Merge pull request #181 from Ralith/pbr-specular-glossiness

Implement KHR_materials_pbrSpecularGlossiness

Cargo.toml

@@ -34,6 +34,7 @@ extras = ["gltf-json/extras"]
 names = ["gltf-json/names"]
 utils = []
 import = ["base64", "image"]
+KHR_materials_pbrSpecularGlossiness = ["gltf-json/KHR_materials_pbrSpecularGlossiness"]
 
 [[example]]
 name = "gltf-display"

gltf-json/Cargo.toml

@@ -16,3 +16,4 @@ serde_json = "1.0"
 default = []
 names = []
 extras = []
+KHR_materials_pbrSpecularGlossiness = []

gltf-json/src/extensions/material.rs

@@ -1,16 +1,130 @@
+use validation::{Error, Validate};
+use material::StrengthFactor;
+use {texture, Extras, Root, Path};
+
 /// The material appearance of a primitive.
 #[derive(Clone, Debug, Default, Deserialize, Serialize, Validate)]
-pub struct Material {}
+pub struct Material {
+    #[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+    #[serde(default, rename = "KHR_materials_pbrSpecularGlossiness", skip_serializing_if = "Option::is_none")]
+    pub pbr_specular_glossiness: Option<PbrSpecularGlossiness>,
+}
 
 /// A set of parameter values that are used to define the metallic-roughness
 /// material model from Physically-Based Rendering (PBR) methodology.
 #[derive(Clone, Debug, Default, Deserialize, Serialize, Validate)]
 pub struct PbrMetallicRoughness {}
 
+/// A set of parameter values that are used to define the specular-glossiness
+/// material model from Physically-Based Rendering (PBR) methodology.
+///
+/// This model supports more materials than metallic-roughness, at the cost of
+/// increased memory use. When both are available, specular-glossiness should be
+/// preferred.
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+#[derive(Clone, Debug, Default, Deserialize, Serialize, Validate)]
+#[serde(default, rename_all = "camelCase")]
+pub struct PbrSpecularGlossiness {
+    /// The material's diffuse factor.
+    ///
+    /// The RGBA components of the reflected diffuse color of the
+    /// material. Metals have a diffuse value of `[0.0, 0.0, 0.0]`. The fourth
+    /// component (A) is the alpha coverage of the material. The `alphaMode`
+    /// property specifies how alpha is interpreted. The values are linear.
+    pub diffuse_factor: PbrDiffuseFactor,
+
+    /// The diffuse texture.
+    ///
+    /// This texture contains RGB(A) components of the reflected diffuse color
+    /// of the material in sRGB color space. If the fourth component (A) is
+    /// present, it represents the alpha coverage of the material. Otherwise, an
+    /// alpha of 1.0 is assumed. The `alphaMode` property specifies how alpha is
+    /// interpreted. The stored texels must not be premultiplied.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub diffuse_texture: Option<texture::Info>,
+
+    /// The material's specular factor.
+    pub specular_factor: PbrSpecularFactor,
+
+    /// The glossiness or smoothness of the material.
+    ///
+    /// A value of 1.0 means the material has full glossiness or is perfectly
+    /// smooth. A value of 0.0 means the material has no glossiness or is
+    /// completely rough. This value is linear.
+    pub glossiness_factor: StrengthFactor,
+
+    /// The specular-glossiness texture.
+    ///
+    /// A RGBA texture, containing the specular color of the material (RGB
+    /// components) and its glossiness (A component). The values are in sRGB
+    /// space.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub specular_glossiness_texture: Option<texture::Info>,
+
+    /// Optional application specific data.
+    #[cfg_attr(feature = "extras", serde(skip_serializing_if = "Option::is_none"))]
+    pub extras: Extras,
+}
+
+
 /// Defines the normal texture of a material.
 #[derive(Clone, Debug, Default, Deserialize, Serialize, Validate)]
 pub struct NormalTexture {}
 
 /// Defines the occlusion texture of a material.
 #[derive(Clone, Debug, Default, Deserialize, Serialize, Validate)]
 pub struct OcclusionTexture {}
+
+/// The diffuse factor of a material.
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+pub struct PbrDiffuseFactor(pub [f32; 4]);
+
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+impl Default for PbrDiffuseFactor {
+    fn default() -> Self {
+        PbrDiffuseFactor([1.0, 1.0, 1.0, 1.0])
+    }
+}
+
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+impl Validate for PbrDiffuseFactor {
+    fn validate_completely<P, R>(&self, _: &Root, path: P, report: &mut R)
+        where P: Fn() -> Path, R: FnMut(&Fn() -> Path, Error)
+    {
+        for x in &self.0 {
+            if *x < 0.0 || *x > 1.0 {
+                report(&path, Error::Invalid);
+                // Only report once
+                break;
+            }
+        }
+    }
+}
+
+/// The specular factor of a material.
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+pub struct PbrSpecularFactor(pub [f32; 3]);
+
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+impl Default for PbrSpecularFactor {
+    fn default() -> Self {
+        PbrSpecularFactor([1.0, 1.0, 1.0])
+    }
+}
+
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+impl Validate for PbrSpecularFactor {
+    fn validate_completely<P, R>(&self, _: &Root, path: P, report: &mut R)
+        where P: Fn() -> Path, R: FnMut(&Fn() -> Path, Error)
+    {
+        for x in &self.0 {
+            if *x < 0.0 || *x > 1.0 {
+                report(&path, Error::Invalid);
+                // Only report once
+                break;
+            }
+        }
+    }
+}

gltf-json/src/extensions/mod.rs

@@ -37,7 +37,12 @@ pub mod texture;
 pub use self::root::Root;
 
 /// Names of glTF 2.0 extensions enabled by the user.
-pub const ENABLED_EXTENSIONS: &'static [&'static str] = &[];
+pub const ENABLED_EXTENSIONS: &'static [&'static str] = &[
+    #[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+    "KHR_materials_pbrSpecularGlossiness",
+];
 
 /// Names of glTF 2.0 extensions supported by the library.
-pub const SUPPORTED_EXTENSIONS: &'static [&'static str] = &[];
+pub const SUPPORTED_EXTENSIONS: &'static [&'static str] = &[
+    "KHR_materials_pbrSpecularGlossiness"
+];

src/material.rs

@@ -92,6 +92,13 @@ impl<'a> Material<'a> {
         PbrMetallicRoughness::new(self.document, &self.json.pbr_metallic_roughness)
     }
 
+    /// Parameter values that define the specular-glossiness material model from
+    /// Physically-Based Rendering (PBR) methodology.
+    #[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+    pub fn pbr_specular_glossiness(&self) -> Option<PbrSpecularGlossiness<'a>> {
+        self.json.extensions.pbr_specular_glossiness.as_ref().map(|x| PbrSpecularGlossiness::new(self.document, x))
+    }
+
     /// A tangent space normal map.
     ///
     /// The texture contains RGB components in linear space. Each texel represents
@@ -225,6 +232,81 @@ impl<'a> PbrMetallicRoughness<'a> {
     }
 }
 
+/// A set of parameter values that are used to define the specular-glossiness
+/// material model from Physically-Based Rendering (PBR) methodology.
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+pub struct PbrSpecularGlossiness<'a> {
+    /// The parent `Document` struct.
+    document: &'a Document,
+
+    /// The corresponding JSON struct.
+    json: &'a json::extensions::material::PbrSpecularGlossiness,
+}
+
+#[cfg(feature = "KHR_materials_pbrSpecularGlossiness")]
+impl<'a> PbrSpecularGlossiness<'a> {
+    /// Constructs `PbrSpecularGlossiness`.
+    pub(crate) fn new(
+        document: &'a Document,
+        json: &'a json::extensions::material::PbrSpecularGlossiness,
+    ) -> Self {
+        Self {
+            document: document,
+            json: json,
+        }
+    }
+
+    /// Returns the material's base color factor.
+    ///
+    /// The default value is `[1.0, 1.0, 1.0, 1.0]`.
+    pub fn diffuse_factor(&self) -> [f32; 4] {
+        self.json.diffuse_factor.0
+    }
+
+    /// Returns the base color texture.
+    pub fn diffuse_texture(&self) -> Option<texture::Info<'a>> {
+        self.json.diffuse_texture.as_ref().map(|json| {
+            let texture = self.document.textures().nth(json.index.value()).unwrap();
+            texture::Info::new(texture, json)
+        })
+    }
+
+    /// Returns the specular factor of the material.
+    ///
+    /// The default value is `[1.0, 1.0, 1.0]`.
+    pub fn specular_factor(&self) -> [f32; 3] {
+        self.json.specular_factor.0
+    }
+
+    /// Returns the glossiness factor of the material.
+    ///
+    /// A value of 1.0 means the material has full glossiness or is perfectly
+    /// smooth. A value of 0.0 means the material has no glossiness or is
+    /// completely rough. This value is linear.
+    ///
+    /// The default value is `1.0`.
+    pub fn glossiness_factor(&self) -> f32 {
+        self.json.glossiness_factor.0
+    }
+
+    /// The specular-glossiness texture.
+    ///
+    /// A RGBA texture, containing the specular color of the material (RGB
+    /// components) and its glossiness (A component). The color values are in
+    /// sRGB space.
+    pub fn specular_glossiness_texture(&self) -> Option<texture::Info<'a>> {
+        self.json.specular_glossiness_texture.as_ref().map(|json| {
+            let texture = self.document.textures().nth(json.index.value()).unwrap();
+            texture::Info::new(texture, json)
+        })
+    }
+
+    /// Optional application specific data.
+    pub fn extras(&self) -> &json::Extras {
+        &self.json.extras
+    }
+}
+
 /// Defines the normal texture of a material.
 pub struct NormalTexture<'a> {
     /// The parent `Texture` struct.