Add an example and running_geometry field to state

Author: Nitish-bot

crates/processing_pyo3/examples/particles.py

@@ -0,0 +1,40 @@
+from processing import *
+from math import sin, cos
+from random import gauss
+
+geometry = None
+
+def setup():
+    global geometry
+    size(800, 600)
+    mode_3d()
+    create_geometry()
+
+def draw():
+    global geometry
+
+    camera_position(150.0, 150.0, 150.0)
+    camera_look_at( 0.0, 0.0, 0.0)
+    background(220, 200, 140)
+
+    draw_geometry(geometry)
+
+def create_geometry():
+    global geometry
+
+    beginGeometry()
+
+    for i in range(60):        
+        x = gauss(400, 200)
+        y = gauss(350, 175)
+        z = gauss(0, 100)
+        
+        push_matrix()
+        translate(x, y, z)
+        sphere(10)
+        pop_matrix()
+
+    geometry = endGeometry()
+
+# TODO: this should happen implicitly on module load somehow
+run()

crates/processing_render/src/geometry/mod.rs

@@ -60,7 +60,7 @@ impl Topology {
     }
 }
 
-#[derive(Component)]
+#[derive(Debug, Component)]
 pub struct Geometry {
     pub handle: Handle<Mesh>,
     pub layout: Entity,

crates/processing_render/src/render/mod.rs

@@ -60,6 +60,7 @@ pub struct RenderState {
     pub stroke_color: Option<Color>,
     pub stroke_weight: f32,
     pub transform: TransformStack,
+    pub running_geometry: Option<Geometry>,
 }
 
 impl Default for RenderState {
@@ -69,6 +70,7 @@ impl Default for RenderState {
             stroke_color: Some(Color::BLACK),
             stroke_weight: 1.0,
             transform: TransformStack::new(),
+            running_geometry: None,
         }
     }
 }