for unsigned shorts, 4294967295 for unsigned ints).
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#meshes-overview
if (unlikely(p_size > 4294967294LL)) {
return GLTFAccessor::COMPONENT_TYPE_UNSIGNED_LONG;
}
if (p_size > 65534LL) {
return GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT;
}
if (p_size > 254LL) {
return GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT;
}
return GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE;
}
GLTFAccessor::GLTFAccessorType GLTFAccessor::_get_accessor_type_from_str(const String &p_string) {
if (p_string == "SCALAR") {
return GLTFAccessor::TYPE_SCALAR;
@ -277,6 +421,690 @@ String GLTFAccessor::_get_accessor_type_name() const {
ERR_FAIL_V("SCALAR");
}
int64_t GLTFAccessor::_get_vector_size() const {
switch (accessor_type) {
case GLTFAccessor::TYPE_SCALAR:
return 1;
case GLTFAccessor::TYPE_VEC2:
return 2;
case GLTFAccessor::TYPE_VEC3:
return 3;
case GLTFAccessor::TYPE_VEC4:
return 4;
case GLTFAccessor::TYPE_MAT2:
return 4;
case GLTFAccessor::TYPE_MAT3:
return 9;
case GLTFAccessor::TYPE_MAT4:
return 16;
default:
break;
}
ERR_FAIL_V(0);
}
int64_t GLTFAccessor::_get_bytes_per_component(const GLTFComponentType p_component_type) {
switch (p_component_type) {
case GLTFAccessor::COMPONENT_TYPE_NONE:
ERR_FAIL_V(0);
case GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE:
return 1;
case GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT:
case GLTFAccessor::COMPONENT_TYPE_HALF_FLOAT:
return 2;
case GLTFAccessor::COMPONENT_TYPE_SIGNED_INT:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT:
case GLTFAccessor::COMPONENT_TYPE_SINGLE_FLOAT:
return 4;
case GLTFAccessor::COMPONENT_TYPE_DOUBLE_FLOAT:
case GLTFAccessor::COMPONENT_TYPE_SIGNED_LONG:
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_LONG:
return 8;
}
ERR_FAIL_V(0);
}
int64_t GLTFAccessor::_get_bytes_per_vector() const {
const int64_t raw_byte_size = _get_bytes_per_component(component_type) * _get_vector_size();
return _determine_padded_byte_count(raw_byte_size);
}
bool GLTFAccessor::is_equal_exact(const Ref<GLTFAccessor> &p_other) const {
if (p_other.is_null()) {
return false;
}
return (buffer_view == p_other->buffer_view &&
byte_offset == p_other->byte_offset &&
component_type == p_other->component_type &&
normalized == p_other->normalized &&
count == p_other->count &&
accessor_type == p_other->accessor_type &&
min == p_other->min &&
max == p_other->max &&
sparse_count == p_other->sparse_count &&
sparse_indices_buffer_view == p_other->sparse_indices_buffer_view &&
sparse_indices_byte_offset == p_other->sparse_indices_byte_offset &&
sparse_indices_component_type == p_other->sparse_indices_component_type &&
sparse_values_buffer_view == p_other->sparse_values_buffer_view &&
sparse_values_byte_offset == p_other->sparse_values_byte_offset);
}
// Private encode functions.
PackedFloat64Array GLTFAccessor::_encode_variants_as_floats(const Array &p_input_data, Variant::Type p_variant_type) const {
const int64_t vector_size = _get_vector_size();
const int64_t input_size = p_input_data.size();
PackedFloat64Array numbers;
numbers.resize(input_size * vector_size);
for (int64_t input_index = 0; input_index < input_size; input_index++) {
Variant variant = p_input_data[input_index];
const int64_t vector_offset = input_index * vector_size;
switch (p_variant_type) {
case Variant::NIL:
case Variant::BOOL:
case Variant::INT:
case Variant::FLOAT: {
// For scalar values, just append them. Variant can convert all of these to double. Some padding may also be needed.
numbers.set(vector_offset, variant);
if (unlikely(vector_size > 1)) {
for (int64_t i = 1; i < vector_size; i++) {
numbers.set(vector_offset + i, 0.0);
}
}
} break;
case Variant::PLANE:
case Variant::QUATERNION:
case Variant::RECT2: {
// Evil hack that relies on the structure of Variant, but it's the
// only way to accomplish this without a ton of code duplication.
*(Variant::Type *)&variant = Variant::VECTOR4;
}
[[fallthrough]];
case Variant::VECTOR2:
case Variant::VECTOR3:
case Variant::VECTOR4: {
// Variant can handle converting Vector2/3/4 to Vector4 for us.
Vector4 vec = variant;
for (int64_t i = 0; i < vector_size; i++) {
numbers.set(vector_offset + i, vec[i]);
}
if (unlikely(vector_size > 4)) {
for (int64_t i = 4; i < vector_size; i++) {
numbers.set(vector_offset + i, 0.0);
}
}
} break;
case Variant::RECT2I: {
*(Variant::Type *)&variant = Variant::VECTOR4I;
}
[[fallthrough]];
case Variant::VECTOR2I:
case Variant::VECTOR3I:
case Variant::VECTOR4I: {
// Variant can handle converting Vector2i/3i/4i to Vector4i for us.
Vector4i vec = variant;
for (int64_t i = 0; i < vector_size; i++) {
numbers.set(vector_offset + i, vec[i]);
}
if (unlikely(vector_size > 4)) {
for (int64_t i = 4; i < vector_size; i++) {
numbers.set(vector_offset + i, 0.0);
}
}
} break;
case Variant::COLOR: {
Color c = variant;
for (int64_t i = 0; i < vector_size; i++) {
numbers.set(vector_offset + i, c[i]);
}
if (unlikely(vector_size > 4)) {
for (int64_t i = 4; i < vector_size; i++) {
numbers.set(vector_offset + i, 0.0);
}
}
} break;
case Variant::TRANSFORM2D:
case Variant::BASIS:
case Variant::TRANSFORM3D:
case Variant::PROJECTION: {
// Variant can handle converting Transform2D/Transform3D/Basis to Projection for us.
Projection p = variant;
if (vector_size == 16) {
for (int64_t i = 0; i < 4; i++) {
numbers.set(vector_offset + 4 * i, p.columns[i][0]);
numbers.set(vector_offset + 4 * i + 1, p.columns[i][1]);
numbers.set(vector_offset + 4 * i + 2, p.columns[i][2]);
numbers.set(vector_offset + 4 * i + 3, p.columns[i][3]);
}
} else if (vector_size == 9) {
for (int64_t i = 0; i < 3; i++) {
numbers.set(vector_offset + 3 * i, p.columns[i][0]);
numbers.set(vector_offset + 3 * i + 1, p.columns[i][1]);
numbers.set(vector_offset + 3 * i + 2, p.columns[i][2]);
}
} else if (vector_size == 4) {
numbers.set(vector_offset, p.columns[0][0]);
numbers.set(vector_offset + 1, p.columns[0][1]);
numbers.set(vector_offset + 2, p.columns[1][0]);
numbers.set(vector_offset + 3, p.columns[1][1]);
}
} break;
default: {
ERR_FAIL_V_MSG(PackedFloat64Array(), "glTF export: Cannot encode accessor from Variant of type " + Variant::get_type_name(p_variant_type) + ".");
}
}
}
return numbers;
}
void GLTFAccessor::_store_sparse_indices_into_state(const Ref<GLTFState> &p_gltf_state, const PackedInt64Array &p_sparse_indices, const bool p_deduplicate) {
// The byte offset of a sparse accessor's indices buffer view MUST be a multiple of the indices primitive componentType.
// https://github.com/KhronosGroup/glTF/blob/main/specification/2.0/schema/accessor.sparse.indices.schema.json
const int64_t bytes_per_index = _get_bytes_per_component(sparse_indices_component_type);
PackedByteArray indices_bytes;
indices_bytes.resize(bytes_per_index * p_sparse_indices.size());
uint8_t *ret_write = indices_bytes.ptrw();
int64_t ret_byte_offset = 0;
for (int64_t i = 0; i < p_sparse_indices.size(); i++) {
switch (sparse_indices_component_type) {
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE: {
*(uint8_t *)&ret_write[ret_byte_offset] = p_sparse_indices[i];
} break;
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT: {
*(uint16_t *)&ret_write[ret_byte_offset] = p_sparse_indices[i];
} break;
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT: {
*(uint32_t *)&ret_write[ret_byte_offset] = p_sparse_indices[i];
} break;
case GLTFAccessor::COMPONENT_TYPE_UNSIGNED_LONG: {
*(uint64_t *)&ret_write[ret_byte_offset] = p_sparse_indices[i];
} break;
default: {
ERR_FAIL_MSG("glTF export: Invalid sparse indices component type '" + _get_component_type_name(sparse_indices_component_type) + "' for sparse accessor indices.");
} break;
}
ret_byte_offset += bytes_per_index;
}
const GLTFBufferViewIndex buffer_view_index = GLTFBufferView::write_new_buffer_view_into_state(p_gltf_state, indices_bytes, bytes_per_index, GLTFBufferView::TARGET_NONE, -1, 0, p_deduplicate);
ERR_FAIL_COND_MSG(buffer_view_index == -1, "glTF export: Failed to write sparse indices into glTF state.");
set_sparse_indices_buffer_view(buffer_view_index);
}
// Low-level encode functions.
GLTFAccessor::GLTFComponentType GLTFAccessor::get_minimal_integer_component_type_from_ints(const PackedInt64Array &p_numbers) {
bool has_negative = false;
for (int64_t i = 0; i < p_numbers.size(); i++) {
if (p_numbers[i] < 0) {
has_negative = true;
break;
}
}
if (has_negative) {
GLTFComponentType ret = GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE;
for (int64_t i = 0; i < p_numbers.size(); i++) {
const int64_t num = p_numbers[i];
if (ret == GLTFAccessor::COMPONENT_TYPE_SIGNED_BYTE && (num < -128LL || num > 127LL)) {
ret = GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT;
}
if (ret == GLTFAccessor::COMPONENT_TYPE_SIGNED_SHORT && (num < -32768LL || num > 32767LL)) {
ret = GLTFAccessor::COMPONENT_TYPE_SIGNED_INT;
}
if (ret == GLTFAccessor::COMPONENT_TYPE_SIGNED_INT && (num < -2147483648LL || num > 2147483647LL)) {
return GLTFAccessor::COMPONENT_TYPE_SIGNED_LONG;
}
}
return ret;
}
GLTFComponentType ret = GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE;
for (int64_t i = 0; i < p_numbers.size(); i++) {
const int64_t num = p_numbers[i];
// 3.7.2.1. indices accessor MUST NOT contain the maximum possible value for the component type used
// (i.e., 255 for unsigned bytes, 65535 for unsigned shorts, 4294967295 for unsigned ints).
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#meshes-overview
if (ret == GLTFAccessor::COMPONENT_TYPE_UNSIGNED_BYTE && num > 254LL) {
ret = GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT;
}
if (ret == GLTFAccessor::COMPONENT_TYPE_UNSIGNED_SHORT && num > 65534LL) {
ret = GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT;
}
if (ret == GLTFAccessor::COMPONENT_TYPE_UNSIGNED_INT && num > 4294967294LL) {
return GLTFAccessor::COMPONENT_TYPE_UNSIGNED_LONG;
}
}
return ret;
}
PackedByteArray GLTFAccessor::encode_floats_as_bytes(const PackedFloat64Array &p_input_numbers) {
// Filter and update `count`, `min`, and `max` based on the given data.
PackedFloat64Array filtered_numbers = _filter_numbers(p_input_numbers);
count = filtered_numbers.size() / _get_vector_size();
_calculate_min_and_max(filtered_numbers);
// Actually encode the data.
const int64_t input_size = filtered_numbers.size();
const int64_t bytes_per_component = _get_bytes_per_component(component_type);
int64_t raw_byte_size = _determine_padded_byte_count(bytes_per_component * input_size);
int64_t skip_every = 0;
int64_t skip_bytes = 0;
_determine_pad_skip(skip_every, skip_bytes);
PackedByteArray ret;
ret.resize(raw_byte_size);
uint8_t *ret_write = ret.ptrw();
int64_t ret_byte_offset = 0;
for (int64_t i = 0; i < input_size; i++) {
switch (component_type) {
case COMPONENT_TYPE_NONE: {
ERR_FAIL_V_MSG(ret, "glTF export: Invalid component type 'NONE' for glTF accessor.");
} break;
case COMPONENT_TYPE_SIGNED_BYTE: {
*(int8_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_BYTE: {
*(uint8_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_SIGNED_SHORT: {
*(int16_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_SHORT: {
*(uint16_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_SIGNED_INT: {
*(int32_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_INT: {
*(uint32_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_SINGLE_FLOAT: {
*(float *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_DOUBLE_FLOAT: {
*(double *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_HALF_FLOAT: {
*(uint16_t *)&ret_write[ret_byte_offset] = Math::make_half_float(filtered_numbers[i]);
} break;
case COMPONENT_TYPE_SIGNED_LONG: {
// Note: This can potentially result in precision loss because int64_t can store some values that double can't.
*(int64_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_LONG: {
// Note: This can potentially result in precision loss because uint64_t can store some values that double can't.
*(uint64_t *)&ret_write[ret_byte_offset] = filtered_numbers[i];
} break;
default: {
ERR_FAIL_V_MSG(ret, "glTF export: Godot does not support writing glTF accessor components of type '" + itos(component_type) + "'.");
} break;
}
ret_byte_offset += bytes_per_component;
if (unlikely(skip_every > 0)) {
if ((i + 1) % skip_every == 0) {
ret_byte_offset += skip_bytes;
}
}
}
ERR_FAIL_COND_V_MSG(ret_byte_offset != raw_byte_size, ret, "glTF export: Accessor encoded data did not write exactly the expected number of bytes.");
return ret;
}
PackedByteArray GLTFAccessor::encode_ints_as_bytes(const PackedInt64Array &p_input_numbers) {
// Filter and update `count`, `min`, and `max` based on the given data.
count = p_input_numbers.size() / _get_vector_size();
_calculate_min_and_max(Variant(p_input_numbers));
// Actually encode the data.
const int64_t input_size = p_input_numbers.size();
const int64_t bytes_per_component = _get_bytes_per_component(component_type);
int64_t raw_byte_size = _determine_padded_byte_count(bytes_per_component * input_size);
int64_t skip_every = 0;
int64_t skip_bytes = 0;
_determine_pad_skip(skip_every, skip_bytes);
PackedByteArray ret;
ret.resize(raw_byte_size);
uint8_t *ret_write = ret.ptrw();
int64_t ret_byte_offset = 0;
for (int64_t i = 0; i < input_size; i++) {
switch (component_type) {
case COMPONENT_TYPE_NONE: {
ERR_FAIL_V_MSG(ret, "glTF export: Invalid component type 'NONE' for glTF accessor.");
} break;
case COMPONENT_TYPE_SIGNED_BYTE: {
*(int8_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_BYTE: {
*(uint8_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_SIGNED_SHORT: {
*(int16_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_SHORT: {
*(uint16_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_SIGNED_INT: {
*(int32_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_INT: {
*(uint32_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_SINGLE_FLOAT: {
*(float *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_DOUBLE_FLOAT: {
*(double *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_HALF_FLOAT: {
*(uint16_t *)&ret_write[ret_byte_offset] = Math::make_half_float(p_input_numbers[i]);
} break;
case COMPONENT_TYPE_SIGNED_LONG: {
*(int64_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
case COMPONENT_TYPE_UNSIGNED_LONG: {
*(uint64_t *)&ret_write[ret_byte_offset] = p_input_numbers[i];
} break;
default: {
ERR_FAIL_V_MSG(ret, "glTF export: Godot does not support writing glTF accessor components of type '" + itos(component_type) + "'.");
} break;
}
ret_byte_offset += bytes_per_component;
if (unlikely(skip_every > 0)) {
if ((i + 1) % skip_every == 0) {
ret_byte_offset += skip_bytes;
}
}
}
ERR_FAIL_COND_V_MSG(ret_byte_offset != raw_byte_size, ret, "glTF export: Accessor encoded data did not write exactly the expected number of bytes.");
return ret;
}
PackedByteArray GLTFAccessor::encode_variants_as_bytes(const Array &p_input_data, Variant::Type p_variant_type) {
const int64_t bytes_per_vec = _get_bytes_per_vector();
ERR_FAIL_COND_V_MSG(bytes_per_vec == 0, PackedByteArray(), "glTF export: Cannot encode an accessor of this type.");
PackedFloat64Array numbers = _encode_variants_as_floats(p_input_data, p_variant_type);
return encode_floats_as_bytes(numbers);
}
GLTFAccessorIndex GLTFAccessor::store_accessor_data_into_state(const Ref<GLTFState> &p_gltf_state, const PackedByteArray &p_data_bytes, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const GLTFBufferIndex p_buffer_index, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_data_bytes.is_empty(), -1, "glTF export: Cannot store nothing.");
// Update `count` based on the size of the data. It's possible that `count` may already be correct, but this function is public, so this prevents footguns.
const int64_t bytes_per_vec = _get_bytes_per_vector();
ERR_FAIL_COND_V_MSG(bytes_per_vec == 0 || p_data_bytes.size() % bytes_per_vec != 0, -1, "glTF export: Tried to store an accessor with data that is not a multiple of the accessor's bytes per vector.");
count = p_data_bytes.size() / bytes_per_vec;
// 3.6.2.4. The byte offset of an accessor's buffer view MUST be a multiple of the accessor's primitive size.
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#data-alignment
const int64_t alignment = _get_bytes_per_component(component_type);
// 3.6.2.4. Each element of a vertex attribute MUST be aligned to 4-byte boundaries inside a bufferView.
int64_t byte_stride = -1;
if (p_buffer_view_target == GLTFBufferView::TARGET_ARRAY_BUFFER) {
byte_stride = bytes_per_vec;
ERR_FAIL_COND_V_MSG(byte_stride < 4 || byte_stride % 4 != 0, -1, "glTF export: Vertex attributes using TARGET_ARRAY_BUFFER must have a byte stride that is a multiple of 4 as required by section 3.6.2.4 of the glTF specification.");
}
// Write the data into a new buffer view.
const GLTFBufferViewIndex buffer_view_index = GLTFBufferView::write_new_buffer_view_into_state(p_gltf_state, p_data_bytes, alignment, p_buffer_view_target, byte_stride, 0, p_deduplicate);
ERR_FAIL_COND_V_MSG(buffer_view_index == -1, -1, "glTF export: Accessor failed to write new buffer view into glTF state.");
set_buffer_view(buffer_view_index);
// Add the new accessor to the state, but check for duplicates first.
TypedArray<GLTFAccessor> state_accessors = p_gltf_state->get_accessors();
const GLTFAccessorIndex accessor_count = state_accessors.size();
for (GLTFAccessorIndex i = 0; i < accessor_count; i++) {
Ref<GLTFAccessor> existing_accessor = state_accessors[i];
if (is_equal_exact(existing_accessor)) {
// An identical accessor already exists in the state, so just return the index.
return i;
}
}
Ref<GLTFAccessor> self = this;
state_accessors.append(self);
p_gltf_state->set_accessors(state_accessors);
return accessor_count;
}
Ref<GLTFAccessor> GLTFAccessor::make_new_accessor_without_data(GLTFAccessorType p_accessor_type, GLTFComponentType p_component_type) {
Ref<GLTFAccessor> accessor;
accessor.instantiate();
accessor->set_accessor_type(p_accessor_type);
accessor->set_component_type(p_component_type);
return accessor;
}
// High-level encode functions.
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_colors(const Ref<GLTFState> &p_gltf_state, const PackedColorArray &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedFloat64Array numbers;
numbers.resize(p_input_data.size() * 4);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Color &color = p_input_data[i];
numbers.set(i * 4, color.r);
numbers.set(i * 4 + 1, color.g);
numbers.set(i * 4 + 2, color.b);
numbers.set(i * 4 + 3, color.a);
}
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC4, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_float64s(const Ref<GLTFState> &p_gltf_state, const PackedFloat64Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_SCALAR, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(p_input_data);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_int32s(const Ref<GLTFState> &p_gltf_state, const PackedInt32Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedInt64Array numbers;
numbers.resize(p_input_data.size());
for (int64_t i = 0; i < p_input_data.size(); i++) {
numbers.set(i, p_input_data[i]);
}
const GLTFComponentType component_type = get_minimal_integer_component_type_from_ints(numbers);
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_SCALAR, component_type);
PackedByteArray encoded_bytes = accessor->encode_ints_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_int64s(const Ref<GLTFState> &p_gltf_state, const PackedInt64Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
const GLTFComponentType component_type = get_minimal_integer_component_type_from_ints(p_input_data);
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_SCALAR, component_type);
PackedByteArray encoded_bytes = accessor->encode_ints_as_bytes(p_input_data);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_quaternions(const Ref<GLTFState> &p_gltf_state, const Vector<Quaternion> &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedFloat64Array numbers;
numbers.resize(p_input_data.size() * 4);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Quaternion &quat = p_input_data[i];
numbers.set(i * 4, quat.x);
numbers.set(i * 4 + 1, quat.y);
numbers.set(i * 4 + 2, quat.z);
numbers.set(i * 4 + 3, quat.w);
}
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC4, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_variants(const Ref<GLTFState> &p_gltf_state, const Array &p_input_data, Variant::Type p_variant_type, GLTFAccessorType p_accessor_type, GLTFComponentType p_component_type, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(p_accessor_type, p_component_type);
// Write the data into a new buffer view.
PackedByteArray encoded_bytes = accessor->encode_variants_as_bytes(p_input_data, p_variant_type);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_vector2s(const Ref<GLTFState> &p_gltf_state, const PackedVector2Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedFloat64Array numbers;
numbers.resize(p_input_data.size() * 2);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Vector2 &vec = p_input_data[i];
numbers.set(i * 2, vec.x);
numbers.set(i * 2 + 1, vec.y);
}
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC2, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_vector3s(const Ref<GLTFState> &p_gltf_state, const PackedVector3Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedFloat64Array numbers;
numbers.resize(p_input_data.size() * 3);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Vector3 &vec = p_input_data[i];
numbers.set(i * 3, vec.x);
numbers.set(i * 3 + 1, vec.y);
numbers.set(i * 3 + 2, vec.z);
}
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC3, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_vector4s(const Ref<GLTFState> &p_gltf_state, const PackedVector4Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedFloat64Array numbers;
numbers.resize(p_input_data.size() * 4);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Vector4 &vec = p_input_data[i];
numbers.set(i * 4, vec.x);
numbers.set(i * 4 + 1, vec.y);
numbers.set(i * 4 + 2, vec.z);
numbers.set(i * 4 + 3, vec.w);
}
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC4, COMPONENT_TYPE_SINGLE_FLOAT);
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_accessor_from_vector4is(const Ref<GLTFState> &p_gltf_state, const Vector<Vector4i> &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_input_data.is_empty(), -1, "glTF export: Cannot encode an accessor from an empty array.");
PackedInt64Array numbers;
numbers.resize(p_input_data.size() * 4);
for (int64_t i = 0; i < p_input_data.size(); i++) {
const Vector4i &vec = p_input_data[i];
numbers.set(i * 4, vec.x);
numbers.set(i * 4 + 1, vec.y);
numbers.set(i * 4 + 2, vec.z);
numbers.set(i * 4 + 3, vec.w);
}
const GLTFComponentType component_type = get_minimal_integer_component_type_from_ints(numbers);
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC4, component_type);
PackedByteArray encoded_bytes = accessor->encode_ints_as_bytes(numbers);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_buffer_view_target, 0, p_deduplicate);
}
GLTFAccessorIndex GLTFAccessor::encode_new_sparse_accessor_from_vec3s(const Ref<GLTFState> &p_gltf_state, const PackedVector3Array &p_input_data, const PackedVector3Array &p_base_reference_data, const double p_tolerance_multiplier, const GLTFBufferView::ArrayBufferTarget p_main_buffer_view_target, const bool p_deduplicate) {
const int64_t input_size = p_input_data.size();
ERR_FAIL_COND_V_MSG(input_size == 0, -1, "glTF export: Cannot encode an accessor from an empty array.");
const bool is_base_empty = p_base_reference_data.is_empty();
ERR_FAIL_COND_V_MSG(!is_base_empty && p_base_reference_data.size() != input_size, -1, "glTF export: Base reference data must either be empty, or have the same size as the main input data.");
PackedInt64Array sparse_indices;
PackedFloat64Array sparse_values;
PackedFloat64Array dense_values;
int64_t highest_index = 0;
dense_values.resize(input_size * 3);
for (int64_t i = 0; i < input_size; i++) {
Vector3 vec = p_input_data[i];
Vector3 base_ref_vec;
Vector3 displacement;
if (is_base_empty) {
base_ref_vec = Vector3();
displacement = vec;
} else {
base_ref_vec = p_base_reference_data[i];
displacement = vec - base_ref_vec;
}
if ((displacement * p_tolerance_multiplier).is_zero_approx()) {
vec = base_ref_vec;
} else {
highest_index = i;
sparse_indices.append(i);
sparse_values.append(vec.x);
sparse_values.append(vec.y);
sparse_values.append(vec.z);
}
dense_values.set(i * 3, vec.x);
dense_values.set(i * 3 + 1, vec.y);
dense_values.set(i * 3 + 2, vec.z);
}
// Check if the sparse accessor actually saves space, or if it's better to just use a normal accessor.
const int64_t sparse_count = sparse_indices.size();
const int64_t bytes_per_value_component = _get_bytes_per_component(COMPONENT_TYPE_SINGLE_FLOAT);
const GLTFComponentType indices_component_type = _get_indices_component_type_for_size(highest_index);
const int64_t sparse_data_bytes = _get_bytes_per_component(indices_component_type) * sparse_count + bytes_per_value_component * sparse_values.size();
const int64_t dense_data_bytes = bytes_per_value_component * 3 * input_size;
// Sparse accessors require more JSON, a bit under 200 characters when minified, so factor that in.
constexpr int64_t sparse_json_fluff = 200;
Ref<GLTFAccessor> accessor = make_new_accessor_without_data(TYPE_VEC3, COMPONENT_TYPE_SINGLE_FLOAT);
if (sparse_data_bytes + sparse_json_fluff >= dense_data_bytes) {
// Sparse accessor is not worth it, just use a normal accessor instead.
// However, note that we use the calculated dense values instead of the original input data.
// This way, regardless of the underlying storage layout, the data is the same in both cases.
PackedByteArray encoded_bytes = accessor->encode_floats_as_bytes(dense_values);
ERR_FAIL_COND_V_MSG(encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, encoded_bytes, p_main_buffer_view_target, 0, p_deduplicate);
}
// Encode as a sparse accessor.
if (sparse_count > 0) {
accessor->set_sparse_count(sparse_count);
accessor->set_sparse_indices_component_type(indices_component_type);
accessor->_store_sparse_indices_into_state(p_gltf_state, sparse_indices, p_deduplicate);
const PackedByteArray sparse_values_encoded_bytes = accessor->encode_floats_as_bytes(sparse_values);
ERR_FAIL_COND_V_MSG(sparse_values_encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode sparse values as bytes.");
// Note: Sparse values always use TARGET_NONE, it does NOT match the target of the main buffer view.
const GLTFBufferViewIndex sparse_values_buffer_view_index = GLTFBufferView::write_new_buffer_view_into_state(p_gltf_state, sparse_values_encoded_bytes, bytes_per_value_component, GLTFBufferView::TARGET_NONE, -1, 0, p_deduplicate);
accessor->set_sparse_values_buffer_view(sparse_values_buffer_view_index);
}
// If the base reference data is empty, just directly add the accessor with only sparse data.
if (is_base_empty) {
// This is similar to `encode_floats_as_bytes` + `store_accessor_data_into_state` but we don't write a buffer view.
// Filter and update `count`, `min`, and `max` based on the given data.
accessor->set_count(input_size);
const PackedFloat64Array filtered_numbers = accessor->_filter_numbers(dense_values);
accessor->_calculate_min_and_max(filtered_numbers);
// Add the new accessor to the state, but check for duplicates first.
TypedArray<GLTFAccessor> state_accessors = p_gltf_state->get_accessors();
const GLTFAccessorIndex accessor_count = state_accessors.size();
for (GLTFAccessorIndex i = 0; i < accessor_count; i++) {
Ref<GLTFAccessor> existing_accessor = state_accessors[i];
if (accessor->is_equal_exact(existing_accessor)) {
// An identical accessor already exists in the state, so just return the index.
return i;
}
}
state_accessors.append(accessor);
p_gltf_state->set_accessors(state_accessors);
return accessor_count;
}
// Encode the base reference alongside the sparse data.
PackedFloat64Array base_reference_values;
base_reference_values.resize(input_size * 3);
for (int64_t i = 0; i < input_size; i++) {
const Vector3 &base_ref_vec = p_base_reference_data[i];
base_reference_values.set(i * 3, base_ref_vec.x);
base_reference_values.set(i * 3 + 1, base_ref_vec.y);
base_reference_values.set(i * 3 + 2, base_ref_vec.z);
}
const PackedByteArray base_reference_encoded_bytes = accessor->encode_floats_as_bytes(base_reference_values);
ERR_FAIL_COND_V_MSG(base_reference_encoded_bytes.is_empty(), -1, "glTF export: Accessor failed to encode data as bytes (was the input data empty?).");
return accessor->store_accessor_data_into_state(p_gltf_state, base_reference_encoded_bytes, p_main_buffer_view_target, 0, p_deduplicate);
}
// Dictionary conversion.
Ref<GLTFAccessor> GLTFAccessor::from_dictionary(const Dictionary &p_dict) {

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@ -81,8 +81,21 @@ private:
int64_t sparse_values_byte_offset = 0;
// Trivial helper functions.
static GLTFAccessor::GLTFAccessorType _get_accessor_type_from_str(const String &p_string);
void _calculate_min_and_max(const PackedFloat64Array &p_numbers);
void _determine_pad_skip(int64_t &r_skip_every, int64_t &r_skip_bytes) const;
int64_t _determine_padded_byte_count(int64_t p_raw_byte_size) const;
PackedFloat64Array _filter_numbers(const PackedFloat64Array &p_numbers) const;
static String _get_component_type_name(const GLTFComponentType p_component);
static GLTFComponentType _get_indices_component_type_for_size(const int64_t p_size);
static GLTFAccessorType _get_accessor_type_from_str(const String &p_string);
String _get_accessor_type_name() const;
int64_t _get_vector_size() const;
static int64_t _get_bytes_per_component(const GLTFComponentType p_component_type);
int64_t _get_bytes_per_vector() const;
// Private encode functions.
PackedFloat64Array _encode_variants_as_floats(const Array &p_input_data, Variant::Type p_variant_type) const;
void _store_sparse_indices_into_state(const Ref<GLTFState> &p_gltf_state, const PackedInt64Array &p_sparse_indices, const bool p_deduplicate = true);
protected:
static void _bind_methods();
@ -156,6 +169,30 @@ public:
int64_t get_sparse_values_byte_offset() const;
void set_sparse_values_byte_offset(int64_t p_sparse_values_byte_offset);
bool is_equal_exact(const Ref<GLTFAccessor> &p_other) const;
// Low-level encode functions.
static GLTFComponentType get_minimal_integer_component_type_from_ints(const PackedInt64Array &p_numbers);
PackedByteArray encode_floats_as_bytes(const PackedFloat64Array &p_input_numbers);
PackedByteArray encode_ints_as_bytes(const PackedInt64Array &p_input_numbers);
PackedByteArray encode_variants_as_bytes(const Array &p_input_data, Variant::Type p_variant_type);
GLTFAccessorIndex store_accessor_data_into_state(const Ref<GLTFState> &p_gltf_state, const PackedByteArray &p_data_bytes, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const GLTFBufferIndex p_buffer_index = 0, const bool p_deduplicate = true);
static Ref<GLTFAccessor> make_new_accessor_without_data(GLTFAccessorType p_accessor_type = TYPE_SCALAR, GLTFComponentType p_component_type = COMPONENT_TYPE_SINGLE_FLOAT);
// High-level encode functions.
static GLTFAccessorIndex encode_new_accessor_from_colors(const Ref<GLTFState> &p_gltf_state, const PackedColorArray &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_float64s(const Ref<GLTFState> &p_gltf_state, const PackedFloat64Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_int32s(const Ref<GLTFState> &p_gltf_state, const PackedInt32Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_int64s(const Ref<GLTFState> &p_gltf_state, const PackedInt64Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_quaternions(const Ref<GLTFState> &p_gltf_state, const Vector<Quaternion> &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_variants(const Ref<GLTFState> &p_gltf_state, const Array &p_input_data, Variant::Type p_variant_type, GLTFAccessorType p_accessor_type = TYPE_SCALAR, GLTFComponentType p_component_type = COMPONENT_TYPE_SINGLE_FLOAT, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_vector2s(const Ref<GLTFState> &p_gltf_state, const PackedVector2Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_vector3s(const Ref<GLTFState> &p_gltf_state, const PackedVector3Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_vector4s(const Ref<GLTFState> &p_gltf_state, const PackedVector4Array &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_accessor_from_vector4is(const Ref<GLTFState> &p_gltf_state, const Vector<Vector4i> &p_input_data, const GLTFBufferView::ArrayBufferTarget p_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
static GLTFAccessorIndex encode_new_sparse_accessor_from_vec3s(const Ref<GLTFState> &p_gltf_state, const PackedVector3Array &p_input_data, const PackedVector3Array &p_base_reference_data, const double p_tolerance_multiplier = 1.0, const GLTFBufferView::ArrayBufferTarget p_main_buffer_view_target = GLTFBufferView::TARGET_NONE, const bool p_deduplicate = true);
// Dictionary conversion.
static Ref<GLTFAccessor> from_dictionary(const Dictionary &p_dict);
Dictionary to_dictionary() const;

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@ -110,14 +110,73 @@ void GLTFBufferView::set_vertex_attributes(bool p_attributes) {
Vector<uint8_t> GLTFBufferView::load_buffer_view_data(const Ref<GLTFState> p_gltf_state) const {
ERR_FAIL_COND_V(p_gltf_state.is_null(), Vector<uint8_t>());
ERR_FAIL_COND_V_MSG(byte_stride > 0, Vector<uint8_t>(), "Buffer views with byte stride are not yet supported by this method.");
const TypedArray<Vector<uint8_t>> &buffers = p_gltf_state->get_buffers();
ERR_FAIL_INDEX_V(buffer, buffers.size(), Vector<uint8_t>());
const PackedByteArray &buffer_data = buffers[buffer];
const int64_t byte_end = byte_offset + byte_length;
// Note that for buffer views with a byte stride, the parts of this data which get used may
// only be determined in combination with the accessors that reference this buffer view.
return buffer_data.slice(byte_offset, byte_end);
}
GLTFBufferViewIndex GLTFBufferView::write_new_buffer_view_into_state(const Ref<GLTFState> &p_gltf_state, const PackedByteArray &p_input_data, const int64_t p_alignment, const ArrayBufferTarget p_target, const int64_t p_byte_stride, const GLTFBufferIndex p_buffer_index, const bool p_deduplicate) {
ERR_FAIL_COND_V_MSG(p_buffer_index < 0, -1, "Buffer index must be greater than or equal to zero.");
const bool target_is_indices = p_target == ArrayBufferTarget::TARGET_ELEMENT_ARRAY_BUFFER;
const bool target_is_vertex_attributes = p_target == ArrayBufferTarget::TARGET_ARRAY_BUFFER;
if (target_is_vertex_attributes) {
ERR_FAIL_COND_V_MSG(p_byte_stride < 4 || p_byte_stride % 4 != 0, -1, "glTF export: Vertex attributes using TARGET_ARRAY_BUFFER must have a byte stride that is a multiple of 4 as required by section 3.6.2.4 of the glTF specification.");
}
// Check for duplicate buffer views before adding a new one.
TypedArray<GLTFBufferView> state_buffer_views = p_gltf_state->get_buffer_views();
const int buffer_view_index = state_buffer_views.size();
if (p_deduplicate) {
for (int i = 0; i < buffer_view_index; i++) {
const Ref<GLTFBufferView> existing_buffer_view = state_buffer_views[i];
if (existing_buffer_view->get_byte_offset() % p_alignment == 0 &&
existing_buffer_view->get_byte_length() == p_input_data.size() &&
existing_buffer_view->get_byte_stride() == p_byte_stride &&
existing_buffer_view->get_indices() == target_is_indices &&
existing_buffer_view->get_vertex_attributes() == target_is_vertex_attributes) {
if (existing_buffer_view->load_buffer_view_data(p_gltf_state) == p_input_data) {
// Duplicate found, return the index of the existing buffer view.
return i;
}
}
}
}
// Write the data into the buffer at the specified index.
TypedArray<PackedByteArray> state_buffers = p_gltf_state->get_buffers();
if (state_buffers.size() <= p_buffer_index) {
state_buffers.resize(p_buffer_index + 1);
}
PackedByteArray state_buffer = state_buffers[p_buffer_index];
const int64_t input_data_size = p_input_data.size();
// This is used by accessors. The byte offset of an accessor MUST be a multiple of the accessor's component size.
// https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#data-alignment
int64_t byte_offset = state_buffer.size();
if (byte_offset % p_alignment != 0) {
byte_offset += p_alignment - (byte_offset % p_alignment);
}
state_buffer.resize(byte_offset + input_data_size);
uint8_t *buffer_ptr = state_buffer.ptrw();
memcpy(buffer_ptr + byte_offset, p_input_data.ptr(), input_data_size);
state_buffers[p_buffer_index] = state_buffer;
p_gltf_state->set_buffers(state_buffers);
// Create a new GLTFBufferView that references the new buffer.
Ref<GLTFBufferView> buffer_view;
buffer_view.instantiate();
buffer_view->set_buffer(p_buffer_index);
buffer_view->set_byte_offset(byte_offset);
buffer_view->set_byte_length(input_data_size);
buffer_view->set_byte_stride(p_byte_stride);
buffer_view->set_indices(target_is_indices);
buffer_view->set_vertex_attributes(target_is_vertex_attributes);
// Add the new buffer view to the state.
state_buffer_views.append(buffer_view);
p_gltf_state->set_buffer_views(state_buffer_views);
return buffer_view_index;
}
Ref<GLTFBufferView> GLTFBufferView::from_dictionary(const Dictionary &p_dict) {
// See https://github.com/KhronosGroup/glTF/blob/main/specification/2.0/schema/bufferView.schema.json
Ref<GLTFBufferView> buffer_view;

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@ -90,6 +90,7 @@ public:
void set_vertex_attributes(bool p_attributes);
Vector<uint8_t> load_buffer_view_data(const Ref<GLTFState> p_gltf_state) const;
static GLTFBufferViewIndex write_new_buffer_view_into_state(const Ref<GLTFState> &p_gltf_state, const PackedByteArray &p_input_data, const int64_t p_alignment = 1, const ArrayBufferTarget p_target = TARGET_NONE, const int64_t p_byte_stride = -1, const GLTFBufferIndex p_buffer_index = 0, const bool p_deduplicate = true);
static Ref<GLTFBufferView> from_dictionary(const Dictionary &p_dict);
Dictionary to_dictionary() const;