Readd tex deduplication by value

formats/gltf/extensions_test.go

@@ -154,9 +154,9 @@ func TestMaterialExtension_ToExtensionData(t *testing.T) {
 			extension: gltf.PolyformPbrSpecularGlossiness{
 				DiffuseFactor:             color.Black,
 				SpecularFactor:            color.White,
-				DiffuseTexture:            &gltf.PolyformTexture{},
+				DiffuseTexture:            &gltf.PolyformTexture{URI: "DiffuseTexture.png"},
 				GlossinessFactor:          pointer(.5),
-				SpecularGlossinessTexture: &gltf.PolyformTexture{},
+				SpecularGlossinessTexture: &gltf.PolyformTexture{URI: "SpecularGlossinessTexture.png"},
 			},
 			want: map[string]any{
 				"diffuseFactor":    [4]float64{0., 0., 0., 1.},
@@ -238,11 +238,11 @@ func TestMaterialExtension_ToExtensionData(t *testing.T) {
 		"Iridescence/everything": {
 			extension: gltf.PolyformIridescence{
 				IridescenceFactor:           1,
-				IridescenceTexture:          &gltf.PolyformTexture{},
+				IridescenceTexture:          &gltf.PolyformTexture{URI: "IridescenceTexture.png"},
 				IridescenceIor:              pointer(1.),
 				IridescenceThicknessMinimum: pointer(1.),
 				IridescenceThicknessMaximum: pointer(1.),
-				IridescenceThicknessTexture: &gltf.PolyformTexture{},
+				IridescenceThicknessTexture: &gltf.PolyformTexture{URI: "IridescenceThicknessTexture.png"},
 			},
 			want: map[string]any{
 				"iridescenceFactor":           1.,
@@ -289,8 +289,8 @@ func TestMaterialExtension_ToExtensionData(t *testing.T) {
 		"Sheen/everything": {
 			extension: gltf.PolyformSheen{
 				SheenRoughnessFactor:  1,
-				SheenRoughnessTexture: &gltf.PolyformTexture{},
-				SheenColorTexture:     &gltf.PolyformTexture{},
+				SheenRoughnessTexture: &gltf.PolyformTexture{URI: "SheenRoughnessTexture.png"},
+				SheenColorTexture:     &gltf.PolyformTexture{URI: "SheenColorTexture.png"},
 				SheenColorFactor:      color.White,
 			},
 			want: map[string]any{
@@ -447,9 +447,9 @@ func TestMaterialExtension_ToExtensionData(t *testing.T) {
 		"Specular/everything": {
 			extension: gltf.PolyformSpecular{
 				Factor:       pointer(1.),
-				Texture:      &gltf.PolyformTexture{},
+				Texture:      &gltf.PolyformTexture{URI: "Texture.png"},
 				ColorFactor:  color.White,
-				ColorTexture: &gltf.PolyformTexture{},
+				ColorTexture: &gltf.PolyformTexture{URI: "ColorTexture.png"},
 			},
 			want: map[string]any{
 				"specularFactor":       1.0,

formats/gltf/model.go

@@ -70,6 +70,35 @@ type PolyformTexture struct {
 	Extensions []TextureExtension
 }
 
+func (pm *PolyformTexture) prepareExtensions(w *Writer) (map[string]any, map[string]any) {
+	var texInfoExt map[string]any
+	var texExt map[string]any
+
+	for _, ext := range pm.Extensions {
+		id := ext.ExtensionID()
+		if ext.IsInfo() {
+			if texInfoExt == nil {
+				texInfoExt = make(map[string]any)
+			}
+
+			texInfoExt[id] = ext.ToTextureExtensionData(w)
+		} else {
+			if texExt == nil {
+				texExt = make(map[string]any)
+			}
+
+			texExt[id] = ext.ToTextureExtensionData(w)
+		}
+
+		w.extensionsUsed[id] = true
+		if ext.IsRequired() {
+			w.extensionsRequired[id] = true
+		}
+	}
+
+	return texExt, texInfoExt
+}
+
 func (pm *PolyformMaterial) equal(other *PolyformMaterial) bool {
 	if pm == other {
 		return true

formats/gltf/model_trackers.go

@@ -33,8 +33,5 @@ type meshEntry struct {
 // materialIndices handle deduplication of GLTF materials
 type meshIndices map[meshEntry]int
 
-// samplerIndices handle deduplication of texture samplers
-type samplerIndices map[*Sampler]int
-
 // textureIndices handle deduplication of textures
 type textureIndices map[*PolyformTexture]int

formats/gltf/sampler.go

@@ -35,3 +35,50 @@ type Sampler struct {
 	WrapS     SamplerWrap      `json:"wrapS,omitempty"`     // S (U) wrapping mode.  All valid values correspond to WebGL enums.
 	WrapT     SamplerWrap      `json:"wrapT,omitempty"`     // T (V) wrapping mode.
 }
+
+func (s *Sampler) equal(other *Sampler) bool {
+	if s == other { // Either both nil or point to the same object
+		return true
+	}
+
+	if s == nil || other == nil { // only one can be nil at this point
+		return false
+	}
+
+	if s.MagFilter != other.MagFilter || s.MinFilter != other.MinFilter ||
+		s.WrapS != other.WrapS || s.WrapT != other.WrapT {
+		return false
+	}
+
+	if !s.ChildOfRootProperty.equal(other.ChildOfRootProperty) {
+		return false
+	}
+
+	return true
+}
+
+func (s ChildOfRootProperty) equal(other ChildOfRootProperty) bool {
+	if s.Name != other.Name {
+		return false
+	}
+	if len(s.Extensions) != len(other.Extensions) {
+		return false
+	}
+	if len(s.Extras) != len(other.Extras) {
+		return false
+	}
+
+	for key, val := range s.Extensions {
+		if other.Extensions[key] != val {
+			return false
+		}
+	}
+
+	for key, val := range s.Extras {
+		if other.Extras[key] != val {
+			return false
+		}
+	}
+
+	return true
+}

formats/gltf/structure.go

@@ -144,3 +144,24 @@ type Gltf struct {
 	Skins       []Skin       `json:"skins,omitempty"`       // An array of skins.  A skin is defined by joints and matrices.
 	Textures    []Texture    `json:"textures,omitempty"`    // An array of textures
 }
+
+func (t Texture) equal(other Texture) bool {
+	if !ptrIEqual(t.Source, other.Source) || !ptrIEqual(t.Sampler, other.Sampler) {
+		return false
+	}
+	if len(t.Extensions) != len(other.Extensions) {
+		return false
+	}
+
+	for key, val := range t.Extensions {
+		if other.Extensions[key] != val {
+			return false
+		}
+	}
+
+	if !t.ChildOfRootProperty.equal(other.ChildOfRootProperty) {
+		return false
+	}
+
+	return true
+}

formats/gltf/write.go

@@ -60,6 +60,10 @@ func ptrI(i int) *int {
 	return &i
 }
 
+func ptrIEqual(i, j *int) bool {
+	return (i == nil && j == nil) || (i != nil && j != nil && *i == *j)
+}
+
 func flattenSkeletonToNodes(offset int, skeleton animation.Skeleton, out *bytes.Buffer) []Node {
 	nodes := make([]Node, 0)
 

formats/gltf/write_test.go

@@ -15,6 +15,21 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+type mockTextureExtension struct{}
+
+func (m mockTextureExtension) ExtensionID() string {
+	return "mocXtension"
+}
+func (m mockTextureExtension) ToTextureExtensionData(w *gltf.Writer) map[string]any {
+	return nil
+}
+func (m mockTextureExtension) IsRequired() bool {
+	return false
+}
+func (m mockTextureExtension) IsInfo() bool {
+	return false
+}
+
 func TestWriteBasicTri(t *testing.T) {
 	// ARRANGE ================================================================
 	tri := modeling.NewTriangleMesh([]int{0, 1, 2}).
@@ -555,8 +570,9 @@ func TestWrite_TexturedTriWithMaterialWithColor_ImageSampleDedupe(t *testing.T)
 						BaseColorFactor: color.RGBA{255, 100, 80, 255},
 						RoughnessFactor: &roughness,
 						BaseColorTexture: &gltf.PolyformTexture{
-							URI:     "this_is_a_test.png",
-							Sampler: sampler,
+							URI:        "this_is_a_test.png",
+							Sampler:    sampler,
+							Extensions: []gltf.TextureExtension{&mockTextureExtension{}},
 						},
 					},
 				},
@@ -567,6 +583,9 @@ func TestWrite_TexturedTriWithMaterialWithColor_ImageSampleDedupe(t *testing.T)
 	// ASSERT =================================================================
 	assert.NoError(t, err)
 	assert.Equal(t, `{
+    "extensionsUsed": [
+        "mocXtension"
+    ],
     "accessors": [
         {
             "bufferView": 0,
@@ -832,13 +851,16 @@ func TestWrite_TexturedTriWithMaterialWithColor_ImageSampleDedupe(t *testing.T)
         },
         {
             "sampler": 0,
-            "source": 0
+            "source": 0,
+            "extensions": {
+                "mocXtension": null
+            }
         }
     ]
 }`, buf.String())
 }
 
-func TestWrite_TexturedTriWithMaterialWithColor_TextureDedupe(t *testing.T) {
+func TestWrite_TexturedTriWithMaterialWithColor_TextureValueDedupe(t *testing.T) {
 	// ARRANGE ================================================================
 	tri1 := modeling.NewTriangleMesh([]int{0, 1, 2}).
 		SetFloat3Attribute(
@@ -895,16 +917,6 @@ func TestWrite_TexturedTriWithMaterialWithColor_TextureDedupe(t *testing.T) {
 
 	// ACT ====================================================================
 	roughness := 0.
-	texture := &gltf.PolyformTexture{
-		URI: "this_is_a_test.png",
-		Sampler: &gltf.Sampler{
-			WrapS:     gltf.SamplerWrap_REPEAT,
-			WrapT:     gltf.SamplerWrap_REPEAT,
-			MinFilter: gltf.SamplerMinFilter_LINEAR_MIPMAP_LINEAR,
-			MagFilter: gltf.SamplerMagFilter_LINEAR,
-		},
-	}
-
 	err := gltf.WriteText(gltf.PolyformScene{
 		Models: []gltf.PolyformModel{
 			{
@@ -913,9 +925,17 @@ func TestWrite_TexturedTriWithMaterialWithColor_TextureDedupe(t *testing.T) {
 				Material: &gltf.PolyformMaterial{
 					Name: "My Material1",
 					PbrMetallicRoughness: &gltf.PolyformPbrMetallicRoughness{
-						BaseColorFactor:  color.RGBA{255, 100, 80, 255},
-						RoughnessFactor:  &roughness,
-						BaseColorTexture: texture,
+						BaseColorFactor: color.RGBA{255, 100, 80, 255},
+						RoughnessFactor: &roughness,
+						BaseColorTexture: &gltf.PolyformTexture{
+							URI: "this_is_a_test.png",
+							Sampler: &gltf.Sampler{
+								WrapS:     gltf.SamplerWrap_REPEAT,
+								WrapT:     gltf.SamplerWrap_REPEAT,
+								MinFilter: gltf.SamplerMinFilter_LINEAR_MIPMAP_LINEAR,
+								MagFilter: gltf.SamplerMagFilter_LINEAR,
+							},
+						},
 					},
 				},
 			},
@@ -925,9 +945,17 @@ func TestWrite_TexturedTriWithMaterialWithColor_TextureDedupe(t *testing.T) {
 				Material: &gltf.PolyformMaterial{
 					Name: "My Material2",
 					PbrMetallicRoughness: &gltf.PolyformPbrMetallicRoughness{
-						BaseColorFactor:  color.RGBA{255, 100, 80, 255},
-						RoughnessFactor:  &roughness,
-						BaseColorTexture: texture,
+						BaseColorFactor: color.RGBA{255, 100, 80, 255},
+						RoughnessFactor: &roughness,
+						BaseColorTexture: &gltf.PolyformTexture{
+							URI: "this_is_a_test.png",
+							Sampler: &gltf.Sampler{
+								WrapS:     gltf.SamplerWrap_REPEAT,
+								WrapT:     gltf.SamplerWrap_REPEAT,
+								MinFilter: gltf.SamplerMinFilter_LINEAR_MIPMAP_LINEAR,
+								MagFilter: gltf.SamplerMagFilter_LINEAR,
+							},
+						},
 					},
 				},
 			},