const.go
//go:generate stringer -linecomment -type ComponentType,AccessorType,PrimitiveMode,AlphaMode,MagFilter,MinFilter,WrappingMode,Interpolation,Target,TRSProperty -output const_strings.go
package gltf
import (
"encoding/json"
"fmt"
)
var (
// DefaultMatrix defines an identity matrix.
DefaultMatrix = [16]float64{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}
// DefaultRotation defines a quaternion without rotation.
DefaultRotation = [4]float64{0, 0, 0, 1}
// DefaultScale defines a scaling that does not modify the size of the object.
DefaultScale = [3]float64{1, 1, 1}
// DefaultTranslation defines a translation that does not move the object.
DefaultTranslation = [3]float64{0, 0, 0}
)
// Attribute names defined in the spec.
const (
POSITION = "POSITION"
NORMAL = "NORMAL"
TANGENT = "TANGENT"
TEXCOORD_0 = "TEXCOORD_0"
TEXCOORD_1 = "TEXCOORD_1"
WEIGHTS_0 = "WEIGHTS_0"
JOINTS_0 = "JOINTS_0"
COLOR_0 = "COLOR_0"
)
var (
emptyMatrix = [16]float64{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
emptyRotation = [4]float64{0, 0, 0, 0}
emptyScale = [3]float64{0, 0, 0}
)
// The ComponentType is the datatype of components in the attribute. All valid values correspond to WebGL enums.
// 5125 (UNSIGNED_INT) is only allowed when the accessor contains indices.
type ComponentType uint16
const (
ComponentFloat ComponentType = iota // FLOAT
ComponentByte // BYTE
ComponentUbyte // UNSIGNED_BYTE
ComponentShort // SHORT
ComponentUshort // UNSIGNED_SHORT
ComponentUint // UNSIGNED_INT
)
// ByteSize returns the size of a component in bytes.
func (c ComponentType) ByteSize() uint32 {
return map[ComponentType]uint32{
ComponentByte: 1,
ComponentUbyte: 1,
ComponentShort: 2,
ComponentUshort: 2,
ComponentUint: 4,
ComponentFloat: 4,
}[c]
}
// UnmarshalJSON unmarshal the component type with the correct default values.
func (c *ComponentType) UnmarshalJSON(data []byte) error {
var tmp uint16
err := json.Unmarshal(data, &tmp)
if err == nil {
*c = map[uint16]ComponentType{
5120: ComponentByte,
5121: ComponentUbyte,
5122: ComponentShort,
5123: ComponentUshort,
5125: ComponentUint,
5126: ComponentFloat,
}[tmp]
}
return err
}
// MarshalJSON marshal the component type with the correct default values.
func (c *ComponentType) MarshalJSON() ([]byte, error) {
return json.Marshal(map[ComponentType]uint16{
ComponentByte: 5120,
ComponentUbyte: 5121,
ComponentShort: 5122,
ComponentUshort: 5123,
ComponentUint: 5125,
ComponentFloat: 5126,
}[*c])
}
// AccessorType specifies if the attribute is a scalar, vector, or matrix.
type AccessorType uint8
const (
AccessorScalar AccessorType = iota // SCALAR
AccessorVec2 // VEC2
AccessorVec3 // VEC3
AccessorVec4 // VEC4
AccessorMat2 // MAT2
AccessorMat3 // MAT3
AccessorMat4 // MAT4
)
// Components returns the number of components of an accessor type.
func (a AccessorType) Components() uint32 {
return map[AccessorType]uint32{
AccessorScalar: 1,
AccessorVec2: 2,
AccessorVec3: 3,
AccessorVec4: 4,
AccessorMat2: 4,
AccessorMat3: 9,
AccessorMat4: 16,
}[a]
}
// UnmarshalJSON unmarshal the accessor type with the correct default values.
func (a *AccessorType) UnmarshalJSON(data []byte) error {
var tmp string
err := json.Unmarshal(data, &tmp)
if err == nil {
accType, ok := map[string]AccessorType{
"SCALAR": AccessorScalar,
"VEC2": AccessorVec2,
"VEC3": AccessorVec3,
"VEC4": AccessorVec4,
"MAT2": AccessorMat2,
"MAT3": AccessorMat3,
"MAT4": AccessorMat4,
}[tmp]
if !ok {
return fmt.Errorf("gltf: unknown accessor's type: %s", tmp)
}
*a = accType
}
return err
}
// MarshalJSON marshal the accessor type with the correct default values.
func (a *AccessorType) MarshalJSON() ([]byte, error) {
return json.Marshal(map[AccessorType]string{
AccessorScalar: "SCALAR",
AccessorVec2: "VEC2",
AccessorVec3: "VEC3",
AccessorVec4: "VEC4",
AccessorMat2: "MAT2",
AccessorMat3: "MAT3",
AccessorMat4: "MAT4",
}[*a])
}
// The Target that the GPU buffer should be bound to.
type Target uint16
const (
TargetNone Target = 0 // NONE
TargetArrayBuffer Target = 34962 // ARRAY_BUFFER
TargetElementArrayBuffer Target = 34963 // ELEMENT_ARRAY_BUFFER
)
// Attribute is a map that each key corresponds to mesh attribute semantic and each value is the index of the accessor containing attribute's data.
type Attribute = map[string]uint32
// PrimitiveMode defines the type of primitives to render. All valid values correspond to WebGL enums.
type PrimitiveMode uint8
const (
PrimitiveTriangles PrimitiveMode = iota // TRIANGLES
PrimitivePoints // POINTS
PrimitiveLines // LINES
PrimitiveLineLoop // LINE_LOOP
PrimitiveLineStrip // LINE_STRIP
PrimitiveTriangleStrip // TRIANGLE_STRIP
PrimitiveTriangleFan // TRIANGLE_FAN
)
// UnmarshalJSON unmarshal the primitive mode with the correct default values.
func (p *PrimitiveMode) UnmarshalJSON(data []byte) error {
var tmp uint8
err := json.Unmarshal(data, &tmp)
if err == nil {
*p = map[uint8]PrimitiveMode{
0: PrimitivePoints,
1: PrimitiveLines,
2: PrimitiveLineLoop,
3: PrimitiveLineStrip,
4: PrimitiveTriangles,
5: PrimitiveTriangleStrip,
6: PrimitiveTriangleFan,
}[tmp]
}
return err
}
// MarshalJSON marshal the primitive mode with the correct default values.
func (p *PrimitiveMode) MarshalJSON() ([]byte, error) {
return json.Marshal(map[PrimitiveMode]uint8{
PrimitivePoints: 0,
PrimitiveLines: 1,
PrimitiveLineLoop: 2,
PrimitiveLineStrip: 3,
PrimitiveTriangles: 4,
PrimitiveTriangleStrip: 5,
PrimitiveTriangleFan: 6,
}[*p])
}
// The AlphaMode enumeration specifying the interpretation of the alpha value of the main factor and texture.
type AlphaMode uint8
const (
AlphaOpaque AlphaMode = iota // OPAQUE
AlphaMask // MASK
AlphaBlend // BLEND
)
// UnmarshalJSON unmarshal the alpha mode with the correct default values.
func (a *AlphaMode) UnmarshalJSON(data []byte) error {
var tmp string
err := json.Unmarshal(data, &tmp)
if err == nil {
*a = map[string]AlphaMode{
"OPAQUE": AlphaOpaque,
"MASK": AlphaMask,
"BLEND": AlphaBlend,
}[tmp]
}
return err
}
// MarshalJSON marshal the alpha mode with the correct default values.
func (a *AlphaMode) MarshalJSON() ([]byte, error) {
return json.Marshal(map[AlphaMode]string{
AlphaOpaque: "OPAQUE",
AlphaMask: "MASK",
AlphaBlend: "BLEND",
}[*a])
}
// MagFilter is the magnification filter.
type MagFilter uint16
const (
MagUndefined MagFilter = iota // UNDEFINED
MagLinear // LINEAR
MagNearest // NEAREST
)
// UnmarshalJSON unmarshal the mag filter with the correct default values.
func (m *MagFilter) UnmarshalJSON(data []byte) error {
var tmp uint16
err := json.Unmarshal(data, &tmp)
if err == nil {
*m = map[uint16]MagFilter{
9728: MagNearest,
9729: MagLinear,
}[tmp]
}
return err
}
// MarshalJSON marshal the alpha mode with the correct default values.
func (m *MagFilter) MarshalJSON() ([]byte, error) {
return json.Marshal(map[MagFilter]uint16{
MagNearest: 9728,
MagLinear: 9729,
}[*m])
}
// MinFilter is the minification filter.
type MinFilter uint16
const (
MinUndefined MinFilter = iota // UNDEFINED
MinLinear // LINEAR
MinNearestMipMapLinear // NEAREST_MIPMAP_LINEAR
MinNearest // NEAREST
MinNearestMipMapNearest // NEAREST_MIPMAP_NEAREST
MinLinearMipMapNearest // LINEAR_MIPMAP_NEAREST
MinLinearMipMapLinear // LINEAR_MIPMAP_LINEAR
)
// UnmarshalJSON unmarshal the min filter with the correct default values.
func (m *MinFilter) UnmarshalJSON(data []byte) error {
var tmp uint16
err := json.Unmarshal(data, &tmp)
if err == nil {
*m = map[uint16]MinFilter{
9728: MinNearest,
9729: MinLinear,
9984: MinNearestMipMapNearest,
9985: MinLinearMipMapNearest,
9986: MinNearestMipMapLinear,
9987: MinLinearMipMapLinear,
}[tmp]
}
return err
}
// MarshalJSON marshal the min filter with the correct default values.
func (m *MinFilter) MarshalJSON() ([]byte, error) {
return json.Marshal(map[MinFilter]uint16{
MinNearest: 9728,
MinLinear: 9729,
MinNearestMipMapNearest: 9984,
MinLinearMipMapNearest: 9985,
MinNearestMipMapLinear: 9986,
MinLinearMipMapLinear: 9987,
}[*m])
}
// WrappingMode is the wrapping mode of a texture.
type WrappingMode uint16
const (
WrapRepeat WrappingMode = iota // REPEAT
WrapClampToEdge // CLAMP_TO_EDGE
WrapMirroredRepeat // MIRRORED_REPEAT
)
// UnmarshalJSON unmarshal the wrapping mode with the correct default values.
func (w *WrappingMode) UnmarshalJSON(data []byte) error {
var tmp uint16
err := json.Unmarshal(data, &tmp)
if err == nil {
*w = map[uint16]WrappingMode{
33071: WrapClampToEdge,
33648: WrapMirroredRepeat,
10497: WrapRepeat,
}[tmp]
}
return err
}
// MarshalJSON marshal the wrapping mode with the correct default values.
func (w *WrappingMode) MarshalJSON() ([]byte, error) {
return json.Marshal(map[WrappingMode]uint16{
WrapClampToEdge: 33071,
WrapMirroredRepeat: 33648,
WrapRepeat: 10497,
}[*w])
}
// Interpolation algorithm.
type Interpolation uint8
const (
InterpolationLinear Interpolation = iota // LINEAR
InterpolationStep // STEP
InterpolationCubicSpline // CUBICSPLINE
)
// UnmarshalJSON unmarshal the interpolation with the correct default values.
func (i *Interpolation) UnmarshalJSON(data []byte) error {
var tmp string
err := json.Unmarshal(data, &tmp)
if err == nil {
*i = map[string]Interpolation{
"LINEAR": InterpolationLinear,
"STEP": InterpolationStep,
"CUBICSPLINE": InterpolationCubicSpline,
}[tmp]
}
return err
}
// MarshalJSON marshal the interpolation with the correct default values.
func (i *Interpolation) MarshalJSON() ([]byte, error) {
return json.Marshal(map[Interpolation]string{
InterpolationLinear: "LINEAR",
InterpolationStep: "STEP",
InterpolationCubicSpline: "CUBICSPLINE",
}[*i])
}
// TRSProperty defines a local space transformation.
// TRSproperties are converted to matrices and postmultiplied in the T * R * S order to compose the transformation matrix.
type TRSProperty uint8
const (
TRSTranslation TRSProperty = iota // translation
TRSRotation // rotation
TRSScale // scale
TRSWeights // weights
)
// UnmarshalJSON unmarshal the TRSProperty with the correct default values.
func (t *TRSProperty) UnmarshalJSON(data []byte) error {
var tmp string
err := json.Unmarshal(data, &tmp)
if err == nil {
*t = map[string]TRSProperty{
"translation": TRSTranslation,
"rotation": TRSRotation,
"scale": TRSScale,
"weights": TRSWeights,
}[tmp]
}
return err
}
// MarshalJSON marshal the TRSProperty with the correct default values.
func (t *TRSProperty) MarshalJSON() ([]byte, error) {
return json.Marshal(map[TRSProperty]string{
TRSTranslation: "translation",
TRSRotation: "rotation",
TRSScale: "scale",
TRSWeights: "weights",
}[*t])
}
const (
glbHeaderMagic = 0x46546c67
glbChunkJSON = 0x4e4f534a
glbChunkBIN = 0x004e4942
)
type chunkHeader struct {
Length uint32
Type uint32
}
type glbHeader struct {
Magic uint32
Version uint32
Length uint32
JSONHeader chunkHeader
}
const (
mimetypeApplicationOctet = "data:application/octet-stream;base64"
mimetypeImagePNG = "data:image/png;base64"
mimetypeImageJPG = "data:image/jpeg;base64"
)