Add GLTF support. (#79)

Author: tychedelia

Cargo.toml

@@ -82,6 +82,10 @@ path = "examples/pbr.rs"
 name = "midi"
 path = "examples/midi.rs"
 
+[[example]]
+name = "gltf_load"
+path = "examples/gltf_load.rs"
+
 [profile.wasm-release]
 inherits = "release"
 opt-level = "z"

assets/gltf/Duck.glb

@@ -568,7 +568,16 @@ pub extern "C" fn processing_perspective(
 ) {
     error::clear_error();
     let graphics_entity = Entity::from_bits(graphics_id);
-    error::check(|| graphics_perspective(graphics_entity, fov, aspect, near, far));
+    error::check(|| {
+        graphics_perspective(
+            graphics_entity,
+            fov,
+            aspect,
+            near,
+            far,
+            bevy::math::Vec4::new(0.0, 0.0, -1.0, -near),
+        )
+    });
 }
 
 #[unsafe(no_mangle)]

crates/processing_ffi/src/lib.rs

@@ -0,0 +1,46 @@
+import math
+from processing import *
+
+gltf = None
+duck_geo = None
+duck_mat = None
+light = None
+frame = 0
+
+def setup():
+    global gltf, duck_geo, duck_mat, light
+    size(800, 600)
+
+    gltf = load_gltf("gltf/Duck.glb")
+    duck_geo = gltf.geometry("LOD3spShape")
+    duck_mat = gltf.material("blinn3-fx")
+
+    mode_3d()
+    gltf.camera(0)
+    light = gltf.light(0)
+
+def draw():
+    global frame
+    t = frame * 0.02
+
+    radius = 1.5
+    lx = math.cos(t) * radius
+    ly = 1.5
+    lz = math.sin(t) * radius
+    light.position(lx, ly, lz)
+    light.look_at(0.0, 0.8, 0.0)
+
+    r = math.sin(t * 8.0) * 0.5 + 0.5
+    g = math.sin(t * 8.0 + 2.0) * 0.5 + 0.5
+    b = math.sin(t * 8.0 + 4.0) * 0.5 + 0.5
+    duck_mat.set_float4("base_color", r, g, b, 1.0)
+
+    background(25)
+    use_material(duck_mat)
+    draw_geometry(duck_geo)
+
+    frame += 1
+
+
+# TODO: this should happen implicitly on module load somehow
+run()

crates/processing_pyo3/examples/gltf_load.py

@@ -0,0 +1,53 @@
+use bevy::prelude::Entity;
+use processing::prelude::*;
+use pyo3::{exceptions::PyRuntimeError, prelude::*};
+
+use crate::graphics::{Geometry, Light, get_graphics};
+use crate::material::Material;
+
+#[pyclass(unsendable)]
+pub struct Gltf {
+    entity: Entity,
+}
+
+#[pymethods]
+impl Gltf {
+    pub fn geometry(&self, name: &str) -> PyResult<Geometry> {
+        let entity = gltf_geometry(self.entity, name)
+            .map_err(|e| PyRuntimeError::new_err(format!("{e}")))?;
+        Ok(Geometry { entity })
+    }
+
+    pub fn material(&self, name: &str) -> PyResult<Material> {
+        let entity = gltf_material(self.entity, name)
+            .map_err(|e| PyRuntimeError::new_err(format!("{e}")))?;
+        Ok(Material { entity })
+    }
+
+    pub fn mesh_names(&self) -> PyResult<Vec<String>> {
+        gltf_mesh_names(self.entity).map_err(|e| PyRuntimeError::new_err(format!("{e}")))
+    }
+
+    pub fn material_names(&self) -> PyResult<Vec<String>> {
+        gltf_material_names(self.entity).map_err(|e| PyRuntimeError::new_err(format!("{e}")))
+    }
+
+    pub fn camera(&self, index: usize) -> PyResult<()> {
+        gltf_camera(self.entity, index).map_err(|e| PyRuntimeError::new_err(format!("{e}")))
+    }
+
+    pub fn light(&self, index: usize) -> PyResult<Light> {
+        let entity =
+            gltf_light(self.entity, index).map_err(|e| PyRuntimeError::new_err(format!("{e}")))?;
+        Ok(Light { entity })
+    }
+}
+
+#[pyfunction]
+#[pyo3(pass_module)]
+pub fn load_gltf(module: &Bound<'_, PyModule>, path: &str) -> PyResult<Gltf> {
+    let graphics = get_graphics(module)?;
+    let entity =
+        gltf_load(graphics.entity, path).map_err(|e| PyRuntimeError::new_err(format!("{e}")))?;
+    Ok(Gltf { entity })
+}

crates/processing_pyo3/src/gltf.rs

@@ -1,3 +1,4 @@
+use bevy::math::Vec4;
 use bevy::prelude::Entity;
 use processing::prelude::*;
 use pyo3::{exceptions::PyRuntimeError, prelude::*, types::PyDict};
@@ -26,7 +27,7 @@ impl Drop for Surface {
 #[pyclass]
 #[derive(Debug)]
 pub struct Light {
-    entity: Entity,
+    pub(crate) entity: Entity,
 }
 
 #[pymethods]
@@ -62,7 +63,7 @@ impl Drop for Image {
 
 #[pyclass(unsendable)]
 pub struct Geometry {
-    entity: Entity,
+    pub(crate) entity: Entity,
 }
 
 #[pyclass]
@@ -132,7 +133,7 @@ impl Geometry {
 
 #[pyclass(unsendable)]
 pub struct Graphics {
-    entity: Entity,
+    pub(crate) entity: Entity,
     pub surface: Surface,
 }
 
@@ -357,8 +358,15 @@ impl Graphics {
     }
 
     pub fn perspective(&self, fov: f32, aspect: f32, near: f32, far: f32) -> PyResult<()> {
-        graphics_perspective(self.entity, fov, aspect, near, far)
-            .map_err(|e| PyRuntimeError::new_err(format!("{e}")))
+        graphics_perspective(
+            self.entity,
+            fov,
+            aspect,
+            near,
+            far,
+            Vec4::new(0.0, 0.0, -1.0, -near),
+        )
+        .map_err(|e| PyRuntimeError::new_err(format!("{e}")))
     }
 
     #[allow(clippy::too_many_arguments)]

crates/processing_pyo3/src/graphics.rs

@@ -9,6 +9,7 @@
 //! To allow Python users to create a similar experience, we provide module-level
 //! functions that forward to a singleton Graphics object pub(crate) behind the scenes.
 mod glfw;
+mod gltf;
 mod graphics;
 pub(crate) mod material;
 
@@ -21,6 +22,7 @@ use pyo3::{
 };
 use std::ffi::{CStr, CString};
 
+use gltf::Gltf;
 use std::env;
 
 #[pymodule]
@@ -30,6 +32,8 @@ fn processing(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<Light>()?;
     m.add_class::<Topology>()?;
     m.add_class::<Material>()?;
+    m.add_class::<Gltf>()?;
+    m.add_function(wrap_pyfunction!(gltf::load_gltf, m)?)?;
     m.add_function(wrap_pyfunction!(size, m)?)?;
     m.add_function(wrap_pyfunction!(run, m)?)?;
     m.add_function(wrap_pyfunction!(mode_3d, m)?)?;

crates/processing_pyo3/src/lib.rs

@@ -34,4 +34,6 @@ pub enum ProcessingError {
     MaterialNotFound,
     #[error("Unknown material property: {0}")]
     UnknownMaterialProperty(String),
+    #[error("GLTF load error: {0}")]
+    GltfLoadError(String),
 }